Tuning the Electronic Metal–Support Interaction in Cu/ZnAl2O4 Spinel via La Modification for Efficient CO2 Hydrogenation to Methanol

The Cu/ZnAl2O4 spinel holds significant promise for the conversion of CO2 to methanol, which serves as a pivotal link in the carbon cycle network. However, the design of electron-rich supports to further boost the catalytic performance of Cu/ZnAl2O4 catalysts remains challenging. Here, Cu/ZnAl2–xLaxO4 catalysts enriched with electrons at the Zn and Al sites have been ingeniously constructed. The Cu/ZnAl1.8La0.2O4 catalyst exhibits a high CO2 conversion of 16.8% and a methanol selectivity of 86.9% at 240 °C, accompanied by a 39.6% improvement (344.2 gCH3OH·kgcat–1·h–1) in STY of methanol compared to the Cu/ZnAl2O4 catalyst. The CO2 adsorption capacity of the Cu/ZnAl1.8La0.2O4 catalyst with an electron-rich state support has been dramatically increased. And the electron-rich Zn sites promote the hydrogen storage in the spinel, thus facilitating the rapid formation of formate species. Furthermore, the enhanced EMSI effect promotes the formation of smaller Cu species over the Cu/ZnAl1.8La0.2O4 catalyst, which is beneficial for the dissociation and spillover of hydrogen, thus accelerating the conversion of CO2 to methanol via the formate pathway. This work elucidates the utility of developing electron-rich supports for CO2 hydrogenation and offers valuable insights into the rational refinement of high-performance catalysts.