Synergistic Ir‐Ir Duet Atoms on CoOOH Enable Efficient Water Oxidation

ABSTRACT Single‐atom catalysts (SACs) have been extensively explored for the oxygen evolution reaction (OER) owing to their maximal atom utilization and high mass activity. However, isolated single‐metal centers often suffer from intrinsic linear scaling relationships among oxygenated intermediates, thereby limiting their catalytic efficiency in the complex four‐electron OER process. To overcome these limitations, we construct atomically dispersed Ir‐Ir duet atoms anchored on CoOOH surface (Ir 2 /CoOOH) to break the intrinsic scaling relationships governing the OER. Benefiting from the synergistic interaction between adjacent Ir atoms, Ir 2 /CoOOH exhibits an ultralow overpotential of ∼235 mV at 10 mA cm −2 and outstanding durability over 1200 h at 500 mA cm −2 in 1 M KOH. Remarkably, Ir 2 /CoOOH achieves a turnover frequency approximately three times higher than that of isolated Ir single atoms on the CoOOH surface (Ir 1 /CoOOH), highlighting the critical role of synergistic duet cooperation in enhancing intrinsic OER activity. Operando spectroscopic measurements combined with theoretical calculations reveal that cooperative Ir‐Ir interactions and strong metal‐support interactions optimize the local charge density of Ir active centers, regulate the rate‐determining step, and significantly lower the activation free energy of the OER. These findings demonstrate the effectiveness of atomically dispersed duet‐metal sites in overcoming activity limitations in water oxidation catalysis.