| 摘要 |
PURPOSE:To provide a high-performance catalyst improved in activity, etc., for use in maleic anhydride production, containing the title oxide having specific principal X ray diffraction peaks with the intensity ratio of specific two of said peaks falling within a specified range. CONSTITUTION:A V-P crystalline oxide (hereafter referred to as calcined form oxide) with the intensity ratio of the peak 1 (corresponding to 2theta=23.0 deg.) to the peak 2 (corresponding to 2theta=28.4 deg.) among the principal X ray diffraction peaks given in the table being greater than 1.25 or less than 0.8 is prepared. This oxide is heat treated at >=40 deg.C in an aqueous solvent medium to produce a calcined form oxide with the ratio of the peak 1 to the peak 2 falling between 0.8 and 1.25. The resultant calcined form oxide or a catalyst containing this oxide is excellent in activity and selectivity, and can be used, as an active component of a catalyst or a catalyst itself, for the production of maleic anhydride by gaseous phase oxidation of a >=4C hydrocarbon. |
