Process for the preparation of a microspheroidal catalyst

Abstract

Process for preparing a catalyst active for the fluid bed acetoxylation of ethylene to produce vinyl acetate. The process comprises the steps of (a) impregnating microspheroidal silica support particles by the incipient wetness technique with an aqueous solution of palladium and gold compounds, whilst agitating the support particles; (b) drying the impregnated support particles produced in step (a) whilst agitating the impregnated support particles; (c) reducing the palladium and gold compounds of the impregnated support particles produced in step (b) to respective metals by adding the dried, impregnated support particles to an aqueous solution of hydrazine, whilst stirring, to form a slurry; (d) filtration of the slurry produced in step (c) to remove the excess reduction solution; (e) washing the filter cake/slurry produced in step (d) with water and removing excess water to form a cake; (f) impregnating the cake produced in step (e) with one or more salts of Group I, Group II, lanthanide and transition metals by blending the cake produced in step (e) with one or more solid salts of Group I, Group II, lanthanide and transition metals; and (g) drying the impregnated cake produced in step (f) whilst agitating the impregnated cake to form free-flowing catalyst particles.