Effect of Zr and pH in the preparation of Cu/ZnO catalysts for the methanol synthesis by CO2 hydrogenation

Abstract

Methanol synthesis by carbon dioxide hydrogenation was investigated over a series of Cu/ZnO catalysts prepared by various pH conditions. These catalysts were confirmed by XRD, BET, N2O chemisorption and TPR measurements before and after the reaction. It was revealed that pH conditions on catalyst preparation played an important role in active metal formation on the catalysts surface and catalytic performance in the hydrogenation of carbon dioxide. Zr added to Cu/ZnO catalysts favorably served in enhancing copper dispersion on the catalyst surface and improving carbon dioxide conversion. Among the catalysts tested, Cu/ZnO/ZrO2/Al2O3 catalyst exhibited the highest carbon dioxide conversion, methanol yield and CO concentration in the outlet gas.