| 摘要 |
PURPOSE:To obtain a catalyst for producing unsaturated carboxylic acid advantageously by preliminarily applying heat treatment to the mixture of the Ce- component and La-component of a catalyst for producing unsaturated carboxylic acid by the gaseous phase catalytic oxidation of unsaturated aldehyde before introducing the same into the catalyst. CONSTITUTION:When unsaturated carboxylic acid is produced by the gaseous phase catalytic oxidation of unsaturated aldehyde, a catalyst represented by general formula PaMobVcCedLaeXfYgXhOi (wherein X is an element such as Fe, Cu or the like, Y is an element such as As, Sb or the like, Z is an element such as K, Pb or the like and a-i are the atomic ratios of respective elements and, at the time of b=12, a is 0.5-3, c is 0.01-3, d is 0.012, e is 0.01-2, f is 0-3, g is 0-3 and h is 0.01-2) is used. In preparing this catalyst, a mixture of a Ce- component and an La-component is preliminarily subjected to heat treatment at 500-1200 deg.C and introduced into the general formula as composite oxide and/or an oxide mixture. By using this catalyst, unsaturated carboxylic acid is obtained in high yield and at a low temp. |
