Reconstruction of Nickel Chalcogenide Induced Ruthenium Nanoparticles Embedding for Oxygen Evolution: Mechanism Switching Enables Enhanced Catalytic Activity

ABSTRACT Atomic‐level understanding of structure‐performance relationships and electrocatalytic mechanisms is pivotal for efficient oxygen evolution reaction (OER). Unlike conventional strategies that focus on developing pre‐catalysts, a unique design conception is proposed in this work to maximize metal‐support interactions through reconstruction. We prepare the ruthenium nanoparticles supported nickel chalcogens (Ru/NiX, X = S, Se), which enable fast electrooxidation to form an adaptively Ru embedding structure, featured by the compressed Ru─O─Ni bridge bonds at the Ru/NiOOH interface. Combined experimental analyses and theoretical calculations reveal that both thermodynamics and kinetics of the OER process are optimized. On the one hand, Ru nanoparticles have a high affinity for capturing the OH ⁻ , consequently increasing the *O radical coverage. On the other hand, a shorter inter atomic Ru─Ni distance facilitates the *O–*O radical coupling, validating the mechanism switching from the adsorbate evolution mechanism (AEM) to the oxide path mechanism (OPM). The reconstructed catalyst merely requires an overpotential of 175 mV at 10 mA cm ⁻² and maintains stable operation for over 250 h, implying a superior OER performance.