Chemical comprises the form of nanoparticles, of a noble metal and of an oxide of transition metals and method of obtaining of the compound associated

摘要

The chemical composition comprises a mixture of particles of a noble metal, selected from gold, platinum and palladium, and a Group IVB metal oxide, where the metal is, e.g., zirconium, titanium or hafnium. The particles have granulometry less than 20 nm. The amount of noble metal in the composition is above 20 atomic %. An Independent claim is given for production of the chemical composition according to the invention. The production process includes a principal stage of oxidizing a crystallized composition of formula A1-xBx, where A is the Group IVB metal oxide (sic) and B is the noble metal, at a temperature below 280 deg C, preferably at room temperature in air. The pre-oxidized crystallized composition of formula A1-xBx, where x = 0.3-0.4, is prepared by melting or by powder metallurgy. Powders of A and B having granulometry less than 100 microns are mixed together, and the mixture is compacted to form a pellet, and then heated to at least 900 deg C in an inert or reducing atmosphere. Prior to the principal stage, thermal treatment is carried out in an inert or reducing atmosphere.