| abstract |
A silica-supported catalyst used for producing a corresponding unsaturated nitrile by a gas phase catalytic ammoxidation reaction of propane or isobutane, which has the following formula (1) MoV a Nb b X c T d Z e O n ··· (1) (In the formula (1), X represents at least one element selected from Sb and Te, T represents at least one element selected from Ti, W, Mn and Bi; Represents at least one element selected from La, Ce, Yb and Y. a, b, c, d, e and n are 0.05 ≦ a ≦ 0.5 and 0.01, respectively. ≦ b ≦ 0.5, 0.001 ≦ c ≦ 0.5, 0 ≦ d ≦ 1, 0 ≦ e ≦ 1, and n is a value that satisfies the balance of valence.) An average pore diameter of 60 to 120 nm, a total pore volume of 0.15 cm 3 / g or more, a specific surface area of 5 to 25 m 2 / g, and X-ray diffraction A silica-supported catalyst having a crystallite size of 40 to 250 nm determined from the half-value width of the (001) peak by |