Highly selective hydrogenation of CO2 to methanol over CuO–ZnO–ZrO2 catalysts prepared by a surfactant-assisted co-precipitation method

Abstract

A series of CuO–ZnO–ZrO2 catalysts are synthesized by a surfactant-assisted co-precipitation method and tested for the synthesis of methanol from CO2 hydrogenation. The effects of calcination temperature on the physicochemical properties of as-prepared catalysts are investigated extensively by TG-DSC, N2 adsorption/desorption, XRD, N2O chemisorption, SEM/TEM, EDX, XPS, TPR, H2-TPD and CO2-TPD techniques. The results show that the size of copper particles increases with the increase in calcination temperature, leading to the decrease in turnover frequency (TOF) for methanol formation. Moreover, compared with the counterparts prepared by the conventional co-precipitation method, the CuO–ZnO–ZrO2 catalysts prepared by this novel method show significantly high methanol selectivity. The superior property of the prepared CuO–ZnO–ZrO2 catalyst can be attributed to the formation of more amounts of Cu–ZnOx and/or Cu–ZrOx species resulted from the homogeneous element distribution, intimate interface contact of Cu species with ZnO and/or ZrO2, and to porous structure with larger pore size.