| 摘要 |
<p>Mixed oxide active catalysts having the formula: AaMocWdBbOx wherein: A is at least one of the metals cobalt, nickel, manganese and/or lead; B is at least one of the metals iron, bismuth, chromium and/or thallium; a is the sum of the values indicating the amounts present of each of the metals A, and is a number ranging from greater than 0 to about 12; c and d are numbers each equal to or greater than 0 and ranging to 12, with the sum c+d being about 12; b is the sum of the values indicating the amounts present of each of the metals B, and is a number ranging from greater than 0 to about 1.5 [(c+d)-a]; and x is a number satisfying all unbalanced valences, are prepared by, in a first stage, intimately admixing in aqueous phase the salts of all metals to comprise such active catalyst, with the salts of molybdenum and/or tungsten being ammonium salts and at least one salt of at least one of the metals A and B being a nitrate or a chloride whereby ammonia is added to an aqueous solution comprising the ammonium salts of molybdenum and/or tungsten in an amount sufficient to adjust the pH thereof to a value ranging from about 6 to 8 and then adding to the resulting solution simultaneously, a second aqueous solution comprising the A and B metal salts and sufficient ammonia to maintain the pH in the range of from about 6 to 8. The resulting suspension is then filtered with the recovered paste being dried and calcined.</p> |
