CO 2 hydrogenation to methanol over Cu/Zn/Al/Zr catalysts prepared by liquid reduction

Cu/Zn/Al/Zr catalysts containing Cu in three valence states (Cu2+, Cu+ and Cu0) were prepared using a liquid reduction method and subsequently calcined at different temperatures. The effects of the calcination temperature on the catalyst structure, interactions among components, reducibility and dispersion of Cu species, surface properties and exposed Cu surface area were systematically investigated. These materials were also applied to the synthesis of methanol via the hydrogenation of CO2. The results show that a large exposed Cu surface area promotes catalytic CO2 conversion and that there is a close correlation between the Cu+/Cu0 ratio and the selectivity for methanol. A calcination temperature of 573 K was found to produce a Cu/Zn/Al/Zr catalyst exhibiting the maximum activity during the synthesis of methanol.