Process for the preparation of composite materials which contain small

Abstract

Composite materials which contain small particles of metal or metal oxide an oxide matrix are prepared by a process which comprises a) subjecting (1) one or more metal compounds and (2) one or more bifunctional compounds which contain at least one group capable of complexing the metal and at least one group which forms an inorganic network during the polycondensation, and if appropriate (3) one or more network-forming agents which are capable of polycondensation to the conditions of a complexing reaction and hydrolytic polycondensation by the sol-gel process in a liquid reaction medium, compounds (1), (2) and (3) being soluble in the reaction medium, and b) oxidizing the resulting polycondensate to form a composite material which contains small metal oxide particles with the very narrow particle size distribution in an oxide matrix, and if appropriate c) reducing the metal oxide particles of the resulting composite material to the metal. These composite materials are used as catalysts and in electrical or electronic components.