PRODUCTION OF VINYLTOLUENE BY THE DEHYDROGENATION OF ETHYLTOLUENE ON OXIDE ZINC-CHROMIUM, ZINC-CHROMIUM-IRON AND VANADIUM-MAGNESIUM CATALYSTS

An investigation has been made of the catalytic properties of oxide zi nc-chromium, zinc-chromium-iron and vanadium-magnesium catalysts in th e dehydrogenation and oxidative dehydrogenation of ethyltoluene of dif ferent isomeric composition. The influence of the reaction conditions on the vinyltoluene yield and the selectivity of conversion of the ini tial methylethylbenzenes into the target product has been examined. Th e high effectiveness of an oxide zinc-chromium-iron catalyst in the sy nthesis of p-vinyltoluene by the dehydrogenation of p-ethyltoluene has been shown (the monomer yield reaches 68% with a selectivity of 90%). It has been established that the oxidative dehydrogenation of ethylto luene on a vanadium-magnesium catalyst with the use of air oxygen as t he hydrogen acceptor does not ensure high vinyltoluene yields. (C) 199 7 Elsevier Science Ltd.