Johnson Matthey Emission Control Technologies, Orchard Road, Royston, Hertfordshire SG8 5HE, UK Email: robert.hanley@matthey.com “Palladium-Catalyzed Coupling Reactions”, published by Wiley in 2013, is a comprehensive handbook and guide to modern aspects of this reaction type. The book focuses on state of the art techniques. The use of different reaction media, catalyst recycling, supported catalysts, microwave assisted synthesis and continuous fl ow reaction systems are all examined, making this book an excellent resource. The book avoids delving into the specifi cs of each type of coupling reaction and instead presents a variety of topics, discussing recent progress and potential future work in each given area. It was edited by Arpad Molnar, a Professor of Chemistry in the University of Szeged, Hungary, who has no less than 200 publications to his name. Numerous research papers in the fi eld of catalyst development, coupled with review papers on many of the subjects covered in this book, qualify Professor Molnar for his position of editor. The content of this book covers fi ve general topics: an introduction and background to Pd-catalysed coupling reactions, Pd catalysts on various support materials, coupling reactions in different reaction media, reaction conditions for coupling reactions and industrial applications of Pd catalysed coupling reactions.
Recently, the increasing importance and scope of nanotechnology has extended the need for high resolution characterisation tools beyond their traditional domains. As a consequence, advanced high-resolution tools at the nanoscale are now increasingly used in research and development (R&D) activities, offering the chance for a better understanding of submicron feature size dependence. This paper gives an overview of the synergic application of two high resolution techniques on the platinum group metals (pgms): focused ion beam (FIB) coupled with electron beam imaging, milling and deposition techniques; and nanoindentation testing. After a brief description of both techniques (architecture, probe-sample interaction basics and operation modes), the effectiveness of this combined approach is demonstrated for microstructural and nanomechanical investigations on very small samples. The advantages are low cost, fast and site-specific sample preparation for transition electron microscopy (TEM) analysis; study of the mechanical hardening effect on microstructure and hardness profile at the micron scale; failure analysis; and understanding of plasticity and elasticity behaviour. Two specific case studies related to a platinum-copper alloy for jewellery use and a platinum-rhodium alloy for sensor manufacturing are presented and discussed.
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The Hydrogen South Africa (HySA) programme is based upon the beneficiation of South Africa's large platinum group metal (pgm) resources. The present article summarises some of the progress by HySA Systems, one of the three Competence Centres under the HySA Programme, since 2008. Work has been carried out on membrane electrode assembly and stack development for high-temperature proton exchange membrane fuel cells (HT-PEMFCs) for use in combined heat and power (CHP) supplied by natural gas and hydrogen fuelled vehicle (HFV) applications. The emphasis is on improved carbon monoxide tolerance and simplified heat and humidity management, allowing simpler fuel cell systems to be designed. Metal hydrides modified with palladium are being explored as poisoning-tolerant hydrogen storage materials for stationary and special mobile applications, and metal organic frameworks (MOFs) modified with platinum as light-weight hydrogen storage with a high hydrogen storage capacity. Lastly research into hydrogen purification using Pd membrane reactors is focused on membrane support synthesis, hollow fibre seeding and development of the plating procedure.
Since the previous update on new isotopes of the platinum group of elements (1), further isotopes have been discovered and reported by Kurcewicz et al. (2) in 2011. These are: 202Os, 203Os, 204Ir, 205Ir and 206Pt to 209Pt. The discovery of the isotope 201Os was also claimed but this was previously identifi ed by Kurtukian-Nieto (3) in 2007. All of these isotopes are particle stable (resistant to proton and neutron decay) and are likely to be – emitters. These discoveries bring the total number of known isotopes for the platinum group of elements as shown in Table I.
