Periodic Frustrated Lewis Pairs on Bimetallic Oxide Semiconductors for CO<sub>2</sub> Adsorption and Photocatalytic Conversion
Linqun Yu, Qiushi Wang, Chunqiang Zhuang, Jindou Huang, Yongan Zhu, Xuedong Jing, Yuhang Guo, Yexiang Tong, Zhenyi Zhang
Abstract
Lewis acids (LAs) or Lewis bases (LBs) have been recognized as crucial catalytically active sites for enhancing the adsorption and conversion of inert CO 2 . However, engineering of periodic frustrated Lewis pairs (PFLPs) on the surfaces of semiconductor photocatalysts presents significant challenges, and the synergistic mechanism of PFLPs in CO 2 photoreduction remains unclear. In this study, we propose a strategy that utilizes periodic oxygen vacancies to engineer dual-metallic PFLPs on bimetallic oxide semiconductor surfaces. We employ SrNb 2 O 6– x as a model photocatalyst to elucidate the synergistic effect of PFLPs on CO 2 photoreduction. Within each FLP unit, the LA (Sr 2+ ) captures an O atom from CO 2 while the LB (Nb 4+ ) engages in an interaction with the C atom and concurrently facilitates transfer of photoinduced electrons from SrNb 2 O 6– x to adsorbed CO 2 . Thus, SrNb 2 O 6– x with the PFLPs-enriched surface exhibits ultrahigh CO 2 adsorption and a low energy barrier for CO desorption. Under focused sunlight irradiation, SrNb 2 O 6– x demonstrates nearly 100% selectivity in converting CO 2 to CO at a rate of 25.5 μmol g –1 h –1 . This study presents a method for designing metal PFLPs on inorganic photocatalyst surfaces, which could contribute to the practical implementation of CO 2 photoreduction.