Controlling H2 adsorption of Cu/ZnO/Al2O3/MgO with enhancing the performance of CO2 hydrogenation to methanol at low temperature

Abstract

In the hydrogenation of CO2 to methanol, it was difficult to achieve good methanol yields at low temperature with conventional Cu/ZnO/Al2O3 catalysts. In this study, the Cu/ZnO/Al2O3 catalysts were modified by doping with MgO promoter by co-precipitation and impregnation, respectively. The catalysts (P-CZAM-R) prepared by co-precipitation method doped with MgO promoter can effectively inhibit the growth of Cu particles during the reduction process, resulting in small size and high dispersion of Cu particles in the catalyst. The strong H2 adsorption capacity provided more active H to facilitate the hydrogenation of CO2. Thus, the P-CZAM-R catalyst showed that CO2 conversion was up to 10%, the methanol selectivity reached 80% and displayed high stability for 120 h at 190 °C, 3 MPa and 10000 mL·gcat−1·h−1.