Impact of Coordination Environment on Single-Atom-Embedded C<sub>3</sub>N for Oxygen Electrocatalysis
Xiting Wang, Huan Niu, Xuhao Wan, Anyang Wang, Feng Ryan Wang, Yuzheng Guo
Abstract
Herein, utilizing density functional theory (DFT) calculations, we have assessed the feasibility of single-atom-embedded C3N with various coordination environments of TM-C3, TM-C2N1, TM-C4, and TM-C2N2 for oxygen electrocatalysis. It has been proved that most TM-CxNy candidates are stable and all of them possess metallic features to ensure fast electron transfer. Importantly, Co-C2N2 is a bifunctional noble-free single-atom catalyst with low OER/ORR overpotentials (0.33/0.39 V). Furthermore, the impact of the coordination environment on the adsorption trend is revealed by the electronic properties of TM-CxNy. Considering that TM-d electron counts are multiplied by the sum of TM and C/N electronegativity, we propose a universal descriptor and offer more understanding of the coordination–activity correlation. Our findings not only show promising single-atom-embedded C3N candidates for oxygen electrocatalysis but also deeply unveil the impact of the coordination environment on catalytic activity.