Highly dispersed platinum on silica pellets was prepared by sol-gel processing. A solution of a platinum compound, a silane of the type (RO)₃Si(CH₂)_nA (A=coordinating organic group) and Si(OR)₄ as the network former was reacted with water and then sprayed on silica pellets. The organic groups were then removed by oxidation and/or pyrolysis. Elemental Pt was formed at temperatures above 500°C. Lower temperatures require subsequent reduction by hydrogen. The average Pt particle size was determined by XRD and the percentage of accessible Pt atoms by CO titration. Both strongly depend on the chemical composition of both the platinum precursor and the organo(alkoxy)silane. Particularly small particles were obtained if removal of the organic groups was carried out by a combination of pyrolysis and oxidation or by treatment with an oxygen plasma, instead of removing the organic groups by air oxidation at high temperatures.