Process for making highly active and selective catalysts for the production of unsaturated nitriles
AssigneeSaudi Basic Industries Corporation
InventorsMazhar Abdulwahed, Khalid El-Yahyaoui
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Abstract
An improved catalyst for the production of unsaturated nitrites from their corresponding olefins, the catalyst having the atomic ratios described by the empirical formula BiaMobVcSbdNbeAfBgOx and methods of making and using the same.
Claims40
A method for preparing a catalyst for olefin ammoxidation, comprising bismuth, molybdenum, vanadium, antimony, and niobium, comprising the steps of:
- (a) preparing a vanadium antimonate phase by heating a slurry of vanadium oxide and antimony oxide thereby forming a vanadium-antimony paste and subsequently drying the paste and calcining it to form said vanadium antimonate phase;
- (b) preparing a niobium-molybdenum solution by mixing niobium oxide hydrate and molybdenum oxide hydrate in water;
- (c) preparing bismuth, niobium, and molybdenum mixed oxide hydrates by adding bismuth to the niobium-molybdenum solution of step (b);
- (d) combining said vanadium antimonate phase, said bismuth, niobium and molybdenum mixed oxide hydrates and a support thereby forming a catalyst precursor mixture, wherein said mixed oxide hydrates are not subjected to heat treatment prior to forming said catalyst precursor mixture;
- (e) stirring the catalyst precursor mixture for a period of time sufficient to form a catalyst precursor paste;
- and
- (f) drying said catalyst precursor paste to form a dried catalyst precursor material and calcining said dried catalyst precursor material to form said catalyst.
A method for preparing a catalyst for olefin ammoxidation, said catalyst containing bismuth, molybdenum, vanadium, antimony, and niobium, comprising the steps of:
- (a) preparing a niobium-molybdenum solution at a pH of 3.5 to 10;
- (b) adding bismuth to said niobium-molybdenum solution and precipitating bismuth, niobium, and molybdenum mixed oxide hydrates at room temperature and without heat post-treatment of said mixed oxide hydrates;
- (c) combining a vanadium antimonate phase and said mixed oxide hydrates of bismuth, niobium, and molybdenum with pre-acidified silica colloidal thereby forming a catalyst precursor mixture;
- (d) stirring the catalyst precursor mixture for a period of time sufficient to form a paste;
- and
- (e) drying said paste to form a dried material and calcining said dried material to form said catalyst.
A method for preparing a catalyst for olefin ammoxidation, said catalyst containing bismuth, molybdenum, vanadium, antimony, and niobium, comprising the steps of:
- (a) preparing a vanadium antimonate phase;
- (b) preparing a niobium-molybdenum solution at a pH of 3.5 to 5;
- (c) adding bismuth to said niobium-molybdenum solution and precipitating bismuth, niobium, and molybdenum mixed oxide hydrates without heat post-treatment of said mixed oxide hydrates;
- (d) combining said vanadium antimonate phase and said mixed oxide hydrates of bismuth, niobium, and molybdenum with pre-acidified silica colloidal thereby forming a catalyst precursor mixture;
- (e) stirring the catalyst precursor mixture for a period of time sufficient to form a paste;
- and
- (f) drying said paste to form a dried material and calcining said dried material to form said catalyst.
Dependencies are inferred from the claim text.