| 摘要 |
a -b -unsaturated aliphatic nitriles are prepared by reacting an olefine with air and/or oxygen and ammonia at elevated temperature in the presence of a catalyst which contains at least one oxide of chromium, manganese, iron, cobalt and nickel and optionally at least one oxide of bismuth, vanadium and phosphorus. The molar proportions of oxides are such that for each atom of the metal other than bismuth there are 0-10.5 atoms of bismuth, 0-3.5 atoms of phosphorus and 1-26 atoms of oxide oxygen. The catalyst is supported, on a carrier, e.g. silicon dioxide, silicon carbide, aluminium oxide, pumice or mixtures thereof and is prepared by calcining the mixture of silica and metal salts, and activating by calcination. Propylene and isobutylene may be treated to form acrylonitrile and methacrylonitrile respectively.ALSO:Catalysts for the preparation of a ,b -unsaturated aliphatic nitriles by reacting an olefine with air and/or oxygen with ammonia, contain at least one oxide of chromium, manganese, iron, cobalt and nickel, and optionally at least one oxide of bismuth, vanadium and phosphorus. The molar proportions are such that for each atom of the metals, other than bismuth, there are 0-10,5 atoms of bismuth, 0-3,5 atoms of phosphorus and 1-26 atoms of oxide oxygen. A carrier such as silicon dioxide, silicon carbide, aluminium oxide, pumice or mixtures thereof may be used and the catalysts may be as a solid, fluidized or flowing bed. In the preparation of the catalysts the carrier is added to an aqueous solution of the salts, e.g. nitrates or ammonium salts, and it desired phosphoric acid, the mixture evaporated to dryness and calcined at 300-1100 DEG C. and activated by heating in an air-ammonia mixture containing 10-20% by volume of ammonia at the calcination temperature. Examples describe the preparation of catalysts containing bismuth oxide, iron oxide and phosphorus pentoxide; iron oxide and phosphorus pentoxide; bismuth oxide and nickel oxide and phosphorus pentoxide; iron oxide, bismuth oxide, vanadium oxide and phosphorus pentoxide; and iron oxide and bismuth oxide, and the preparation of acrylonitrile from propylene. |
