| 摘要 |
<p>In conventional procedures for the preparation of phosphorus-vanadium-oxygen catalysts, with or without promoting elements or carriers, the phosphorus compounds and vanadium compounds are mixed under conditions to form precursors. These precursors are then heated to temperatures up to 600.degree.C. to form phosphorus-vanadium-oxygen catalsyts suitable for the conversion of saturated hydrocarbons, such as butane, to maleic anhydride. According to this invention, a preheat step (60-120.degree.C.) is introduced for a period of time sufficient to form an intermediate prior to the above described heat step, according to which a new phosphorus-vanadium-oxygen composition is formed which is converted to the precursor. Catalysts formed by the process of the present invention, when used for the conversion of saturated hydrocarbons to maleic anhydride, provide higher yields of maleic anhydride.</p> |
