First-Principles Insights into the Selectivity of CO<sub>2</sub> Electroreduction over Heterogeneous Single-Atom Catalysts
Tianyang Liu, Yu Jing, Yafei Li
Abstract
Heterogeneous metal–nitrogen–carbon (M–N–C) single-atom catalysts (SACs) have garnered considerable attention in the two-electron CO 2 reduction reaction (2e–CO 2 RR). Interestingly, almost M–N–C SACs mainly produce CO, while Sb is one of the few SACs reported so far that can produce HCOOH. Nevertheless, the underlying factors for different selectivities on Sb–N–C SAC remain controversial, and the lack of in-depth understanding of limiting factors hampers further regulations. Here, by using constant-potential first-principles calculations, we revealed that the high HCOOH selectivity of Sb–N–C SAC is mainly attributed to their weak charge accumulation ability. Remarkably, considering the highly tunable geometric structure of M–N–C SACs, we provide that Sb–N–C SAC with the SbN 3 S 1 center is a promising candidate for CO production. Our work provides the mechanism insight into 2e-CO 2 RR selectivity and further paves the way toward electrocatalyst regulation and design.