Michael Laing - Johnson Matthey Technology Review
Transcription
Michael Laing - Johnson Matthey Technology Review
VOLUME 52 NUMBER 4 OCTOBER 2008 Platinum Metals Review www.platinummetalsreview.com E-ISSN 1471–0676 E-ISSN 1471–0676 PLATINUM METALS REVIEW A Quarterly Survey of Research on the Platinum Metals and of Developments in their Application in Industry www.platinummetalsreview.com VOL. 52 OCTOBER 2008 NO. 4 Contents Thermophysical Properties of L12 Intermetallic Compounds of Iridium 208 By Yoshihiro Terada Platinum Group Metal Chemistry of Functionalised Phosphines 215 By Martin B. Smith EuropaCat VIII: “From Theory to Industrial Practice” 222 A conference review by Emma Schofield, Nadia Acerbi and Cristian Spadoni “Catalysis for Renewables: From Feedstock to Energy Production” 229 A book review by John Birtill Platinum Group Metals Patent Analysis and Mapping 231 By Richard Seymour Creep 2008: 11th International Conference on Creep and Fracture of Engineering Materials and Structures 241 A conference review by J. Preußner, R. Völkl and U. Glatzel Global Release Liner Industry Conference 2008 243 A conference review by Andrew J. Holwell “The Periodic Table: Its Story and Its Significance” 247 A book review by Michael Laing John Ward Jenkins 249 A tribute by S. E. Golunski Abstracts 251 New Patents 254 Indexes to Volume 52 256 Acting Editor: David Jollie; Editorial Assistant: Sara Coles; Senior Information Scientist: Keith White Platinum Metals Review, Johnson Matthey PLC, Orchard Road, Royston, Hertfordshire SG8 5HE, U.K. E-mail: [email protected] DOI: 10.1595/147106708X361321 Thermophysical Properties of L12 Intermetallic Compounds of Iridium THERMAL CONDUCTIVITY AND THERMAL EXPANSION OF Ir3X FOR ULTRA HIGH-TEMPERATURE APPLICATIONS By Yoshihiro Terada Department of Materials, Physics and Energy Engineering, Nagoya University, Chikusa-ku, Nagoya 464-8603, Japan; E-mail: [email protected] Thermal conductivity and thermal expansion for the intermetallic compounds Ir3X (X = Ti, Zr, Hf, V, Nb or Ta) were measured in the temperature range between 300 and 1100 K. The thermal conductivities of Ir3X are distributed in the range from 41 to 99 W m–1 K–1 at 300 K, while the difference of thermal conductivities becomes less emphasised at higher temperatures. The coefficient of thermal expansion (CTE) values of Ir3X are insensitive to temperature, and fall around 8 × 10–6 K–1 at 800 K. The Ir3X intermetallic compounds with X = Ti, Zr, Hf, Nb or Ta are suitable for ultra high-temperature structural applications due to their higher thermal conductivities and smaller CTE values. The L12 intermetallic compounds based on iridium (Ir3X) have been pursued as the next generation of high-temperature structural materials (1–6). The advantages of Ir3X are summarised as follows. Firstly, the melting points are between 600 and 1000 K higher than those of nickel-based superalloys (7). Secondly, an L12 crystal structure offers the possibility of enhanced ductility as a result of the large number of possible slip systems. Finally, the two-phase γ/γ' type microstructure formed in Ni-based superalloys can also be produced in Ir-based alloys (8–10). Thermal conductivity and thermal expansion are key parameters to evaluate the suitability of metallic materials for high-temperature structural applications (11, 12). Rapid heat transfer afforded by high thermal conductivity enables efficient cooling, which suppresses the appearance of lifelimiting heat-attacked spots (6). A smaller thermal expansion is desirable to avoid thermal fatigue by cyclic thermal conditions, since thermal stress depends directly on the magnitude of the thermal expansion. However, no data on the thermal properties of Ir3X are available in the literature. The Ir-based compounds Ir3X form an L12 crystal structure when the partner component X belongs to Group 4 or 5 of the Periodic Table Platinum Metals Rev., 2008, 52, (4), 208–214 (13–15). The present study was conducted to provide the data for thermal conductivity and thermal expansion of Ir3X (X = Ti, Zr, Hf, V, Nb or Ta) which serve to evaluate the suitability of the compounds for high-temperature structural applications. The alloy compositions prepared in this study are given in Table I, together with the compositional range of the L12 phase at the homogenised temperature (1573 K) (7). The stoichiometric composition was chosen for each compound except Ir3Hf. Note that the composition close to stoichiometry with L12 single phase was selected for Ir3Hf, since an L12 single phase is not achieved at the stoichiometric composition. Thermal conductivity measurements were performed by the laser flash method in vacuum in the temperature range between 300 and 1100 K, using a disc specimen of diameter 10 mm and thickness 2 mm (16). A short duration laser pulse is emitted from a ruby rod onto the surface of the disc specimen. The temperature change on the other side of the specimen was measured over time by both an infrared detector and a type R thermocouple. From the temperature-time profile, thermal conductivity was obtained (17). Thermal expansion measurements were made using a dilatometer 208 Table I Chemical Composition of the Ir3X Compounds Used in This Investigation, Together with the Composition Range of the L12 Phase at the Homogenised Temperature (1573 K) (7) Compound Ir3Ti Ir3Zr Ir3Hf Ir3V Ir3Nb Ir3Ta Nominal composition, at.% Composition range of L12 phase at 1573 K, at.% Ir-25.0Ti Ir-25.0Zr Ir-24.4Hf Ir-25.0V Ir-25.0Nb Ir-25.0Ta 23.6–26.7Ti 22.2–25.5Zr 23.5–24.5Hf 22.6–36.1V 24.0–32.0Nb 24.6–27.2Ta which consists of an alumina pushrod driving a linear voltage differential transformer (LVDT) (18). Dilatometer specimens were normally 3 mm square and 8 mm long. Thermal expansion tests were conducted over the temperature range from 300 to 1100 K at a heating rate of 10 K min–1 in an argon atmosphere. Thermal Conductivity Figure 1 shows the thermal conductivities of Ir3X compounds as a function of temperature. The thermal conductivity tends to decrease with increasing temperature for Ir3Nb and Ir3Ta, which have thermal conductivities above 80 W m–1 K–1 at 300 K. Conversely, a continuous increase in thermal conductivity with increasing temperature is observed for Ir3V, which has a smaller thermal conductivity at 300 K. The thermal conductivities of Ir3Ti, Ir3Zr and Ir3Hf are rather insensitive to temperature. The thermal conductivities of Ir3X at 300 K are widely distributed in the range from 41 to 99 W m–1 K–1, while the difference becomes less emphasised at higher temperatures. Fig. 1 Thermal conductivity versus temperature for Ir3X (X = Ti, Zr, Hf, V, Nb or Ta). Note that the value of Ir3Hf is the offstoichiometric data Thermal conductivity, λ, W m–1 K–1 Ir3Nb 100 Ir3Ta Ir3Zr Ir3Ti Ir3Hf 50 Ir3V 0 500 1000 1500 Temperature, K Platinum Metals Rev., 2008, 52, (4) 209 The temperature coefficient of thermal conductivity, k, in the temperature range between 300 and 1100 K can be estimated from Equation (i): k = (1/λ300 K)(dλ/dT) ≈ (1/λ300 K){(λ1100 K–λ300 K)/(1100–300)} (i) where λ300 K and λ1100 K are the thermal conductivities at the temperature indicated by the subscript. The temperature coefficients of Ir3X are plotted against the thermal conductivity at 300 K in Figure 2, together with the plots for pure metals (19–21) and intermetallic compounds (22–24). As a general rule, the thermal conductivity and the temperature coefficient are inversely correlated in pure metals and intermetallic compounds. All the Ir3X compounds other than Ir3V are characterised by larger thermal conductivities and smaller temperature coefficients. In particular, the thermal conductivities of Ir3Nb and Ir3Ta are nearly equal to that of NiAl, which is widely recognised as a high thermal conductivity compound (17, 25). The thermal conductivity of an intermetallic compound is quantitatively correlated with those of the constituents of the compound though Nordheim’s relation (26). The high thermal conductivities of Ir3X may be partly due to the high thermal conductivity of pure Ir, whose thermal conductivity at 300 K is 147 W m–1 K–1. Ir3X 34.1 25 f.c.c. b.c.c. h.c.p. L12 B2 Other crystal structures CoGa Temperature coefficient of thermal conductivity, k, 104 K–1 20 Pt3Ge NiTi 15 NiGa Rh3Ti Ni2Al3 10 Pt3Ga Pt3Ti 5 FeAl 0 –5 Ni3Al Ir3V Pd V Rh3V Nb Ni3Ge Ni3Ga CoTi CoAl Ir3Hf Pt NiAl Zr Ir3Zr NiAl3 Ta Ti Ir3Ti Os Ir3Nb Rh Hf 3 Ir Hf Re Rh3Zr Rh Ru Mo Ir3Ta Ni3Ti Rh3Ta Cr Rh3Nb W FeTi Au Cu Ag Be –10 3 5 7 10 20 30 50 70 100 200 300 Thermal conductivity at 300 K, λ300 K, W m–1 K–1 500 700 1000 Fig. 2 Correlation between thermal conductivity at 300 K and temperature coefficient for Ir3X. The data for pure metals (19–21) and intermetallic compounds (22–24) are also indicated Platinum Metals Rev., 2008, 52, (4) 210 Thermal Expansion Table II Results of the thermal expansion measurements (ΔL/L) are shown in Figure 3. The dilatation curves for all the Ir3X compounds are smooth functions of temperature exhibiting no sudden changes in slope. The curves in Figure 3 reveal that the thermal expansion of Ir3Ta is slightly smaller than that of either Ir3V or Ir3Nb over the temperature range between 300 and 1100 K. Also, the data indicate the smaller thermal expansion of Ir3Ti in comparison with those of Ir3Zr and Ir3Hf. The slope of the curve of ΔL/L vs. temperature is the CTE. The relatively flat dilatation curve for each compound indicates that the CTE of Ir3X are insensitive to temperature in the range 300 to 1100 K. The CTE of Ir3X compounds at 800 K are summarised in Table II. All the values of CTE are concentrated around 8 × 10–6 K–1. The largest CTE is found in Ir3V with 8.4 × 10–6 K–1, while Ir3Ti shows the smallest at 7.5 × 10–6 K–1. Figure 4 shows the correlation between the CTE at 800 K and the melting point for Ir3X, together with the plots for pure metals (21, 27) and intermetallic compounds (22, 28). It is found that Coefficient of Thermal Expansion of Ir3X Compounds at 800 K Compound Coefficient of thermal expansion at 800 K, K–1 7.5 × 10–6 8.2 × 10–6 8.2 × 10–6 8.4 × 10–6 8.0 × 10–6 7.6 × 10–6 Ir3Ti Ir3Zr Ir3Hf* Ir3V Ir3Nb Ir3Ta *Note that the value of Ir3Hf is the off-stoichiometric data all the plots of pure metals and intermetallic compounds including Ir3X are arranged by a universal curve, irrespective of crystal structure. The CTE of Ir3X are approximately equal to that of pure Ir and one half those of conventional intermetallic compounds such as Ni3Al and NiAl. The smaller CTE values of Ir3X correlate well with the higher melting points of the compounds. The interatomic force in metallic materials is characterised by cohesive energy, Ecoh, defined as the difference between the potential energy of atoms in the gas state and that in a crystal of the 1.0 1.0 0.5 Ir3Ti Ir3Zr ΔL/L, % Ir3Hf Fig. 3 Thermal expansion of Ir3X during heating from 300 to 1100 K. The heating rate is 10 K min–1. Note that the curve of Ir3Hf is the off-stoichiometric data. Left-hand axis: Ir3V, Ir3Ta, Ir3Nb Right-hand axis: Ir3Hf, Ir3Ti, Ir3Zr ΔL/L, % 0 0.5 Ir3V Ir3Nb Ir3Ta 0 300 400 500 Platinum Metals Rev., 2008, 52, (4) 600 700 800 900 Temperature, K 1000 1100 211 40 Ir3X f.c.c. b.c.c. h.c.p. L12 B2 D019 Mg Coefficient of thermal expansion, α, 10–6 K–1 Al 30 AgMg Ag 20 10 FeAl Cu CoGa Be NiGa Ni Sn 3 Ni Ni3In Au Fe NiAl Co Ni3Al Ni3Ga Ni3Ge Rh3Zr Ni3Si Pd CoAl FeTi Y Rh3V Rh3Hf NiTi V Ir3Zr Ti Cr Rh CoTi Ir3V Rh3Ti CoHf Pt Ir3Hf Rh3Nb Zr Ta Ir3Nb Ir Re Ir3Ti Hf Ir3Ta Rh3Ta Os Mo W 0 1000 2000 3000 Melting point, Tm, K 4000 5000 Fig. 4 Correlation between coefficient of thermal expansion at 800 K and melting point for Ir3X. The data for pure metals (21, 27) and intermetallic compounds (22, 28) are also indicated material. The cohesive energy in intermetallic compounds is expressed as the sum of the sublimation energy of the alloy, Esub, and the heat of formation of ordered structure, ΔH (29), Equation (ii): Ecoh = Esub + ΔH (ii) Table III summarises the Ecoh, Esub and ΔH values for the Ir3X compounds, where Esub was obtained from the data source (30) and ΔH was calculated from Miedema’s formula (31, 32). The data for Ni3Al and NiAl are also indicated in Table III. It can be seen that the cohesive energy of intermetallic compounds originates mostly from the sublimation energy rather than the heat of forma- Platinum Metals Rev., 2008, 52, (4) tion of ordered structure. The cohesive energy for Ir3X is located around 700 kJ mol–1, which is 1.7 times larger than that of Ni3Al and NiAl. The larger cohesive energy of Ir3X would result in the higher melting point and in the smaller CTE of the compounds. Conclusions Thermal conductivity and thermal expansion of Ir3X (X = Ti, Zr, Hf, V, Nb or Ta) were surveyed in the temperature range between 300 and 1100 K. The thermal conductivity and the temperature coefficient are inversely correlated for Ir3X. All the Ir3X compounds other than Ir3V have larger thermal conductivities and smaller temperature 212 Table III Cohesive Energy, Sublimation Energy and Heat of Formation for Ir3X, Ni3Al and NiAl Compound Cohesive energy, Ecoh, kJ mol–1 Ir3Ti Ir3Zr Ir3Hf Ir3V Ir3Nb Ir3Ta Ni3Al NiAl 675 732 728 662 737 749 436 426 Sublimation energy*, Esub, kJ mol–1 Heat of formation**, ΔH, kJ mol–1 620 653 658 631 685 698 403 378 55 79 70 31 52 51 33 48 *Sublimation energy is obtained from the data source (30) **Heat of formation is calculated from Miedema’s formula (31, 32) coefficients. The CTE of Ir3X compounds are insensitive to temperature, and fall around 8 × 10–6 K–1 at 800 K. The smaller CTE of Ir3X are well correlated with the higher melting points of the compounds. The L12 intermetallic compounds Ir3X with X = Ti, Zr, Hf, Nb and Ta are characterised by larger thermal conductivity and smaller thermal expansion. References 1 R. L. Fleischer, J. Met., 1985, 37, (12), 16 2 R. L. Fleischer, J. Mater. Sci., 1987, 22, (7), 2281 3 S. M. Bruemmer, J. L. Brimhall and C. H. Henager, Jr., Mater. Res. Soc. Symp. Proc., 1990, 194, 257 4 A. M. Gyurko, G. E. Vignoul, J. K. Tien and J. M. Sanchez, Metall. Trans. A, 1992, 23, (11), 3073 5 A. M. Gyurko and J. M. Sanchez, Mater. Sci. Eng. A, 1993, 170, (1–2), 169 6 Y. Terada, K. Ohkubo, S. Miura, J. M. Sanchez and T. Mohri, Mater. Chem. Phys., 2003, 80, (2), 385 7 “Binary Alloy Phase Diagrams”, 2nd Edn., ed. T. B. Massalski, ASM International, Materials Park, OH, U.S.A., 1990 8 Y. Yamabe, Y. Koizumi, H. Murakami, Y. Ro, T. Maruko and H. Harada, Scr. Mater., 1996, 35, (2), 211 9 Y. Yamabe-Mitarai, Y. Ro, T. Maruko and H. Harada, Metall. Mater. Trans. A, 1998, 29, (2), 537 10 Y. Yamabe-Mitarai, Y. Ro, T. Maruko and H. Harada, Intermetallics, 1999, 7, (1), 49 11 M. F. Ashby, Acta Metall., 1989, 37, (5), 1273 12 D. L. Ellis and D. L. McDanels, Metall. Trans. A, 1993, 24, (1), 43 13 W. B. Pearson, “A Handbook of Lattice Spacings and Structures of Metals and Alloys”, Vol. 2, Pergamon Press, Oxford, 1967 14 S. Miura, K. Ohkubo, Y. Terada, Y. Kimura, Y. Mishima, Y. Yamabe-Mitarai, H. Harada and T. Mohri, J. Alloys Compd., 2005, 393, (1–2), 239 15 S. Miura, K. Ohkubo, Y. Terada, Y. Kimura, Y. Mishima, Y. Yamabe-Mitarai, H. Harada and T. Mohri, J. Alloys Compd., 2005, 395, (1–2), 263 16 W. J. Parker, R. J. Jenkins, C. P. Butler and G. L. Platinum Metals Rev., 2008, 52, (4) Abbott, J. Appl. Phys., 1961, 32, (9), 1679 17 Y. Terada, K. Ohkubo, K. Nakagawa, T. Mohri and T. Suzuki, Intermetallics, 1995, 3, (5), 347 18 T. Honma, Y. Terada, S. Miura, T. Mohri and T. Suzuki, Proceedings of the 1998 International Symposium on Advanced Energy Technology, Centre for Advanced Research of Energy Technology, Hokkaido University, Sapporo, 1998, p. 699 19 Y. S. Touloukian, R. W. Powell, C. Y. Ho and P. G. Klemens, “Thermal Conductivity, Metallic Elements and Alloys”, Plenum, New York, 1970 20 C. Y. Ho, R. W. Powell and P. E. Liley, ‘Thermal conductivity of the elements: A comprehensive review’, J. Phys. Chem. Ref. Data, 1974, 3, Suppl. (1) 21 “Tables of Physical and Chemical Constants”, 16th Edn., eds. G. W. C. Kaye and T. H. Laby, Longman, Harlow, Essex, 1995 22 Y. Terada, K. Ohkubo, S. Miura and T. Mohri, Platinum Metals Rev., 2006, 50, (2), 69 23 Y. Terada, K. Ohkubo, T. Mohri and T. Suzuki, Mater. Sci. Eng. A, 1997, 239–240, 907 24 Y. Terada, T. Mohri and T. Suzuki, Proceedings of the Third Pacific Rim International Conference on Advanced Materials and Processing (PRICM-3), Honolulu, Hawaii, 12th–16th July, 1998, eds. M. A. Imam, R. DeNale, S. Hanada, Z. Zhong and D. N. Lee, TMS, Warrendale, Pennsylvania, U.S.A., 1998, p. 2431 25 R. Darolia, J. Met., 1991, 43, (3), 44 26 Y. Terada, K. Ohkubo, T. Mohri and T. Suzuki, Mater. Sci. Eng. A, 2000, 278, (1–2), 292 27 Y. S. Touloukian, R. K. Kirby, R. E. Taylor and P. 213 D. Desai, “Thermal Expansion, Metallic Elements and Alloys”, Plenum, New York, 1975 28 T. Honma, M.Sc. Thesis, Hokkaido University, Sapporo, Japan, 1998 29 T. Mohri, Mater. Jpn., 1994, 33, (11), 1416 30 C. Kittel, “Introduction to Solid State Physics”, John Wiley & Sons, New York, 1953 31 A. R. Miedema, P. F. de Châtel and F. R. de Boer, Physica B+C, 1980, 100, (1), 1 32 F. R. de Boer, R. Boom, W. C. M. Mattens, A. R. Miedema and A. K. Niessen, “Cohesion in Metals, Transition Metal Alloys”, Elsevier, Amsterdam, 1988 The Author Yoshihiro Terada is an Associate Professor in the Department of Materials, Physics and Energy Engineering, Nagoya University, Japan. His main activities are in the thermal and mechanical properties in metallic materials for high-temperature applications. His major field of present interest is the creep mechanisms of heat resistant magnesium alloys. Platinum Metals Rev., 2008, 52, (4) 214 DOI: 10.1595/147106708X361493 Platinum Group Metal Chemistry of Functionalised Phosphines PROPERTIES AND APPLICATIONS OF THEIR COORDINATION COMPLEXES By Martin B. Smith Department of Chemistry, Loughborough University, Loughborough, Leicestershire LE11 3TU, U.K.; E-mail: [email protected] Tertiary phosphines are a large class of fascinating ligands commonly used in platinum group metal (pgm) coordination chemistry. They play an important role in areas ranging from homogeneous catalysis to selective metal extraction chemistry and to therapeutic applications. In this article, pgm-containing complexes of new functionalised mono-, di- and polytertiary phosphines, derived from straightforward condensation reactions, are reviewed. These phosphines have been used as building blocks in supramolecular chemistry and for constructing novel hexanuclear pgm complexes, as ligands for bridging homo- and heterobimetallic late transition metals, and in the field of precious metal-based catalysis. Tertiary phosphines arguably remain the linchpin of much of our understanding about coordination chemistry, catalysis and other applications using metal complexes. Their extreme flexibility originates from the ease with which their steric and electronic properties, bite angle, solubility and chirality can be regulated in a precise and controlled way. Trivalent phosphorus ligands have frequently been used in coordination and organometallic chemistry as a means of stabilising the metal centre, typically a pgm. Tertiary phosphines can dictate the coordination number of a metal centre. For example, low-coordinate linear or trigonal planar geometries can be stabilised by bulky ligands such as tricyclohexylphosphine (PCy3) and tri(tert-butyl)phosphine (P(tBu)3). Furthermore the electronic properties, and hence reactivity, of the metal centre can be influenced by substituents bound to the phosphorus donor atom. In our research group at Loughborough University, we have been interested in phosphorus H2 C N H H R HO –- H2O PR2 N H PR2 C H2 R ligands for over a decade. In this article, some of our recent achievements are reviewed, along with contributions from others, in this stimulating field of pgm chemistry. The preparative strategy for ligands 1 and 2, illustrated in Scheme I, relies on an established variant of the classic Mannich condensation reaction (1). In our work, many ligands of both types have been synthesised in high yields by a single step procedure, using a phosphorus-based Mannich condensation (PBMC) reaction. Adaptation of this simple methodology to nonsymmetric ditertiary phosphines will also be discussed. Our initial contribution to this field stemmed from reports (2, 3) that diphenyl-2pyridylphosphine (Ph2P(2-C5H4N)) could be used, in conjunction with simple palladium(II) salts and a strong acid, typically p-toluenesulfonic acid (pMeC6H4SO3H), as an efficient homogeneous alkyne carbonylation catalyst system. Drent et al. (2) proposed that the 2-pyridyl (2-C5H4N) group is H2 C HO PR2 –- H2O 1(1) R2 P N C H2 PR2 C H2 R 2 (2) Scheme I Synthetic approaches to new aminophosphine ligands 1 and 2 Platinum Metals Rev., 2008, 52, (4), 215–221 215 necessary for two reasons. Firstly, it facilitates the carbonylation of alkynes by accessing different coordination capabilities of Ph2P(2-C5H4N), using the phosphorus and/or nitrogen donor atoms. Secondly, it acts as a ‘proton messenger’ through an intermediate Pd(II) species bearing a pendant pyridinium group. We have prepared new functionalised pyridylphosphines and investigated their ligating properties to pgms (4). As will be shown, hydrogen bonding, invariably using the secondary amine group, was a key aspect. Its action was characterised through crystallographic solid-state studies. Using the PBMC approach illustrated in Scheme I, the first ligand synthesised was 3a. Phosphine 3a and its derivatives 3b and 3c exhibited a plethora of coordination modes (monodentate, chelating, bridging) when complexed to an array of pgms such as ruthenium(II), rhodium(III), iridium(III) and platinum(II). X H N N PPh2 X X X X = = = = OH OP(O)Ph2 OPPh2 H 3a (3a) 3b (3b) 3c (3c) (3d) 3d Recently, phosphine 3d was shown to bridge two dichloropalladium(II) (Cl2Pd(II)) metal centres in a head-to-tail fashion (Figure 1), affording the 12-membered metallocycle 4 (5, 6). One feature we routinely observed when closely related pyridylphosphines were studied by single-crystal X-ray diffraction (XRD) was the presence of 4 Fig. 1 Single crystal X-ray structure of palladium(II) phosphine complex 4 Platinum Metals Rev., 2008, 52, (4) intermolecular H-bonded dimer pairs involving the secondary amine (–NH) group (7). These early findings prompted us to probe in more detail these secondary interactions with other pgm complexes of functionalised tertiary and ditertiary phosphines. In particular, the ability of carboxylic acids to associate through H-bonding led us to design and synthesise new ligands for supramolecular chemistry and crystal engineering. Crystal Engineering Given the versatility of tertiary phosphines, we were intrigued to find that their use in supramolecular chemistry is often reserved to that of spectator or ancillary ligand (8). Our efforts to study the solid-state packing behaviour of an isomeric series of metal complexes containing phosphorus-based ligands were thwarted by a lack of suitable examples in the literature. With this in mind, and identifying commercially available isomeric amines with hydroxyl/carboxylic acid groups as attractive reagents, a range of highly functionalised ditertiary phosphines were synthesised using a PBMC route (Scheme I). These were isolated in good to high yields and complexed to afford an isomeric series of seven square-planar dichoropalladium(II) compounds. Crystallographic studies showed that these complexes H-bond in a manner highly dependent on the disposition of the functional groups on the N-arene ring. Some of the isomers are shown in Figure 2. Solid-state structures are formed, composed of 20-membered dimer pairs, 5a, 1D-polymeric chains, 5b, or ladders, 5c, containing 38-membered rings (9). More strikingly, changing the labile Pd(II) source from PdCl2(cod) to Pd(CH3)Cl(cod) (cod = cycloocta-1,5-diene) afforded the novel self-assembled hexameric Pd compound 6 in high yield (10). In this example, the ligand bridges two Pd(II) metal centres via an unusual P2O-tridentate coordination mode to give a large 48-membered metallocycle possessing a unique hexagonal arrangement. Other hexameric analogues, of nanometre