| 摘要 |
1,177,515. Oxidation catalysts. BP CHEMICALS (U.K.) Ltd. 22 April, 1968 [31 May, 1967], No. 25059/67. Heading B1E. [Also in Division C2] A catalyst comprising a platinum group metal i.e. platinum, palladium, rhodium, ruthenium, osmium or iridium, or metal compound together with gold or a compound of gold on a support comprising tin oxide may be prepared by simultaneous or sequential impregnation of the tin oxide support with an aqueous solution of a salt or salts of the respective metal or metals followed by drying. The deposited salt or salts may be reduced to the elemental metal or metals by a reducing agent such as hydrogen or alkaline hydrazine. The support may be tin oxide alone or comprise additional material such as silica which may be admixed with the tin oxide by forming an aqueous slurry of tin oxide, admixing with an aqueous solution of a suitable silicate e.g. an alkali metal silicate, followed by precipitation of silica by the addition of acid to the mixture and recovery of the admixed solids by filtration. Examples describe the preparation of catalysts containing 1.6% Pd, 0.46% Au, 1.42% Na and 0.2% C1; and 1.1% Pd, 0.36% Au, 2.0% Na and 0.17% Cl all percentages being by weight. The catalysts may be used in the preparation of vinyl acetate from ethylene, oxygen and acetic acid (see Division C2). |
