Process for preparing vinyl acetate using a supported palladium and gold catalyst

摘要

A process for the production of a catalyst for preparing vinyl acetate in the gas phase from ethylene, acetic acid and oxygen or oxygen- containing gases which catalyst comprises palladium and/or its compounds, gold and/or its compounds and also alkali metal compounds on a particulate, porous support obtained byPPa) impregnating the support with soluble palladium and gold compounds,PPb) converting the soluble palladium and gold compounds into insoluble palladium and gold compounds by addition of an alkaline solution to the support.PPc) reducing the insoluble palladium and gold compounds on the support with a reducing agent in the liquid or gaseous phase,PPd) impregnating the support with at least one soluble alkali metal compound andPPe) finally drying the support at a maximum of 150 C.,PPwherein the catalyst is brought into contact with at least one peroxidic compound in step b).