| abstract |
A process for producing methacrolein by the vapor-phase catalytic oxidation of at least either isobutylene or tert-butyl alcohol with a gas containing molecular oxygen in the presence of an oxidation catalyst composition, characterized in that the catalyst composition is represented by the general formula: Mo12BiaCebKcFedAeBfOg (wherein A represents Co alone or a mixture of Co with Mg in an atomic ratio of 1:0.7 or less; B represents Rb, Cs, or a mixture thereof; and a, b, c, d, e, f and g represent respectively the numbers of atoms of Bi, Ce, K, Fe, A, B and O per twelve atoms of Mo) and that the atomic ratio (a to f) of each element and the content and relative amount of each of Bi, Ce, K and Fe are each in a specified range. This process permits methacrolein to be produced stably in a high yield by using an oxidation catalyst composition that is easy to prepare because of the comparatively simple chemical composition thereof, does not contain toxic elements and other elements unfavorable for the environment, can dispense with the use as the starting material of compounds of W, Sb, Nb and the like having such a low solubility as to make the preparation of a homogeneous catalyst difficult, is excellent in thermal stability and reduction resistance, has a long catalytic life, and is excellent in methacrolein selectivity. |