Electrochemical oxygen coordination engineering of nickel single atoms for enhanced oxygen evolution reactions

Abstract Oxygen‐coordinated single atom catalysts (SACs) hold promise for enhancing electrocatalytic performance in oxygen evolution reactions (OER). However, their synthesis remains challenging due to the instability of metal‐oxygen bonds under traditional high‐temperature methods. This difficulty is compounded by the lack of model SACs with well‐defined oxygen coordination, hindering the study of structural evolution during catalysis. Herein we propose a stepwise electrochemical oxidation strategy to synthesize nickel SACs on graphite foil with precisely controlled oxygen coordination numbers. The initial oxygen coordination number significantly influences the structural evolution of these SACs during OER, with partial Ni‐O 5 configurations undergoing reconstruction into clusters, while others maintain atomic dispersion. By establishing a direct correlation between the initial coordination environment and the SACs' dynamic behavior under operational conditions, this study provides a comprehensive framework for understanding and designing adaptive and active OER catalysts.