摘要 |
<p>PURPOSE:To obtain methacrylic acid in high yield, by catalytically oxidizing methacrolein in the vapor phase in the presence of a catalyst containing specific amounts of iron, Sb and another specific element added to a catalyst containing P, Mo, V and copper and having high activity, selectivity and long life. CONSTITUTION:Methacrolein is catalytically oxidized with molecular oxygen in the vapor phase to give methacrylic acid. In the process, a catalyst expressed by formula I (X is at least one selected from K, Rb, Cs and Tl; Y is at least one selected from Te, La, B, Ag, Mg and Ba; a is 0.3-4; c is 0.01-3; d is 0.01-4; e is 0.01-3; f is 0.01-3; g is 0.01-3; h is 0.001-5 when b is 12 and i is the number of oxygen atoms satisfying the valence of each component), e.g. catalyst having the composition of elements other than oxygen is formula II, etc., is used.</p> |