dimensions, have also been reported (10). Self-assembly, using a range of H-bonding interactions, have also been studied in linear gold(I) complexes (11) and half-sandwich 216 O H OH N O Cl Cl P Pd P P Cl P Cl P P Cl Cl O OH HO H O O N P Cl N Pd Pd Cl H O P P Cl N Pd OH N Pd O H Cl O P O H OH O 5b (5b) 5a (5a) HO Cl Cl Cl Pd P P O H Cl N Cl Pd P P O H Pd Cl N O N P P H O O Cl P O N P Pd O P Pd HO N P Cl O O O O O OH O H H H H H H O O O O O O O N P H O P N Cl O P Pd H Cl P Cl P Pd Cl N H O 5c (5c) Cl O Pd P P N OH Cl P N N O P Pd Cl O O P Cl P Pd Cl OH P Pd Cl P Pd P O O O N O OH 6(6) Fig. 2 Structural motifs of different square-planar palladium(II) phosphine complexes 5a–5c and 6. Phenyl groups on phosphorus (pink) are omitted for clarity and dashed lines indicate hydrogen-bonding contacts organometallic Ru(II) complexes (12) using our isomeric phosphine ligands. This area of pgm tertiary phosphine chemistry, coupled with controlled H-bonding capabilities, coincides with new interest in supramolecular-based pgm catalysts (13). Mixed Metal Complexes Symmetric diphosphines are normally known to use both phosphorus donor sites for coordination, thereby forming a classic chelate ring. We were interested in investigating whether, by manipulating the ligand structure, it would be possible to sequentially coordinate a metal centre at one P-donor site, then add a second metal centre to the remaining noncoordinated position (14). To accomplish this, our PBMC approach was modified such that two sterically dissimilar P-based groups (P1 and P2) could be introduced in two consecutive steps (Scheme II, Steps (a) and (b)). By choosing suitable pgm precursors, for example dichloro(pcymene)ruthenium(II) dimer [RuCl2(p-cymene)]2, or a dichloropentamethylcyclopentadienyl metal dimer [MCl2(Cp*)]2 (M = Rh, Ir), novel Platinum Metals Rev., 2008, 52, (4) organometallic ‘piano-stool’ complexes were obtained (Scheme II, Step (c)). These ‘metalloligands’ were used to prepare heterobimetallic complexes (Scheme II, Step (d)) with distinct metal combinations such as Ru(II)/Au(I) or Ir(III)/Au(I), 7. A recent extension to this work, using a new nonsymmetric ligand incorporating –PPh2 and –PAd groups (PAd = phosphaadamantane), allowed us to prepare Ru2Pd and Ru2Pt trinuclear complexes, in which the square-planar PdCl2 or PtCl2 metal centres have two bulky phosphaadamantane cages trans to each other (15). Supported P–C–N–C–P Catalysts Complexes of the pgms are extremely valuable as catalysts for many homogeneous catalysed reactions in the chemical and pharmaceutical industries. While homogeneous catalysis offers many rewards over heterogeneous catalysis, its major handicap is the requirement to separate the catalyst from (by)products and unused reactants. This has important industrial implications, affecting the economic viability of a process. Modification of the skeletal P–C–N–C–P frame- 217 P1 R NH2 R P2 P1 (a) (a) NH R P1 (b) (b) N P2 [M] (c ) (c) R P1 Cl(1) N P2 Au(1) P(1) (d) [M´] [M`] (d) O(1) C(25) C(19) C(12) [M] C(11) N(1) P(2) C(18) C(4) Ir(1) C(1) O(3) R P1 N Cl(3) P2 Cl(2) O(2) [M´] [M`] 7(7) [M] Scheme II Cartoon illustration showing the synthesis of mixed metal dinuclear phosphine complexes (P1 and P2 are Pbased groups). The insert shows an X-ray structure of the heterobimetallic phosphine complex 7 work of ligand 2, shown in Scheme I, has enabled phosphines to be studied in homogeneous catalysis, and allowed the development of new methods for the separation of the pgm catalyst. The variety of these ligands will be illustrated later in this article, and hinges on the tunability of the R group on the central N atom, rather than on the P donor atoms as discussed previously. This facilitates attachment to different solid supports. The following examples serve to illustrate some recently published approaches, and highlight the importance of using chelating diphosphines to aid catalyst stability. Lu and Alper (16) showed how the recovery and recycling of catalysts could be realised using dendrimers peripherally decorated with catalytically active Pd(II) metal centres, supported on silica gel. The preparation of dendrimer complexes on silica, such as 8, involved first synthesising the diphosphine by reaction of the appropriate primary amine with (hydroxymethyl)then diphenylphosphine (Ph2PCH2OH), complexing using the labile Pd(II) complex PdCl2(PhCN)2. These Pd-based dendrimers were used for the intramolecular cyclocarbonylation of Cl Ph 2 P Pd Cl N O Silica support O Si (CH2) 3 Ph2 PPh N Ph N 8(8) Platinum Metals Rev., 2008, 52, (4) PPh 2 Cl Pd P Ph 2 Cl Pd R2 P N O Cy2 P AcO OAc AcO P Cy2 Cy AcO Cy2 P Pd P R2 OAc N Pd RR == Ph, Ph,CyCy 9(9) AcO N N (CH23)44 (CH N Cy2 OAc P Pd OAc P Cy2 Cy N Cy2 OAc P Pd OAc P Cy2 Cy N P Cy22 Cy Pd(Pd 4-10 4-10) (Pd8 and Pd16 not (Pd 8 and Pd 16 notshown) shown) 218 iodinated aryl amines and various 12- to 18-membered ring macrocycles were generated. Dendrimer complexes such as 8 attached to silica gel permitted simple filtration and reuse (up to eight times) without any significant diminution in catalytic activity. On a similar theme, the monomeric complex 9 and metallodendrimer Pd4-10, along with two higher generations related to Pd4-10, were found to be efficient catalysts for Suzuki coupling reactions of chloro- and bromoarenes (17). Recovery and reuse was possible with the dendrimer-based Pd catalysts, while recovery of the single metal site complex 9 was hampered by rapid decomposition, affording a catalytically inactive black precipitate. Two independent research groups (18, 19) have prepared the silica-supported P–C–N–C–P diphosphine catalyst 11 using the PBMC ligand synthesis strategy shown in Scheme I. Long and coworkers (18) loaded the supported catalyst 11 into standard teflon tubing and performed carbonylative cross-coupling reactions with different aryl halides and benzylamine. The microtube reactor permitted catalyst reuse for a number of cycles. 11CO radiolabelled amides could also be synthesised by this method. Uozumi and Nakai (20) prepared a supported diphosphine from ArgoGelTM-NH2 (from Argonaut Technologies Inc, now owned by Biotage AB) and Ph2PCH2OH, and characterised the product by gel-phase 31P magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopic studies. Reacting the diphosphine with the allylpalladium dimer [PdCl(η3-C3H5)]2 in toluene at 25ºC for 15 min gave complex 12. In aqueous potassium carbonate, complex 12 was an effective catalyst for the Suzuki-Miyaura coupling of aryl halides and aryl- or vinylboronic acids and could be reused up to three times. Employing the same tactic for attachment to solid supports, treatment of the commercially available ArgoGelTM amine resin with diphenylphosphine/paraformaldehyde (Ph2PH/(CH2O)n), followed by addition of [Ru6C(CO)17], gave compound 13 as dark red beads (21). No catalytic data was reported for 13; however, phosphine-free [Ru6C(CO)17] variants were shown to be promising hydrogenation catalysts for cyclohexene. Related phosphine-modified ArgoGelTM amine-based compounds, in this instance containing the pentaruthenium cluster [Ru5C(CO)15], were shown to act as gas sensors for hydrogen sulfide (H2S), carbon monoxide (CO) and sulfur dioxide (SO2) (22). Changes were monitored by Fourier transform infrared (FTIR) spectroscopy and by colour changes of the beads prior to and after gas addition. Furthermore the TM ArgoGel -NH2 resin was used to prepare sup− O Silica support Si O N OEt Et Ph 2 Cl P Pd P Cl Ph 2 ArgoGel res in resin Ph 2 P O O O Ph2 P (CH 2)2 [Ru6C(CO)17] N n P Ph Ph22 ArgoGel resin N Ph2 Cl Ph2 P P Ru N P P Cl Ph Ph Ph22 Ph22 13 (13) ArgoG el resin + + Pd P Ph2 12 (12) 11 (11) A rgoGel resin N n C l– Cl Ph2 H P H Ru N P PPh3 Ph22 PPh Ph 3 15 (15) Platinum Metals Rev., 2008, 52, (4) Ar goGel resin 14 (14) Cl PCy3 Ru Cl Ph PCy3 16 (16) 219 ported octahedral Ru(II) diphosphine complexes 14 and 15 as brown and yellow beads respectively (23). Both compounds were shown to hydrogenate supercritical carbon dioxide in the presence of dimethylamine (HN(CH3)2) to give dimethylformamide (DMF, HCON(CH3)2). The catalysts could be reused up to four times, after decantation and drying under vacuum, with some loss in catalytic activity. Polymer-based phosphine resins have recently been shown to act as scavengers for removal of Grubbs’ catalyst, 16, from reaction mixtures, and could be separated by simple filtration delivering > 95% Ru-free reaction products (24). Conclusions and Future Work The PBMC approach continues to be an attractive, yet simple, preparative method for accessing new trivalent phosphorus(III) ligands. Phosphines offer important insights into how structural ligand modifications can be made, allowing different ligating modes to be adopted at pgm centres. Furthermore, careful incorporation of highly polar functional groups can lead to diverse solid-state structures. The ease of using the PBMC approach to target late transition metal-based catalysts, with recyclable properties, offers practical alternatives in the field of homogeneous catalysis. Unpublished recent work from our group has taken us back to some earlier studies reviewed in Platinum Metals Review (25). We are using tetrakis(hydroxymethyl)phosphonium chloride (THPC), itself a precursor used to prepare tris(hydroxymethyl)phosphine (THP), as a starting reagent for the preparation of neutral and cationic phosphorus-containing ligands. The pgm coordination chemistry of these new ligands has provided us with some interesting results that will be published shortly (26). Acknowledgements The author would like to acknowledge those involved in supporting our research activities, especially Johnson Matthey PLC. Many thanks to all group members, past and present, who have made valuable contributions in the areas of pgm chemistry with phosphorus-based ligands, catalysis and supramolecular chemistry. References 1 M. Tramontini and L. Angiolini, “Mannich Bases, Chemistry and Uses”, CRC Press, Boca Raton, Florida, 1994 2 E. Drent, P. Arnoldy and P. H. M. Budzelaar, J. Organomet. Chem., 1993, 455, (1–2), 247 3 M. L. Clarke, D. J. Cole-Hamilton, D. F. Foster, A. M. Z. Slawin and J. D. Woollins, J. Chem. Soc., Dalton Trans., 2002, (8), 1618 4 S. E. Durran, M. B. Smith, A. M. Z. Slawin and J. W. Steed, J. Chem. Soc., Dalton Trans., 2000, (16), 2771 5 S. E. Durran, M. B. Smith, S. H. Dale, S. J. Coles, M. B. Hursthouse and M. E. Light, Inorg. Chim. Acta, 2006, 359, (9), 2980 6 H.-B. Song, Z.-Z. Zhang and T. C. W. Mak, J. Chem. Soc., Dalton Trans., 2002, (7), 1336 7 S. J. Coles, S. E. Durran, M. B. Hursthouse, A. M. Z. Slawin and M. B. Smith, New J. Chem., 2001, 25, (3), 416 8 B. J. Holliday and C. A. Mirkin, Angew. Chem. Int. Ed., 2001, 40, (11), 2022 9 M. B. Smith, S. H. Dale, S. J. Coles, T. Gelbrich, M. B. Hursthouse, M. E. Light and P. N. Horton, CrystEngComm, 2007, 9, (2), 165 10 M. R. J. Elsegood, M. B. Smith and P. M. Staniland, Inorg. Chem., 2006, 45, (17), 6761 11 M. B. Smith, S. H. Dale, S. J. Coles, T. Gelbrich, M. Platinum Metals Rev., 2008, 52, (4) 12 13 14 15 16 17 18 19 20 21 J. Hursthouse and M. E. Light, CrystEngComm, 2006, 8, (2), 140 S. E. Dann, S. E. Durran, M. R. J. Elsegood, M. B. Smith, P. M. Staniland, S. Talib and S. H. Dale, J. Organomet. Chem., 2006, 691, (23), 4829 T. Šmejkal and B. Breit, Angew. Chem. Int. Ed., 2008, 47, (2), 311 G. M. Brown, M. R. J. Elsegood, A. J. Lake, N. M. Sanchez-Ballester, M. B. Smith, T. S. Varley and K. Blann, Eur. J. Inorg. Chem., 2007, (10), 1405 T. J. Cunningham, M. R. J. Elsegood, P. F. Kelly, M. B. Smith and P. M. Staniland, Eur. J. Inorg. Chem., 2008, (14), 2326 S.-M. Lu and H. Alper, Chem. Eur. J., 2007, 13, (20), 5908 J. Lemo, K. Heuzé and D. Astruc, Org. Lett., 2005, 7, (11), 2253 P. W. Miller, N. J. Long, A. J. de Mello, R. Vilar, H. Audrain, D. Bender, J. Passchier and A. Gee, Angew. Chem. Int. Ed., 2007, 46, (16), 2875 T. Posset and J. Blümel, J. Am. Chem. Soc., 2006, 128, (26), 8394 Y. Uozumi and Y. Nakai, Org. Lett., 2002, 4, (17), 2997 C. M. G. Judkins, K. A. Knights, B. F. G. Johnson, Y. R. de Miguel, R. Raja and J. M. Thomas, Chem. 220 Commun., 2001, (24), 2624 22 C. M. G. Judkins, K. A. Knights, B. F. G. Johnson and Y. R. de Miguel, Polyhedron, 2003, 22, (1), 3 23 Y. Kayaki, Y. Shimokawatoko and T. Ikariya, Adv. Synth. Catal., 2003, 345, (1–2), 175 24 M. Westhus, E. Gonthier, D. Brohm and R. Breinbauer, Tetrahedron Lett., 2004, 45, (15), 3141 25 P. G. Pringle and M. B. Smith, Platinum Metals Rev., 1990, 34, (2), 74 26 A. T. Ekubo, M. R. J. Elsegood, A. J. Lake and M. B. Smith, manuscript in preparation The Author Martin Smith was born in Royston, Hertfordshire, U.K., and grew up in the neighbouring village of Melbourn. He was awarded a B.Sc. in Chemistry at the University of Warwick, U.K., and completed his Ph.D. at Bristol University in the group of Professor Paul Pringle. After postdoctoral positions and a Royal Society Fellowship with Professors Tony Deeming (University College London), Brian James (University of British Columbia, Canada) and Derek Woollins (Loughborough University) he took up a Lectureship at Loughborough University in 1997. He was promoted to Senior Lecturer in 2008. His research interests are focused on pgm phosphine complexes and their applications in catalysis. Platinum Metals Rev., 2008, 52, (4) 221 DOI: 10.1595/147106708X363437 EuropaCat VIII: “From Theory to Industrial Practice” PLATINUM GROUP METALS RETAIN FUNDAMENTAL ROLE IN CATALYSIS Reviewed by Emma Schofield*, Nadia Acerbi and Cristian Spadoni Johnson Matthey Technology Centre, Blounts Court, Sonning Common, Reading RG4 9NH, U.K.; *E-mail: [email protected] This biennial European Federation of Catalysis Societies (EFCATS) conference took place on the 26th to 31st August 2007, in the town of Turku on the southwestern coast of Finland, and was hosted by the Nordic Catalysis Society (1). It was attended by 1350 scientists from Asia, the U.S.A. and Europe, of whom 65% were men, with an industrial representation of 40%. The oral presentations included seven plenary lectures, one or more keynote lectures for each session, 180 oral presentations in four parallel sessions and 750 posters. The significance of this conference was highlighted by the fact that there were up to ninety submissions for a session from which only ten presentations could be selected. Presentations were divided into eighteen topic areas: – Catalysis from first principles – Nanotechnology in catalysis, novel catalytic materials – Surface science in catalysis – New experimental approaches and characterisation under reaction conditions (combinatorial methods included) – Catalysis for pharma and fine chemistry (homoand heterogeneous catalysis) – Catalysis by enzymes – Polymerisation – Electro-catalysis and catalysis related to fuel cells – Catalysis in oil refining – Natural gas conversion (GTL, MTO, methanol, etc.) – The Hydrogen Society (hydrogen production and storage) – Catalysis in the conversion of renewable resources (biofuels, catalysis for sustainable developments) – Catalysis for pollution control (stationary) Platinum Metals Rev., 2008, 52, (4), 222–228 – Catalysis for pollution control (mobile) – Catalysis for bulk and specialty chemicals – Catalytic reaction engineering (novel reactor systems and novel reaction media included) – Photocatalysis – Catalyst deactivation, regeneration and recycling There was also a workshop entitled “Towards 100% Selectivity in Catalytic Oxidation over Nanostructured Metal Oxides” (VIII European Workshop on Selective Oxidation ISO 2007, hosted by EuropaCat VIII). Platinum group metals (pgms) featured in most of these sessions, and retain their pivotal roles in fuel cell catalysis, automotive applications, surface science and photocatalysis. The Berzelius Lecture Among the plenary lectures of the conference was the Berzelius Lecture, resurrected by the EuropaCat committee in honour of the Swedish scientist who, in a report in 1836, highlighted the “significance of reactions which take place in the presence of some substance which remains unaffected” (2). This year, this prestigious lecture was given by Nobel Laureate R. H. Grubbs (California Institute of Technology, U.S.A.) after whom is named the homogeneous Grubbs’ catalyst. This catalyst is an efficient, selective catalyst for olefin metathesis which works under mild reaction conditions that tolerate the presence of a range of other functionalities. More than fifty Grubbs’ catalysts have been synthesised. Grubbs demonstrated that, by tuning the N-heterocyclic carbene ligands on the ruthenium centre, the catalyst can be made more reactive or more stable, water soluble or enantioselective. Recent work has focused on increasing the barrier to decomposition by hindering the ligand rotation which is the initial 222 step in this pathway. The consequences of modifying the catalyst ligands by a single methyl group were further illustrated in ethanolysis, in which this structural refinement resulted in a decrease in reaction times from 20 h to 1 h, maintaining the high selectivity. For larger scale applications, a Grubbs’ catalyst is being explored for conversion of seed oils – corn and soy bean – into value added chemicals. In these clean, solvent-free reactions, the functionalities already present in the oils are retained at high turnover numbers. Catalysis from First Principles J. A. van Bokhoven (ETH Zurich, Switzerland) gave a well-attended and inspirational talk on the ways in which oxide supported nanoparticles of gold are different from bulk metal or crystals. The catalysts discussed were prepared by base deposition precipitation from hydrogen tetrachloroaurate (HAuCl4) on a range of supports: alumina (Al2O3), silica (SiO2), ceria (CeO2), titania (TiO2), zirconia (ZrO2) or niobium oxide (Nb2O5). Independent of the support, as the size of Au particles decreases, melting point, coordination number and bond lengths to adjacent atoms all decrease. The reason is that smaller particles have a different electronic structure. This was explained in terms of the fact that the d-band narrows and shifts up in energy towards the Fermi level as particle size decreases. The consequence is that the particles are catalytically reactive where the bulk metal is not. Using X-ray techniques – X-ray absorption near edge structure (XANES), extended X-ray absorption fine structure (EXAFS) – and in particular by the use of hard X-rays for high resolution, van Bokhoven showed that nanosized Au interacts with H2 and O2 and demonstrated that, for the hydrogenation of cinamaldehyde, smaller particles exhibit a higher selectivity. The issue of support effects was raised in the questions; the point was reiterated that, while support effects are clearly important in catalysis on Au, they did not influence the electronic particle properties under discussion. Novel phenomena related to Au clusters deposited on ultra-thin oxide films were discussed by G. Pacchioni (Università degli Studi di Milano- Platinum Metals Rev., 2008, 52, (4) Bicocca, Italy). He showed by means of density functional theory (DFT) calculations how oxide thin films may exhibit special properties which differ from the bulk oxide. He considered a system in which a thin layer of magnesium oxide (MgO) is grown on a metal, in this case silver or molybdenum. Subsequently Au particles are deposited on the metal oxide support. The formation of a metal/oxide interface can change the chemical properties of the oxide support and the system work function. When the supporting metal is Mo, what results is the charging of the supported metal atoms and clusters by direct tunneling of electrons from the metal substrate to the supported metal; this is not observed when Ag is used. The reason for this electronic behaviour is that the Fermi level of Ag is lower in energy than the Au 6s orbital, so spontaneous electron tunneling is not allowed; in contrast the Fermi level of Mo lies at higher energy than the Au 6s. This fundamental approach to the behaviour of catalytic metal particles was taken further by J. K. Nørskov (Technical University of Denmark) who discussed the reactivity of catalysts in terms of the geometrical and electronic structure of metal nanoparticles. Having discussed the correlations between the energy of d-states and the reactivity of a catalyst, he illustrated the practical applications of the theoretical principles in the synthesis of ammonia on 11% Ru on a MgAl spinel. On the Ru nanoparticle surface in this catalyst there are closepacked regions, on which there is a large barrier to dissociation, and steps, where the barrier is much lower and where the catalysis occurs. The question is then how many step sites there are on the nanoparticles, which can be modelled from transmission electron microscope (TEM) images. Around 2–3 nm, the required steps are no longer possible, hence the optimal nanoparticle size is > 3 nm. Although these are simple examples, they serve to illustrate the enormous potential of computational chemistry in predicting useful catalyst structures. Surface Science Investigating the surface science of platinum and palladium, T. Visart de Bocarmé (Université 223 Libre de Bruxelles, Belgium) illustrated the usefulness of field ion microscopy to elucidate the active sites and chemical species relevant to a catalytic reaction. Observing the reaction between H2 and NO on a Pt tip showed that an oscillatory reaction occurs with local oxide reduction by H2 during the oscillating cycles. The reaction occurs on the kink surfaces of the (012) planes where there are [001] zones. For Pd in contrast, there are no plane-specific effects and hysteresis rather than oscillation is observed; here reduction of oxides is only possible at high pressures of H2. Extending the scope of his studies to all the pgms, M. Johansson (Technical University of Denmark) measured splitting coefficients and desorption rates in the hydrogen–deuterium exchange reaction with and without added carbon monoxide on a range of pgms in 1 bar H2 at temperatures between 40 and 200ºC. Surprisingly, in the absence of CO, Ru and Rh proved to have the highest sticking probabilities: the order followed: Ru > Rh >> Pd ~ Pt > Ir. The addition of CO slows the reaction for all the metals, in particular Pt and iridium. Pd was the focus of the talk by W. T. Tysoe (University of Wisconsin-Milwaukee, U.S.A.). He used deuterium-labelling to investigate the reaction mechanism of the industrially significant vinyl acetate monomer (VAM) reaction on, in this case, a Pd(111) surface, in which ethene reacts oxidatively with acetic acid. Using an elegant combination of variable temperature infrared (IR) and temperature-programmed desorption (TPD) spectroscopy, he showed that changing the labelled ethenes – CHD=CHD or CH2=CD2 – gave different rates of reaction. The conclusion that the reaction on Pd proceeds via the Samanos pathway (3) was substantiated by DFT, which predicts that the Samanos pathway is energetically more favourable. In the subsequent discussion the possibility was raised that the pathway may be different on a PdAu alloy. S. Schauermann (Fritz-Haber-Institut der MaxPlanck-Gesellschaft, Germany) demonstrated the active role played by the support iron oxide (Fe2O3) in the decomposition of methanol. In a model system in which crystalline particles of Pd Platinum Metals Rev., 2008, 52, (4) were prepared on an Fe2O3 film deposited on a Pt(111) surface, at T > 450 K she showed that O2 was chemisorbed on metallic Pd. At T > 500 K, layers of PdO formed at the particle–support interface, leading to the coexistence of PdO and Pd metal. At T > 600 K, there was nearly complete oxidation of the particle. The consequences of the decomposition of MeOH are that a reservoir of predissociated methoxy species build up on the Fe2O3 support which spill over onto the Pd particles in order to react. On the theme of reactions of MeOH, R. Blume (Fritz-Haber-Institut der MaxPlanck-Gesellschaft, Germany) showed that in the oxidation of MeOH to formaldehyde on oxidic Ru surfaces, different precatalysts evolve into the same catalytically active surface. The amount of transition surface oxide in the first few layers proved to be the parameter which determines which catalytic pathway is followed rather than the amount of RuO2. Alcohols also featured in the investigation of N. Bion (Université de Poitiers, France) into the steam reforming of bioethanol over Rh/MgAl2O4/Al2O3 to generate H2. In crude bioethanol there are a range of impurities which deactivate this reaction. Each impurity was tested individually and it was shown that there is a strong poisoning effect of acetic acid – although there are only low levels of acetic acid in bioethanol – and no inhibition by diethylamine. Of a series of alcohols, the order of poisoning was: branched > linear > other functional groups. This was thought to be due partly to coke deposition and partly influenced by the hydrophobicity of the alcohol, where the C4 and C5 alcohols hinder water activation. Following the ethanol theme, W. Shen (Dalian Institute of Chemical Physics, Chinese Academy of Sciences) proposed an Ir/CeO2 catalyst for steam reforming of ethanol. He showed that, while there was only limited sintering of Ir during the 60 h test reaction, there was significant growth and morphological changes of the ceria particles, although this did not influence the catalytic activity noticeably. New Experimental Approaches In situ techniques, which can be used to study the structural modification of catalysts under real- 224 life reaction conditions, are of critical importance to any scientist who is trying to understand how a catalyst really behaves. J.