Catalyst for production of substituted benzaldehyde and method for production of the catalyst

A method for the production of a catalyst to be used in the preparation a substituted benzaldehyde represented by the general formula I:

• ##STR5## wherein R is tert-butyl group, methoxy group, phenoxy group, isopropyl group, or hydroxy group and n is an integer in the range of from 1 to 3, by catalytic vapor-phase oxidation of a substituted toluene represented by the general formula II:
• ##STR6## wherein R and n have the same meanings as defined above, which method comprises mixing a powdered inactive carrier with the starting raw materials for an oxide represented by the general formula III:
• V.sub.a Mo.sub.b X.sub.c Y.sub.d O.sub.e (III)
• wherein V, Mo, and O are respectively vanadium, molybdenum, and oxygen, X is at least one element selected from the group consisting of potassium, rubidium, cesium, and thallium, Y is at least one element selected from the group consisting of niobium, tantalum, phosphorus, antimony, bismuth, tellurium, tin, lead, boron, copper, and silver, and a, b, c, d, and e indicate the atomic ratios of relevant elements such that where a+b=1, then b=0.05 to 0.4, c =0.1 to 1, d=0 to 1, and e=the value determined by the state of oxidation of other elements, molding the resultant mixture, drying the molded particulates and calcining the dried particulates.