| 摘要 |
PURPOSE: To obtain methacrolein and/or methacrylic acid from isobutane in a high activity with a good selectivity by using a heteropolyacid-based catalyst prepared by using a trivalent vanadium compound as a vanadium raw material. CONSTITUTION: This method for producing methacrolein and/or methacrylic acid comprises a gas phase catalytic oxidation of isobutane with molecular oxygen in the presence of a heteropolyacid-based catalyst of the formula, Pa Mob Vc Xd Ye Zf Og (X is As, B etc.; Y is K, Cs, etc.; Z is Cr, Fe, etc.; (a) to (e) are each an atomic ratio, (a), (c) and (d) are each <=3 not containing 0 when (b)=12, (f) is <=3 not containing 0, and (g) is a value decided by atomic values and atomic ratios of each of the elements) prepared by using a trivalent vanadium compound as a vanadium raw material. Vanadium trioxide is preferable as the trivalent vanadium compound. The aforementioned catalyst is obtained e.g. by heating an aqueous slurry of molybdenum trioxide, phosphoric acid and a trivalent vanadium compound for a long period, adding the X to Z components to the obtained heteropolyacid consisting of P, Mo and V, then evaporating and drying the resultant slurry, and burning. |