-D. Grunwaldt (ETH Zurich, Switzerland) presented 2D mapping of supported pgm catalysts under operational conditions in order to investigate the variation of the catalyst structure that can occur inside a catalytic reactor as a result of prominent temperature or concentration gradients. The catalytic systems studied were alumina supported pgms (Rh/Al2O3, Pt-Rh/Al2O3, Pt/Al2O3, Pt-Ru/Al2O3, Pd/Al2O3) prepared by flame-spray pyrolysis and the reaction studied was the total oxidation of methane. X-Ray absorption spectroscopy (XAS), recorded with a micro-focused beam scanning over the sample coupled with a 2D-area detector, is particularly effective for in situ studies since it requires shorter acquisition times. The temperature profile was analysed using an IR thermography camera and the catalytic performance by means of mass spectrometry. It was shown that the structure of a catalyst during partial oxidation of methane varies strongly along the axial coordinate of a tubular catalytic microreactor. There are considerable structural differences between the pgm particles of less than 100 μm diameter, and a strong dependence on the reaction conditions (temperature, space velocity). This talk highlighted the importance of 2D-spectroscopic studies under operational reaction conditions. A. Tompos (Chemical Research Center, Institute of Surface Chemistry and Catalysis, Hungarian Academy of Sciences) used catalysts combinatorially designed for methane total oxidation in order to understand the role of Pt and Au on the performance of trimetallic Pt-Pd-Au/CeO2 catalysts. Ceria was obtained by the urea precipitation route and subsequently impregnated with the three metals. By X-ray photoelectron spectroscopy, in situ Fourier transform infrared (FTIR) spectroscopy, TPD of H2 and CO chemisorption measurements, direct evidence was found for alloying of Pt with Pd. The conclusion was that the improved catalytic properties of multimetallic PtPd-Au/CeO2 catalysts over the monometallic Pd analogues are due to: (a) the increase of the number of Pd(0)–PdO dual-type active sites, Platinum Metals Rev., 2008, 52, (4) (b) stronger methane adsorption at the Pd(0)–PdO boundary, (c) a higher accessible metallic area in the working catalyst, (d) suppression of the reduction of Ce(IV), and (e) suppression of the concentration of ionic Pd(II). Novel Catalytic Materials The pgms are the first port of call for scientists in search of new catalytic materials. Pd featured in the talk by G. L. Chiarello (Università degli Studi di Milano, Italy). He compared 0.5% Pd/LaCoO3 catalysts made by flame-spray pyrolysis with more conventional catalysts prepared by impregnation in the reaction in which small amounts of H2 in exhaust gases are used to reduce NO. In the flame-made catalyst, the Pd(II) partially replaces Co in the perovskite structure. When this catalyst is calcined at 800ºC and reduced at 300ºC in 5% H2/He, Pd segregates to the catalyst surface. In contrast, reduction at 600ºC leads to the formation of a PdCo alloy. A further feature of the flamemade catalyst is that at temperatures over 500ºC, EXAFS evidence suggested that the Pd redissolves in the perovskite framework instead of sintering, putting this in the class of so-called ‘intelligent catalysts’ which redisperse following sintering. The flame-based preparation route gave a clear advantage in catalyst performance over the impregnation method; the catalyst yielded 100% conversion at 160ºC along with 78% selectivity to nitrogen and after 100 h there was no deactivation of the flamemade catalyst. Encapsulated pgm nanoparticles are the novel approach to preventing sintering described by M. Paul (Max-Planck-Institute for Coal Research, Germany). He proposed encapsulating Au or Pt nanoparticles in hollow metal oxide spheres. In this way the nanoparticles are physically separate and sintering is prevented at high temperatures. By this method a colloidal nanoparticle is encapsulated in a silica shell, which is then coated with zirconia or titania and calcined at 900ºC. Subsequently the silica core is leached out by treatment with sodium hydroxide. TEM images showed the effective encapsulation. Using the CO oxidation reaction, it was shown that hollow sphere encapsulation does stabilise the catalyst 225 against sintering while causing no mass-transfer limitation and thus retaining catalytic activity. As a catalytic element, Au has proved a particularly popular subject of study since Haruta’s work in the 1980s (4). In this meeting, S. Carrettin (Instituto de Tecnología Química, CSIC, Spain) gave a pioneering example of a heterogeneous Au catalyst used for a carbon–carbon bond formation, namely the isomerisation of ω-alkynylfurans to phenols. The 1.8% Au on ceria catalyst was prepared using HAuCl4 and nanocrystalline ceria. The nanocrystalline support seems to stabilise the cationic species Au(I) and Au(III): the presence of these species on the surface was established by observing CO probe molecules by FTIR spectroscopy. The hypothesis that the Au cationic species is the active site was challenged during the discussion, and the question remained as to whether FTIR is a sufficiently sensitive technique to allow Au(I) and Au(III) differentiation. Well known in the field of Au catalysis, G. J. Hutchings (Cardiff University, U.K.) presented a new synthetic approach to supports for highly active oxidation catalysts. Au supported on ceria prepared using supercritical antisolvent (scCO2) precipitation was demonstrably more active and more stable for CO oxidation than comparable nanoparticles supported on conventional ceria derived from the direct calcination of cerium(III) acetylacetonate. In search of new industrial uses for Au catalysts J. McPherson (Project AuTEK, South Africa) deposited Au on hopcalite with the aim of improving the stability of this filter material to water. Despite extremely efficient deposition of Au, Au/ZnO and Au/TiO2 proved more active for aspirator applications. Automotive Catalysis As ever, pgms played a starring role in the section on automotive catalysis. In the section on NOx traps E. C. Corbos (Université de Poitiers, France) elegantly illustrated the redispersion of Pt on ceria-containing supports at temperatures greater than 800ºC in an oxidising atmosphere. The techniques used were in situ time-resolved turbo XAS in fluorescence mode and in situ TEM. In a cycling regime of 3% H2/He (60 s) followed Platinum Metals Rev., 2008, 52, (4) by 20% O2/He (60 s), the particles which start at 7 nm decrease in size to 5 nm within 30 s and to 3 nm within 1000 s. The hypothesis was that the oxidised atoms migrate. In the discussion the question was raised concerning the influence of water on these process, which is yet to be studied. H. Grönbeck (Chalmers University of Technology, Sweden) approached NOx storage from a computational perspective, using super-cell calculations to examine the adsorption of NO2 on layers of barium oxide(100) on Pt(100). The adsorption energy of BaO (Ea = 1.04) is enhanced by a factor of 2 (Ea = 2.38) when two layers of BaO are arranged on the Pt surface and there is a noticeable effect even up to 5 layers, 16 Å, of BaO between the Pt and the NO2. It was proposed that a similarly substantial effect would be observed on Pt supported MgO(100) (Ea = 1.65) with charging of the NO2 molecule induced by the Pt–MgO interaction. The theme of the talk by R. Burch (University of Belfast, Northern Ireland) was the importance of scientific rigour, in particular in not theorising beyond the available data. This is particularly important in studying non-steady state processes. In order to study NOx storage on 1% Pt/17.5% Ba/γ-alumina, Burch uses fast transient kinetics apparatus with very short residence times and a full gas mixture. The conclusion was that NH3 is only observed in large quantities over a Pt catalyst when H2 alone is used as the reductant. With the typical 3:1 CO:H2 mixture, CO inhibits the formation (release) of NH3. Among the talks devoted to catalytic combustion, A. Baylet (Université de Poitiers, France) and P. Gélin (Université de Lyon, France) shared a theme of catalytic combustion of natural gas over supported PdO. Since metallic Pd is much less reactive than its oxide, and reoxidation of Pd may be the rate limiting step in the reaction, different approaches were taken to increase the PdO:Pd ratio. A. Baylet doped highly thermally stable hexaaluminate supports (La0.2Sr0.3Ba0.5)(MnAl11)O19 with 1% Pd; the most effective catalyst proved to be a hexaaluminate/alumina mixture. The approach of P. Gélin was to vary the support in order to increase the PdO–Pd transition temperature, 226 achieving the highest activity on Pd/YSZ in the absence of sulfur. Only Pd/Al2O3 was not poisoned by sulfur. The theme of catalytic combustion was continued by A. de Lucas-Consuegra (Universidad de Castilla-La Mancha, Spain) who discussed the use of solid electrolytes to make conducting electroactive catalyst supports for use in the catalytic combustion of hydrocarbons, exemplified by propane. Promoting 1% Pt/β-Al2O3 with potassium ions gives a catalyst that operates, both in near-stoichiometric and O2 rich conditions, at lower temperatures – around 200ºC – well within the 190–310ºC working exhaust temperature. Fuel Cells For some time a lot of scientific effort has been devoted to decreasing the amount of pgm required for efficient operation of a fuel cell. M. Tada (University of Tokyo, Japan) used an impressive range of in situ XAS techniques to study the mechanism of the O2 reduction reaction at the cathode on a Pt/C catalyst under realistic operating conditions. Two in situ time-resolved techniques were used: time-gated EXAFS (TG-EXAFS), with a time resolution of 1 s and in situ time-resolved energy-dispersive EXAFS (DXANES), with a resolution of 4 ms. Having estimated all kinetic parameters for the reaction, she concluded that there are eight elementary steps involved, and there is a significant time lag between electron transfer and structural changes in the Pt catalyst. Since the Pt–Pt bond dissociation rate and the PtO bond formation rate constants are similar, it was shown that at higher potentials than the open circuit voltage oxygen atoms break in to the subsurface of the Pt nanoparticles. N. Tsiouvaras (Universidad de la Laguna, Spain) gave a controversial presentation on ternary catalysts for direct methanol fuel cells in which Mo had been introduced to PtRu/C at loadings of between 2 and 12 wt.% for an overall 30% metal loading. Pt crystallite sizes of 2–5 nm were observed; there was no evidence of alloying. Although the catalyst displayed high metal losses on electrochemical cycling – mostly of Mo – the CO stripping potentials were lower than the com- Platinum Metals Rev., 2008, 52, (4) mercial 30% PtRu/C standard. Using differential electrochemical mass spectrometry, the gases produced during electrochemical processes were analysed demonstrating that the onset of CO2 production was at lower potentials than observed for commercial catalysts. Similarly, by carrying out in situ FTIR on the electrochemical cell, it appeared that qualitatively a small quantity of CO poisoned the ternary catalyst surface. Finally, tests for activity in MeOH oxidation again gave higher current densities than the commercial standard. Photocatalysis A. Kudo (Tokyo University of Science, Japan) demonstrated an exciting system for solar H2 production from water. Ru/SiTiO3 doped with Rh was the catalyst for H2 generation; this proved better than the Pt analogue because the presence of Ru effectively suppresses the back reaction. By preparing the catalyst by a hydrothermal rather than solid state route, an improvement in quantum yield to 3.9% from 0.3% resulted. The improvement was thought to be due to the better crystallinity, smaller particle size and decrease in grain boundaries in the hydrothermally prepared catalyst, providing fewer sites where recombination could occur. The optimal system combined Ru/SiTiO3:Rh for H2 generation with BiVO4 for O2 generation, using Fe(III) as the couple mediator, and gave a system responsive up to 520 nm. Selective Oxidation A. Pashkova (DECHEMA, Germany) presented a new approach for the synthesis of hydrogen peroxide directly from H2 and O2. Single channel asymmetric membranes were used as the support for the active Pd or Pd-Ag alloy species. The selectivity for H2O2 could be increased from 20% to 80% by changing the concentration profiles of O2 and H2 from countercurrent to equicurrent profiles. The selective generation of propylene oxide by epoxidation of propylene was the subject of a paper by N. Mimura (Research Institute for Innovation in Sustainable Chemistry, Japan). The epoxidation was carried out using a mixture of H2 and O2 over titania supported Au nanoparticles 227 prepared by deposition precipitation. Characterisation showed that the nanoparticles had deposited only on the four-coordinate titanium sites. The problem of the explosion limit was solved by feeding in H2 and O2 in two separate streams and using a membrane in the catalyst area. Similarly good performances were obtained with Au on titanium silicalite-1 (TS-1) and with Mo oxide on silica for epoxidation by molecular O2. Conclusion EuropaCat VIII proved to be a key conference for any researcher studying the behaviour and characterisation of catalysts. An impressive selection of oral and written presentations generated what was certainly high quality if occasionally somewhat heated discussion both in and out of the conference venue. The high industrial representa- tion attested to the significance of the conference to the wider commercial world. It was clear that pgms retain their fundamental role in many branches of catalysis and, despite or perhaps as a result of all efforts at substitution and thrifting, will continue to be the focus of considerable catalyst research activity for the foreseeable future. EuropaCat IX: “Catalysis for a Sustainable World” will take place in Salamanca, Spain, from 30th August to 4th September 2009 (5). References 1 2 3 4 5 EuropaCat VIII: http://www.europacat.org/ Berzelius, Ann. Chim. Phys. (Paris), 1836, 61, 146 B. Samanos, P. Boutry and R. Montarnal, J. Catal., 1971, 23, (1), 19 M. Haruta, T. Kobayashi, H. Sano and N. Yamada, Chem. Lett., 1987, 16, (2), 405 EuropaCat IX: http://www.europacat2009.eu/ The Reviewers After her Ph.D. in Coordination Chemistry in Basel, Switzerland (1999), Emma Schofield spend two years as a post-doctoral researcher in Strasbourg, France, before taking up a Lectureship in Inorganic Chemistry at Trinity College in Dublin, Ireland. In 2004 she moved to Johnson Matthey in the U.K. where she specialises in developing new synthetic routes to heterogeneous catalysts. After specialising in heterogeneous catalysis applied to environmental technology at the Universidad Complutense de Madrid, Spain, and graduating from the Università di Urbino, Italy, Nadia Acerbi started her Ph.D. with Johnson Matthey in the framework of the Marie Curie Actions and in collaboration with the University of Oxford, U.K. Her research is focused on ‘Novel Nano-Coated Catalysts for Selective Oxidation of Hydrocarbons’. Cristian Spadoni graduated from the Facoltà di Chimica Industriale, Università di Bologna, Italy, with a specialisation in heterogeneous catalysis. He started his Ph.D. in Chemical Engineering with Johnson Matthey in the framework of the Marie Curie Actions and in collaboration with the University of Bath, U.K. His research has been focused on ‘Direct Synthesis of Hydrogen Peroxide from Oxygen and Hydrogen’. Platinum Metals Rev., 2008, 52, (4) 228 DOI: 10.1595/147106708X364922 “Catalysis for Renewables: From Feedstock to Energy Production” EDITED BY GABRIELE CENTI (University of Messina, Italy) and RUTGER A. VAN SANTEN (Eindhoven University of Technology, The Netherlands), Wiley-VCH, Weinheim, Germany, 2007, 448 pages, ISBN 978-3-527-31788-2, £105.00, €141.80, U.S.$200.00 Reviewed by John Birtill 15 Portman Rise, Guisborough, Cleveland TS14 7LW, U.K.; E-mail: [email protected] The drive for renewable feedstocks and fuels is a hot topic for scientists and governments, and catalysis is a key enabling technology for the development of new and improved processes. Hence, the appearance of this book is well timed. I am not sure about the publisher’s claim that “this will be a white book in the field”. The sixteen chapters are mostly reviews, and some of them have overlapping content. As with any type of boom, this research field is prone to exaggerated claims and false trails. Competition between food and biofeedstocks is likely in due course to discourage the use of food crops, but agricultural (lignocellulosic) waste products and targeted crops from marginal land have long-term potential. The content originated in a workshop, “Catalysis for Renewables”, held in the Netherlands in 2006, and organised within the EU sponsored ‘IDECAT’ (Integrated Design of Catalytic Nanomaterials for a Sustainable Production) framework (1). The editors of the book were members of the Organising Committee. The aim was to define “new directions and opportunities for catalytic research in this field by integrating industrial, governmental and academic points of view”. The authors are mostly academic and government scientists from the Netherlands and Italy, with a few more from France and Finland. There are very few industrial scientists. Hence, although the subject matter is of global geopolitical and industrial significance, the content reflects the views of attendees at this regional, academic workshop. However, the reviews cover a wide range of literature, and so the book serves as a useful source of information. Each chapter clearly stands alone as the work of its authors, suggesting a light editorial touch. Most Platinum Metals Rev., 2008, 52, (4), 229–230 of the reviews are informative, and a few are excellent. I liked the overall perspective on renewable catalytic technologies in the early chapters and the roadmap in the final chapter. Various controversial points are well described, regarding the magnitude of environmental challenges and the effectiveness of proposed solutions. However, the lists of academic studies of catalytic reactions in chapters on chemical transformations are not very helpful without some critical appraisal of their true potential for application (cost, robustness, effectiveness). The early chapters cover the biomass conversion chain, from the biorefinery to fuels and chemical products. The ordering of later chapters seems more random. Chapter 8, which describes combustion modelling, appears to be in the wrong book. There are further chapters on bioethanol production and upgrading, the conversion of glycerol to diesel components, other chemicals and syngas (carbon monoxide and hydrogen), and the methodology of cascade catalysis. The chapters on hydrogen production and fuel cells, and the techno-commercial and environmental case for hydrogen in transportation are loosely linked to the title theme, but are relevant for strategic reasons. The production of hydrogen by solar photocatalysis is the biggest challenge for the future. In general, there is little novel catalysis in this book. The production chain from the biorefinery is based on catalytic unit operations familiar to the chemical industry. Hence, processes such as reforming, hydrogenation, oxidation, hydrolysis and etherification appear throughout the book. New catalytic requirements do appear, for example, in the selective deoxygenation of certain intermediates. There is an interesting roadmap in the final chapter for priorities in 229 catalysis research into renewable raw materials and sources of energy. Not surprisingly, there are many passing references throughout the book to supported and/or bifunctional platinum group metal catalysts, for example hydrogenation (palladium, platinum, ruthenium, rhodium, iridium), hydrogenolysis (Pd), dehydrogenation (Pd), oxidation (Pt, Pd), homogeneous telomerisation (Pd), homogeneous hydrogenation (Rh), steam reforming (Pt), aqueous reforming (Ru, Pt, Pd) and electrocatalysis (Pt). However, many of these references have not been included in the index. The practical conversion of biofeedstocks is certain to place new demands on the robustness of catalysts, but this aspect is hardly mentioned by the mainly academic authors. A chapter on new challenges for catalyst design might have been useful, but I suppose that no-one talked about this at the IDECAT workshop. Besides the lack of industrial experience of bioprocessing, other notable omissions include the potential use of marine harvests and municipal waste. In conclusion, this book will be useful to anyone who wants an academic, strategic perspective on the potential contributions from various catalytic technologies to this field of research. The lack of industrial perspective is its most serious weakness. The price will limit its purchase mainly to libraries. It will be read by academic and industrial scientists, research students seeking a wider perspective, and those concerned with science policy. For instance, the issues of food competition and poor overall effectiveness attached to use of some food crops as industrial feedstocks are well explained, and it is surprising that these issues have only recently become politically controversial. Anyone interested in detailed catalytic science will find texts dedicated to the respective catalytic technologies to be more useful; for a general source, see for example Reference (2). References 1 2 IDECAT Conference Series, Catalysis for Renewables Conference: http://idecat.unime.it/index.php?pag=CatForRen C. H. Bartholomew and R. J. Farrauto, “Fundamentals of Industrial Catalytic Processes”, 2nd Edn., Wiley-Interscience, Weinheim, Germany, 2006 The Reviewer John Birtill is a consultant in industrial catalytic technology, an Honorary Research Fellow at the University of Glasgow, U.K., and Secretary of the Royal Society of Chemistry Applied Catalysis Group. See his website at: www.catalyst-decay.com for more information. Platinum Metals Rev., 2008, 52, (4) 230 DOI: 10.1595/147106708X362735 Platinum Group Metals Patent Analysis and Mapping A REVIEW OF PATENTING TRENDS AND IDENTIFICATION OF EMERGING TECHNOLOGIES By Richard Seymour Johnson Matthey Technology Centre, Blounts Court, Sonning Common, Reading RG4 9NH, U.K.; E-mail: [email protected] The patent literature contains a wealth of detailed information about existing and new uses for the platinum group metals (pgms). While excellent searching tools have existed for many years for identifying patents relating to specific topics, it is only relatively recently that it has been feasible to