| 摘要 |
1347193 Supported catalysts MITSUBISHI CHEMICAL INDUSTRIES Ltd 17 April 1972 [17 April 1971 29 Dec 1971 7 Feb 1972] 17530/72 Heading B1E [Also in Division C2] Solid catalysts comprising Pd and, in addition, one or more of Sb, Bi, Te and Se are prepared by supporting a palladium compound and at least one antimony, bismuth, tellurium or selenium compound on a carrier (e.g. active carbon optionally treated with an oxidising agent) and then reducing the supported compounds to the elements. Other suitable carriers are silica gel, silica-alumina, alumina, clay, bauxite, magnesia, diatomaceous earth and pumice. The amounts, based on the total weight of catalyst plus carrier, of Pd, Sb and/or Bi, and Te and/or Se supported on the carrier are preferably within the respective ranges: 0.1 to 20% by weight; 0.03 to 30% by weight; and 0.01 to 30% by weight. The catalyst preferably contains a total of 0.01 to 10 gram atoms of Sb and Bi, and a total of 0.01 to 10 gram atoms of Te and Se, per gram atom of Pd. The Examples describe the preparation of binary and ternary catalysts by reduction of the corresponding salts (nitrates and chlorides) or ammine complexes. The catalysts are used in the preparation of unsaturated diesters by reaction of a conjugated diene with a carboxylic acid and oxygen. |
