Full Text for October 2011, Volume 55, Number 4

 

Articles in This Issue:

Investigating the Strengthening Mechanisms in Platinum-5% Rhodium DPH
Platinum has a high melting point and remarkable resistance to high temperature corrosion and oxidation. These high temperature properties can be improved by hardening platinum by solid solution (by adding rhodium) and/or oxide particles. A joint project from Rainer Völkl and his collaborators from Metals and Alloys, University Bayreuth and W. C. Heraeus GmbH, Germany, researched the strengthening mechanism of the dispersion hardened alloy platinum-5% rhodium (Pt-5%Rh DPH) for high temperature applications using transmission and scanning electron microscopy. The oxide particle distribution (including the location and size distribution) is important for the high temperature strength properties.The study concludes that the observed strengthening mechanisms by the oxide particles of various size ranges lead to the deceleration of creep deformation of Pt-5%Rh DPH at 1600ºC compared to pure platinum, solid solution strengthened Pt-5%Rh and Pt-10%Rh.

 

Using X-Ray Absorption Spectroscopy to Study Vehicle Emission Control Catalysts
As emission control regulations become increasingly stringent, vehicle emission control (VEC) catalysts are continually being studied and developed. VEC systems typically contain platinum group metals (pgms) with a mixed oxide catalytic functional support and a thermally stable structural support. This collaborative study led by Gopinathan Sankar et al. from the Johnson Matthey Technology Centre, Sonning Common, and University College London, UK, aimed to analyse the nature of the species present in fresh and road aged light-duty diesel VEC catalysts using X-ray absorption spectroscopy methods, specifically X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS). XANES alone was not sufficient to identify the species present. By using EXAFS, the study found a mix of oxidic and metallic species in fresh catalysts and predominantly metallic species in aged catalysts.

 

Discoverers of Ruthenium Isotopes
In this sixth and final review on the circumstances surrounding the findings of the isotopes of the six platinum group elements, John Arblaster summarises the discovery and discoverers of the thirty-eight known ruthenium isotopes with mass numbers from 87 to 124 found between 1931 and 2010. An update on the new isotopes of palladium, osmium, iridium and platinum discovered since the previous reviews in this Journal is also provided.

 

Determination of Precious Metal Content
In this issue's Final Analysis, Dippal Manchanda from The Birmingham Assay Office, UK, considers the advantages of using inductively coupled plasma-optical emission spectrometry (ICP-OES) for precious metal analysis and compares this technique with classical methods such as gravimetry. The aim of this process is to determine the precious metal content in different materials (the analysis of pgms in powder and ore samples). Accurate determination is also crucial for fineness determination for the hallmarking of precious metals for jewellery. The precision and accuracy of the ICP technique makes it very suitable for this purpose.

 

Book Reviews:

Sarah Ball, Jonathan Sharman and Ian Harkness from Johnson Matthey Technology Centre, Sonning Common, UK, provide a selective review on the book "Proton Exchange Membrane Fuel Cells: Materials Properties and Performance", edited by David P. Wilkinson, Jiujun Zhang, Rob Hui, Jeffrey Fergus and Xianguo Li. Up-to-date and comprehensive background information on progress in material properties and performance for PEMFCs is described in this book. PEMFCs have progressed in the last few years and are at an early commercialisation stage, although significant technical challenges such as operational flexibility, cost, technology simplification and integration still remain. The chapters on pgm electrocatalysts, catalyst layers and diffusion layers are outlined in this review.

 

Simon Fricker of Genzyme Corp, Framingham, USA, reviews "Medicinal Organometallic Chemistry", edited by Gérard Jaouen and Nils Metzler-Nolte. This book outlines recent developments in the design, synthesis, mechanistic understanding and medical application of organometallic compounds. The medicinal organometallic complexes of iron, titanium, technetium and gold are explained in the book, but the review concentrates on the chapters featuring the pgms. The work on ruthenium arene complexes and their potential antitumour activity and the research on metal complexes as scaffolds for novel kinase inhibitors are particular highlights of the book.

 

"Catalysis in the Refining of Fischer-Tropsch Syncrude", by Arno de Klerk and Edward Furimsky, is the fourth book in the Royal Society of Chemistry's Catalysis Series and is reviewed by Stewart Brown of Johnson Matthey Precious Metals Marketing, Royston, UK. This book focusses on refining and upgrading catalysts and provides a thorough assessment of the catalytic processes for syncrude conversion to useful products such as fuel and oils. Fischer-Tropsch technology has the potential to provide an alternative to conventional fuel sources.

 

Conference Review:

The 25th Santa Fe Symposium on Jewelry Manufacturing Technology was held Albuquerque, New Mexico, USA, from 15th–18th May 2011.This review by Christopher Corti of COReGOLD Technology Consultancy, Reading, UK, highlights a selection of presentations on topics such as the soldering of platinum, investment casting of platinum, the beneficial effects of hot working on the microstructure and properties of precious metals and the manufacture of wrought wedding bands.

Also included in this issue is a summary of Fuel Cell Today's latest Industry Review, which was released on 14th September 2011. This provides details of the developments in unit shipments and megawatts shipped during the period 2007–2010 which are supported by data tables. A forecast for the full year of 2011 is also discussed. Portable, stationary and transport applications are analysed.

 

Contact
The Editor, Platinum Metals Review, Johnson Matthey PLC, Orchard Road, Royston, Hertfordshire SG8 5HE, United Kingdom; Fax +44 (0) 1763 256359; Email jmpmr@matthey.com

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