map the complete archive of patent literature to identify important trends relating to potential new applications. This paper summarises the results of such an exercise for the pgms carried out in early 2008 and shows that one such ‘hot spot’ relates to organic light emitting diodes (OLEDs). Previous articles in this Journal have described the importance of patents as a key source of technical and commercial intelligence (1, 2). The use of patent mapping to visualise large sets of patent data and to identify trends contained within that data has also been demonstrated (2). The present paper further develops these themes by examining the patent literature on pgms published since 1983, in particular that on the minor metals iridium and ruthenium. Searching – What and Where? I will begin by thinking about search strategy. In this case, the initial objective is to create a large set of patents relating to the pgms, which will later be analysed and refined. The choice of keywords is therefore straightforward: platinum, palladium, rhodium, iridium, osmium and ruthenium. In the patent literature it is unlikely that the names of these metals would be used in other contexts. However, this might be a difficult problem if we were searching the news or business press, where the names of the pgms are associated with many brand names – for example there would probably be many hits on topics such as platinum credit cards or iridium satellite communication systems, and strategies for removing such material would need to be found. Perhaps a more important question to ask is which patent collections to use to search for these words? The software package used at the Johnson Platinum Metals Rev., 2008, 52, (4), 231–240 Matthey Technology Centre is Aureka® (a product available from Thomson Reuters) (3), which includes patent data sets from the Patent Cooperation Treaty (PCT) and European Patent offices, plus a range of national patent collections including those of the U.S.A., Japan, the U.K., France and Germany. With the exception of Japan, these collections contain full-text patent documents, available either as PDF or HTML files. In the case of Japanese patents, a text version of the English-language title, abstract and other front page details is available, together with a PDF file of the full specification in Japanese. It must be borne in mind that using the French and German collections would require us to search in French or German respectively, and of course the results obtained would also be in French or German. The patent collections of other countries, for example China and India, are not currently available in Aureka. However at this stage we are looking for the big picture. The detail can follow later if necessary, for example by adding Chinese patent documents retrieved from other patent databases. We also need to think about where in the patent document we might wish to search for information on pgms. This is an important question and to understand the various possibilities and their implications we first need to think about the structure of a typical patent: 231 – Title: often deliberately rather vague and nonspecific. – Abstract: a short summary of the invention, in perhaps 100 to 200 words. – Claims: the claims of a patent govern its legal effect, that is, the areas of technology that are to be monopolised. Generally it can be said that a feature is not protected unless that feature is claimed or covered by the general language in the claims. So these are key – get the claims wrong and your invention may be seriously compromised. Then, depending on the particular country, there may also be sections on: – Background: provides details on the context of the invention, current technology, and why existing solutions may be inadequate. – Description: a detailed description of the invention and possible variants thereof. – Examples: worked examples, covering aspects such as how the invention is made. Scientists sometimes wrongly concentrate on the examples just as they would read the experimental sections of scientific papers. Now let us suppose we are searching for patents in which a new pgm chemical or material is disclosed, or in which the use of a pgm is a key part of the invention. In this case restricting the search to terms in the title or abstract, and possibly also the claims, will be adequate. Clearly if the word ‘platinum’ appears in any of these sections then it is likely to be a very important part of the invention. But what about the case when the name of the pgm appears somewhere in the rest of the patent, but not in the title, abstract or claims? Can these patents safely be ignored? An example of such patents might be the use of a standard palladium on carbon hydrogenation catalyst in a multi-stage organic synthesis route. The novelty is in the endproduct, not the catalyst used, and therefore the term ‘palladium’ is unlikely to occur in the title, abstract or claims. However it may well come up in the examples. While we can probably ignore such patents for the purpose of identifying key new application areas, important information may nevertheless be obtained from them. For example, they may provide valuable intelligence on sales Platinum Metals Rev., 2008, 52, (4) opportunities for suppliers of catalysts, the customer being the owner of the patent. Table I illustrates the wide variation in the number of retrieved patents obtained according to where in the patent the search is performed. The table clearly shows that choosing which part of the patent document to search is critical. If we search in the patent title, abstract and claims then we retrieve over five times as many patents as exactly the same search restricted to just title and abstract. If we search in the full text of the patent then we retrieve five times as many again. Table I Searches on the Term ‘Platinum’ Conducted in the U.S. Granted Patent Collection, for Patents Published between 1st January 2001 and 31st December 2007 Criteria Number of ‘hits’ ‘Platinum’ in the patent title or abstract 1611 ‘Platinum’ in the patent title, abstract or claims 8878 ‘Platinum’ in the patent full-text 44,541 ‘Platinum’ in the patent full-text but not title, abstract or claims 35,663 Table II shows the top fifteen assignees for each set of results in Table I. It shows that we might expect to obtain quite different results for the various searches, even though the keyword is the same in each case. Apart from Micron Technology Inc, which heads up each list, there are some very significant differences. Engelhard (now BASF Catalysts) comes in at number five in the ‘title or abstract’ search but does not appear in the ‘title, abstract or claims’ or full-text searches. On the other hand, the Semiconductor Energy Laboratory, while it does not appear in the ‘title or abstract’ search, and only reaches number twelve in the ‘title, abstract or claims’ search, comes in at number two in the full-text search. Pfizer is another good example. Like Semiconductor Energy Laboratory, this company 232 Table II Search Results by Top Fifteen Assignees for Patents in the U.S. Granted Patent Collection, Published between 1st January 2001 and 31st December 2007 Rank ‘Platinum’ in patent title or abstract (1611 patents) ‘Platinum’ in patent title, abstract or claims (8878 patents) ‘Platinum’ in patent full-text but not title, abstract or claims (35,663 patents) 1 Micron Technology Inc Micron Technology Inc Micron Technology Inc 2 General Electric General Electric Semiconductor Energy Laboratory 3 Shin-Etsu Chemical Co IBM Fuji Photo Film Co Ltd 4 UOP LLC Samsung Electronics Co Ltd Eastman Kodak Advanced Micro Devices Inc Canon KK 1 5 Engelhard Corporation 6 Dow Corning Matsushita Electric Industrial Co Ltd Matsushita Electric Industrial Co Ltd 7 Matsushita Electric Industrial Co Ltd Shin-Etsu Chemical Co General Electric 8 Texas Instruments Inc Intel Corp 3M Innovative Properties Co 9 Dow Corning Toray Silicone Infineon Technologies AG IBM 10 IBM Hitachi Ltd NGK Insulators Ltd 11 Advanced Cardiovascular Systems Institut Francais du Petrole Seiko Epson 12 Samsung Electronics Co Ltd Semiconductor Energy Laboratory Medtronic Inc 13 Honeywell International Inc UOP LLC Pfizer 14 Infineon Technologies AG Texas Instruments Inc Sony Corp 15 BASF Hewlett-Packard Development Co Hitachi Ltd 1 Now BASF Catalysts only appears in the top assignees from the full-text search. One would expect Pfizer’s main interest in platinum to be as a user of catalysts in pharmaceutical manufacturing, rather than as a developer of new pgm-based technologies. Manual inspection of selected Pfizer patents confirms this to be the case. The Results List and Initial Analysis For the remainder of this paper we will be considering the results of searches based on the names of the pgms in the patent title or abstract. We have undertaken the search in the U.S., European and PCT patent collections, for patent applications or granted patents published in the period from 1st January 1983 to 31st December 2007. The search results have then been ‘deduplicated’ to exclude Platinum Metals Rev., 2008, 52, (4) patent family members filed in different geographical regions, to leave one patent per invention. The final document list contains just over 13,540 patents. Figure 1 shows a basic breakdown of these patents by metal and by five-year timeslices. Overall growth in pgm patents in the period from 1983 to 2007 is about 6% per annum. In the last seven years, this growth rate has been nearly 13%. However, growth in the number of patents by individual metal is not completely uniform. There has been somewhat higher growth for platinum, ruthenium and iridium patents, and slightly lower growth for palladium and rhodium, as shown in Table III. A comparison between the pgm patent picture and that for a number of other metals (gold, silver, 233 Number of patents published 7000 6000 Osmium 5000 Iridium 4000 Fig. 1 PGM patents by metal – number published in five-year time periods Ruthenium 3000 Rhodium 2000 Palladium 1000 Platinum 0 20 7 00 –2 03 2 00 –2 7 2 99 –1 98 93 19 19 99 –1 7 98 –1 88 83 19 19 Time period nickel and cobalt) is shown in Figure 2. The number of patents on all these metals has increased. However the rate of increase for pgms and gold is considerably higher than that for nickel, cobalt and silver. This is illustrated in Table IV by looking at the earliest (1983–1987) and latest (2003–2007) time periods. Figure 3 shows the importance of these metals in selected technology areas. The analysis was based on selected International Patent Classification (IPC) codes (4). Patent Mapping The Aureka ThemeScapeTM tool (3) was used to create a visualisation of the pgm document list described above. The results are shown in Figure 4. The resulting map looks like a mountainous island surrounded by sea. The visualisation is helpful because ThemeScape groups together similar documents and labels these groups according to frequently used key terms found within those groups. The more documents contained within each group, the higher the ‘mountain’ appears. The automatic labelling sometimes produces meaningful headings (e.g. silicone, rubber, polysiloxane), but sometimes these are less obviously meaningful (compounds, preparation, reaction). Where necessary these can be edited following an inspection of documents contained within the groups. The grey dots represent sample documents – in this set of 13,540 documents only a small proportion are shown in this view, but more (or all) documents will be shown when specific areas are magnified. Clicking on specific dots will display the Table III PGM Patents by Metal: Number and Proportion of Patents Containing Specific PGMs Published in Early (1983–1987) and Recent (2003–2007) Time Periods Metal Patents containing specific pgms vs. total pgm patents, 1983–1987 Patents containing specific pgms vs. total pgm patents, 2003–2007 Number Number Proportion, % Proportion, % Platinum Palladium Rhodium Ruthenium Iridium Osmium 840 659 408 349 184 56 46 36 22 19 10 3 2265 1452 689 1024 613 189 52 33 16 23 14 4 1 18331 – 43921 – Total 1 This is not the arithmetic sum as more than one pgm can appear in any given document Platinum Metals Rev., 2008, 52, (4) 234 Number of patents published 20000 18000 16000 14000 12000 10000 8000 6000 4000 2000 0 Cobalt Nickel Silver Gold Fig. 2 Comparison of pgms with selected other metals – number of patents published in five-year time periods PGM 20 00 7 2 7 00 –2 03 –2 99 2 7 99 –1 98 93 19 19 –1 98 –1 88 83 19 19 Time period Heterogeneous catalysts Technology area Semiconductors or Electronics PGM Homogeneous catalysts Gold Fuel cells and batteries Silver Nickel Coated products Cobalt Alloys Medical 0 500 1000 1500 Number of patents 2000 Fig. 3 Relative importance of various metals in selected technology areas, by IPC code, for the time period between 1st January 2003 and 31st December 2007 Table IV PGM Patents vs. Other Metals: Number and Proportion of Patents Containing Specific Metals Published in Early (1983–1987) and Recent (2003–2007) Time Periods Metal PGMs Gold Silver Nickel Cobalt 1 Total Patents containing specific metals vs. total metal patents, 1983–1987 Patents containing specific metals vs. total metal patents, 2003–2007 Number Number Proportion, % Proportion, % 1833 646 2009 2200 1279 28 10 31 34 20 4392 2152 4062 4626 2441 31 15 28 32 17 65361 – 14,2931 – 1 This is not the arithmetic sum as more than one pgm can appear in any given document Platinum Metals Rev., 2008, 52, (4) 235 Fig. 4 PGM patent map covering granted patents or patent applications published between 1st January 1983 and 31st December 2007 original document. The contour lines enclosing particular areas can be used to select groups of documents for inspection or further analysis. In Figure 5, we have further processed the basic map shown in Figure 4 in two ways. Firstly, to create a timeslice covering documents published only in the period January 2003 to December 2007; secondly, to show patents on platinum as red dots and patents on palladium as green dots. Where specific documents cover both platinum and palladium, these are shown as white dots. The reason for this exercise is to show the relative importance of particular metals in specific technology areas. For example, the ‘silicone, rubber, organopolysiloxane’ and ‘fuel cell, fuel, electrode’ areas are dominated by red dots, indicating that platinum is the preferred metal in these applications. The ‘plating, deposited, substrate’ region is dominated by green dots, confirming the importance of palladium in electronic applications. Platinum Metals Rev., 2008, 52, (4) The ‘exhaust, engine, oxide’ area contains many red, green and white dots, indicating that both metals may be used in emission control applications. Figure 6 is a similar image showing the minor metals rhodium, ruthenium, iridium and osmium. Of particular interest here are the two boxed areas, the first just left of centre, the second centre right. These contain a cluster of mainly light blue dots (ruthenium) and dark blue dots (iridium), respectively. Comparison of the number of dots with the same areas in Figure 7, covering the 1993 to 1997 timeslice, shows a marked increase in the numbers of iridium and ruthenium patents published in 2003–2007. These are examples of emerging technologies. Magnification of one of these areas (see Figure 8) shows that this area includes many patents on organic light emitting diodes (OLEDs), which is an important potential new application for iridium-based fluorescent or phosphorescent dopants. OLEDs (see also 236 Fig. 5 PGM patent map timeslice 2003–2007, showing occurrences of platinum patents (red dots), palladium patents (green dots), and patents covering both platinum and palladium (white dots) References (5, 6)) are solid-state devices composed of thin films of organic molecules that create light with the application of an electric current. Compared with conventional light-emitting diodes (LEDs) or liquid crystal displays (LCDs), OLEDs provide brighter, crisper displays which require less power. It has been discovered that in some iridium complexes, strong spin-orbit coupling leads to singlet-triplet mixing, ideal for highly efficient electrophosphorescence required for future OLEDs. Companies with pgm patents in the OLED area currently include DuPont (U.S.A.), Samsung (Korea), LG Electronics (Korea), Idemitsu Kosan (Japan) and Konica Minolta (Japan). Further analysis of the map shows that ruthenium-based interconnects and electrodes, iridium-based capacitor materials, new magnetic materials containing iridium or ruthenium, ruthenium-based metathesis catalysts (for example Platinum Metals Rev., 2008, 52, (4) Grubbs’ catalyst) and the application of ruthenium in silane production are other emerging technology areas. The Non-Patent Literature While patents are an extremely important source of technical and commercial intelligence, there is also a huge amount of non-patent literature covering the pgms. This is illustrated in Figure 9, which compares the size of the patent literature on ruthenium with that of the non-patent scientific literature on the uses of this metal in chemistry-related areas. The top ten uses for ruthenium in the non-patent literature, based on controlled index terms used in the Chemical Abstracts database, are shown in Table V. Specialised software tools such as STN® AnaVistTM (7) are now available to assist with the analysis of non-patent (as well as patent) literature, similar to that described above for the patent data. 237 Fig. 6 PGM patent map timeslice 2003–2007, showing occurrences of rhodium patents (yellow dots), iridium patents (dark blue dots), ruthenium patents (light blue dots), osmium patents (purple dots), and patents covering two or more minor metals (white dots) Table V Top Ten Uses for Ruthenium from the Non-Patent Chemical Literature, 2003–2007 Publication index term Fuel cells Oxidation catalysts Hydrogenation catalysts Nanoparticles Oxidation, electrochemical Carbon black, uses Fluoropolymers, uses Magnetisation Spin valves Vapour deposition process Proportion of total, 2003–2007, % 11.2 10.7 9.4 5.2 4.4 4.1 3.7 3.7 3.7 3.4 Conclusions The patent literature is an extensive and detailed source of information on existing and potential new applications for the pgms. At the Platinum Metals Rev., 2008, 52, (4) time of writing, there are in the region of 13,540 inventions, covering the period from January 1983, in which the use of one or more pgms is a key part of the inventive step. There are many others in which pgms may be used, for example as part of a complex organic synthesis route. Growth of this literature is expected to continue to increase at a rate slightly higher than that of certain base metals. Patent mapping tools can be used to identify key areas of development and ‘hot spots’ of activity which may lead to future volume applications. ‘Hot spot’ areas for the minor metals ruthenium and iridium currently include iridium in organic light emitting diodes (OLEDs), ruthenium-based interconnects and electrodes, iridium-based capacitor materials, new magnetic materials containing iridium and/or ruthenium, and the application of ruthenium in silane production. 238 Fig. 7 PGM patent map timeslice 1993–1997, showing occurrences of rhodium patents (yellow dots), iridium patents (dark blue dots), ruthenium patents (light blue dots), osmium patents (purple dots), and patents covering two or more minor metals (white dots) Fig. 8 Magnified view of centre-right box shown in Figure 6 for timeslice 2003–2007, showing occurrences of iridium patents (dark blue dots), ruthenium patents (light blue dots), and patents covering two or more minor metals (white dots) Iridium OLED Electroluminescent Platinum Metals Rev., 2008, 52, (4) 239 Number of publications 3500 3000 2500 Patents 2000 1500 Fig. 9 Trends in the non-patent literature – number of publications in patent and non-patent literature for ruthenium Non-patents (uses) 1000 500 0 20 03 –2 7 2 00 00 7 2 99 –2 –1 98 93 19 19 7 99 98 –1 –1 88 83 19 19 Time period References 1 2 3 4 I. Wishart, Platinum Metals Rev., 2005, 49, (2), 98 R. Seymour, Platinum Metals Rev., 2006, 50, (1), 27 ® Thomson Reuters, Scientific: Products: Aureka : http://scientific.thomsonreuters.com/products/aureka/ World Intellectual Property Organization, IP Services, WIPO International Classifications: 5 6 7 http://www.wipo.int/classifications/ J. A. G. Williams, Platinum Metals Rev., 2007, 51, (2), 85 R. J. Potter, Platinum Metals Rev., 2008, 52, (3), 155 ® CAS, STN AnaVistTM: http://www.cas.org/products/anavist/ The Author Richard Seymour is the Head of Technology Forecasting and Information at the Johnson Matthey Technology Centre, U.K. He is interested in the use of information in the areas of competitive intelligence and commercial development. Platinum Metals Rev., 2008, 52, (4) 240 DOI: 10.1595/147106708X363888 Creep 2008: 11th International Conference on Creep and Fracture of Engineering Materials and Structures HIGH-TEMPERATURE BEHAVIOUR OF PLATINUM GROUP METALS Reviewed by J. Preußner, R. Völkl and U. Glatzel* Metals and Alloys, University Bayreuth, Ludwig-Thoma-Straße 36b, D-95447 Bayreuth, Germany; *E-mail: [email protected] From 4th to 9th May 2008, 149 participants met in Bad Berneck, a small village close to Bayreuth, Germany, for the 11th International Conference on Creep and Fracture of Engineering Materials and Structures, in short, Creep 2008 (1, 2). The attendees came from twenty-two different nations all over the world to participate in Creep 2008, organised by Uwe Glatzel (Metals and Alloys, University Bayreuth, Germany) and by Gunther Eggeler (Research Group for Materials Science and Engineering, Ruhr-University Bochum, Germany). During five days 111 oral presentations were given. The programme was divided into twenty sessions: General I–III, Steel I–VI, Nickel I–III, Refractory I–II, Ti & TiAl, Magnesium, Cu & MMC (Metal Matrix Composites), Steel Welding, Light Metals and Testing Techniques. Creep deformation is a time-dependent deformation of materials at high temperatures. Hence, the topics of the conference included modelling and simulation of creep deformation, high resolution microanalysis and the development of new high-temperature materials. During the meeting engineers and scientists shared their experience and knowledge in order to explore new materials and applications. A short overview of the talks related to platinum group metals (pgms) is given here. L. A. Cornish (University of the Witwatersrand, Johannesburg, South Africa) gave an overview of the ‘Derivation of the Creep Properties of Twophase Pt-Al-Cr-Ru Alloys by Modelling’. She presented the development of two-phase Pt-based alloys, which have a similar structure to the wellknown and very successful nickel-based Platinum Metals Rev., 2008, 52, (4), 241–242 superalloys. Progress in developing a thermodynamic database for phase diagram predictions was also presented (see also References (3–5)). The aim of this work is to use these predictions to calculate the volume fraction of the Pt3Al precipitates, then combine microstructural data derived from a series of different alloy compositions to develop a relationship for the stability of the precipitates. As she pointed out, this allows the size and precipitate distribution against temperature to be modelled for a given alloy composition in the (Pt) and (Pt3Al) phase field in the Pt-Al-Cr-Ru quaternary system. K. Maruyama (Tanaka Kikinzoku Kogyo K.K., Japan) reviewed ‘High Temperature Creep of GTH (Gottsu-Tsuyoi Hakkin)’. In his talk, hightemperature creep properties of GTH and GTHR, which are trade names of oxide dispersion strengthened platinum alloys developed by the Tanaka Kikinzoku Group, are explained and compared with commercial platinum and platinum-rhodium alloys. It was presented that, comparing the same rupture time; GTHR is several times stronger than the normal Pt-10% Rh alloy, which may be of interest for the glass melting industry for the production of liquid crystal displays and optical glass and the spinning of glass fibres. The presentation of J. Preußner (Metals and Alloys, University Bayreuth, Germany) addressed the ‘Determination of Phases in the System Pt-AlCr-Ni and Thermodynamic Calculations’. Pt base alloys have been developed at the Metals and Alloys group to receive creep, oxidation and corrosion resistant alloys for high-temperature applications with room temperature ductility. 