Unveiling the Activity Origin of Electrocatalytic Oxygen Evolution over Isolated Ni Atoms Supported on a N‐Doped Carbon Matrix

: Exploring highly efficient electrocatalysts for the oxygen evolution reaction (OER) and unveiling their activity origin are pivotal for energy conversion technologies. Herein, atomically distributed Ni sites over a N-doped hollow carbon matrix are reported as a promising electrocatalyst for OER in alkaline conditions. Significantly boosted activity is observed after the decoration of the active Ni sites with well-controlled coordination geometry. Results of X-ray absorption spectroscopy investigation and density functional theory (DFT) calculation reveal that the effective electronic coupling via the Ni-N coordination can move down the Fermi level and lower the adsorption energy of intermediates, thus resulting in the facilitated OER kinetics.