Patent ID: 8642501

Claim:
A vapor-phase catalytic oxidation reaction or a vapor-phase catalytic ammoxidation reaction of propane or isobutane with a composite oxide catalyst, wherein said composite oxide catalyst comprises a catalyst particle of the following formula (1) and a carrier containing silica, Mo 1 V a Nb b Y c X d O n (1) wherein a, b, c, d and n each represent an atomic ratio per Mo atom, in which a is in the range of 0.01≦a≦1; b is in the range of 0.01≦b≦1; c is in the range of 0.01≦c≦1; a/c as a ratio of a to c is in the range of 0<a/c<1; d is in the range of 0.002≦d<0.01; and n is the number determined by an atomic valence of a component metal; X is at least one selected from the group consisting of Sr, Ba, Sc, yttrium, La, Ce, Pr and Yb; and Y is at least one selected from the group consisting of Te and Sb: wherein the composite oxide catalyst is carried by the carrier, wherein the component X is uniformly distributed in the catalyst particle, and wherein a dispersion value D X of a signal intensity ratio as measured by EPMA of the component X to Si, at the time of composition analysis of a cross-section of the catalyst particle, is 0<D X <0.5: wherein said composite oxide catalyst is prepared in a method comprising, mixing a silica and an Nb compound into a mixture containing an Mo compound, a V compound, a Y compound and an X compound to prepare a raw material mixture, spray-drying the raw material mixture to prepare a dry powder, and calcining the dry powder: wherein the vapor-phase catalytic oxidation reaction or the vapor-phase catalytic ammoxidation reaction of propane or isobutane comprises a step of contacting said composite oxide catalyst with propane or isobutane.