Dual Active Sites of Embedded Ni and Surface Frustrated Lewis Pairs on CeO <sub>2</sub> (110) for Efficient Photocatalytic CO <sub>2</sub> Methanation
Xiaolei Guo, Yuqi Wu, Yuhang Shao, Shengrong Zhou, Hui Song, Yasuo Izumi, Liangwei Deng, Wenguo Wang, Jinlu He, Hongwei Zhang
Abstract
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 CeO 2 (110) surface to stabilize Ni nanoparticles, effectively integrating frustrated Lewis pair (FLP, Ce 3+ –O 2– ) sites for photocatalytic CO 2 activation with adjacent Ni sites for hydrogenation. Compared to shallow Ni embedding on CeO 2 (111), Ni nanoparticles are embedded significantly deeper in the CeO 2 (110) lattice. Concurrently, surface analyses reveal that CeO 2 (110) more readily generates FLPs (Ce 3+ and oxygen vacancy pairs) than CeO 2 (111). The resultant Ni 10 /CeO 2 photocatalyst delivers a CH 4 production rate of 2402.6 μmol·g –1 ·h –1 under UV–visible light irradiation, far exceeding the performance of control catalysts constructed on CeO 2 (111). In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and density functional theory (DFT) calculations reveal a synergistic mechanism involving enhanced surface CO 2 adsorption (adsorption energy lowered to ∼ −1.2 eV), efficient photocarrier separation, and reduced kinetic barriers for reaction intermediates, greatly promoting CO 2 activation, and subsequent hydrogenation.