A linear correlation of p-band center with the performance of electrochemical CO2 reduction revealed by Sn single-atom catalysts

The correlation between p-orbital energy level and catalytic activity of electrochemical CO2 reduction reaction (ECRR) is rarely reported, but significantly desired for further design of highly effective main group single-atom catalysts (SACs). Herein, a series of Sn-SACs (Sn-N3S1, Sn-N3P1, Sn-N3B1, and Sn-N4) were developed as a model system to explore structure-activity relationships of main group SACs for ECRR. Coordination environment regulation could upshift the p-band center of Sn, facilitating the adsorption of intermediates and improving the catalytic activity. Sn-N3S1 with the most positive p-band center shows a 100% Faradaic efficiency of CO (FECO), superior over that of Sn-N4 and other reported SACs. Notably, the catalytic performance of Sn-SACs shows a linear relationship with p-band center of Sn, indicating a high applicability of p-band center as a descriptor for catalytic performance. This work provides a new way to boost ECRR by lowering the p-orbital energy level of main group metal.