ABSTRACT Heteroatom modification effectively tailors the electronic structure of the p‐block metal for CO 2 reduction reaction, but the p‐orbital hybridization of sulfur‐induced in the electroreduction process remains unclear. Here, an in‐situ electrochemical modification approach is developed to tailor bismuth catalysts coordinated with sulfur atoms. The pronounced interaction between bismuth and sulfur p orbital optimizes the electronic states for efficient CO 2 electroreduction, achieving high Faradaic efficiency of 95.5% for formate and near 100% selectivity for C 1 products, while maintaining 93% formate Faradaic efficiency under pH‐universal electrolytes. In‐situ characterization and theoretical calculations reveal a descriptor‐based design principle, wherein tuning the sulfur atom configuration modulates bismuth p‐orbital delocalization with an optimized p‐band center, thereby reducing energy barrier for formate generation. Based on the fundamental insights, a solar‐driven CO 2 ‐H 2 O electrolyzer was constructed with a FE formate of 93.7% and an energy conversion efficiency of 13.9%. This work establishes an electronic structure design strategy based on p‐orbital delocalization modulation, offering theoretical insights and practical guidance for developing advanced main‐group metal electrocatalysts.
Zhang et al. (Mon,) studied this question.