CATALYTIC-OXIDATION OF ISOBUTENE ON A POLYCOMPONENT CATALYST

The catalytic gas-phase oxidation of isobutene has been studied on polycomponent Mo-Co-Ni-Bi-Fe-K oxide catalysts suitable for industrial preparation of propenal from propene. It has been found that within the temperature interval of 290 - 350-degrees-C the main oxidation products are 2-methylpropenal, acetone, 2-methylpropenoic acid, acetic acid and carbon dioxide. A modification of the mentioned catalyst by addition of a further component (W, P, Te, and Zn) showed that zinc increases the conversion of isobutene and at the same time markedly increases its selectivity for 2-methylpropenal, whereas the additions of tungsten and phosphorus decrease the conversion of isobutene with a simultaneous increase of selectivity for CO2. If tert-butyl alcohol is used as the starting material instead of isobutene, then the extent of reaction is slightly decreased with simultaneous increase of selectivity for 2-methylpropenal, whereas the selectivities for the acids remain almost unchanged.