High temperature behaviour of platinum group metals in oxidizing atmospheres

Abstract

The high temperature behaviour of the platinum group metals in oxidizing atmospheres is characterized by the formation of volatile oxides in addition to the evaporation of pure metal. The pressure- and temperature-dependent oxide evaporation can considerably increase the metal losses when compared with high vacuum or inert atmosphere conditions. Solid or liquid oxides are not formed on the surface because of their high dissociation pressure. In this paper the high temperature oxidation behaviour of the six platinum group metals (ruthenium, rhodium, palladium, osmium, iridium and platinum) is reviewed and the dependence on temperature, pressure and experimental conditions as well as the oxidation mechanism are discussed.