At high temperatures, the equiatomic binary compounds formed by Groups 4 and 8 transition metals are known to undergo martensitic transformation, which may be accompanied by a shape memory effect. Among these compounds, titanium-rhodium (TiRh) is of special interest not only because it undergoes two martensitic transformations at high temperature, for one of which the shape memory effect has been observed, but also because it demonstrates unusual shape recovery behaviour at temperatures higher than 400°C. The present work focuses upon the thermomechanical and mechanical properties of 50 at% rhodium-scandium-titanium ternary alloys where Ti is substituted by Sc. These alloys were investigated for the first time using electrical resistance, dilatometry and three-point bending techniques in the temperature range 20°C to 850°C. It was found that the sample with 0.1 at% Sc exhibited full shape restoration in the ranges of both martensitic transformations at ~340°C and ~750°C. Two-way shape recovery was also observed. A small temperature hysteresis, desirableforalloysused inactuator applications, is present in TiRh and Rh-Sc-Ti alloys. Both TiRh and Sc-containing alloys exhibit continuity of the deformation process on cooling and shape restoration on heating in a wide range of temperatures. This feature of both TiRh and Rh-Sc-Ti alloys implies the possibility of their application in different heat-regulating elements at temperature ranges from room temperature to 850°C.
Johnson Matthey Plc, PO Box 1, Belasis Avenue, Billingham TS23 1LB, UK Email: martin.fowles@matthey.com Introduction A commemorative symposium was held at the University of Durham, UK, on 3rd–4th April 2013 to celebrate the career of Professor Dennis Albert Dowden (1914–2012). The meeting was organised by the Royal Society of Chemistry (RSC) Applied Catalysis Group (ACG) and the RSC Surface Reactivity and Catalysis Group (SURCAT) and sponsored by Johnson Matthey. The meeting was attended by approximately 100 attendees from industry and academia and consisted of a series of oral and poster presentations.
Titanium-platinum (Ti50Pt50) (all compositions in at%) alloy exhibits thermoelastic martensitic phase transformation above 1000°C and has potential for high-temperature shape memory material applications. However, as has been previously reported, Ti50Pt50 alloy exhibited a negligible recovery ratio (0–11%) and low strength in martensite and especially in the austenite phase due to low critical stress for slip deformation. In order to improve the high-temperature strength and shape memory properties, the effects of partial substitution of Ti with other Group 4 elements such as zirconium and hafnium and the effect of partial substitution of Pt with other platinum group metals (pgms) such as iridium and ruthenium on the high-temperature mechanical and shape memory properties of Ti50Pt50 alloy were recently investigated. This paper reviews the transformation temperatures and high-temperature mechanical and shape memory properties of recently developed Ti site substituted (Ti,Zr)50Pt50, (Ti,Hf)50Pt50 and Pt site substituted Ti50(Pt,Ru)50 and Ti50(Pt,Ir)50 alloys for high-temperature (~800°C–1100°C) material applications.
Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Main College, Park Place, Cardiff CF10 3AT, UK Email: knightdw@cardiff.ac.uk The purpose of this relatively small volume is to provide methods for carrying out representative examples of palladium-catalysed couplings on a solid support, essentially in the style of Organic Syntheses (1). There are contributions from both academic and industrial groups. This is a somewhat specialised area of synthesis, requiring techniques additional to those employed in ‘normal’ organic synthesis. Solid-phase synthesis has a number of pros and cons. The idea of immobilising part of, say, a drug candidate to a solid support on quite a large scale and then coupling a series of ‘second’ parts of the drug target to samples of the initial species can be a very convenient and attractive approach to library synthesis and one which is potentially very effi cient and rapid. Alternatively, a diverse series of precursors can be built up on a solid support then cyclised using palladium catalysis. On the downside, it is often rather time-consuming to follow the progress of such syntheses and to manage the inevitable differences in reaction rates between a diverse range of reactants. Hence, the purpose of this book is to provide experimental guidance across a range of palladiumcatalysed coupling reactions of the types which have made such an important impact on organic synthesis in general. These reactions represent a true paradigm shift in the way that organic synthesis is currently viewed and executed.
