Selective Atomic Incorporation: Synergistically Tailoring Adsorbate Evolution and Lattice Oxygen Pathways for Enhanced Water Oxidation

Abstract Oxygen evolution reaction (OER) remains a key bottleneck in water splitting, hindered by sluggish kinetics and complex catalytic mechanisms. Here, we synergistically tailor adsorbate evolution mechanism (AEM) and lattice oxygen mechanism (LOM) for enhanced water oxidation by selectively doping atomic Ir into binary metal oxide NiMoO 4 . Microscopic characterization and density functional theory (DFT) calculations confirm that atomic Ir preferentially occupies the octahedral Mo sites in NiMoO 4 . The selective Ir incorporation upshifts O 2p orbital energy, activating lattice oxygen bridging Ni and Ir (Ni─O─Ir). This enables synergistic AEM and LOM activation, validated by in situ spectroscopy/mass spectrometry and chemical probes. Benefiting from the synergistic mechanism, the optimized Ir‐NMO (NM 98 I 2 O) catalyst exhibits superior OER performance: low overpotential (253 mV at 10 mA cm −2 ), exceptional stability (>1000 h continuous operation), and good practicality in water electrolyzers.