Hydrogenolysis of methyl formate by H2/CO mixtures with CuO/ZnO/Al2O3 based methanol synthesis catalysts

Tenary copper-based catalysts of type CuO/ZnO/Al2O3, CuO/ZnO/Cr2O3, and CuO/ZnO/La2O3 have been advantageously used in the hydrogenolysis of methyl and ethyl formate to methanol. The catalysts are active under mild conditions (150-185 degrees C; 5-10 MPa) both in gas-solid and in gas-liquid-solid phases with high selectivities to methanol (80-90%). The decarbonylation of the formic ester is the only side reaction, but the catalysts, different from other copper-based systems, do not suffer from the presence of CO in the reaction gases. Accordingly the hydrogenolysis may be carried out with a hydrogen feed containing CO without any poisoning of the catalyst or decrease of the selectivity to methanol. A preliminary screening of different copper catalysts points out that the insensitivity to CO might be related to the presence of basic sites on the catalysts.