Structure–Performance Correlations over Cu/ZnO Interface for Low-Temperature Methanol Synthesis from Syngas Containing CO₂

Cu/ZnO catalysts with varied Cu/(Cu + Zn) molar ratios were prepared by a facile solid-state method. The Cu/(Cu + Zn) molar ratio displayed a significant effect on the oxygen vacancy formation of the calcined catalysts, thereby influencing the CuO–ZnO interaction and the reducibility of CuO. The Cu/(Cu + Zn) molar ratio also exhibited a significant effect on Cu0 surface area, oxygen vacancy, the ratio of ZnO(002) plane to ZnO(100) plane, as well as the basicity and acidity of the reduced catalysts, thereby affecting the catalytic performance for low-temperature methanol synthesis from syngas containing CO2. The correlations of methanol space time yield (STY) versus the physicochemical characteristics of Cu/ZnO catalysts were studied. The catalyst with equal amounts of Cu and Zn displayed the best catalytic activity owing to higher Cu0 surface area, more oxygen vacancy and ZnO(002) plane, as well as more moderately basic sites.