Method for the preparation of (meth)acrylonitriles

A method for the preparation of (meth)acrylonitrile by an ammoxidation process in which at least one saturated hydrocarbon selected from the group consisting of propane and isobutane is catalytically oxidized with a mixed gas containing molecular oxygen and ammonia in the presence of a catalyst, wherein the catalyst comprises a complex oxide expressed by the general formula (I)

• Cr.sub..alpha. Sb.sub..beta. W.sub..gamma. O.sub.x (I)
• wherein
• .alpha., .beta. and .gamma. denote the number of atoms of Cr, Sb and W, respectively, and when .alpha. is 1, .beta. is 0.5-5 and .gamma. is 0.2-2, and x is a value determined by the valances of the existing elements,
• and said catalyst contains, concurrently with the constituent elements of the complex oxide as expressed by the general formula (I),
• (i) at least one element selected from the group consisting of Nb, Mo, Mn, Fe, Co and Ni, in such an amount that the atomic ratio of the selected element or elements to Cr is 0 or exceeds 0 but is not more than 0.1, or
• (ii) at least one element selected from the group consisting of V, Nb, Mo, Mn, Fe, Co and Ni, in such an amount that the atomic ratio of the selected element or elements to Cr is 0 or exceeds 0 but is not more than 0.1 and the atomic ratio of the selected element or elements to Sb is 0 or exceeds 0 but is not more than 0.04.