Interfacial Co─N Coordination Engineering in Bimetallic Carbide Nanocluster‐Embedded Chainmail Catalysts Boosts Water Oxidation

Abstract Developing efficient and stable oxygen evolution reaction (OER) catalysts is critical for renewable energy applications. Guided by theoretical calculations, this work develops a rational interfacial design in OER chainmail catalysts composed of bimetallic carbide nanoclusters embedded within nitrogen‐doped carbon nanotubes (CoMoC‐NCNTs), derived from a CoMo‐MOF precursor. Utilizing X‐ray absorption fine structure spectroscopy and in situ characterization, the synthesized CoMoC‐NCNTs chainmail catalyst exhibits precisely tunable interfacial Co─N coordination regulated by pyrolysis temperature and abundant active carbon sites on a highly conductive network for OER via the adsorbate evolution mechanism. Density functional theory (DFT) calculations reveal that the introduction of interfacial Co─N coordination in CoMoC nanocluster‐embedded chainmail catalysts triggers electron transfer from inner CoMoC nanoclusters to outer carbon layers, which further optimizes OER intermediate adsorption on carbon sites with a lower energy barrier for the rate‐determining step (0.44 eV). Consequently, the optimal CoMoC‐NCNTs chainmail catalyst for alkaline OER exhibits exceptional catalytic activity (overpotential of 297 mV at 10 mA cm −2 ) and excellent durability (500 mA cm −2 for 200 h). The constructed volcanic plot further establishes structure‐activity relationships for guiding future designs of chainmail catalysts. This work provides a universal strategy for engineering nanocluster‐embedded chainmail catalysts with tailored electronic structures for advanced electrocatalysis.