Effect of CO/sub 2/ on the conversion of H/sub 2//CO to methanol over copper-chromia catalysts

Addition of levels of CO/sub 2/ as low as 2% to the system was noted to cause a decline of approximately 30% in the rate of formation of Ch/sub 3/OH when Cu-Cr/sub 2/O/sub 3/ was used as the catalyst for the H/sub 2//CO synthesis gas for feed stream. The rate of formation of CH/sub 3/OH remained essentially constant for additions of CO/sub 2/ in amounts from 2-13% suggesting a pseudo-zero order CO/sub 2/ dependence for the reaction. The effects of the addition of CO/sub 2/ on surface Cu/sup +/ concentrations for the catalyst were also studied. It was concluded that the presence of CO/sub 2/ in the syngas inhibited the rate of formation of CH/sub 3/OH by being adsorbed on Cu/sup +/ sites of the catalyst necessary for the adsorption of CO.