Platinum Metals Review - Volume 37, Issue 2, 1993

The introduction of knitted catalyst gauzes into the nitric acid industry has had a major impact on both that industry and on the catalyst production procedures employed by Johnson Matthey. It is now two years since this technological advance was first reported and, because of this time interval, a summary of previous work is included here to serve as a background to this significant technical progress and the commercial acceptance that has taken place over the past few years.

Since the discovery of the first high temperature superconductor, YBaCuO, many attempts have been made to improve its properties by the addition of modifiers; indeed almost all of the elements in the Periodic Table have already been tried in this way. The present survey, covering both our own work and the published literature, examines the effects of adding the platinum group metals to the superconductor, resulting in the formation of several new compounds, many of which are semiconducting and some of which may have potential value in engineering and chemical technology. The complex oxides formed are characterised and data on the superconducting properties of the modified YBaCuO oxide phases are presented.

A critical study is presented here of the contribution made by Joseph Louis Proust, Professor of Chemistry and Metallurgy at the Royal Artillery School in Segovia, to the early investigation of platinum. His researches were carried out in Spain, mainly at the Segovian House of Chemistry during the latter years of the eighteenth century, and at the platinum laboratory in Madrid in the early years of the nineteenth century. These investigations resulted in three papers about the metal; one of them is almost unknown, but it gives a procedure which he had established for the possible purification of platinum. In the other two, Proust incorrectly interpreted the results of his experimental work, but he showed a systematic approach to his scientific investigations and paid great attention to detail, being the only investigator of platinum in Spain at that time to do so.