Abstract:
A catalyst for production of unsaturated aldehydes, such as methacrolein, by gas phase catalytic oxidation of olefins, such as isobutylene contains oxides of molybdenum, bismuth, iron, cesium and, optionally, other metals, such as tungsten, cobalt, nickel, antimony, magnesium, zinc and phosphorus. The catalyst has a certain relative amount ratio of cesium to bismuth, a certain relative amount ratio of iron to bismuth and a certain relative amount ratio of bismuth, iron and cesium to molybdenum. For a catalyst of the formula:Mo12BiaWbFecCodNieSbfCsgMghZniPjOxwherein a is 0.1 to 1.5, b is 0 to 4, c is 0.2 to 5.0, d is 0 to 9, e is 0 to 9, f is 0 to 2.0, g is from 0.4 to 1.5, h is 0 to 1.5, i is 0 to 2.0, j is 0 to 0.5 and x is determined by the valences of the other components, c:gnull3.3-5.0, c:anull2.0-6.0 and (3anull3cnull2dnull2enullgnull2hnull2i)/(2x12null2b)null0.90-1.10.