Influence of catalyst surface properties on product selectivity in CO2 hydrogenation over Cu–Ce–Zr oxide solid solutions

The surface properties of catalysts play a crucial role in CO 2 hydrogenation. In this study, Cu-loaded Ce–Zr oxide (CCZ) catalysts with distinct activities were synthesized via four methods. Catalytic testing revealed that the CCZ-HM catalyst exhibited the highest performance, achieving the greatest methanol space–time yield (STY). Structural and surface analyses revealed that low-valence Cu specie, oxygen vacancies, strong metal–support interactions, and balanced acid–base properties contributed to enhanced catalytic performance of the CCZ catalysts. Mechanistic studies indicated that CCZ-CP and CCZ-HM catalysts exhibited higher oxygen vacancy concentrations and enhanced surface acidity-basicity, which promoted CO₂ adsorption and the formation of carbonate species. In a CO 2 + H 2 atmosphere, both catalysts mainly formed bidentate formate species, which served as key intermediates in methanol synthesis. However, the strong adsorption capacity and limited H 2 spillover of the CCZ-CP catalyst hindered further hydrogenation of these intermediates, thereby reducing methanol production. In contrast, the excellent acid–base synergy and efficient H₂ spillover of CCZ-HM promoted the hydrogenation of CO₂-derived intermediates to methanol, resulting in enhanced STY. These findings indicate that the rational control of catalyst surface acidity, oxygen vacancy concentration, and H 2 activation ability is crucial for improving overall catalyst performance.