Mimicking Frustrated Lewis Pairs on Graphitic Carbon Nitride for CO<sub>2</sub> Photoreduction
Yaru Shang, Zheng Ming, Hengjie Liu, Xiaoli Jin, Chunshuang Yan, Li Song, Zeming Qi, Fengyang Jing, Pin Song, Xin Zhou, Gang Chen, Chade Lv
Abstract
Photocatalytic carbon dioxide (CO 2 ) reduction is an emerging approach to synthesizing carbon monoxide (CO) but still suffers from poor selectivity and low catalytic efficiency because of the high energy barrier toward the *COOH formation. Herein, we report the selective and high-efficiency photosynthesis of CO with a boron (B)- and sulfur (S)-codoped graphitic carbon nitride (g-C 3 N 4 ) catalyst (B,S-CN), which shifts the rate-determining-step (RDS) from CO 2 protonation to CO 2 adsorption. This is realized by the local mimicking frustrated Lewis pairs (M-FLPs) constructed with abundant electron-deficient S and electron-rich N adjacent to B. The “push–pull” effect provided by the as-designed metal-free M-FLP configuration allows the spontaneous formation of *COOH and *CO intermediates through balancing the *COOH adsorption energy, as evidenced by theoretical calculations and in situ characterizations. In addition to the free-energy changes, B and S codoping can also promote the separation and transfer of charges and improve the utilization rate of light. Strikingly, the B,S-CN catalyst exhibits a high CO selectivity of 100% with an average yield of 313.20 μmol g –1 h –1 (70.7 times that of bulk g-C 3 N 4 ). This study provides a strategy for the development of highly selective photocatalysts and paves the way for rational intermediate regulation by mimicking the FLP configuration.