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.