Facet Engineering-Tailored Directional Electron Transfer from TiO2 to Cu Nanoparticles Enhances CO2 Hydrogenation to Methanol

TiO₂ as a reducible metal oxide has been extensively employed as a support for noble and transition metals. Numerous studies have demonstrated that optimizing metal–TiO₂ interactions can significantly enhance the catalytic performance. Meanwhile, the weak metal–support interaction between Cu and TiO₂ generally results in unsatisfactory catalytic performance for the hydrogenation of CO₂ to methanol. Herein, through support facet and defect engineering, the electron transfer from TiO₂ to Cu nanoparticles (NPs) is successfully constructed over Cu/TiO₂ (001) catalysts, enabling a sharply enhanced methanol yield of about 7.2% at 5 MPa and 280 °C. Detailed characterizations reveal that the regulation of support defects and the catalyst preparation process boost the defect density over TiO₂ and then facilitate the electron transfer from TiO₂ to Cu NPs and the highly dispersed electron-rich Cu NPs. This, in turn, promotes the dissociation and spillover of H₂, further producing support defects and achieving dynamic regulation. Ultimately, these synergistic interactions drive the hydrogenation of CO₂ to methanol. These findings not only demonstrate the Cu/TiO₂-based catalyst as one of the most promising catalysts for CO₂ hydrogenation to methanol but also establish a generalizable strategy for enhancing catalytic performance through support facet and defect-engineered electron transfer modulation.