Dual Active Sites of Embedded Ni and Surface Frustrated Lewis Pairs on CeO 2 (110) for Efficient Photocatalytic CO 2 Methanation

Developing efficient catalysts to drive the Sabatier reaction under mild conditions remains a grand challenge. Here we present an “embedded dual active site” strategy that exploits the strong metal–support interaction (SMSI) on the CeO2(110) surface to stabilize Ni nanoparticles, effectively integrating frustrated Lewis pair (FLP, Ce3+–O2–) sites for photocatalytic CO2 activation with adjacent Ni sites for hydrogenation. Compared to shallow Ni embedding on CeO2(111), Ni nanoparticles are embedded significantly deeper in the CeO2(110) lattice. Concurrently, surface analyses reveal that CeO2(110) more readily generates FLPs (Ce3+ and oxygen vacancy pairs) than CeO2(111). The resultant Ni10/CeO2 photocatalyst delivers a CH4 production rate of 2402.6 μmol·g–1·h–1 under UV–visible light irradiation, far exceeding the performance of control catalysts constructed on CeO2(111). In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and density functional theory (DFT) calculations reveal a synergistic mechanism involving enhanced surface CO2 adsorption (adsorption energy lowered to ∼ −1.2 eV), efficient photocarrier separation, and reduced kinetic barriers for reaction intermediates, greatly promoting CO2 activation, and subsequent hydrogenation.