Abstract: The invention relates to Pd/K/Au, Pd/K/Ba or Pd/K/Cd supported catalysts built up in the form of an outer layer, the production thereof and the use thereof for preparing vinylacetate from ethylene, acetic acid and oxygen in the gas phase. The specified catalysts are produced by impregnating the support particles with a solution of salts of the corresponding elements and then drying them, with the dynamic viscosity of the solution being at least 0.003 Pa.s and the solution volume in impregnation being more than 80% of the pore volume of the support particles and the duration of the impregnation and also the time until commencement of the drying being selected so as to be sufficiently short for, after completion of the drying, the specified metal salts to be present in an outer layer of from 5% to 80% of the pore volume of the support particles.

Abstract: The invention relates to Pd/K/Au, Pd/K/Ba or Pd/K/Cd supported catalysts built up in the form of an outer layer, the production thereof and also the use thereof for preparing vinyl acetate from ethylene, acetic acid and oxygen in the gas phase. The catalysts specified are produced by impregnating the support particles, while mixing intimately, with a solution of salts of the corresponding elements and then drying the support particles immediately, with the dynamic viscosity of the solution being at least 0.003 Pa.s and the solution volume in impregnation being from 5 to 80% of the pore volume of the support particles.

Abstract: The invention relates to Pd/K/Au, Pd/K/Ba, or Pd/K/Cd supported catalysts having an impregnated layer structure, the production thereof and also the use thereof for preparing vinyl acetate from ethylene, acetic acid and oxygen in the gas phase. The catalysts specified are produced by spraying the support particles, while mixing intimately with a solution of salt of the corresponding elements in the form of drops having an average diameter of at least 0.3 mm or in the form of liquid jets and then drying the support particles immediately, with the dynamic viscosity of the solution being at least 0.003 Pa.cndot.s and the solution volume in spraying being from 5 to 80% of the pore volume of the support particles.

Abstract: The invention relates to Pd/K/Au, Pd/K/Ba, or Pd/K/Cd supported catalysts having an impregnated layer structure, the production thereof and also the use thereof for preparing vinyl acetate from ethylene, acetic acid and oxygen in the gas phase. The catalysts specified are produced by spraying the support particles, while mixing intimately with a solution of salt of the corresponding elements in the form of drops having an average diameter of at least 0.3 mm or in the form of liquid jets and then drying the support particles immediately, with the dynamic viscosity of the solution being at least 0.003 Pa.multidot.s and the solution volume in spraying being from 5 to 80% of the pore volume of the support particles.

Abstract: The invention relates to Pd/K/Au, Pd/K/Ba or Pd/K/Cd supported catalysts built up in the form of an outer layer, the production thereof and the use thereof for preparing vinylacetate from ethylene, acetic acid and oxygen in the gas phase. The specified catalysts are produced by impregnating the support particles with a solution of salts of the corresponding elements and then drying them, with the dynamic viscosity of the solution being at least 0.003 Pa.s and the solution volume in impregnation being more than 80% of the pore volume of the support particles and the duration of the impregnation and also the time until commencement of the drying being selected so as to be sufficiently short for, after completion of the drying, the specified metal salts to be present in an outer layer of from 5% to 80% of the pore volume of the support particles.

Abstract: Surface impregnated catalyst, process for the production thereof, and use thereof for the preparation of vinyl acetate. The invention relates to Pd/K/Au, Pd/K/Ba or Pd/K/Cd supported catalysts built up in the form of an outer layer, the production thereof and also the use thereof for preparing vinyl acetate from ethylene, acetic acid and oxygen in the gas phase. The catalysts specified are produced by impregnating the support particles, while mixing intimately, with a solution of salts of the corresponding elements and then drying the support particles immediately, with the dynamic viscosity of the solution being at least 0.003 Pa.multidot.s and the solution volume in impregnation being from 5 to 80% of the pore volume of the support particles.

Abstract: Supported catalyst, process for its preparation and its use for the preparation of vinyl acetateThe invention relates to improved Pd/K/Au, Pd/K/Ba and Pd/K/Cd supported catalysts, their preparation and their use for the preparation of vinyl acetate from ethylene, acetic acid and oxygen in the gas phase. The stated catalysts are prepared by atomizing a solution of corresponding metal salts by means of ultrasonics and then applying them in such limited amounts and within such a limited time to the carrier particles, and beginning to dry them, so that the catalytically active metal salts cannot penetrate into the carrier particles as far as the core but only into a larger or smaller outer part.

Abstract: The invention relates to improved Pd/K/Au, Pd/K/Ba and Pd/K/Cd supported catalysts, their preparation and their use for the preparation of vinyl acetate from ethylene, acetic acid and oxygen in the gas phase. The stated catalysts are prepared by atomizing a solution of corresponding metal salts by means of ultrasonics and then applying them in such limited amounts and within such a limited time to the carrier particles, and beginning to dry them, so that the catalytically active metal salts cannot penetrate into the carrier particles as far as the core but only into a larger or smaller outer part.

Abstract: The invention relates to a process for the preparation of a catalyst which contains palladium and/or compounds thereof and alkali metal compounds, and additionally cadmium compounds and/or gold and/or compounds thereof, on support particles which have been pressed from SiO.sub.2 or an iO.sub.2 -Al.sub.2 O.sub.3 mixture with the aid of a binder which comprisesa) washing the roasted support particles with an acid which does not react with SiO.sub.2 or SiO.sub.2 -Al.sub.2 O.sub.3 mixtures, until no further cations of the binder employed during pressing of the support particles are released from the support particles;b) then impregnating the support particles with palladium, and gold or cadmium;c) then bringing the impregnated support particles into contact with a solution of a base at least until the thickness of the nobel metal shell generated in this way on the support particles no longer changes substantially; andd) then impregnating the support particles with an alkali metal compound.

Abstract: The invention relates to a process for the preparation of a catalyst which contains palladium and/or compounds thereof and alkali metal compounds, and additionally cadmium compounds and/or gold and/or compounds thereof, on support particles which have been pressed from SiO.sub.2 or an iO.sub.2 -Al.sub.2 O.sub.3 mixture with the aid of a binder which comprisesa) washing the roasted support particles with an acid which does not react with SiO.sub.2 or SiO.sub.2 -Al.sub.2 O.sub.3 mixtures, until no further cations of the binder employed during pressing of the support particles are released from the support particles;b) then impregnating the support particles with palladium, and gold or cadmium;c) then bringing the impregnated support particles into contact with a solution of a base at least until the thickness of the nobel metal shell generated in this way on the support particles no longer changes substantially; andd) then impregnating the support particles with an alkali metal compound.