Method for preparing methacrolein

Abstract

A method for preparing methacrolein by oxidizing isobutylene or tertiary butanol with molecular oxygen, characterized by contacting a gaseous mixture of isobutylene or tertiary butanol, air or oxygen and optionally steam and an inert gas with a catalyst having the general combination: Mo.sub.12 Fe.sub.a Ni.sub.b Te.sub.c Tl.sub.d Pb.sub.f X.sub.g O.sub.h wherein a, b, c, d, f and g represent the numbers of atoms of the respective elements per 12 molybdenum atoms; X is at least one element selected from the group consisting of Cu, Nd and Sm; a is a value of 0.2-6; b is a value of 0.2-6; a+b is a value of 1-10; c is a value of 0.1-4; d is a value of 0.1-3; f is a value of 0.1-5; g is a value of 0.1-5; and h is the number of oxygen atoms for satisfying the valencies of the existing elements. The use of this catalyst enables the selectivity for methacrolein to be improved to 90-94% and the yield based on the starting material to be increased to 89-91%. In addition, the activity of said catalyst is stably maintained for a long period of time.

Dependencies are inferred from the claim text.