Abstract: A shell impregnated catalyst of Pd—Au produced on a silica support by impregnating the support with aqueous solutions of palladium and gold salts or acids and thereafter precipitating water insoluble compounds of Pd and Au on the support with alkali metal silicate or hydroxide fixing agents, then drying the support which has precipitated compounds of Pd and Au on its surface and reducing the surface precipitated compounds of Pd and Au until substantially all of the Pd and Au contents are reduced to a free metal state, after which the catalyst precursor is impregnated with potassium acetate and then dried. Improvements in the catalyst are realized by certain factors in process and composition.

Abstract: A shell impregnated catalyst of Pd—Au produced on a silica support by impregnating the support with aqueous solutions of palladium and gold salts or acids and thereafter precipitating water insoluble compounds of Pd and Au on the support with alkali metal silicate or hydroxide fixing agents, then drying the support which has precipitated compounds of Pd and Au on its surface and reducing the surface precipitated compounds of Pd and Au until substantially all of the Pd and Au contents are reduced to a free metal state, after which the catalyst precursor is impregnated with potassium acetate and then dried. Improvements in the catalyst are realized by certain factors in process and composition.