Comparative Study on the Effect of Cerina and Alumina on the Catalytic Activity of CuO-ZnO Based Catalyst in CO2 Hydrogenation to Methanol

Ternary Cu/ZnO/Al₂O₃ and Cu/ZnO/CeO₂ catalysts were prepared by polyol method and tested for gas-phase low-temperature methanol synthesis from hydrogenation of CO₂. The catalysts were characterized by N₂ physisorption, SEM–EDX, XRD, H₂-TPR and XPS. The activity of the catalysts was evaluated in a fixed-bed micro-reactor at atmospheric pressure and 40 bar at different reaction temperatures, and H₂/CO₂ ratio of 3:1. The results showed that the nature of the promoter influenced the physicochemical properties of the catalysts as well as the catalytic activity and product selectivity. Compared with ternary Cu/ZnO/Al₂O₃ catalyst, Cu/ZnO/CeO₂ catalyst indicated that modifcation of CuO/ZnO catalyst with CeO₂ promoted the CuO dispersion, reduced the CuO crystallite size, decreased the reduction temperature of highly dispersed CuO, decreased the activation energy and improved the catalytic activity of the Cu/ZnO/CeO₂ catalyst.

Graphical Abstract