241 Thermodynamic modelling has been used to support the alloy development. The Cr-Pt system has been reassessed with the CALPHAD method based on experimental data and first-principles calculations. He presented a calculated Cr-Ni-Pt ternary phase diagram and an outlook on the calculation of the quaternary Pt-Al-Cr-Ni system. R. Völkl (Metals and Alloys, University Bayreuth, Germany) summarised the ‘Development of a Precipitation Strengthened Pt Base Superalloy’. He reviewed the process of designing an alloy with good mechanical properties and excellent oxidation resistance up to very high temperatures. Similarly to the approach of Cornish (described above), Pt-Al-Cr has been used as a starting point for alloy development. A variety of ternary additions to the Pt-Al base have been investigated to secure the L12 structure of the hardening Pt3Al phase. He explained that Ni has been added for solid solution strengthening. A comparison to the common alloy development route in the industry has been shown. P. Panfilov (Urals State University, Ekaterinburg, Russia) gave a presentation ‘On Specific Feature of Plastic Deformation in Iridium’. He stated that the refractory f.c.c.-metal Ir, with a melting point of 2443ºC, exhibits excellent mechanical properties at high temperatures. According to experiments he presented, the deformation behaviour of Ir is well in accordance with empirical knowledge on f.c.c.-metals, while some features of Ir seem to be puzzling. He compared the deformation behaviour of single crystals to polycrystalline material at different temperatures. One feature of the deformation behaviour of Ir, he pointed out, is that single crystals show a remarkable total elongation, but no necking, whereas polycrystals only reach a small deformation, but considerable necking. With the help of transmission electron micrographs, Panfilov explained the dislocation structures in deformed Ir samples. A collection of the conference contributions will be published in a special issue of the journal Materials Science and Engineering A (6). The 12th International Conference on Creep and Fracture of Engineering Materials and Structures, Creep 2011, will be held in Japan, and will be chaired by Kouichi Maruyama (Tohoku University) and Hideharu Nakashima (Kyushu University). References 1 2 3 4 5 6 Creep 2008: 11th International Conference on Creep and Fracture of Engineering Materials and Structures: http://www.metalle.uni-bayreuth.de/creep2008 Abstract Book for Creep 2008: http://www.metalle.uni-bayreuth.de/creep2008/ abstractbook_Creep2008.pdf L. A. Cornish, R. Süss, A. Watson and S. N. Prins, Platinum Metals Rev., 2007, 51, (3), 104 A. Watson, R. Süss and L. A. Cornish, Platinum Metals Rev., 2007, 51, (4), 189 J. Preußner, S. N. Prins, M. Wenderoth, R. Völkl and U. Glatzel, Platinum Metals Rev., 2008, 52, (1), 48 Mater. Sci. Eng. A, in press (publication date will be early 2009) The Reviewers Johannes Preußner is a scientific researcher and Ph.D. student at the Chair of Metals and Alloys at the University Bayreuth, Germany. His main interests include modelling and simulation in materials science and new high-temperature materials. Dr.-Ing. Rainer Völkl is senior researcher at the Chair of Metals and Alloys, University Bayreuth, Germany. His main fields of research include alloys of platinum group metals as well as nickel base alloys, testing of mechanical properties at high temperatures and electron microscopy. Professor Dr.-Ing. Uwe Glatzel is head of the Chair of Metals and Alloys at the University Bayreuth, Germany. His work has had a big impact on the development of modern hightemperature alloys, mainly nickel base superalloys. He advises several research groups, including those working on platinum-based superalloys and other alloys for high-temperature applications, laser metallurgy, material analysis and artificial knee joints. Platinum Metals Rev., 2008, 52, (4) 242 DOI: 10.1595/147106708X366975 Global Release Liner Industry Conference 2008 OPTIMISED TECHNOLOGIES ARE EMERGING WHICH REDUCE PLATINUM USAGE IN SILICONE CURING Reviewed by Andrew J. Holwell Johnson Matthey, Precious Metals Marketing, Orchard Road, Royston, Hertfordshire SG8 5HE, U.K.; E-mail: [email protected] Global Release Liner Industry Conference 2008 was organised by AWA Alexander Watson Associates BV and took place from 6th to 8th February 2008, at the Hilton Amsterdam Hotel, The Netherlands (1). It was attended by all the major players in the silicones industry, major label and paper manufacturers and representatives of the precious metals industry. The conference focused much attention on the development of next-generation low platinum catalyst solutions and the potential for complete removal of platinum from silicone curing systems. This review describes the technical developments, their related benefits and shortcomings, and summarises the trends expected to prevail in the release liner industry during the next few years. The release liner industry is an important sector of the overall market for silicones. Background Silicones, or polyorganosiloxanes, are used in a variety of applications, particularly in pressure-sensitive adhesives and release coatings. A key market in this sector is that of release liner coatings for labels and tapes, where the good adhesion and clean release properties of silicone release coatings are highly desirable. (a) Pt catalyst R3SiH + H2C=CHR' R3SiCH2CH2R' (i) Karstedt’s catalyst (chloroplatinic acid-symdivinyltetramethyldisiloxane complex) is a Pt(0) complex containing vinyl-siloxane ligands, and it initiates the addition of a silicon–hydrogen bond across a carbon–carbon double bond, known as curing, which hardens the silicone by crosslinking siloxane chains, Figure 1. The reaction, at temperatures in the region of 80 to 120ºC, is carried out in a platinum-containing Karstedt’s catalyst bath in which the silicone is cured rapidly as the paper label, or ‘labelstock’, is applied to its backing, forming a release coating between the two layers on a sub-second timescale. Free radical-based alternatives to platinum catalysis, initiated either by ultraviolet (UV) light or an electron beam, can be used to generate the radical initiator, but require labile groups such as epoxides or acrylates and thus the properties of the cured silicone vary from conventional silicones. (b) CH3 (CH3)3Si Platinum is widely used as a catalyst for the curing of these silicones by promoting a hydrosilylation reaction, Reaction (i), (2): O Si CH3 O Si x H CH3 CH3 CH3 O Si(CH3)3 y Si CH3 O Si CH3 CH3 O Si CH3 O x Si y CH3 Fig. 1 (a) Silicone monomer typically used in solventless platinum-catalysed hydrosilylation reactions; (b) Conventional crosslinker for platinum-catalysed hydrosilylation reactions Platinum Metals Rev., 2008, 52, (4), 243–246 243 Platinum in the Release Liner Industry Presentations were given by silicones suppliers Dow Corning, Bluestar Silicones and Wacker Silicones, and perhaps the hottest topic of the conference was that of platinum, its price and ways to reduce its usage. Platinum-catalysed thermal curing remains the industry standard approach and because the catalyst is irretrievably lost in the product, the cost of platinum is one of the biggest challenges facing the industry today. Highlights related to platinum included a joint presentation by Norm Kanar (Dow Corning, U.S.A.) and Wolfgang Wrzesniok-Rossbach (W. C. Heraeus, Germany) entitled ‘Platinum Challenges: Trends and Developments’, showcasing the cost benefits of Dow Corning’s low platinum product series. There was also a paper by Karsten Schlichter (Bluestar Silicones, France), entitled ‘Radiation Curing Silicone Release Systems, the Pt Alternative?’, appraising a range of curing chemistries. According to this presentation, the market split between platinum and radiation cured systems is expected to stand at around 80:20 by 2015 compared to 85:15 at present. A small and diminishing share of the market uses solvent-based tin-catalysed emulsions, but this is expected to fall to zero within the next few years, according to these projections. Taking a slightly different angle, Hans Lautenschlager (Wacker Silicones, Germany) described smarter ways of monitoring and using silicone in his presentation ‘More or Less Silicone?’. Growth in the silicones industry is strongly linked to growth in consumer spending, as labelstock is primarily a consumer-driven industry. Annual global growth of around 5 per cent is expected for the next few years. In terms of platinum uptake, industry growth will be at least offset by the increased use of low platinum solutions, particularly when platinum prices are high. During this conference, platinum successively set then-record high prices, fixing in London at U.S.$1852 per troy ounce on 7th February and U.S.$1860 per troy ounce on 8th February (3). Platinum Metals Rev., 2008, 52, (4) Low Platinum Technologies Johnson Matthey estimates that the silicones industry worldwide used around 180,000 troy ounces (5.6 tonnes) of platinum in 2007 (4), which at average Johnson Matthey base prices for the year of U.S.$1307 per troy ounce, is worth around U.S.$235 million; in the eighteen months from the start of 2007 to July 2008, the price of platinum almost doubled (3). This accelerated the development of low platinum technologies, which have the advantage of being largely drop-in replacement systems for existing coating units, unlike free radical initiated systems. Through advanced engineering of the silicone polymers and crosslinkers, Dow Corning has developed a system which allows the use of a catalyst bath containing only 25–35 ppm platinum, compared to the standard 100 ppm typically in use around the industry. Dow Corning claims that its “branched polymers [and] a new crosslinker structure… [which] enables cure of the release coating at platinum catalyst levels as low as 25 ppm” (5) can overcome operational and performance issues typically seen with the modified components in the radiation-cured field. Bluestar Silicones and other companies market similar solutions, which are commercially available. The feeling in the industry is that platinum reduction, rather than widespread uptake of UV solutions, is likely to be the key trend in the next decade. The technical barriers to reduced platinum usage are less significant, less costly and appear closer to being resolved. The market share of platinum-based solventless emulsions remains at around 85% according to Bluestar Silicones, who themselves offer a platinum-free option to paper manufacturers. This level of market share is unlikely to decline significantly in the near future, although as explained below, platinum-free UV cured systems will continue to take some market share, most likely in lower performance applications. Non-Platinum Technologies Free radical-initiated curing was pioneered by Goldschmidt GmbH, latterly Degussa and now Evonik, in the early 1980s and has gradually taken limited market share since that time. The technol- 244 ogy uses unconventional side chains such as epoxy and acrylate groups to generate free radicals at ambient temperature, usually by UV activation, as shown in Figure 2, (6). Occasionally cationic curing can be used, although only under certain process and substrate conditions. Evonik state that ‘post-curing’ in both UV-initiated and in particular cationic systems can be a problem (7), in other words the rate of curing is not comparable to the platinum-catalysed reaction. The UV process itself displays operational and product performance limitations, in terms of clean release and rate of curing, which has a direct impact on the throughput of the coating equipment. It is generally thought that both coat weights and curing times are higher for radiation-cured silicones, although a number of companies claim to have achieved similar curing times and therefore throughput to the conventional process. This would represent a significant technical advance, and may promote the transition to non-platinum technologies in the future. In a paper entitled ‘The Influence of the Release Liner on Label Properties’, Hervé Vigny (Label Experts, France) described a phenomenon known as the ‘zippy effect’, observed in UV-initiated systems. After curing, the adhesion of the label to the release liner takes some time to stabilise, compromising the clean release performance of the product. Although the effect is not fully understood at this time, the cause is widely thought to be the modified side chains which are essential for UV-initiated processes. Perhaps the greatest barrier to a move to UV (a) Conclusions Global Release Liner Industry Conference 2008 focused on the key topic of platinum usage in silicone curing applications and potential opportunities for reducing the amount of platinum used. These include the use of advanced silicone monomers and crosslinkers to reduce the amount of platinum catalyst required, or the use of alternative curing technologies, specifically UV-initiated free radical curing. Low platinum solutions are becoming available to the release liner industry from silicones manufacturers and are expected to achieve significant market share within a few years, as high platinum prices (at the time of this conference) stimulate efforts to use less of the precious metal. Doubts over the financial viability of installing and using radiation curing technology remain, as do technical limitations of the product and process, meaning that this production method will only be used for around twenty per cent of release liner curing applications in the next decade, with the balance still to use platinum catalysts. (b) CH3 (CH3)3Si technologies is the significant capital and operational expenditure needed to install the UV light source and its related equipment. There are also process control issues associated with the requirement to carry out the reaction in an inert atmosphere of nitrogen. Opinion varies on whether the transition is financially viable at all, even at the platinum prices that were current at the time of the conference. In an industry relatively averse to change, conventional methodology is not expected to be displaced quickly. O Si CH3 CH3 O Si CH3 O Si(CH3)3 R x O Si CH3 O O (CH3)3Si y CH3 O Si x O Si(CH3)3 R O y R = (CH2)n Fig. 2 (a) Acrylate-based crosslinked silicone, as produced by UV-cured process; (b) Epoxy-based crosslinked silicone, as produced by UV-cured process (6) Platinum Metals Rev., 2008, 52, (4) 245 Acknowledgements ® Publically available literature from Dow Corning (8), Bluestar Silicones (9), Wacker Silicones (10) and Evonik (11) was used as background information for this review. Global Release Liner Industry Conference 2008 was organised by AWA Alexander Watson Associates BV. References 1 Global Release Liner Industry Conference 2008: http://www.awa-bv.com/?c=event&t=brochure&id=35 2 L. N. Lewis, J. Stein, Y. Gao, R. E. Colborn and G. Hutchins, Platinum Metals Rev., 1997, 41, (2), 66 3 Johnson Matthey, Platinum Today, Price Charts: http://www.platinum.matthey.com/prices/price_ charts.html 4 Johnson Matthey Precious Metals Marketing, U.K. 5 ‘Release System Information Guide, Syl-Off Advantage Series Solventless Release Coatings from Dow Corning’, Dow Corning Corporation, U.S.A., 2006 ® 6 ‘Free Radical Curing TEGO RC Silicones, A Practical Guide’, Goldschmidt GmbH, Essen, Germany, 06/2007 7 ‘Goldschmidt Radiation Curable Silicones, An Overview’, Goldschmidt GmbH, Essen, Germany, 08/2007 8 Dow Corning Silicones: http://www.dowcorning.com/ 9 Bluestar Silicones: http://www.bluestarsilicones.com/ 10 Wacker Silicones: http://www.wacker.com/cms/en/wacker_group/ divisions/silicones/silicones.jsp 11 Evonik Industries: http://corporate.evonik.com/ The Reviewer Andy Holwell is a Market Analyst for Johnson Matthey PLC. He received an MChem in Chemistry from the University of York, U.K., in 2004. He joined Johnson Matthey in September 2005, initially as a Process Development Chemist specialising in autocatalyst development, and has held his current position since January 2007. Mr Holwell specialises in pgm market research in the chemical, petroleum and energy sectors and is a member of the Royal Society of Chemistry. Platinum Metals Rev., 2008, 52, (4) 246 DOI: 10.1595/147106708X364481 “The Periodic Table: Its Story and Its Significance” BY ERIC R. SCERRI (University of California, Los Angeles, U.S.A.), Oxford University Press, Inc, New York, U.S.A., 2007, 368 pages, ISBN 978-0-19-530573-9, £19.99, U.S.$35.00 Reviewed by Michael Laing Professor Emeritus, University of KwaZulu-Natal; 61 Baines Road, Durban 4001, South Africa; E-mail: [email protected] The author, Eric Scerri, teaches chemistry and the history and philosophy of science at the University of California, Los Angeles, U.S.A. He has published widely about the development and structure of the Periodic Table, and is the Editorin-Chief of the journal Foundations of Chemistry (1). He was an invited speaker at the 2003 conference, “The Periodic Table: Into the 21st Century” (see also (2)). This book is timely – it is over thirty years since books about the periodic system by Mazurs (3) and van Spronsen (4) were published. It is not simply a plodding, step by step history nor a collection of all known tabular arrangements of the elements. The author describes developments, explains what led to them, comments on them and discusses their implications. He carefully describes the philosophical thinking of Dimitri Mendeleev and how he differentiated between “the element” and “simple substance”, a difference that was critical in helping Mendeleev deduce the periodic law and system. One must ask: for whom is this book written? It is for all chemists. What is there for the chemist involved with the platinum group metals (pgms)? Mendeleev in 1869 (5, 6) specifically quotes the similar atomic weights of platinum, iridium and osmium as being an important foundation of his periodic system. Now jump forward fifty years to quantum mechanics and the deduction of electron configurations of the elements. The commonly held doctrine says that the chemical properties of an element are determined by the configuration of the valence electrons. This implies that elements in the same group, having Platinum Metals Rev., 2008, 52, (4), 247–248 similar chemical properties, will have the same electron configurations. Unfortunately, this is not true. An example is the group: nickel, palladium, platinum: Ni 4s 2 3d 8 ; Pd 5s 0 4d 10; Pt 6s1 4f 14 5d 9 . It is evident to any pgm chemist that these electron configurations do not fit the chemistry of refining. Conversely, we have the group copper, silver, gold: Cu 4s1 3d 10; Ag 5s1 4d 10; Au 6s1 4f 14 5d 10, whose common oxidation states are Cu2+, Ag1+, Au3+. The author discusses these problems. The brightly coloured cover is attractive and calls out: “Read me”. There are many black-andwhite portraits of chemists. Unfortunately, those of de Chancourtois, Newlands and Odling are missing although their contributions are discussed at length. There is one surprising omission. There is no current form Periodic Table. Similarly it would have been valuable to have had the 1950 short form “W. M. Welch Scientific Company” table for comparison, known as the Periodic Chart of the Atoms. There is a very complete set of references and notes at the back of the book which are keyed to the relevant pages in the text. These are a mine of information for those who want to further pursue this interesting subject. There is one surprising and disappointing shortcoming. There seem to be a larger-thannormal number of printing errors. Some examples are: p. 129, it is stated that “Based on its formation of tetravalent compounds, Mendeleev realized that uranium had a predominant valence of 4, as do such elements as chromium.” (sic); p. 217, iutetium (for lutetium); p. 239, 4s 2 3d should be 4s 2 3d 9 for copper. There are others, 247 which will (I hope) be corrected in the next printing. This book deserves better editing and proofreading. This is a book for the thinking chemist. It reflects the personal interests of the author. Scerri advocates a different layout: the left-step table of Janet, in which the long periods follow the Madelung rule and begin with Group 3 elements: boron, aluminium; scandium, yttrium; lanthanum, actinium; and helium is above beryllium. His discussion of this topic is valuable. There is no requirement that we agree with all of his conclusions, but Eric Scerri makes us think, and that, after all, is what good science is all about. This is a book that is well worth reading. References 1 2 3 4 5 6 Foundations of Chemistry, Philosophical, Historical, Educational and Interdisciplinary Studies of Chemistry, Editor-in-Chief Eric R. Scerri, Springer, The Netherlands: http://www.springer.com/philosophy/philosophy+ of+sciences/journal/10698 “The Periodic Table: Into the 21st Century”, eds. D. H. Rouvray and R. B. King, Research Studies Press, Baldock, Hertfordshire, U.K., 2004 E. G. Mazurs, “Graphic Representations of the Periodic System During One Hundred Years”, 2nd Edn., University of Alabama Press, Alabama, U.S.A., 1974 J. W. van Spronsen, “The Periodic System of Chemical Elements: A History of the First Hundred Years”, Elsevier, Amsterdam, The Netherlands, 1969 D. Mendeleev, Zhur. Russ. Khim. Obshch., 1869, 1, 60 D. Mendelejeff, Z. Chem., 1869, 12, 405 The Reviewer Michael Laing was born in Durban, South Africa, and obtained his B.Sc. (Hons) and M.Sc. degrees from the University of Natal in 1960. He earned his doctorate from the University of California, Los Angeles, U.S.A., in 1964, and taught Inorganic Chemistry at the University of Natal, Durban, from 1965 until he retired in 1997. He was twice Visiting Professor at California State University, Northridge. His main field of interest was the determination of molecular structure and bonding by single crystal X-ray diffraction. He has also applied the X-ray powder diffraction method to the analysis of materials such as urinary calculi, fossil-bearing breccia, failed construction materials and intractables from a pgm refinery. He also generated specialist academic courses, including metal extraction for chemical engineers, material failures for architects and explosives for graduate chemists. He has over 200 publications in such diverse fields as crystallography, bonding, coordination compounds, the Periodic Table, chemical education and military history. Platinum Metals Rev., 2008, 52, (4) 248 DOI: 10.1595/147106708X366704 John Ward Jenkins A TRIBUTE John Ward Jenkins “The most exciting expression uttered by a scientist, the one that heralds new discoveries and inventions, is not ‘Eureka!’ …… but ‘That’s funny’.” Isaac Asimov could have been thinking of John Jenkins when he made this comment. John was an instinctive lateral thinker, who could take a simple laboratory test and turn it into one of the most widely used techniques for characterising complex solid materials, or could see the potential for a new hydrogen-generating technology in a spontaneous catalytic reaction that was taking place in a small glass tube in a fume cupboard. John was born on 23rd March 1932 in the U.S.A., but grew up in England’s Lake District, which instilled in him his love of nature and the countryside. After studying Natural Sciences at Cambridge University, U.K., he returned to the U.S.A. to complete his education, with a Master’s in Chemical Engineering at Princeton University. His scientific career fell into two almost equal halves. He worked for Shell in their Hydrocarbon Cracking group at their MTM Process R & D Platinum Metals Rev., 2008, 52, (4), 249–250 Laboratory in Texas for twenty years, before he and his family finally settled in the U.K. when he accepted a research post at the Johnson Matthey Technology Centre in 1976. After a similar length of time at the Technology Centre, he retired from science in 1995, and he and his wife moved to a farm in West Sussex. While at Shell, John perfected the technique of monitoring the controlled reduction of catalytic materials (1), which many of us now recognise as temperature-programmed reduction (TPR). His role is often overlooked because TPR is one of those inventions that was never patented. However, as a non-proprietary technique, it could be quickly adopted in laboratories around the world, as news of it spread through the scientific literature (see, for example, Reference (2)). John was also particularly proud of the fact that its usefulness relies on the skill with which the results are interpreted and not on the cost of the equipment! John’s personal TPR rig, which hardly even registered as a capital asset, followed 249 alternatives, but also included fundamental studies of platinum group metal (pgm) catalyst behaviour (3). Latterly, though, his name was invariably associated with the HotSpotTM reactor (Figure 1), which he had invented in the late 1980s (4–6). The reformer can be used to generate H2 from hydrocarbon fuels and oxygenates in the presence of a pgm-containing catalyst, and may yet prove to be a key technology in a future hydrogen economy. John Jenkins died on the 28th May 2008. He is fondly remembered as a caring and influential colleague and as an impressive scientist. Quite a few of us working in catalysis have benefited from his encouragement and wisdom, and many more of us have benefited – perhaps unknowingly – from the products of his inventive mind. S. E. GOLUNSKI From John’s former colleagues at the Johnson Matthey Technology Centre, Blount’s Court, Sonning Common, Reading RG4 9NH, U.K. References 1 Fig. 1 A prototype of the HotSpotTM reactor for hydrogen generation (4) him from lab to lab throughout his career, and could be stripped down and reassembled in the space of a couple of hours. At Johnson Matthey, John worked on a series of innovative projects. These mostly addressed environmental challenges, such as the replacement of base metal paint pigments by non-toxic Platinum Metals Rev., 2008, 52, (4) 2 3 4 5 6 S. D. Robertson, B. D. McNicol, J. H. de Baas, S. C. Kloet and J. W. Jenkins, J. Catal., 1975, 37, (3), 424 A. Jones and B. D. McNicol, “TemperatureProgrammed Reduction for Solid Materials Characterization”, CRC Press, Boca Raton, Florida, 1986 J. W. Jenkins, Platinum Metals Rev., 1984, 28, (3), 98 J. W. Jenkins and E. Shutt, Platinum Metals Rev., 1989, 33, (3), 118 J. W. Jenkins, Johnson Matthey PLC, European Patent Appl. 0,217,532; 1987 J. W. Jenkins, Johnson Matthey PLC, European Patent Appl. 0,262,947; 1988 250 DOI: 10.1595/147106708X366858 ABSTRACTS CATALYSIS – APPLIED AND PHYSICAL ASPECTS Comparative Study of Aromatization Selectivity During n-Heptane Reforming on Sintered Pt/Al2O3 and Pt-Re/Al2O3 Catalysts A. A. SUSU, J. Chem. Technol. Biotechnol., 2008, 83, (6), 928–942 The main products of n-heptane reforming on fresh Pt were CH4, toluene and benzene, while on fresh Pt-Re, only CH4 was obtained. For Pt/Al2O3, the products ranged from only toluene at a sintering temperature (ST) of 500ºC to CH4 at a ST of 650ºC, with no reaction at 800ºC. On Pt-Re/Al2O3, CH4 was the sole product at a ST of 500ºC while only toluene was produced at a ST of 800ºC. Pt-Re/Al2O3 exhibited superior selectivity. Carbon-Carbon Cross-Coupling Reactions under Continuous Flow Conditions Using Poly(vinylpyridine) Doped with Palladium K. MENNECKE, W. SOLODENKO and A. KIRSCHNING, Synthesis, 2008, (10), 1589–1599 The coordinative immobilisation of an oxime-based palladacycle to PVP/glass composites shaped as Raschig rings or placed within a PASSflowTM microreactor affords devices that can be used for Pd-catalysed C–C cross-coupling in the flow-through mode. Reusability of the immobilised precatalyst as well as reactions in the microwave field were investigated. CATALYSIS – INDUSTRIAL PROCESS Development of a Mild and Robust Method for Large-Scale Palladium-Catalysed Cyanation of Aryl Bromides: Importance of the Order of Addition P. RYBERG, Org. Process Res. Dev., 2008, 12, (3), 540–543 The title reaction is sensitive to cyanide poisoning of the catalyst. For Pd(dba)2 + P(tBu)3 the order of adding the reagents affected the performance of the reaction. Addition of the cyanide source (Zn(CN)2) to a preheated mixture of the aryl bromide, catalyst and Zn dust was found to be critical. This reaction could be run to full conversion within 3 h at 50ºC on a 6.7 kg scale. New efficient catalysts were identified. CATALYSIS – REACTIONS Enhancing H2 and CO Production from Glycerol Using Bimetallic Surfaces O. SKOPLYAK, M. A. BARTEAU and J. G. CHEN, ChemSusChem, 2008, 1, (6), 524–526 TPD experiments revealed an increased production of H2 from glycerol on the Ni surface monolayer on Pt(111) (designated Ni-Pt-Pt(111)) as compared to that on Pt(111), Ni(111) and Pt-Ni-Pt(111). Glycerol reforming activity trends were similar to previous results for ethylene glycol and EtOH. Smaller oxygenates can therefore be used as good models for reforming of larger, biomass-derived oxygenates. Platinum Metals Rev., 2008, 52, (4), 251–253 Efficient and Recyclable Catalyst of Palladium Nanoparticles Stabilized by Polymer Micelles Soluble in Water for Suzuki-Miyaura Reaction, Ostwald Ripening Process with Palladium Nanoparticles I. P. BELETSKAYA, A. N. KASHIN, I. A. KHOTINA KHOKHLOV, Synlett, 2008, (10), 1547–1552 and A. R. The Suzuki-Miyaura cross-coupling of ArX (X = I, Br) with Ar'B(OH)2, catalysed by a Pd-containing H2O-soluble micelle formed by PS-PEO and Ncetylpyridinium chloride, was investigated in H2O and MeOH. The reaction was performed at ≤ 50ºC. The catalyst can be recycled (5 runs) by ultrafiltration. Direct Coupling of Arenes and Iodoarenes Catalyzed by a Rhodium Complex with a Strongly π-Accepting Phosphite Ligand S. YANAGISAWA, T. SUDO, R. NOYORI and K. ITAMI, Tetrahedron, 2008, 64, (26), 6073–6081 A solution of [RhCl(CO)2]2 and P[OCH(CF3)2]3 in dry toluene was stirred at 50ºC for 2 h under Ar to synthesise RhCl(CO){P[OCH(CF3)2]3}2 (1). Under the catalytic influence of (1) and Ag2CO3, the direct C–H arylation of heteroarenes and arenes with iodoarenes was achieved. The product biaryls were obtained in good to excellent yields with high regioselectivity. This method can be used for thiophenes, furans, pyrroles, indoles and alkoxybenzenes. Vinyl and Ring-Opening Metathesis Polymerization of Norbornene with Novel HalfSandwich Iridium(III) Complexes Bearing Hydroxyindanimine Ligands X. MENG, G.-R. TANG and G.-X. JIN, Chem. Commun., 2008, (27), 3178–3180 Half-sandwich Ir(III) complexes bearing hydroxyindanimine ligands were synthesised. The complexes were used as catalysts for the ROMP and vinyl-type polymerisation of norbornene in the presence of methylaluminoxane (MAO). Pure ROMP polymer and vinyl-type polymer were obtained depending on the amount of MAO employed (0–30 equiv. for ROMP and > 30 equiv. for vinyl-type polymerisation). EMISSIONS CONTROL Impact of Redox Conditions on Thermal Deactivation of NOx traps for Diesel K. M. ADAMS and G. W. GRAHAM, Appl. Catal. B: Environ., 2008, 80, (3–4), 343–352 Lean and rich agings were investigated for a model NOx trap, Pt-Ba/Al2O3. These were carried out at 950ºC for 3 h, in air and in 1% H2/N2, respectively. Pretreatments were examined for a commercially feasible NOx trap and two model NOx traps, Pt-Ba/Al2O3 and Pt-Ba-Ce/Al2O3, at 600ºC for 10 min, using feed gas that simulated diesel exhaust under various conditions. 251 Enhanced Degradation of Tetrachloroethylene by Green Rusts with Platinum Graphite Nanofibers as Catalyst Support for Proton Exchange Membrane Fuel Cells and W. LEE, Environ. Sci. Technol., 2008, 42, (9), 3356–3362 H. XU, L. LU and S. ZHU, Chin. J. Catal., 2008, 29, (6), 542–546 J. CHOI The reductive dechlorination of tetrachloroethylene (PCE) by green rusts (GRs) (layered Fe(II)–Fe(III) hydroxide solids with anions such as Cl–, SO42–, CO32–, F–) in the presence of Pt was carried out using a batch reactor system. The rate of PCE reduction was greatly enhanced with the addition of Pt(IV) (95% of PCE was removed in 30 h). PCE was mostly transformed to acetylene. The estimated kinetic rate constants of GR-Cl(Pt) increased significantly with an incremental addition of Pt from 0.5 to 2 mM. FUEL CELLS Application of Atomic Layer Deposition of Platinum to Solid Oxide Fuel Cells Graphite nanofibres (GNFs) were prepared from used C paper by a ball-milling method. 20% Pt was loaded on the GNFs and Vulcan XC-72 to fabricate Pt/GNFs and Pt/XC-72, respectively. CV showed that Pt/GNFs had the same electrochemical surface area (ESA) as Pt/XC-72. The electrochemical stability was measured for XC-72, GNFs, Pt/XC-72 and Pt/GNFs electrodes by the constant potential oxidation. The peak current increased by 2% for GNFs and 60% for XC-72. The corrosion current for Pt/XC-72 was 1.4 times of that for Pt/GNFs. 84.7% ESA was lost for Pt/XC-72 after oxidation for 60 h, while only 37.2% ESA was lost for Pt/GNFs. METALLURGY AND MATERIALS X. JIANG, H. HUANG, F. B. PRINZ and S. F. BENT, Chem. Mater., Purification of Iridium by Electron Beam Melting 2008, 20, (12), 3897–3905 E. K. OHRINER, Atomic layer deposition (ALD) was used to deposit Pt thin films as an electrode/catalyst layer for SOFCs. The measured fuel cell performance showed that comparable peak power densities were achieved for ALD-deposited Pt anodes with only one-fifth of the Pt loading relative to dc-sputtered Pt anodes. A micropatterned Pt structure was fabricated via areaselective ALD and used as a current collector grid/patterned catalyst for the fuel cells. The purification of Ir metal by electron beam melting has been characterised for 48 impurity elements. The average levels of individual elemental impurities in the starting Ir powder varied from 37 μg g–1 to 0.02 μg g–1. Li, Na, Mg, P, S, Cl, K, Ca, Mn, Co, Ni, Cu, Zn, As, Pd, Ag, Cd, Sn, Sb, Te, Ba, Ce, Tl, Pb and Bi were not detectable following the purification. No significant change in the concentration of Ti, V, Zr, Nb, Mo and Re was found. B, C, Al, Si, Cr, Fe, Ru, Rh and Pt were partially removed by vaporisation. Platinum Black Polymer Electrolyte Membrane Based Electrodes Revisited L. KRISHNAN, S. E. MORRIS and G. A. EISMAN, J. Electrochem. J. Alloys Compd., 2008, 461, (1–2), 633–640 Effects of Alloying Elements on Dendritic Segregation in Iridium Alloys Soc., 2008, 155, (9), B869–B876 Y. LIU, C. T. LIU, L. HEATHERLY and E. P. GEORGE, Pt black-coated diffusion media of varying anode and cathode catalyst loadings with H2/air demonstrated successful performance and stability for anode catalyst loadings down to 0.25 mg cm–2 while operating on pure H2 and with a cathode loading of 0.62 mg cm–2, without significant voltage losses. The voltage losses from reducing the Pt black cathode loadings (from 2.6 to 0.62 mg cm–2) are consistent with kinetic losses associated with the O2 reduction reaction and lower electrocatalyst utilisation. Optimisation of the three-phase interface – electrode, electrolyte and reactant gas – was shown to be dependent on the efficacy of the membrane–catalyst layer interface. Compd., 2008, 459, (1–2), 130–134 The Improved Methanol Tolerance Using Pt/C in Cathode of Direct Methanol Fuel Cell J. Alloys The effects of alloying elements on dendritic segregation in ‘Ir-Nb’ (Ir-10Nb-0.5Zr-0.3W-0.3C-0.006Th, at.%) and ‘Ir-Zr’ (Ir-4.5Zr-0.3W-0.3C-0.006Th, at.%) alloys were investigated by Auger electron spectroscopy. The Nb addition induces significant segregation of C and Th to dendritic interfaces. The Zr addition leads to the formation of an Ir3Zr intermetallic phase, which results in less dendritic segregation of C and Th. This dendritic segregation may cause the severe cracking observed in the ‘Ir-Nb’ alloy after casting and heat treatment. Synthesis of Ruthenium Particles by Photoreduction in Polymer Solutions M. HARADA and S. TAKAHASHI, J. Colloid Interface Sci., 2008, Y.-H. CHO, H.-S. PARK, Y.-H. CHO, I.-S. PARK and Y.-E. SUNG, 325, (1), 1–6 Electrochim. Acta, 2008, 53, (20), 5909–5912 Colloidal dispersions of poly(N-vinyl-2-pyrrolidone)-protected Ru particles were conveniently and efficiently synthesised by the photoreduction of Ru(III) ionic solutions (using RuCl3·nH2O) in the presence of a photoactivator. Metallic Ru particles (1.3 nm average diameter) were obtained in the presence of benzophenone, although mixtures of partly oxidised Ru particles and metallic Ru particles were produced in the presence of benzoin. MEAs were prepared using PtRu black and 60 wt.% Pt/C as their anode and cathode catalysts, respectively. The cathode catalyst layers were fabricated using 0.5, 1.0, 2.0 and 3.0 mg cm–2 of Pt. The performance of the single cell that used Pt/C as the cathode catalyst was higher than a single cell that used Pt black; this result was pronounced when highly concentrated MeOH (> 2.0 M) was used as the fuel. Platinum Metals Rev., 2008, 52, (4) 252 APPARATUS AND TECHNIQUE CHEMISTRY Determination of Alcohols Using a Ni–Pt Alloy Amperometric Sensor RuO2–TiO2 Mixed Oxides Prepared From the Hydrolysis of the Metal Alkoxides J.-J. HUANG, W.-S. HWANG, Y.-C. WENG and T.-C. CHOU, Thin Solid Films, 2008, 516, (16), 5210–5216 J. R. OSMAN, J. A. CRAYSTON, A. PRATT and D. T. RICHENS, Mater. Chem. Phys., 2008, 110, (2–3), 256–262 Ni-Pt films were electrodeposited on Au/Al2O3. Electrodes with Ni:Pt atomic proportions of 100:0, 25:75, 70:30, 82:18 and 0:100 all have a linear relationship between response current and EtOH concentration for 50–300 ppm EtOH in alkaline solutions. With increasing Pt content, the response time was reduced and the sensitivity was decreased. The sensor with 70 at.% Pt was most stable (9 weeks). Ru alkoxide/Ti tetraethoxide mixtures were hydrolysed to give gels and powders containing 30–40 mol% Ru. Basic or neutral conditions gave powders consisting of crystalline RuO2 nanoparticles (2–10 nm diameter) embedded in a matrix of crystalline (anatase) and amorphous TiO2. Acid hydrolysis conditions led to gels containing smaller, amorphous RuO2 nanoparticles (1–3 nm). Acid or neutral hydrolysis of Ru ethoxide gave samples with lower surface Ru:Ti ratios compared to the bulk, which also contained more low-valent Ru. A Multi-Walled Carbon Nanotube/Palladium Nanocomposite Prepared by a Facile Method for the Detection of Methane at Room Temperature Y. LI, H. WANG, Y. CHEN and M. YANG, Sens. Actuators B: Chem., 2008, 132, (1), 155–158 A composite (1) of Pd and C MWNTs was prepared by reducing their aqueous mixtures with NaBH4. TEM and AFM were used to investigate the morphology of (1). The electrical responses of (1) to CH4 were measured at room temperature. (1) exhibited a response magnitude of ~ 4.5% towards 2% CH4. BIOMEDICAL AND DENTAL Influence of the Spacer Length on the in Vitro Anticancer Activity of Dinuclear Ruthenium–Arene Compounds M.-G. MENDOZA-FERRI, C. G. HARTINGER, R. E. EICHINGER, N. STOLYAROVA, K. SEVERIN, M. A. JAKUPEC, A. A. NAZAROV and B. K. KEPPLER, Organometallics, 2008, 27, (11), 2405–2407 The title complexes exhibited promising cytotoxic effects in human cancer cells, which could be increased to an IC50 of 0.29 μM by increasing the spacer length between the metal centres. Cytotoxicity could be correlated with lipophilicity and H2O solubility. 1,12-Bis{chlorido[3-(oxo-κO)-2-methyl-4-pyridinonatoκO4](η6-p-isopropyltoluene)ruthenium}dodecane is more active than chlorido[3-(oxo-κO)-2-methyl-4pyronato-κO4](η6-p-isopropyltoluene)ruthenium. Novel Ru(II) Oximato Complexes with Silent Oxygen Atom: Synthesis, Chemistry and Biological Activities N. CHITRAPRIYA, V. MAHALINGAM, L. C. CHANNELS, M. ZELLER, F. R. FRONCZEK and K. NATARAJAN, Inorg. Chim. Acta, 2008, 361, (9–10), 2841–2850 [Ru(CO)(EPh3)2(bhmh)] (E = P or As; H2bhmh = benzoic acid (2-hydroxyimino-1-methyl-propylidene)hydrazide), [Ru(CO)(EPh3)2(ihmh)] (H2ihmh = isonicotinic acid (2-hydroxyimino-1-methyl-propylidene)-hydrazide) and [Ru(CO)(EPh3)2(hhmh)] (H2hhmh = 2-hydroxy-benzoic acid (2-hydroxyimino-1-methylpropylidene)-hydrazide) were prepared. The hydrazone ligand coordinates through the N atoms of the imine and oxime and the O atom of the amide. The N–OH moiety of the oxime is deprotonated. Antibacterial activity and DNA-binding ability of the complexes were investigated. Platinum Metals Rev., 2008, 52, (4) ELECTRICAL AND ELECTRONICS Synthesis of Ru/Multiwalled Carbon Nanotubes by Microemulsion for Electrochemical Supercapacitor S. YAN, P. QU, H. WANG, T. TIAN and Z. XIAO, Mater. Res. Bull., 2008, 43, (10), 2818–2824 Ru nanoparticles were prepared by H2O-in-oil reverse microemulsion, and then anchored on C MWNTs. EDX spectra confirmed the presence of Ru oxide in the as-prepared composites after electrochemical oxidation. CV demonstrated that the specific capacitance of deposited Ru oxide electrode was significantly greater than that of a C MWNTs electrode. PHOTOCONVERSION Phosphorescent Iridium(III) Complexes with Nonconjugated Cyclometalated Ligands Y.-H. SONG, Y.-C. CHIU, Y. CHI, Y.-M. CHENG, C.-H. LAI, P.-T. CHOU, K.-T. WONG, M.-H. TSAI and C.-C. WU, Chem. Eur. J., 2008, 14, (18), 5423–5434 Ir(III) complexes (1–4) with nonconjugated N-benzylpyrazole ligands exhibit blue phosphorescence with yields of 5–45 % in degassed CH2Cl2. (1) showed emission that was nearly true blue at 460 nm with a lack of vibronic progression. (1) was used as the host for the green-emitting Ir(ppy)3 dopant in an OLED. REFINING AND RECOVERY Synthesis of Highly Porous Chitosan Microspheres Anchored with 1,2-Ethylenedisulfide Moiety for the Recovery of Precious Metal Ions Y. KANAI, T. OSHIMA and Y. BABA, Ind. Eng. Chem. Res., 2008, 47, (9), 3114–3120 Highly porous chitosan microspheres (EDSC) with large pores anchoring 1,2-ethylenedisulfide as a ligand were synthesised for perfusion chromatography by means of an oil-in-H2O-in-oil emulsion method. EDSC was found to be a selective adsorbent for Pd(II), Au(III) and Pt(IV) over base metals in HCl. The adsorbed Pd(II) was completely desorbed using aqueous thiourea solution. 253 DOI: 10.1595/147106708X370880 NEW PATENTS CATALYSIS – APPLIED AND PHYSICAL ASPECTS CATALYSIS – REACTIONS Cationic Rhodium Complexes ASTRAZENECA AB World Appl. 2008/084,258 JOHNSON MATTHEY PLC A cationic Rh complex can be synthesised by mixing a Rh-diolefin-1,3-diketonate compound and a P ligand in a ketone solvent; mixing with an acid to form a solution of the Rh complex; evaporating at least part of the solvent; optionally treating with an ether; and treating the resulting complex with an alcohol. The Rh complex may be recovered and used as a catalyst, for example in hydrogenation reactions. Palladium-Germanium Transalkylation Catalysts U.S. Patent 7,378,364 UOP LLC Alkylaromatic transalkylation catalysts containing acidic molecular sieve, Pd and Ge are claimed to have good activities and attenuate aromatic ring saturation and lights co-production, provided that sufficient Pd is present. Pd is 0.2–1 wt.% and the atomic ratio of Ge:Pd is at least 0.9:1. The molecular seive has pore size ≥ 6 Å. CATALYSIS – INDUSTRIAL PROCESS Adhesive Silicone Composition 5-Fluoro-N-hydroxy-pyridine-2-carboxamidine World Appl. 2008/054,284 The title compound (1) is synthesised by reacting 2bromo-5-fluoropyridine with a Pd source in the presence of 1-1'-bis(diphenylphosphino)ferrocene (DPPF) and acetate ions, then with a cyanide source to give 5-fluoro-pyridine-2-carbonitrile (2). The Pd source may be tris(dibenzylideneacetone)dipalladium(0) or Pd acetate. (2) is then reacted with ethanol and hydroxylamine to produce (1). Optically Active 2-Amino-1-phenylethanols LONZA AG World Appl. 2008/077,560 The title compounds or salts thereof are prepared by asymmetric hydrogenation of the corresponding 2aminoacetophenones in the presence of a Ru complex catalyst with a chiral phosphine ligand. The chiral phosphine ligand may be a diphosphine, and the Ru complex catalyst may also have a chiral diamine ligand. EMISSIONS CONTROL Catalyst for Purification of Exhaust Gas EAST CHINA UNIV. SCI. TECHNOL. World Appl. 2008/080,791 World Appl. 2008/086,662 A crosslinkable adhesive silicone composition with short crosslinking time giving suitable mechanical properties for use as an adhesive joint and for waterproofing a seam is claimed. The composition includes: (a) a polyorganosiloxane with at least two alkenyl groups, preferably C2–C6, linked to Si; (b) a polyorganosiloxane crosslinking agent with at least two H atoms linked to Si; (c) a metal catalyst, preferably Pt; and (d) a reinforcing mineral filler. There is also a polyorganosiloxane gum containing 0.001–0.2 wt.% alkenyl group(s), preferably vinyl groups. A close coupled three-way catalyst includes a support selected from cordierite honeycomb ceramic materials having a pore volume of 0.25–0.35 ml g–1. The coating layer contains a mixture of hexaaluminates, perovskite type composite oxides, CeO2-ZrO2 solid solutions, rare earth oxides, alumina, alkali earth metals and zeolites having a high Si:Al ratio. The active components are Pd-Rh, rare earth oxides and transition metals in the hexaaluminates and perovskite type composite oxides. The catalyst works for low temperature oxidation of HC and reduction of NOx. Silicone-Based Pressure-Sensitive Adhesive Engine Exhaust Catalysts Containing Palladium-Gold BLUESTAR SILICONES FRANCE DOW CORNING TORAY CO LTD World Appl. 2008/081,913 NANOSTELLAR INC European Appl. 1,925,362 The title composition contains: (a) the condensation reaction product of a diorganopolysiloxane having silanol groups on both molecular terminals and two or more Si-bonded alkenyl groups in side molecular chains, with an organopolysiloxane resin having one or more hydrolysable groups, in the presence of a catalyst; (b) an organohydrogenpolysiloxane; (c) a diorganopolysiloxane having Si-bonded alkenyl groups on both molecular terminals; (d) an organopolysiloxane resin; and (e) a platinum catalyst. A catalyst for cleaning engine exhaust is claimed to have improved CO oxidation characteristics. The catalyst includes a first supported catalyst containing Pt, Pt-Pd or Pt plus a promoter such as Bi. A second supported catalyst contains Pd and Au in the weight ratio Pd:Au of ~ 0.5:1.0–1.0:0.5, preferably ~ 0.84:1.0. To improve aged catalyst performance, the first and second supported catalysts are coated onto different layers, zones or monoliths of the substrate. Thermoneutral Oil Reforming Catalyst MAZDA MOTOR CORP T. INUI et A catalyst system for exhaust gas purification removes HC and CO from exhaust gas at engine start when the exhaust gas temperature is low, particulates which are collected by a filter, and NOx. An active O2 generating device, an oxidation catalyst, a particulate filter and a Pt-Rh catalyst are arranged in this order from the upstream side of the exhaust passage. al. U.S. Appl. 2008/0,152,572 A catalyst containing Ni, Ce2O3, La2O3, Pt, ZrO2, Rh and Re can be used for the thermoneutral reforming of liquid hydrocarbon fuels to give synthesis gas (H2, CO, CO2 and CH4). The catalyst contains (in wt.%): 0.5–15 Ni, 0.5–10 Ce2O3, 0.5–5 La2O3, 0.1–2 Pt, 0.5–3 ZrO2, 0.1–2 Rh and 0.1–2 Re. Platinum Metals Rev., 2008, 52, (4), 254–255 Exhaust Emission Control Device Japanese Appl. 2008-075,638 254 FUEL CELLS ELECTRICAL AND ELECTRONICS Nanowire Supported Catalysts Sealed Penetration for Lithium Battery GM GLOBAL TECHNOL. OPERATIONS INC COMMISSARIAT À L’ÉNERGIE ATOMIQUE World Appl. 2008/070,482 U.S. Appl. 2008/0,118,831 A fuel cell electrode is formed from C fibres with metal oxide or C-coated metal nanowires directly grown on them, which carry deposited nanoparticles of Pt, Pd, Rh or Ru catalyst material. The metal oxide may be SnO2, TiO2 or WO3, alternatively the C-coated metal may be Sn, Ti or W. The supported catalysts can be used for an electrode in a PEM for a H2/O2 fuel cell. A glass-to-metal penetration for the electrical insulation between two poles of a Li battery includes glass such as TA23 or Cabal 12 glass, a Pt-Ir pin containing Pt:Ir in the weight ratio 90:10, and a body made from SS304L stainless steel. The coefficient of thermal expansion (CTE) of the pin is 8.7 × 10–6 ºC–1. The glass has good resistance in organic electrolyte medium combined with Li salt and a CTE < 8.7 × 10–6 ºC–1. Fuel Electrode Catalyst Organic Memory Device SANYO ELECTRIC CO LTD Japanese Appl. 2008-091,102 An electrode catalyst is claimed to have improved CO poisoning resistance. An electrode for an MEA is formed by arranging an alloy catalyst layer containing Pt, Ru and one or more of Co, Ni, Mo, Pb, Fe, W or Cr; an alloy catalyst layer containing Pt-Ru; and a Ru catalyst layer, in this order from the polyelectrolyte membrane to the gas diffusion layer. The fuel for the fuel cell system may be reformed gas or organic matter. APPARATUS AND TECHNIQUE Palladium Alloy Composite Membrane J.