Patent ID: 7576232

Claim:
A process for the conversion of a hydrocarbon selected from the group consisting of propylene, isobutylene, propane, isobutane or mixtures thereof, to acrylonitrile, methacrylonitrile, or mixtures thereof, the process comprising contacting in a reactor and reacting in the vapor phase at an elevated temperature and pressure said hydrocarbon with a molecular oxygen-containing gas and ammonia, in the presence of a molybdenum-based ammoxidation catalyst and a catalyst modifier, wherein said molybdenum-based ammoxidation catalyst comprises an oxide represented by the following formula: A a B b C c D d Bi e Mo f O x where A is one or more of Li, Na, K, Cs, Rb, Sm, In, Ca, Sr, Ba and Tl, B is one or more of Fe, Co, Mg, Mn, Ni, V and Zn, C is one or more of Cr, Ce, Eu, P, Sb, Ge, Te and W, D is one or more of Sn, B, As, Pt, Pd, Ga, Nd, Nb, Pr and Pb, and a is 0.05 to 3.0, b is 0.1 to 14.0, c is 0.0 to 5.0, d is 0.0 to 2.0, e is 0.2 to 6.0, f is 8.0 to 18.0, and x is a number determined by the oxidation states and amounts of the other elements present in the catalyst (i.e. x a number determined by the valence requirements of the other elements present); and wherein said catalyst modifier comprises a molybdate or a polymolybdate of at least one element M selected from the group consisting of cesium, rubidium, potassium, sodium, thallium, lithium, nickel, cobalt, iron, chromium, copper, magnesium, manganese, cerium and phosphorus.