Electronic States Regulation Induced by the Synergistic Effect of Cu Clusters and Cu‐S1N3 Sites Boosting Electrocatalytic Performance

Abstract The precise coordination environment manipulation and interfacial electron redistribution are significant strategies for the modulation of electronic configuration and intermediates adsorption behaviors, while the complex synergistic effect is yet to materialize due to the lack of catalyst platform. Herein, an atomic‐scale catalyst platform containing single Cu site with tunable coordination environment (Cu‐N 4 or Cu‐S 1 N 3 ) and easy decoration of Cu cluster (Cu x ) for electrochemical O 2 reduction reaction (ORR) is reported. Theoretical analysis shows that the charge redistribution and up‐shifting d ‐band center of single Cu site induced by the asymmetrical coordination environment and Cu x effectively strength *OOH adsorption. The modulation in intermediates adsorption enables Cu‐S 1 N 3 /Cu x a superior ORR performance compared with the samples without S atom and/or Cu x . Moreover, the adsorption behavior of *OOH and d ‐band center of single Cu site tuned by coordination environment and interfacial interactions are correlated linearly with catalytic potential, e.g., half‐wave potential and reaction kinetic, e.g., Tafel slope for ORR, indicating the high applicability of the intermediate adsorption strength and d ‐band center as the indicators for catalytic performance. This study provides a comprehensive modulation strategy for electron configuration and intermediates adsorption behaviors, and can be extended to facilitate other proton‐coupled electron transfer reactions.