Main group tin single atom catalyst supported by C5N monolayer for oxygen evolution reactions

Single atom catalysts (SACs) supported by carbonaceous materials present extraordinary activity for oxygen evolution reaction (OER), which usually contain transition metal atoms serving as active sites. However, when it turns to the SACs containing main group metal atoms, the OER performance is believed to be significantly decreased. We here proposed a strategy of designing SACs with p-block element of Sn as active sites, which exhibit excellent OER performance without nitrogen coordination of the metal centers. Density functional theory calculations demonstrate that atomically dispersed Sn atoms supported by the metallic monolayers of C5N can efficiently catalyze OER, of which the Sn center coordinated with four C atoms give rise to low overpotential of 0.54 V comparable or even lower than those given by the transition-metal-based SACs. Moreover, correlation between the overpotentials and some intrinsic properties of SACs, which demonstrates that the OER performance is not strongly correlated with the charge state of Sn atoms and Sn-N/C bond length. This study paves a new way of theoretically designing SACs containing main group elements toward OER or even broader range of electrochemical reactions.