| 摘要 |
<p>Acrylonitrile is prepared by reacting propylene, ammonia and a molecular oxygen-containing gas at an elevated temperature in the vapour phase and in the presence, as the catalyst, of an oxide composition containing antimony, chromium and vanadium which is heated to 750-950 DEG C. in a molecular oxygen-containing gas prior to use as the catalyst. The catalyst may be regarded as a mixture of Sb, Cr and V oxides. It is preferred to use a catalyst which contains an excess of Sb over the other single components The catalyst may be supported on a carrier, e.g. alumina, silica or titania. The reaction may be effected in the presence of a diluent, preferably steam and/or nitrogen, using a variety of reactant proportions.ALSO:A catalyst for the ammoxidation of propylene comprises an oxide composition containing Sb, Cr and V which is pre-treated by heating to 750-950 DEG C. The catalyst may be a mixture of oxides or may contain an oxygenated compound of Sb, Cr and V. The composition can be made by a variety of methods, e.g. (1) by mixing the oxides, or compounds yielding the oxides on heating, of Sb and Cr with an oxide or compound of V, (2) by cohydrolysis of the chlorides in aqueous solution with ammonia or (3) oxidation of the metals. The preferred composition contains a molar excess of antimony, e.g., an atomic ratio Sb:V in the range 6 to 1 and an atomic ratio Sb:Cr in the range 6 to 1. The catalysts may be supported on a carrier, e.g. alumina, silica or titania.</p> |
