Methanol synthesis from CO2 hydrogenation over CuO-ZnO-ZrO2-MxOy catalysts (M=Cr, Mo and W)

Abstract

Three CuO-ZnO-ZrO2-MxOy (CZZM, M = Cr, Mo and W) mixed oxides were prepared by a co-precipitation method and tested as catalysts for methanol synthesis from CO2 hydrogenation. The catalysts were characterized by XRD, N2 adsorption/desorption, XPS, reactive N2O adsorption, H2-TPR, and CO2-TPD techniques. The results indicated that the methanol selectivity and yield of the CuO-ZnO-ZrO2 catalyst noticeably increased by the additions of MoO3 and WO3, but slightly decreased by Cr2O3 doping. Combining with the characterization results, the difference in methanol yield over the three catalysts can be attributed to the differences in their BET specific surface areas (SBET) and adsorption capacities for CO2, while the methanol selectivity is closely correlated to the ratio of surface contents of Zn to Cu, as well as the fraction of strong basic sites in the total basic sites of the investigated catalysts.