-S. PARK et al. U.S. Appl. 2008/0,116,078 SAMSUNG ELECTRONICS CO LTD U.S. Appl. 2008/0,146,802 An organic memory device includes a first electrode, an organic active layer which contains an Ir organometallic compound and an electrically conductive polymer, and a second electrode. Advantages claimed are rapid switching time, decreased operating voltage, decreased fabrication costs, increased reliability and improved non-volatility. The Ir organometallic compound has a maximum emission wavelength of 450–550 nm. Iridium Oxide Film for a Semiconductor Device OKI ELECTRIC IND. CO LTD Japanese Appl. 2008-075,134 The title composite for H2 separation includes an optional first metal coating layer selected from Ag, Ni, Cu, Ru or Mo, applied by an electroplating process onto a porous support which is preferably porous Ni; a Pd coating layer applied using a sputtering process; and a second metal coating layer, preferably Cu. The second metal coating layer is heat treated to form an alloy layer of Pd and the second metal. An electrode includes an Ir oxide film with a metal membrane formed on its surface. High adhesion is claimed at the boundary between the films. The electrode can be used in a dielectric capacitor for a semiconductor device. The Ir film is formed by a reactive sputtering method using an O2-containing gas and an Ir target with film deposition temperature of 275–400ºC and sputtering pressure of 0.69–1.09 Pa. Nonlinear Optical Organic Single Crystal Formation SURFACE COATINGS FURUKAWA CO LTD Japanese Appl. 2008-001,529 A single crystal of an organic substance such as 4dimethylamino-N-methyl-4-stilbazolium tosylate can be formed on a Pt wire in a supersaturated solution of the organic substance by cooling the supersaturated solution. The crystal nucleus is preferentially generated on the surface of the Pt wire. Generation of multiple nucleation points is suppressed and crystals can be grown at a low degree of supersaturation. Sprayable Water-Base PGM-Containing Paint GENERAL ELECTRIC CO European Appl. 1,936,010 A Pt group metal containing layer can be deposited on a substrate by spraying a H2O-based paint containing metallic Pt group metal powder, H2O and a methyl cellulose binder. Heat can be applied to interdiffuse the Pt group metal containing layer. Optionally an additional layer of NiAl may be applied as an underlayer. The Pt group metal is ≥ 96 wt.% of the paint composition exclusive of H2O and binder. BIOMEDICAL AND DENTAL Methods of Depositing a Ruthenium Film Organometallic Compounds for Cancer Treatment ASM GENITECH KOREA LTD UNIV. NEUCHÂTEL European Appl. 1,950,217 Novel organometallic compounds for photodynamic therapy against cancer include a central porphyrin or phthalocyanine backbone with ligand linkers coordinated to at least one transition metal selected from Ru, Rh, Os, Ir or Fe, preferably Ru. A preferred compound is a tetranuclear Ru(II) complex such as [Ru4(η6-arene)4(TPP)Cl8] (TPP = 5,10,15,20tetra(4-pyridyl)porphyrin). Platinum Metals Rev., 2008, 52, (4) U.S. Appl. 2008/0,171,436 A Ru film can be deposited on a substrate by applying deposition cycles of a Ru organometallic compound gas; purging the reactor; supplying RuO4 gas; and purging the reactor. Alternatively, each cycle includes simultaneously supplying RuO4 and a reducing agent gas; purging; and supplying a reducing agent gas. A high deposition rate is claimed, with good step coverage over structures which have a high aspect ratio. 255 NAME INDEX TO VOLUME 52 Page Abd-El-Aziz, A. S. Abu-Reziq, R. Acerbi, N. Acres, G. Adams, K. M. Adamson, K.-A. Adcock, P. Aiello, I. Aiyer, R. C. Aladjem, A. Aldrich-Wright, J. R. Alivisatos, A. P. Allaert, B. Alper, H. Andersson, S. Antunes, O. A. Arends, I. Arndt, A. Ash, P. Atanasoski, R. 46 56 222 19 251 123 15 58 201 121 98 57 124 56 125 124 83 58 205 201 Baba, Y. 253 Baidina, I. A. 126 Balcom, J. 18 Ballauff, M. 124 Balme, G. 174 Baranowski, B. 120 Barnard, C. 38, 110 Barteau, M. A. 251 Batcha Seneclauze, J. 58 Baudoin, O. 175 Baylet, A. 226 Bedford, R. 111 Beletskaya, I. P. 56, 251 Bellusci, A. 58 Bent, S. F. 252 Beretta, A. 56 Bhushan, B. 202 Bion, N. 224 Birss, V. I. 126 Birtill, J. 229 Blomen, L. 14 Blume, R. 224 Bode, M. 13 Bond, G. C. 107 Borg, A. 126 Page Bredesen, R. Bucur, R. Burch, R. 126 120 226 Cai, F. 56 Calvo, F. 107 Cameron, D. S. 12 Campagna, S. 58 Campbell, C. T. 57 Campesi, R. 201 Cao, C.-N. 202 Cao, F. 125 Carraher, Jr., C. E. 46 Carrettin, S. 226 Carson, N. A. P. 132 Carty, A. J. 58 Castellano, C. 134 Cate, D. M. 57 Cavallaro, S. 58 Cele, L. M. 124 Centi, G. 229 Cermák, J. 120 Chan, W. K. 47 Chang, F. Y. 200 Chang, S.-Y. 58 Chang, Z. 126 Channels, L. C. 253 Che, C.-M. 96 Chen, J. C. 200 Chen, J. G. 251 Chen, M. 126 Chen, P. 200 Chen, S. 57 Chen, W. 57 Chen, X.-Z. 163 Chen, Y. 57, 200, 253 Chen, Z. 200 Cheng, K. W. 47 Cheng, Y.-M. 58, 253 Chi, Y. 58, 253 Chiarello, G. L. 225 Chitrapriya, N. 253 Chiu, Y.-C. 253 Cho, Y.-H. 252 Choi, J. 252 Chou, P.-T. 58, 253 Chou, T.-C. 253 Clark, Jr., W. M. 200 Coelho, A. V. 124 Platinum Metals Rev., 2008, 52, (4), 256–258 Page Colacot, T. J. 124, 172, 175 Connick, W. B. 202 Copping, B. W. 132 Corbos, E. C. 226 Corcoran, C. 200 Cornish, L. A. 241 52 Corti, C. Coville, N. J. 124 Crayston, J. A. 253 Crispini, A. 58 Cuevas, F. 201 Dai, Q. 200 De Lima, P. G. 124 de Lucas-Consuegra, A. 227 De Souza, A. L. F. 124 de Vries, J. 110 Debe, M. K. 201 Di Noto, V. 125 Dixneuf, P. 174 Doppelt, P. 126 Dragutan, I. 71, 157 Dragutan, V. 71, 157 Dunn, P. 110 Dyson, P. J. 98 Egerton, T. A. Eggeler, G. Eichinger, R. E. Eisman, G. A. El-Shall, M. S. Elzanowska, H. Enick, R. Es-Souni, M. 202 241 253 252 107 126 58 125 Fan, H. Fang, Y. Faravelli, T. Farmer, D. B. Farrauto, R. Farrell, N. P. Filatov, E. Yu. Flanagan, T. B. Fricker, S. P. Fronczek, F. R. 126 126 56 58 134 97 126 120 97 253 Page Fu, G. Fu, X. Fujitani, T. 174 200 200 Gac, W. 124 Gadiou, R. 201 Gancs, L. 201 Garje, A. D. 201 Gauffier, A. 57 Gélin, P. 226 George, E. P. 252 Ghedini, M. 58 Ghiotti, G. 124 Glatzel, U. 48, 241 Godbert, N. 58 121 Goltsov, V. A. Golunski, S. E. 249 Goodman, S. N. 200 Gordon, R. G. 58 Graham, G. W. 251 Granite, E. J. 144 Grasa, G. A. 124 Griffith, W. P. 114 Grönbeck, H. 226 Groppi, G. 56 Gross, S. 125 Grove, L. J. 202 Grubbs, R. H. 222 Grünert, W. 56 Grunwaldt, J.-D. 225 Gulari, E. 56 Guryev, Yu. V. 56 Gushchin, A. V. 124 Gustafsson, K. 125 Habouti, S. 125 Habtemariam, A. 97 Haghighat, F. 125 Hamada, H. 200 Hambley, T. W. 97 Haneda, M. 200 Hanefeld, U. 83 Harada, M. 125, 252 Haridoss, P. 125 Hartinger, C. G. 96, 253 He, L.-N. 56 He, P. 126 256 Page He, Y. 200 Heatherly, L. 252 Hedley, G. J. 126 Heinzel, J. 16 Henry, C. R. 108 Hii, M. 112 Hirscher, M. 201 Hiyama, T. 174 Holwell, A. J. 243 Hou, P. Y. 57 Hou, S.-Q. 163 Hou, X. 125 Hou, Y.-Y. 202 Hu, F. P. 201 Hu, J.-M. 202 Huang, C. 126 Huang, H. 57, 200, 252 Huang, J.-J. 253 Hung, J.-Y. 58 Hutchings, G. J. 108, 226 Hwang, S.-H. 47 Hwang, W.-S. 253 Hyakutake, T. 201 Hyde, T. 129 Ikushima, Y. Ilinich, O. Inukai, J. Ioannides, T. Ishigami, Y. Itami, K. Ivanova, I. I. Iyoha, O. 124 134 201 124 201 251 56 58 Jakupec, M. A. Jang, J. H. Janiak, T. Jenkins, J. W. Jennings, Z. Jiang, X. Jin, G.-X. Johansson, M. Johnson, T. Jones, C. J. Jones, S. 253 18 200 249 14 252 251 224 23 21 100 Kanai, Y. Kanar, N. 253 244 Page Kandasamy, K. Karlberg, G. S. Kartopu, G. Kasem, K. K. Kashin, A. N. Kato, K. Kavitha, J. Kawanami, H. Kawi, S. Kayama, T. Keane, M. A. Kempe, R. Keppler, B. K. Khodadadi, A. Khokhlov, A. R. Khotina, I. A. Kiely, C. J. Killimeyer, R. Kim, I. J. Kim, J. Kim, S. Kim, Y. K. Kim, Y. S. Kimura, Y. Kirschning, A. Kitagawa, H. Kizaki, Y. Klette, H. Kobayashi, H. Kobayashi, T. Koermer, G. Korenev, S. V. Kraft, A. Krause, J. A. Krishnan, L. Kubota, Y. Kudo, A. Kumar, K. S. 120 125 125 100 251 201 58 124 200 56 56 124 253 125 56, 251 251 108 58 202 57 57 202 202 125 251 201 56 126 201 201 134 126 177 202 252 201 227 125 Laffont-Dantras, L. Lai, C.-H. Laing, M. Lanza, S. Lapeña Rey, N. Latroche, M. Lautenschlager, H. Lavina, S. Ledoux, N. Lee, E. P. Lee, G.-H. Platinum Metals Rev., 2008, 52, (4) 84 253 247 58 16 201 244 125 124 57 58 Page Lee, W. 252 Leiva, E. P. M. 107 Leroy, E. 201 Leung, S.-K. 202 120 Lewis, F. A. Li, C. 201 Li, D. 200 Li, E. Y. 58 Li, F. 126 Li, H. 58 Li, L. 126 Li, P. 200 Li, W. 200 Li, Y. 201, 253 Lin, X. 58 Lin, Y. 58 Liu, C. T. 252 Liu, M. 201 Liu, W.-P. 163 Liu, Y. 134, 252 Liu, Z. 126 Livi, M. 124 Lo, K. K.-W. 202 Lou, L.-G. 163 Lu, L. 252 Lu, Y. 124 Luan, W. 57 Lucas, M. F. A. 126 Lunin, V. V. 56 Machocki, A. MacLachlan, M. J. Macquarrie, D. Maerz, J. J. Maestri, M. Mahalingam, V. Mallick, K. Malysheva, Y. B. Manners, I. Maruyama, K. Mathiyarasu, J. Mattinson, J. A. Mazzolai, F. McLean, G. McPherson, J. Meek, G. Meggers, E. Mei, Y. Mejdell, A. L. Mendoza-Ferri, M.-G. 124 46 83 52 56 253 46 124 46 241 57 202 120 17 226 111 97 124 126 253 Page Meng, X. Mennecke, K. Merki, D. Miasek, E. Middelman, E. Milhano, C. Miller, A. Mimura, N. Miyatake, K. Moini, A. Mondal, K. C. Morandi, S. Morreale, B. Morris, S. E. Mortazavi, Y. Motohiro, T. Mottet, C. 251 251 200 126 14 202 16 227 201 134 124 124 58 252 125 56 108 Nagumo, Y. Narayanan, S. R. Nastasi, F. Natarajan, K. Nazarov, A. A. Negishi, E. Negro, E. Newkome, G. R. Nishide, H. Nogami, M. Nørskov, J. K. Noyori, R. 201 201 58 253 253 172 125 47 201 57 223 251 Ohriner, E. K. 186, 252 Okumura, K. 56 Oliver, A. G. 202 Orvig, C. 96 Oshima, T. 253 Osman, J. R. 253 Owston, N. 113 Ozkaya, D. 61 Pacchioni, G. Pace, G. Palacio, M. Palmeri, N. Panfilov, P. Park, H.-S. Park, I.-S. Pashkova, A. Pastor, G. M. 223 125 202 58 242 252 252 227 108 257 Page Paul, M. 225 Pavelka, M. 126 Peng, Z. 57 Pérez-Tijerina, E. 108 Perutz, R. 96 Phani, K. L. N. 57 Pittman, Jr., C. U. 46 Pitts, M. R. 64 Pizzaro, D. 14 Pletcher, D. 202 Poizot, P. 84 Pollock, T. M. 125 Post, M. 56 Potter, R. J. 155 Pratt, A. 253 Presto, A. A. 144 Preußner, J. 48, 241 Prinetto, F. 124 Prins, S. N. 48 Prinz, F. B. 252 Proch, S. 124 Pugliese, T. 58 Puntoriero, F. 58 Qazi, A. Qi, Y. Qu, P. 112 57 253 Ramachandran, A. Reedijk, J. Reinecke, H. Retailleau, P. Revere, A. Richens, D. T. Rider, D. A. Rostrup-Nielsen, J. Ruseckas, A. Russo, N. Ryberg, P. 126 2 18 58 52 253 46 12 126 126 251 Sadler, P. J. 21, 97 Saiz, E. 57 Sakamoto, Y. 56, 120 Samuel, I. D. W. 126 Scerri, E. R. 247 Schauermann, S. 224 Schlichter, K. 244 Schofield, E. 222 Seo, J. H. 202 Page Sermon, P. A. Seshadri, S. K. Setsune, J. Severin, K. Seymour, R. Sheldon, R. A. Shen, P. K. Shen, W. Shinjoh, H. Shipman, P. O. Shubin, Yu. V. Simonet, J. Skea, J. Skoplyak, O. Smith, M. B. Solodenko, W. Somorjai, G. A. Song, Y.-H. Spadoni, C. Stasinska, B. Stockdale, G. W. Stolyarova, N. Su, Q. Sudo, T. Sultana, A. Sun, S. Sun, X.-J. Sung, Y.-E. Susu, A. A. Suzuki, A. 108 125 202 253 231 83 201 224 56 46 126 84 13 251 215 251 57 253 222 124 200 253 163 251 200 57 202 252 251 172 Tada, M. Tai, Y.-C. Takahashi, S. Takahashi, T. Takata, M. Tamao, K. Tanaka, A. Tang, G.-R. Tang, M.-C. Tarasenko, E. A. Terada, Y. Theis, J. R. Thomas, Sir J. M. Thompsett, D. Thornback, J. R. Thurier, C. Tian, T. Toda, M. Tompos, A. Tomsia, A. P. 227 201 252 172 201 173 201 251 202 56 208 56 108 108 21 126 253 202 225 57 Platinum Metals Rev., 2008, 52, (4) Page Tong, X.-Q. Topsøe, H. Torker, S. Tromp, M. Tronconi, E. Tsai, M.-H. Tsiouvaras, N. Tu, S.-T. Turner, G. Tysoe, W. T. Tyurin, V. S. 120 12 200 108 56 253 227 57 112 224 56 Ubbelohde, A. R. Ueji, M. Ueno, F. Uma, T. 120 125 17 57 Vaccari, A. 124 Valdez, T. I. 201 van Bokhoven, J. A. 223 van den Berg, M. W. E. 56 van Dokkum, J. 13 van Santen, R. A. 229 Venkataramanan, N. S. 124 Verpoort, F. 124 Vigny, H. 245 Visart de Bocarmé, T. 223 Vix-Guterl, C. 201 Vlassak, J. 58 Völkl, R. 48, 241, 242 Wang, D. 56 Wang, E. 56 Wang, H. 200, 253 Wang, J.-Q. 56 Wang, X. 124 Wang, Y. 57 Wang, Y.-M. 163 Wang, Z. 201 Wardell, J. L. 124 Watanabe, M. 201 Wells, P. 108 Wenderoth, M. 48 Weng, Y.-C. 253 Weston, M. 14 Wey, M. Y. 200 Page Whitacre, J. F. 201 Whiting, A. 112 Wicke, E. 121 Wickleder, M. S. 58 Wicks, M. 12 Wieckowski, A. 201 Wilkie, J. 14 Witcomb, M. J. 124 253 Wong, K.-T. Wrzesniok-Rossbach, W. 244 Wu, C.-C. 253 Wu, X. 113, 200 Xia, Y. Xiao, J. Xiao, Z. Xiong, G. Xu, H. 57 200 253 57 57, 125, 252 Yamauchi, M. Yan, S. Yanagisawa, S. Yang, H. Yang, M. Yang, S. Yang, Y.-P. Yates, J. T. Ye, Q.-S. Yersin, H. Yi, T. Yin, Y. Yoshida, T. Yu, M. Yu, Y. Yusenko, K. V. 201 253 251 57 253 200 163 57 163 155 126 57 202 126 163 126 Zadesenets, A. V. Zeller, M. Zhang, J. Zhang, J.-Q. Zhang, K. Y. Zhang, X. Zhao, K. Zhao, Q. Zheng, S. Zhu, S. Zhu, X. Ziessel, R. 126 253 57 202 202 201 126 126 201 252 58 58 258 SUBJECT INDEX TO VOLUME 52 Page a = abstract AFM Probes, Pt, Pt-Ir, Pt-Ni, coated, a 202 Alcohols, EtOH, sensors, a 253 MeOH, decomposition 222 fuel 12, 134 oxidation 125, 222 steam reforming 134, 222 for synthesis of amides 110 Aldehydes, by hydroformylation 110 hydrogenation 110 reduction, a 200 unsaturated, hydrogenation, selective, a 56 Alkanes, conversions 107 Alkenes, C–C coupling 38 Alkyl Halides, one-electron cleavage of C–Br, C–I 84 Alkynes, C–C coupling 38 carbonylation 215 hydrogenation, selective, a 56 Amides, synthesis 110 Amines, secondary, tertiary, by hydroaminomethylation 110 for synthesis of amides 110 Aminocarbonylation, aryl halides 110 Apparatus and Technique, a 57–58, 125–126, 201, 253 Arenes, + iodoarenes, coupling reactions, a 251 Aryl Halides, reactions 38, 56, 110, 124, 172, 200, 215, 251 Arylation 110, 124 Arylboronic Acids, reactions 110, 251 Biaryls, synthesis 110 Biological Activity, Ru(II) oximato complexes, a 253 Biological Probes, luminescent, Ir(III)-polypyridines, a 202 Biomedical and Dental, a 126, 253 Biosensors, DNA, a 126 Book Reviews, “Adventures at the Bench” 52 “Catalysis for Renewables” 229 “Frontiers in Transition Metal-Containing Polymers” 46 “Green Chemistry and Catalysis” 83 “Highly Efficient OLEDs with Phosphorescent Materials” 155 “Medicinal Applications of Coordination Chemistry” 21 “The Periodic Table: Its Story and Its Significance” 247 Boranes, C–C coupling 38 Boronates, C–C coupling 38 Boronic Acids, C–C coupling 38 Boronic Esters, C–C coupling 38 CALPHAD, Cr-Pt 241 Cancer, anti-, agents, aminoalcohol-Pt complexes 96 azido-Pt(IV) complexes 2 azolato-bridged dinuclear Pt compounds 2 BBR3464 21 bis(azpy)Ru(II) 2 di-Pt complexes 21 dinuclear cationic species containing Ru(II) and Pt(II) 2 dinuclear Ru-arenes, a 253 KP1019 96 NAMI-A 2, 96 Pd complexes 21 Pt chxn 96 Pt(II), Pt(IV) complexes 96 Rh complexes 21 Ru complexes 21 Ru organometallics 96 Ru quinonediimines 96 Ru(II), Ru(III), Ru(IV) complexes 96 [Ru(sandwich)(diamine)Cl] 2 tri-Pt complexes 21 drugs, carboplatin 2, 96, 126, 163 cisplatin 2, 21, 96, 163 Platinum Metals Rev., 2008, 52, (4), 259–266 Page Cancer, (cont.) eptaplatin 163 iproplatin 96 lobaplatin 163 nedaplatin 163 oxaliplatin 2, 163 picoplatin 96, 163 satraplatin 2, 96, 163 Carbenes 38, 71, 200 Carbon, catalyst support, Pt/C, TEM 61 Carbon Oxides, CO, addition, H–D exchange reaction 222 combustion, a 56 from glycerol, a 251 + NO 107 oxidation 56, 222 for reduction, of NO, a 200 sensors 201, 215 transport, through Pt@CoO nanoparticles, a 57 CO2, supercritical, hydrogenation, + HN(CH3)2 215 solvent, a 56 Carbonylation, alkynes 215 Carboxylic Acids, for synthesis of amides 110 Catalysis, Applied and Physical Aspects, a 56, 124, 200, 251 asymmetric 110 book reviews 83, 229 conferences 110, 172, 222, 229 in green chemistry 83, 110 Industrial Process, a 56, 200, 251 microwave heating 64 Reactions, a 56, 124, 200, 251 for renewables 229 Catalysts, analysis, Pt 205 encapsulated 64 nanoalloys 107 pgm, fundamental studies 249 pgm/support, 2D mapping 222 recycling 56, 64, 71, 157, 215, 251 supported, analysis, crystallite size, by XRD 129 particle size, by TEM 61 temperature-programmed reduction 249 Catalysts, Iridium, H–D exchange reaction; + CO 222 hydrogenation 229 Ir/CeO2, steam reforming of EtOH 222 Catalysts, Iridium Complexes, amides, from alcohols 110 half-sandwich Ir(III) hydroxyindanimines, ROMP of norbornene, a 251 vinyl polymerisation of norbornene, a 251 intermolecular enantioselective hydroamination 110 Ir-N-tosyldiamines, aldehyde reduction, in H2O, a 200 monotosylated ethylenediamine Ir(III), hydrogenation 110 Catalysts, Osmium Complexes, Os EnCat 40 64 Catalysts, Palladium, aqueous reforming 229 dehydrogenation 229 electrocatalysts, CuPd, a 202 Ni-Pd, anodes, for DMFCs, a 125 Pd/hollow C spheres, for DAFCs, a 201 Pd/Vulcan XC-72 C, for DAFCs, a 201 Pd-Co-Ag/C, -Au/C, -Pt/C, cathodes, for DMFCs, a 57 Pd-Co-CN, for PEFCs, a 125 H–D exchange reaction; + CO 222 hydrogenation 229 hydrogenolysis 229 oxidation 229 Pd(111), ethene + acetic acid 222 Pd(0) EnCat, microwave heating, hydrogenations 64 Pd(0) EnCat NP30, microwave, nitro reduction 64 transfer hydrogenation 64 Pd nanoparticles, Heck reactions 38 Pd tip of field ion microscope, H2 + NO 222 Pd/Al2O3 , + Co, Cu, Na, Ni, NO reduction/CO, a 200 combustion of natural gas 222 259 Page Page Catalysts, Palladium, (cont.) dechlorination of PVC, a 56 MeOH steam reforming 134 124 oxidation of CH4, a preparation, by flame-spray pyrolysis 222 total oxidation of CH4 222 Pd/(Al2O3 + MOx), oxidation of CH4, a 124 Pd/alumina beads, Hg oxidation 144 Pd/BaSO4, Stille cross-couplings, a 124 Pd/C, o-chlorotoluene hydrogenolysis, a 200 Heck reactions 38 Pd/C microspheres, hydrogenation of ethylene, a 124 Pd/LaCoO3(flame-spray pyrolysis), NO reduction/H2 222 Pd/LaCoO3(impregnation), NO reduction/H2 222 Pd/(La0.2Sr0.3Ba0.5)(MnAl11)O19, natural gas combustion 222 Pd/membrane, synthesis of H2O2 222 Pd/YSZ, natural gas combustion 222 Pd nanoparticles/Celite®, Heck reactions 38 Pd nanoparticles/spherical polyelectrolyte brushes, a 124 PdO/support, natural gas combustion 222 Pd particles/Fe2O3 film/Pt(111), MeOH decomposition 222 PdAu, ethene + acetic acid 222 Pd-Ag/membrane, synthesis of H2O2 222 Pd-Au/Al2O3, selective oxidation of styrene, a 124 PdAu/Al2O3, /C, /TiO2, H2O2 synthesis 107 PdRh/γ-Al2O3, NO-CO reaction 107 ‘Pd-Zn/oxide support’, mechanical strength 134 MeOH steam reforming 134 ‘Pd-ZnO/Al2O3’, MeOH steam reforming 134 Catalysts, Palladium Complexes, aminocarbonylation of aryl halides, synthesis of amides 110 biaryl synthesis 110 + bidentate phosphines, dippb, dppe, Heck reactions 38 + Buchwald ligands, Suzuki couplings 172 + Buchwald ligands, Suzuki-Miyaura reactions 38 C–C bond forming 83 C–C coupling 38 C–H activation 110, 172 C-5 arylation of thiazoles 110 carbene complexes, Heck reactions 38 3 3 Csp –Csp coupling 172 cyclisation of 2-substituted halogenoarenes 110 ‘cyclo-functionalising’ unactivated C–C multiple bonds 172 1,6-diene Pd(0) monophosphine, Suzuki-Miyaura reactions 38 DPEphosPdCl2, organozinc-based transformations 172 dppfPdCl2, organozinc-based transformations 172 Suzuki couplings 172 dtbpfPdCl2, coupling reactions 172 (DtBPF)PdX2, α-arylation of ketones, a 124 enantioselective –OH addition, in cyclisation 110 Hiyama couplings 172 homogeneous telomerisation 229 intermolecular enantioselective hydroamination 110 Kumada couplings 172 + N-heterocyclic carbenes, Kumada reactions 38 Stille reactions 38 Suzuki-Miyaura reactions 38 oxime-based palladacycle/composite, C–C coupling, a 251 palladacycle complexes, Heck reactions 38 Suzuki-Miyaura reactions 38 + PCy3, Stille reactions 38 Suzuki-Miyaura reactions 38 Pd(II) acetate, vinylic substitution reactions, aryl halides 38 t [PdBr(P( Bu)3)]2, Suzuki-Miyaura reactions 38 t Pd( Bu3P)2, organozinc-based transformations 172 Suzuki couplings 172 [PdCl(η3-C3H5)]2, Hiyama reactions 38 PdCl(CH2Ph)(PPh3)2, Stille reactions 38 PdCl2/CuCl, scCO2/PEG, aerobic oxidation, styrene, a 56 PdCl2(dppf), Kumada reactions 38 PdCl2(PhCN) 38 2, Sonogashira reactions i PdCl2(P( Pr)3)2, Hiyama reactions 38 Catalysts, Palladium Complexes, (cont.) PdCl2(PPh3)2, Negishi reactions 38 Sonogashira reactions 38 38 Pd2dba3 + IMes·HCl, Suzuki-Miyaura reactions Pd2(dba)3 + IPr·HCl, Kumada reactions 38 Pd2dba3 + IPr·t HCl, Suzuki-Miyaura reactions 38 Pd(dba)2 + P( Bu)3, cyanation of aryl bromides, a 251 Pd diphosphine dendrimer/SiO2, intramolecular cyclocarbonylation of iodinated aryl amines 215 Pd/dppf-based, Negishi reactions 38 Pd EnCat, microwave, cross-coupling reactions 64 Pd EnCat 30, microwave, cross-coupling reactions 64 Pd EnCat polyTPP30, microwave, cross-couplings 64 Pd(II) + ethylphosphatrioxaadamantane/SiO2, Suzuki coupling 110 Pd nanoparticles, stabilised by polymer micelles, Suzuki-Miyaura cross-coupling, a 251 Pd(OAc)2, olefins + aryl halides 38 Pd(OAc)2 + IPr·HCl, Stille reactions 38 Pd(OAc)2/Cy3P, Suzuki coupling 172 Pd(OAc)2/PPh3, Heck reactions 38 Pd P–C–N–C–P diphosphine/SiO2, carbonylative cross-couplings 215 t Pd(P( Bu)3)2, Negishi reactions 38 Stille reactions 38 Pd(Ph3P)4, Suzuki couplings 172 synthesis of tetradecane 172 Pd(PPh3)4, Kumada reactions 38 Stille reactions 38 Suzuki-Miyaura reactions 38 Pd(II) phosphine, Suzuki couplings 215 Pd4 phosphine metallodendrimer, Suzuki couplings 215 Pd(II) salts + diphenyl-2-pyridylphosphine, alkyne carbonylation 215 Pd(II) with S donors/SiO2, Suzuki coupling 110 Pd/poly(N-vinylimidazole), Mizoroki-Heck reaction, a 56 Pd/poly(N-vinylimidazole-co-N-vinylcaprolactam), Mizoroki-Heck reaction, a 56 phosphine-ArgoGel-Pd, Suzuki-Miyaura couplings 215 pincer complexes, Heck reactions 38 t + P( Bu)3, Heck reactions 38 Stille reactions 38 Suzuki-Miyaura reactions 38 Q-Phos based FibreCat, coupling reactions 172 Suzuki coupling, in synthesis of palytoxin 172 Suzuki-Miyaura reactions 110 Catalysts, Platinum, aqueous reforming 229 BaO(100)/Pt(100), absorption of NO2 222 electrocatalysis 229 electrocatalysts, FePt, formic acid electrooxidation, a 57 Pd-Co-Pt nanoparticles/C, cathodes, for DMFCs, a 57 platinised C, cathodes, for fuel cells, microchips 12 Pt, nanostructured thin film, a 201 for PAFCs 12 for PEMFCs 12, 201 for SOFCs, a 252 Pt black, cathodes, for DMFCs, a 252 electrodes, for PEMs, a 252 Pt/C, aged, SAXS, TEM, XRD 129 cathodes, for DMFCs, a 252 O2 reduction reaction, mechanism 222 electrodes, in H2/O2 fuel cells, a 57 modified by CeO2, cathodes, for PEMFCs, a 125 Pt/GNFs, for PEMFCs, a 252 Pt/XC-72, for PEMFCs, a 252 Pt3Cr nanoalloy, for fuel cells 107 PtNiFe, Pt59Ni39Fe2, nanostructured thin film, a 201 PtNiZr, for PEMFCs, a 201 PtRu, see Catalysts, Ruthenium green rusts(Pt), dechlorination, tetrachloroethylene, a 252 H–D exchange reaction; + CO 222 hydrogenation 229 Ni-Pt-Pt(111), glycerol reforming, a 251 oxidation 229 Pt, diesel oxidation catalyst 23 Platinum Metals Rev., 2008, 52, (4) 260 Page Catalysts, Platinum, (cont.) diesel particulate filter selective catalytic reduction, NOx control Pt(111), glycerol reforming, a Pt(0) EnCat, microwave, hydrogenations, reductions Pt(0) EnCat 40, microwave, hydrogenations Pt nanoparticles, encapsulated in hollow metal oxide spheres, CO oxidation Pt tip of field ion microscope, H2 + NO Pt/activated C fibre cloth, H2 sensor, a Pt/Al2O3, preparation, by flame-spray pyrolysis sintered, n-heptane reforming, a total oxidation of CH4 Pt/β-Al2O3 + K+, combustion of propane Pt/alumina beads, Hg oxidation Pt–Al2O3/Si, NO + H2, a Pt-Ba/Al2O3, Pt-Ba-Ce/Al2O3, NOx trap, a Pt/Ba/γ-alumina, NOx storage Pt/K/Al2O3, lean NOx trap, CO oxidation, a Pt/C, particle size analysis, by TEM Pt/ceria-containing supports, > 800ºC, redispersion Pt/Cu–Mg(Al)O, NOx storage, a Pt–Mg(Al)O, NOx storage, a Pt/SiO2 filter, for TiO2-based O2 sensor, a Pt/TiO2, degradation of dichloroacetate anion, UV, a visible light, a Pt/TiO2–xNx, degradation of