Platinum Metals Review - Volume 26, Issue 2, 1982

Diesel-engined vehicles are highly reliable and use fuel more economically than spark ignition engines, therefore they are being more widely adopted. However, in addition to relatively small quantities of gaseous pollutants, diesel exhaust emissions characteristically contain much higher concentrations of particulate materials. Continuing their clean air policy, the Environmental Protection Agency in the United States of America has imposed limits on the amount of particulates that will be tolerated in diesel exhaust emissions from 1982 model year vehicles to 0.6 grams per mile, with an even lower limit of 0.2 grams per mile proposed for the 1985 model year. The generation of particulates is complex and involves many parameters; this paper discusses the development of an after-treatment system employing platinum group metals that has now successfully controlled particulate emissions during a 50,000 mile durability trial.

The application of electroless plating as a surface coating technique for producing both functional and decorative finishes has increased substantially with the growth in the requirement for printed circuit boards, and with the widespread use of plastics for so many purposes. During the plating process a thin layer of catalyst is applied to the dielectric surface and a layer of metal, generally copper or nickel, is then electroless plated on top. The versatility and cost-effectiveness of tin-palladium catalysts have resulted in their almost universal use.

Interest in rhodium(II) carboxylato complexes, initially stimulated by their unusual structure and oxidation state, has been maintained in recent years by controversy concerning their electronic structure and by their recently discovered anti-tumour activity.

This article completes the review of the relationship between equilibrium pressure and composition, which was started in the first part of the paper, before going on to consider some other aspects of the hydrogen-palladium system.

For thirty years after its recognition as a new element platinum resisted all attempts to melt it, first in the early porcelain furnaces and later by means of enormous burning glasses. Then in April 1782, just two hundred years ago, Antoine Laurent Lavoisier finally succeeded in bringing about its fusion on a small scale by using a blast of oxygen, the gaseous element discovered a few years earlier by Joseph Priestley. Lavoisier repeated his experiment three months later before a most distinguished audience at the Académie Royale des Sciences in Paris.