Methanol synthesis from CO2/H2 over Pd promoted Cu/ZnO/Al2O3 catalysts

Abstract

The kinetics of methanol synthesis from CO 2 /H 2 over Pd-promoted Cu/ZnO/Al 2 O 3 catalysts have been investigated at finite conversions using an internal recycle reactor and at differential conditions in a microflow reactor. Methanol production at finite conversions was promoted by addition of Pd in physical mixtures or to a greater extent by impregnation. There was no evidence of Pd promotion at strict differential conditions, although the rates of CO 2 hydrogenation to methanol were much greater than methanol production rates at finite conversions. Water addition confirmed that Pd promotion was active only in the presence of the product water from CO 2 hydrogenation.