VOCs, visible light, a Pt/zeolites, NO reduction, with diesel, a Pt nanoparticles/magnetite nanoparticles, selective hydrogenation, a PtAu, PtSn, nanoparticles, alkane conversions Pt-Ni-Pt(111), glycerol reforming, a Pt-Pd-Au/CeO2, total oxidation of CH4 Pt-Re/Al2O3, metal segregation, a sintered, n-heptane reforming, a Pt-Rh/Al2O3, preparation, by flame-spray pyrolysis total oxidation of CH4 Pt-Ru/Al2O3, preparation, by flame-spray pyrolysis total oxidation of CH4 steam reforming Catalysts, Platinum Complexes, Karstedt’s catalyst, hydrosilylation, curing of silicones Catalysts, Rhodium, H–D exchange reaction; + CO hydrogenation PdRh/γ-Al2O3, NO-CO reaction Pt-Rh/Al2O3, preparation, by flame-spray pyrolysis total oxidation of CH4 Rh/Al2O3, CO combustion, H2 combustion, a preparation, by flame-spray pyrolysis total oxidation of CH4 Rh/MgAl2O4/Al2O3, steam reforming of bioethanol Ru/SiTiO3:Rh, solar H2 production Catalysts, Rhodium Complexes, BINAPHOS, enantioselective hydroformylation BIPHEPHOS, hydroformylation bisphosphine, asymmetric hydrogenation diazaphospholane, enantioselective hydroformylation Hiyama couplings homogeneous hydrogenation hydroaminomethylation of olefins SM hydroformylation of olefins, LP Oxo Process monophosphoramidite, asymmetric hydrogenation phosphite, enantioselective hydroformylation RhCl(CO){P[OCH(CF3)2]3}2, arenes + iodoarenes, a RhCl(PPh3)3/dendritic SBA-15, hydroformylation, a Wilkinson’s catalyst/dendritic SBA-15, a Catalysts, Ruthenium, aqueous reforming electrocatalysts, PtRu, nanostructured thin film, a PtRu black, anodes, for DMFCs, a PtRu/C, + Mo, for DMFCs H–D exchange reaction; + CO hydrogenation oxidic Ru surfaces, oxidation of MeOH Pt-Ru/Al2O3, preparation, by flame-spray pyrolysis total oxidation of CH4 Platinum Metals Rev., 2008, 52, (4) 23 23 251 64 64 222 222 57 222 251 222 222 144 56 251 222 56 61 222 124 124 125 202 202 200 200 56 107 251 222 56 251 222 222 222 222 229 243 222 229 107 222 222 56 222 222 222 222 110 110 110 110 172 229 110 110 110 110 251 200 200 229 201 252 222 222 229 222 222 222 Page Catalysts, Ruthenium, (cont.) Ru nanoparticles/MgAl spinel, NH3 synthesis 222 Ru/SiTiO3:Rh, solar H2 production 222 RuSn/SiO2, cyclododecatriene selective hydrogenation 107 Catalysts, Ruthenium Complexes, amide preparation 110 C–C bond forming 83 Cp*Ru(COD)Cl, oxidation, regio-, stereoselective 172 F-containing polymer-bound Ru alkylidene, RCM 71 fluoro-tagged, first-generation Grubbs-Hoveyda 157 second-generation Grubbs-Hoveyda 157 Grubbs’ catalyst, conversion of seed oils 222 olefin metathesis 222 polymer-based phosphine resin scavengers 215 Hoveyda’s second-generation, RCM, to SB-462795, a 200 immobilised NHC Ru complex, CM, RCM 71 immobilised Ru benzylidene complex, RCM, dienes 157 self-metathesis, internal olefins 157 ionic liquid-tagged, NHC-Ru, PCy3-Ru 157 NHC Ru complex immobilised on monolithic support 71 oxidation 83 phosphine-ArgoGel-Ru(II), hydrogenation, of scCO2 215 polymer-bound NHC Ru complex, soluble, RCM 71 polystyrene-Ru-allenylidene, cyclisation of olefins 157 hydrogenation of olefins 157 RCM of olefins 157 Ru alkylidenes, immobilisation, via alkylidene ligands 71 via anionic ligands 157 via the arene ligand 157 via N-heterocyclic carbene ligands 71 via phosphane ligands 71 via the Schiff base ligand 157 tagged, fluoro, ionic liquid 157 Ru-based, H2O-soluble, metathesis, RCM, ROMP 71 Ru carbenes, metathesis, gas-phase, a 200 Ru O-hydroxyaryl-substituted NHCs, ROMP, a 124 Ru-pincer, synthesis of amides 110 supported NHC Ru complexes, RCM, ROM/CM 71 zeolite-supported, RCM 71 Chemistry, a 58, 126, 202, 253 Cisplatin 2, 21, 96, 163 Coatings, Ir, by CVD, EBVD, PVD 186 on Rh nozzles 186 IrO2, on DSA®, on Ti electrodes 177 IrO2/RuO2, on DSA®, on Ti electrodes 177 mixed Ir/Ru oxide, on Ti electrodes 177 Pt, on Ti electrodes 177 RuO2, on Ti electrodes 177 Coefficient of Thermal Expansion, Ir3X 208 Colloids, PVP-coated, Pd particles, Pt particles, a 125 Combustion, CO, H2, a 56 natural gas 222 propane 222 186 Composites, Ir-Y2O3 electrode Pd nanoparticle/C template, a 201 Conferences, Catalysis for Renewables, The Netherlands, 2006 229 Challenges in Catalysis for Pharmaceuticals and Fine Chemicals, U.K., 2007 110 Creep 2008, Germany, 2008 241 Creep 2011, Japan, 2011 241 Cross Coupling and Organometallics, France, 2007 172 Dalton Discussion 10: Applications of Metals in Medicine and Healthcare, U.K., 2007 96 EuropaCat VIII: “From Theory to Industrial Practice”, Finland, 2007 222 EuropaCat IX: “Catalysis for a Sustainable World”, Spain, 2009 222 Faraday Discussion 138: Nanoalloys – From Theory to Applications, U.K., 2007 107 10th Grove Fuel Cell Symp., London, 2007 12 Copper, palladised 84 Coupling Reactions, arenes + iodoarenes, a 251 C–C 38, 124, 251 carbonylative 215 conference 172 261 Page Page Creep, conference GTH, GTHR, oxide dispersion strengthened Pt alloys Pt alloys Pt-Al-Cr-Ru, by modelling Pt-Rh Ru-Ni-Al, ternary B2 alloys, a Cross Metathesis, using immobilised Ru alkylidenes Crucibles, Ir CVD, Ir coatings pulsed, Ru thin films, a Cyanation, aryl bromides, a Cyclisation, 2-substituted halogenoarenes by enantioselective –OH addition olefins Cyclocarbonylation, intramolecular, iodinated aryl amines 241 241 241 241 241 125 71 186 186 58 251 110 110 157 Dechlorination, PVC, a tetrachloroethylene, a Decomposition, MeOH Deformation, plastic, Ir Deposition, atomic layer deposition, Ru thin films, a CVD, EBVD, PVD, Ir Pd, on Cu substrate pulsed CVD, Ru thin films, a Deuterium, H–D exchange reaction Diesel, emission control heavy-duty engines, regulations; developments light-duty engines, regulations; developments NOx control NOx traps, a particulate matter control for reduction, of NO, a Diesel Oxidation Catalysts Diesel Particulate Filters Dihydroxylation, encapsulated catalyst, microwave Disinfection, electrochemical, H2O 56 252 222 241 58 186 84 58 222 23 23 23 23 251 23 200 23 23 64 177 Films, Ir oxide/polyaniline composite, a 126 Ni-Pt, electrodeposition, on Au/Al2O3, a 253 Filters, Ir 186 ‘Final Analysis’ 61, 129, 205 Fine Chemicals, by catalysis 110, 172 Flue Gas, Hg oxidation 144 Formic Acid, electrooxidation, a 57 Fuel Cells, a 57, 125, 201, 252 catalysts, analysis by ICPES 205 222 Pt/C, O2 reduction reaction, mechanism conference 12 DAFC, electrocatalysts, Pd/hollow C spheres, a 201 DMFC, catalysts 222 anodes, cathodes, a 252 conference 12 electrocatalysts, anodes, a 125 MeOH, fuel 134 nanocatalysts, cathodes, a 57 O distribution, visualisation, using a Pt porphyrin, a 201 electrocatalysts, nanostructured thin films, a 201 Pt/C, aged, XRD 129 Pt3Cr, O reduction activity 107 electrodes, conference 12 Pt/C, a 57 fuel, H2 12, 57, 134, 229 MeOH 12 “Fuel Cell Today Industry Review 2008” 123 membrane electrode assemblies, conference 12 PAFC, conference 12 PEFC, electrocatalysts, a 125 PEMFC, catalysts, high throughput study, a 201 conference 12 electrocatalysts, cathodes, a 125 graphite nanofibres as catalyst support, a 252 miniature, power source 134 portable applications 134 power, consumer electronics, large stationary 12 reformed MeOH, H2, fuel 134 SOFC, conference 12 current collector grid/patterned catalyst, by ALD, a 252 electrode/catalyst layer, by ALD, a 252 transport: airplane, locomotives, marine, road vehicles 12 Fuels, H2 12, 57, 134, 229, 249 hydrocarbons, a 57 MeOH 12, 134 215 Electrical and Electronics, a 202, 253 Electrochemistry, a 202 formation, IrOx/polyaniline composite films, a 126 H2O disinfection 177 measurements, Pt reference electrode 100 Electrodeposition, CuPd, a 202 Ir 186 Ni-Pt films, on Au/Al2O3, a 253 Pd nanowire arrays, a 125 Electrodes, Cu-Pd, disordered, cleavage, C–Br, C–I 84 modified, reduction, alkyl bromides, iodides 84 in fuel cells, see Fuel Cells 186 Ir-Y2O3 composite IrO2-coated DSA®, free Cl2 production 177 IrO2-coated Ti, hypochlorite generation 177 lifetime 177 ® IrO2-type DSA , degradation, a 202 IrO2/RuO2-coated DSA®, free Cl2 production 177 IrO2/RuO2-coated Ti, hypochlorite generation 177 lifetime 177 micro-, Pt 100 mixed Ir/Ru oxide-coated Ti, in disinfection devices 177 Pd nanoparticles/MWCNTs/Nafion/GCE, a 126 platinised Ti electrodes, in disinfection device 177 Pt, electrochemical reference 100 Pt black, electroplated, human blood cell sensing, a 201 Pt-coated Ti electrodes, lifetime 177 Pt wire, electrochemical reference 100 reference, electrochemical, Pt wire 100 RuO2-coated Ti electrodes, lifetime 177 Emissions Control, a 56, 200, 251–252 catalysts, analysis by ICPES 205 diesel engines, heavy-duty, light-duty 23 Engines, heavy-duty diesel, light-duty diesel 23 Ethylene, hydrogenation, a 124 Platinum Metals Rev., 2008, 52, (4) Gauze, Pt, Pt nanowire coating, a Glycerol, reforming, a Green Chemistry, catalysis 57 251 83, 110 Heck Reactions, Pd-catalysed 38 n-Heptane, reforming, a 251 Heterocycles, synthesis 110 High Temperature, ultra-, Ir3X, thermophysical prop. 208 High Throughput Screening Techniques 134, 201 History, Periodic Table 114, 247 HIV, anti-, Pt(II), Ru(II), Ru(III), Ru(IV) complexes 96 Hiyama Couplings 38, 172 TM HotSpot Reactor, H2 generation 249 Human Blood Cells, sensor, a 201 Hydrides, Pd 120 Hydroamination, intermolecular, enantioselective 110 Hydroaminomethylation, olefins 110 Hydrocarbons, reforming 57, 249 Hydroformylation, enantioselective 110 olefins 110 styrene, a 200 Hydrogen, absorption 120, 201 combustion, a 56 diffusion coefficients, in Pd0.77Ag0.23 120 from bioethanol 222 from glycerol, a 251 from H2O 222 262 Page Page Hydrogen, (cont.) from hydrocarbons, oxygenates 249 fuel 12, 57, 134, 229, 249 H–D exchange reaction 222 membranes 120, 126 + NO 56, 222 sensors, a 57, 201 storage, Pd nanoparticle/C template composites, a 201 222 for synthesis of H2O2 uphill diffusion, ‘Lewis Effect’, Pd 120 Hydrogen Peroxide, synthesis 107, 222 Hydrogen Sulfide, + Pd, + Pd-Cu membranes, a 58 sensors 215 Hydrogenation, aldehydes 110, 200 asymmetric 110 encapsulated catalyst, microwave heating 64 ethylene, a 124 olefins 157 scCO2, + HN(CH3)2 215 selective, alkynes, a 56 cyclododecatriene 107 unsaturated aldehydes, a 56 transfer, aldehydes 110 encapsulated catalyst, microwave heating 64 Hydrogenolysis, o-chlorotoluene, a 200 Hydrolysis, Ru alkoxide/Ti tetraethoxide, a 253 Hydrosilylation, curing of silicones, Pt-catalysed 243 Hypochlorite, generation 177 Iridium Complexes, (cont.) in OLEDs 155, 253 Ir(III) pyridylphosphines 215 Ir(III)/Au(I) phosphines 215 OLEDs 155, 202, 231, 253 Iridium Compounds, electrodes, see Electrodes intermetallic, thermal conductivity, thermal expansion 208 Ir chloride solutions, for plating of Ir 186 Ir hexafluoride, for CVD 186 Ir oxide, in chemical refining of Ir 186 Ir oxide/polyaniline composite films, a 126 sodium hexabromoiridate(II) solutions, plating of Ir 186 ICPES, determination of Pt in solution 205 Ionic Liquids 38, 83 Iridium, coatings, by CVD, EBVD, PVD 186 on Rh nozzles 186 crucibles 186 deformation processing 186 deposition, electrodeposition 186 filters 186 Ir-Y2O3 composite electrode 186 joining 186 melting 186, 252 nanoparticles, a 126 Periodic Table 114, 247 plastic deformation 241 plating 186 powder metallurgy 186 processing 186 purification 186, 252 single crystals, deformation 241 sponge 186 welding 186 wire 186 Iridium Alloys, deformation processing 186 DOP-26 186 Ir-Pt, powder metallurgy 186 ‘Ir-Nb’, dendritic segregation, a 252 ‘Ir-Zr’, dendritic segregation, a 252 joining 186 melting 186 processing 186 Pt-Ir, coating, AFM probes, a 202 welding 186 Iridium Complexes, cyclometalated Ir(III)-polypyridines in biological probes, luminescence, a 202 encapsulated Ir porphyrins, O2 sensors 46 Ir acetylacetonate, for CVD 186 Ir-allyl, for CVD 186 Ir(III) N-benzylpyrazoles, phosphorescence, a 253 Ir(btp)2(acac), in OLEDs 155 Ir-carbonyl, for CVD 186 Ir(COD)(MeCp), for CVD 186 Ir-cyclooctadienyl, for CVD 186 Ir(dfppy)2(pq), in OLEDs, a 202 Ir(ppy)2(DBM), Ir(ppy)2(SB), phosphorescence, a 126 Ir(ppy)3, luminescence, a 126 Platinum Metals Rev., 2008, 52, (4) Jewellery, Pt, manufacture Johnson Matthey, “Platinum 2007 Interim Review” “Platinum 2008” sustainability Joining, Ir, Ir alloys Kumada Couplings 52 54 198 132 186 38, 172 Lasers, Pt jewellery, manufacture welding, Ir alloy Lewis Effect, uphill diffusion of H, in Pd Lipoid, with Pt(II) containing salicylate derivative Lipophilicity, Pt(II) containing salicylate derivative LPG, sensors, a Luminescence, cyclometalated Ir(III)-polypyridines, a dendritic tetranuclear Ru(II) complex Ir(ppy)3, a Pt(II) isoquinolinyl indazolates, a Pt porphyrin, a switching, Pt(II) dithiooxamides, a 52 186 120 163 163 201 202 46 126 58 201 58 Magnetism, nanoalloys, CoPt, CoRh, PdAu, PdFe, PdNi, PtAu, PtFe, PtNi 107 Mannich Condensation, P-based, for aminophosphines 215 MEAs, conference 12 Medical Uses, pgm complexes, anti-HIV 96 anticancer 2, 21, 96, 126, 163 Melting, Ir, a 252 Ir alloys 186 Membranes, Pd, sulfidisation, a 58 Pd/modified α-Al2O3, in reactor, H2 production, a 57 Pd/Ag23%, heat treatment, a 126 Pd0.77Ag0.23, H2 diffusion coefficients, uphill effects 120 Pd-Cu, sulfidisation, a 58 Mercury, oxidation 144 Metal-Ligand Exchange Kinetics, Pt, Ru complexes 2 Metallodendrimers, encapsulated, Ir, Pd, Pt porphyrins 46 Metallurgy and Materials, a 57, 125, 201, 252 Metathesis, olefins 71, 157, 222 Methane, oxidation, a 124 sensors, a 253 total oxidation 222 Microwaves, in organic synthesis 38, 64 syntheses of cycloplatinated complexes, a 58 Mizoroki-Heck Reactions, a 56 Molten Salts, electrodeposition of Ir 186 Nanoalloys, CoPt, CoRh, PdAu, PdFe, PdNi, PdRh, PtAu, Pt3Cr, PtFe, PtNi, PtSn 107 Nanocomposites, C MWNT/Pd, for detection of CH4, a 253 Pd nanoparticles-polyphenosafranine, nitrate sensing, a 58 Ru nanoparticles/C MWNT, for supercapacitor, a 253 Nanoparticles, FePt, a 57 Ir, a 126 Pd 38, 58, 124, 126, 201, 251 PdAu 107 Pd-Co-Ag, Pd-Co-Au, Pd-Co-Pt, a 57 263 Page Page Nanoparticles, (cont.) Pd/Pt, a 201 Pt 56, 61, 222 Pt@CoO, a 57 PtAu 107 PtSn 107 Ru 222, 253 253 RuO2, a Nanostructures, yolk–shell, Pt@CoO nanoparticles, a 57 Nanowires, arrays, Pd, a 125 Pt, on metal gauze, a 57 Natural Gas, combustion 222 Natural Products, synthesis, by cross-coupling 172 Negishi Couplings 38, 172 Nitrite, sensors, a 58 Nitrogen, adsorption, on Pt(111), a 125 on Pt(111)(1×1)H, a 125 Nitrogen Oxides, NO, + CO 107 + H2 56, 222 reduction, with CO, a 200 with diesel, a 200 NO2, adsorption 222 NOx, control 23 lean, trap 23, 56 selective catalytic reduction 23 storage, by catalysts 124, 222 traps, for diesel, a 251 Norbornene, ROMP, a 251 vinyl polymerisation, a 251 Palladium, (cont.) uphill diffusion, ‘Lewis Effect’, H2 120 Palladium Alloys, absorption, H2 120 Cu-Pd, disordered, electrodes 84 modified, electrodes 84 CuPd, crystal structure information 84 electrocatalytic properties, a 202 electrodeposition, a 202 hydrides 120 membranes 58, 120, 126 nano-, PdAu, PdFe, PdNi, PdRh 107 PdAu nanoparticles, synthesis, in a sputter reactor 107 PdNi, PdZn, nanosized powders, a 126 Palladium Complexes, anticancer agents 21 dichloropalladium(II) ditertiary phosphines 215 dichloropalladium(II) pyridylphosphines 215 46 encapsulated Pd porphyrins, O2 sensors OLEDs 155 organometallic polymers 46 [Pd]10[MTD]163, [Pd]50[MTD]113, complex-block 46 Pd(acac)2, decomposition, reduction, a 125 [Pd(NH3)4][Ni(Ox)2(H2O)2]·2H2O, thermal decomp., a 126 [Pd(NH3)4][Zn(Ox)2(H2O)2]·2H2O, thermal decomp., a 126 Pd oxoselenates, preparation, a 58 Pd(Se2O5), Pd(SeO3), Pd(SeO4), preparation, a 58 Ru2Pd phosphaadamantane 215 Palladium Compounds, K2PdCl4 in H2SO4 electrolyte, a125 Pd(II), recovery, with chitosan microspheres, a 253 PdCl2, in HCl, for Pd deposition 84 Pd(NO3)2, in HNO3, for Pd deposition 84 PdSO4·2H2O, in H2SO4, for Pd deposition 84 Particle Size Analysis, Pt/C catalysts, by TEM 61 Particulate Matter, control 23 Patents 59–60, 127–128, 203–204, 254–255 analysis 231 mapping 231 Periodic Table 114, 247 Pharmaceuticals, by catalysis 110, 172 Phase Diagrams, Cr-Ni-Pt 241 Cr-Pt 48 Pt-Al-Cr-Ni 48 Phases, Pt-Al-Cr-Ni 241 Phosphines, pgm complexes, applications, properties 215 Phosphorescence, electro-, Ir(dfppy)2(pq), in OLEDs, a 202 Ir(III) N-benzylpyrazoles, a 253 Ir(ppy)2(DBM), Ir(ppy)2(SB), a 126 Pt(II)–acetylides, a 58 Photocatalysis, degradation, of dichloroacetate anion, a 202 of VOCs, a 200 H2O, to H2 222 Photoconversion, a 58, 126, 202, 253 Photoreduction, Ru(III) ionic solutions, a 252 Plating, Ir 186 Platinum, additions, NiAl, wetting, of alumina, a 57 coating, AFM probes, a 202 colloidal particles, PVP-coated, a 125 Cr-Ni-Pt, phase diagram 241 Cr-Pt, CALPHAD 241 determination, in solution 205 doped, TiO2, O2 sensor, a 125 electrodes, see Electrodes gauze, Pt nanowire coating, a 57 jewellery, manufacture 52 nanoparticles 56, 61, 201 nanowires, a 57 particles, particle size analysis, by TEM 61 Periodic Table 114, 247 phase diagrams 48 Pt(111), Pt(111)(1×1)H, adsorption of N2, a 125 Pt-Al-Cr 241 Pt-Al-Cr-Ni, phases 241 thermodynamic database 48 PtAl12Cr6, PtAl12Cr6Ni5, PtAl12Ni6 48 thin films, by OMCVD, a 126 Platinum Alloys, creep 241 Oils, seed, conversion 222 OLEDs 155, 202, 231, 253 Olefins, C–C couplings, a 124 cyclisation 157 Heck reactions 38 hydroformylation 110 hydrogenation 157 internal, self-metathesis 157 metathesis 71, 157, 222 RCM 157 OMCVD, Pt, precursor chemistry, processes, a 126 Organometallics, Pd 172 Organosilanes, cross-coupling 172 Osmium, Periodic Table 114 , 247 Osmium Complexes, OLEDs 155 organometallic polymers 46 Oxidation, aerobic, styrene, a 56 CH4, a 124 CO 222 electro-, formic acid, a 57 Hg 144 MeOH 125, 222 regio-, stereoselective, using Cp*Ru(COD)Cl 172 Ru catalysts 83 selective, styrene, a 124 222 total, CH4 Oxygen, sensors 46, 125 for synthesis of H2O2 222 Oxygenates, reforming 249 Palladium, absorption, H2 120 C MWNT/Pd nanocomposite, for detection of CH4, a 253 colloidal particles, PVP-coated, a 125 deposition, on Cu substrate 84 H2 storage 12 hydrides 120 membranes, a 57 nanoparticles 38, 58, 124, 126, 201 nanowire arrays, a 125 Pd nanoparticle/C template composites, a 201 Pd nanoparticles-polyphenosafranine, nitrate sensing, a 58 PdAu particles/Al2O3 film, by sequential condensation 107 Periodic Table 114, 247 Platinum Metals Rev., 2008, 52, (4) 264 Page Page Platinum Alloys, (cont.) Ir-Pt, powder metallurgy 186 jewellery, manufacture 52 107 nano-, CoPt, PtAu, Pt3Cr, PtFe, PtNi, PtSn Ni-Pt amperometric sensor, for alcohols, a 253 NiPtAl, wetting, of alumina, a 57 oxide dispersion strengthened, GTH, GTHR, creep 241 Pt-Al-Cr-Ru, creep properties, by modelling 241 Pt-Ir, Pt-Ni, coating, AFM probes, a 202 PtNi, PtZn, nanosized powders, a 126 Pt-Rh, creep 241 superalloys, Pt base 241 thermodynamic database 48 Platinum Complexes, anticancer agents, see Cancer anticancer drugs, see Cancer carbazole-based Pt(II)–acetylides, preparation, a 58 (cod)Pt(Me)2, for OMCVD, a 126 cycloplatinated complexes, synthesis, a 58 encapsulated Pt porphyrins, O2 sensors 46 EtCpPtMe3, MeCpPtMe3, for OMCVD, a 126 fluorene-based Pt(II)–acetylides, preparation, a 58 OLEDs 155 organometallic polymers 46 [Pt]50[MTD]113 complex-block 46 Pt(acac)2, decomposition, reduction, a 125 Pt(II) dithiooxamides, luminescence, switching, a 58 Pt(II) isoquinolinyl indazolates, luminescence, a 58 [Pt(Me2bzimpy)Cl](PF6)·DMF, vapochromic, a 202 [Pt(NH3)4][Ni(Ox)2(H2O)2]·2H2O, thermal decomp., a 126 [Pt(NH3)4][Zn(Ox)2(H2O)2]·2H2O, thermal decomp., a 126 Pt porphyrin, luminescence, a 201 Pt(II) pyridylphosphines 215 [Pt(R2-dto)2], + HCl, photoluminescence; + NH3, a 58 Ru2Pt phosphaadamantane 215 Platinum Compounds, anticancer agents, see Cancer PtCl2 solution, dip coating, nano SnO2 thick films, a 201 Pt(II) salicylate derivatives, biological evaluation, characterisation, design, lipophilicity, liposomal formulation, synthesis 163 Pt(IV), recovery with chitosan microspheres, a 253 Platinum Group Metals, patents 231 Periodic Table 114, 247 Polymerisation, by metathesis 71, 124 vinyl-type, norbornene, a 251 Polymers, Ir oxide/polyaniline composite films, a 126 organometallic 46 PVC, dechlorination, a 56 PVP-coated, Pd, Pt, colloidal particles, a 125 PVP-protected, Ru particles, a 252 transition metal-containing 46 Powder Metallurgy, Ir, Ir alloys 186 Propane, combustion 222 PVD, Ir 186 Reforming, (cont.) glycerol, a 251 n-heptane, a 251 hydrocarbons, a 57 steam, bioethanol, EtOH 222 MeOH 134 using HotSpotTM reactor, hydrocarbons, oxygenates 249 Release Liners, silicone 243 Renewables, catalysis 229 Rhodium, Periodic Table 114 Rhodium Alloys, nano-, CoRh, PdRh 107 Pt-Rh, creep 241 Rhodium Complexes, anticancer agents 21 OLEDs 155 Rh porphyrinoids, synthesis, dynamic structure, a 202 Rh(III) pyridylphosphines 215 ROMP, norbornene, a 251 Ru-based NHC-arene systems, a 124 using immobilised Ru alkylidenes 71 Ruthenium, Periodic Table 114 PVP-protected Ru particles, by photoreduction, a 252 Ru nanoparticles/C MWNTs, for supercapacitor, a 253 thin films, a 58 Ruthenium Alloys, Pt-Al-Cr-Ru, creep, modelling 241 Ru-Ni-Al, ternary B2, a 125 Ruthenium Complexes, anticancer agents, see Cancer dendritic tetranuclear Ru(II) complex, luminescence 46 OLEDs 155 organometallic polymers 46 phosphine-ArgoGel-[Ru5C(CO)15], gas sensors 215 phosphine-ArgoGel-[Ru6C(CO)17] 215 Ru(II) oximato, preparation, biological activity, a 253 Ru(II) pyridylphosphines 215 Ru(II)/Au(I) phosphines 215 Ru2Pd phosphaadamantane, Ru2Pt phosphaadamantane 215 Ruthenium Compounds, bis(N,N'-di-tert-butylacetamidinato)Ru(II) dicarbonyl, deposition, a 58 electrodes, see Electrodes RuCl3·nH2O, for photoreduction, a 252 RuO2 nanoparticles, a 253 RuO2-TiO2 mixed oxides, preparation, a 253 RCM, olefins Ru carbene catalysts, a synthesis, dicyclic compounds macrocyclic compounds SB-462795, a using immobilised Ru alkylidenes Reactors, membrane, H2 production, a packed bed, Hg oxidation Redox Systems, Pt reference electrode Reduction, aldehydes, a electrochemical, alkyl bromide, chlorides, iodides NO, with CO, a with diesel, a with H2 temperature-programmed, catalytic materials Refining, chemical, Ir Refining and Recovery, a Reformer, micro-, H2 production Reforming, catalysts, metal segregation, a ethylene glycol, EtOH, a Platinum Metals Rev., 2008, 52, (4) 157 200 71 71 200 71 57 144 100 200 84 200 200 222 249 186 253 134 56 251 Scavengers, polymer-based phosphine resins 215 Selective Catalytic Reduction, NOx control 23 Self-Metathesis, internal olefins 157 Sensors, CH4, a 253 CO 201, 215 EtOH, a 253 H 2, a 57, 201 H 2S 215 human blood cells, a 201 LPG, a 201 nitrite, a 58 46, 125 O2 SO2 215 Silicones, Pt-catalysed hydrosilylation; release liners 243 Single Crystals, Ir, deformation 241 Soldering, Pt jewellery, manufacture 52 Solvent Extraction, Ir 186 Solvents, in catalysis 83, 110 Sonogashira Couplings 38, 64 Sponge, Ir 186 Sputtering, PdAu nanoparticles 107 Stille Couplings 38, 124 Styrene, hydroformylation, a 200 oxidation, aerobic, a 56 selective, a 124 Sulfidisation, Pd membranes, Pd-Cu membranes, a 58 Sulfur Oxides, SO2, sensors 215 Superalloys, Pt base 241 Pt-based, thermodynamic database 48 Supercapacitors, Ru nanoparticles/C MWNTs, a 253 Supercritical Fluids 38, 56 Surface Coatings, a 58, 126, 202 265 Page Sustainability, Editorial Suzuki Couplings Suzuki-Miyaura Couplings 132 110, 172, 215 38, 110, 215, 251 TEM, Pt/C catalysts, particle size analysis 61 Temperature-Programmed Reduction, catalysts 249 Tetrachloroethylene, dechlorination, a 252 Thermal Conductivity, Ir3X (X = Hf, Nb, Ta, Ti, V, Zr) 208 Thermal Expansion, Ir3X (X = Hf, Nb, Ta, Ti, V, Zr) 208 Thermodynamic Database, Pt-based superalloys 48 Thermophysical Properties, Ir3X 208 Thiazoles, C-5 arylation 110 Thin Films, nanostructured, Pt, PtNiFe, PtRu, a 201 Ru, deposition, by atomic layer deposition, by CVD, a 58 Platinum Metals Rev., 2008, 52, (4) Page Ultrasound, in C–C couplings 38 Vapochromism, [Pt(Me2bzimpy)Cl](PF6)·DMF, a VOCs, degradation, a Water, electrochemical disinfection solvent Welding, Ir Ir alloys Wire, Ir XRD, Pt/C catalysts, crystallite size analysis 202 200 177 110, 200, 251 186 186 186 129 266 Platinum Metals Review Johnson Matthey Plc, Precious Metals Marketing, Orchard Road, Royston, Hertfordshire SG8 5HE, U.K. E-mail: [email protected] http://www.platinummetalsreview.com/