Tailoring Ni Clusters in Ordered Macroporous CeO2 for Efficient Photothermal Reverse Water Gas Shift Reaction
Photothermal catalysis offers a sustainable route for CO2 conversion to value-added chemicals, yet precise control of active sites and light-harvesting materials remains challenging. Here, we report the rational integration of three-dimensional ordered macroporous (3DOM) CeO2 with positively charged (Niδ+)n clusters to construct efficient photothermal catalysts for the reverse water gas shift (RWGS) reaction. The 3DOM architecture enhances light absorption, improves access to active sites, and provides a confined environment for reactant enrichment. Engineering (Niδ+)n clusters within 3DOM CeO2 not only affords highly active sites for H2 adsorption and dissociation but also modulates the local structure of CeO2 to promote CO2 adsorption and activation. Furthermore, the (Niδ+)n clusters significantly enhance light-harvesting capability across the UV-vis-NIR spectrum, generating a pronounced photothermal effect that accelerates reaction kinetics. The optimized (Niδ+)n/CeO2 catalyst exhibits outstanding photothermal catalytic performance, achieving a CO production rate of 63.36 mmol g−1 h−1 in a flowing reaction with CO selectivity of 93% under simulated solar irradiation (2.6 W cm−2). Theoretical calculations reveal that the (Niδ+)n/CeO2 catalyst reduces the thermodynamic energy barrier for *COOH formation in CO2 hydrogenation. This study offers valuable insights into the design of photothermal catalysts, highlighting the significant potential of active-site engineering in promoting efficient CO2 conversion for practical solar-to-fuel production.