BASIC METAL-OXIDES AS COCATALYSTS FOR CU SIO2 CATALYSTS IN THE CONVERSION OF SYNTHESIS GAS TO METHANOL/

The catalytic behavior of Cu catalysts supported on ultrapure silica a nd promoted with Ca, Zn, and La oxides was investigated in the hydroge nation of CO and CO2 to methanol at high pressure. Cu on very pure sil ica produces hardly any methanol, while the addition of basic oxides a nd the use of gamma-alumina as support improve the catalyst performanc e. The strong promoting effect of Ca and La oxide on the silica-suppor ted Cu and the weak promoting effect for alumina-supported Cu suggest that the basic oxide additives must be close to or in contact with the Cu particles to be effective in methanol synthesis. The methanol acti vity of Zn/Cu/SiO2 increased with increasing CO2 content in a CO-CO2-H -2 mixture, suggesting that CO2 is the main carbon source for methanol . (C) 1998 Academic Press.