Full Text for Volume 47 Number 4 (October 2003)

This issue contains the following:

Platinum-Based Shape Memory Alloys
Currently, the uses of shape memory alloys (SMAs) include sensors, temperature sensitive switches, force actuators, fire-safety valves, orthodontic wires, fasteners, and couplers. The possible advantages offered by platinum-based SMAs alloyed with various metals are assessed by Taryn Biggs (formerly of Mintek, South Africa) and colleagues Professor M. B. Cortie (University of Technology, Sydney, Australia), Professor Michael J. Witcomb (University of the Witwatersrand, South Africa) and Lesley A. Cornish (Mintek, South Africa). The most promising candidate systems appear to be ternary-alloyed variations of the Pt₃Al, Fe₃Pt and TiPt phases with ruthenium and nickel. It seems possible to engineer a shape memory transition in the (Pt, Ni)Ti system anywhere between room temperature and 1000°C, a versatility probably unique among known SMAs.

Magnetic Field Increases Benzene Conversion
A magnetic field of 59.42 mT was found to have a remarkable effect on the UV photocatalytic degradation of benzene in the presence of a 0.5% Pt/TiO₂ catalyst. Scientists from Fuzhou University, China, found that when this magnetic field was applied benzene conversion increased from 15.5 to 18% while CO₂ production increased from 52 to 175 ppm.

Recovery of Precious Metals from Spent Catalysts
AquaCat^® is a new Johnson Matthey process for the recovery of platinum, palladium and rhodium from spent heterogeneous and homogeneous catalysts. Piers Grumett from Johnson Matthey Catalysts, Enfield, U.K., describes the two-stage process. The first stage determines the precious metal content of a spent heterogeneous catalyst using a direct sampling method. The second stage, involving supercritical water oxidation, converts noxious carbon-containing material to less noxious forms, leaving the metals as their oxides. The process is totally enclosed, with no release of harmful substances. There is no metal loss and efficiencies close to 100% for organic destruction are achieved.

Osmium Tetroxide Microencapsulated in Polymer
A team of scientists at the University of Tokyo, Japan, have produced a polymer microencapsulated osmium tetroxide catalyst. With this catalyst, and using water as the sole solvent, they successfully achieved catalytic asymmetric dihydroxylation of olefins to produce diols in good yield. The catalyst did not leach, was recyclable and was still active after several runs.

Discovery of Rhodium and Palladium by Wollaston
Historical events surrounding the discovery of rhodium and palladium two hundred years ago by William Hyde Wollaston are described by Professor Bill (W. P.) Griffith (Imperial College, London). Wollaston, a polymath of considerable scientific ability, chose a curious and controversial route to advertise his discovery of the new metal "Palladium".

2003 World Congress of the Society of Automotive Engineers
Martyn V. Twigg, European Technology Director of Johnson Matthey Catalysts, comments on advances in the technology of emissions control systems for conventional gasoline, lean-burn gasoline and diesel engines, reported at the last SAE Congress. All these systems require platinum group metals to achieve the low emissions demanded by ever-stricter legislation worldwide, with the Californian Super Ultra Low Emission Vehicle standard being the current most stringent operating standard. The Congress, held in Detroit each Spring, is the most important annual gathering for car manufacturers and associated industries.

Hydrogen Economy Forum in Russia
Fred (F. A.) Lewis (Queen’s University, Belfast), who has worked with hydrogen in palladium and palladium alloys for many years, attended the second International Symposium of Safety and Economy of Hydrogen Transport, in Sarov, Russia, in August. Around 250 delegates from 12 countries heard presentations on various aspects of hydrogen. Lewis reports on some of the papers concerned with the platinum metals.

The Isotopes of Iridium
The painstaking work undertaken by the scientists who discovered the isotopes of iridium is recorded by John W. Arblaster of Coleshill Laboratories, U.K. Between 1934 and 2001, thirty-six isotopes of iridium were discovered. Enrico Fermi identified a 20 hour activity after bombarding iridium with slow neutrons in 1934. Fermi received the 1938 Nobel Prize in Physics for demonstrating the existence of new radioactive elements produced by neutron irradiation, and for the discovery of nuclear reactions brought about by slow neutrons.

Searching Patent and Literature Sources
Brief advice on how to search the patent literature held in the European Patent Office databases, and a selection of abstracts based on recently published patent and scientific literature are included in this issue. The Name and Subject Indexes for Volume 47, 2003, end the issue.

Platinum Metals Review is available on the internet from the publications section of the Platinum Today site or from the host site Ingenta Select.

Susan V. Ashton
Editor

Anyone with an active interest in the platinum group metals and their uses who does not have ready access to a copy of Platinum Metals Review and who may benefit from reading it, is invited to request a specimen copy from:

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