Hydrogenation of CO2 to CH3OH over Cu/ZnO catalysts with different ZnO morphology

Filament-like ZnO and rod-like ZnO were synthesized by hydrothermal method, and used as a component in CuO/ZnO catalysts. These catalysts were tested in hydrogenation of CO2 to CH3OH and compared with the CuO/ZnO catalyst prepared via conventional coprecipitation process. It was found that the activities of these catalysts depended strongly on the morphology of ZnO. CuO/ZnO catalyst prepared with filament-like ZnO exhibited the best activity, the space time yield of methanol reached 0.55 g-MeOH/(g-cat h) with a 78.2% selectivity of methanol at H2/CO2 = 3, 240 °C, 3.0 MPa and 0.54 mol/(g-cat h). Characterizations found that CuO/ZnO catalyst with filament-like ZnO exhibited stronger interaction between ZnO and Cu, and more oxygen vacancies. The performances of these catalysts for CO2 hydrogenation were compared and discussed with their structure.