| 摘要 |
1362767 Olefin ammoxidation catalysts KNAPSACK AG 18 May 1972 [5 June 1971 10 Nov 1971] 23349/72 Heading B1E Powdered olefin ammoxidation catalyst comprising iron, bismuth, molybdenum and phosphorus in oxidic form supported on silica is prepared by a process wherein preformed powdered bismuth phosphomolybdate/silica catalyst is (a) homogeneously impregnated with an aqueous solution of an iron salt, preferably iron (III) nitrate, (b) slowly dried at 120-250‹C thereby to decompose the iron salt to iron oxide and (c) heated at 600-700‹C, the volume of impregnating solution used being from 1 to 2.5 times the predetermined pore volume of the bismuth phosphomolybdate/silica catalyst which may be fresh catalyst or used/spent catalyst. Homogeneous impregnation may be ensured by kneading the catalyst with the impregnating solution. Prior to impregnation, the catalyst may be heated at 600-700‹C; prior to drying, the moist impregnated catalyst may be contacted with gaseous ammonia, methylamine, dimethylamine, trimethylamine or ethylamine. Silica may constitute from 30 to 95 weight per cent of the bismuth phosphomolybdate/silica catalyst (which may have a Bi:Mo:P elemental atomic ratio of 1-15:15:0.03-3) and of the resulting iron-containing catalyst (which may have a Fe:Bi:Mo:P elemental atomic ratio of 0.5-15:1-15:15:0.03-3); examples relate to the preparation of catalysts having a Fe:Bi:Mo:P elemental_atomic ratio of x:10:15:1.2 wherein x is 1, 2.5, 5 or 10. Data relating to particle size and surface area are given in the Specification which makes reference to Specifications 867,438, 947,364 and 1,313,191. |
