| 摘要 |
<p>The invention provides a catalyst comprising a porous support on the porous surfaces of which is deposited catalytically effective amounts of metallic palladium and gold, and a third metal selected from the group consisting of magnesium, calcium, barium, and cerium, as its oxide or mixture of oxide and metal, said catalyst having been prepared by a method comprising the steps: of impregnating the support with a solution of water-soluble salts of palladium, gold and said third metal; fixing the palladium, gold, and third metal in the latter solution as a water-insoluble compounds by means including the step of rotating and/or tumbling the impregnated support while it is immersed in a solution of an appropriate alkaline compound; and reducing the fixed palladium and gold to their metallic state, and the third metal to its oxide or mixture of oxide and its metal. The invention also provides processes for the production of vinyl acetate by reaction of ethylene, oxygen and acetic acid in the presence of a catalyst according to the invention.</p> |
