Abstract: The invention relates to an improved catalyst for the synthesis of dimethyl carbonate by reacting methanol, carbon monoxide and oxygen in the gas phase and to the use thereof. The catalyst consists of a copper-containing zeolite produced by admixing one or more halide-free copper(II) compounds to a zeolite in a liquid medium, drying the zeolite modified by the admixture, and tempering at 400-900° C. under inert conditions, essentially retaining the crystallinity of the zeolite, said admixing being effected by means of a method selected from the group consisting of impregnation of the zeolite, ion exchange, precipitation of copper(II) hydroxide in the presence of the zeolite, and a combination of these methods. The catalyst shows high space-time yields, is constant over the period of operation and has no corrosive action.

Abstract: Skeletal isomerization of n-alkenes into isoalkenes and enrichment of isoalkenes in alkene-containing hydrocarbon mixtures is effected in the presence of an isomerization catalyst containing a microporous silicon-containing alumophosphate.A goal of the method for skeletal isomerization is to provide a running time in one operating period of over 100 hours. This goal is achieved by using, as isomerization catalysts, microporous alumophosphates with a molecular sieve structure whose pore inlet openings have a diameter of 0.4 to 0.6 nm which are mixed with a binder and activated at temperatures of 623 to 873K.