Atomically Dispersed Amorphous FeCo‐SiWA Catalysts Enable Efficient OER via Lattice Oxygen‐Mediated Mechanism

Developing stable amorphous multimetal oxides for the anodic oxygen evolution reaction (OER) remains challenging due to structural instability and inhomogeneity. Herein, a polyoxometalate (POM)-assisted strategy is presented to fabricate amorphous multimetal oxides (Fe_yCo_1- _yO_x-SiWA) featuring atomically dispersed metal sites and exceptional alkaline stability. Sub-nanometer [SiW₁₂O₄₀]^4- (SiWA) clusters interact strongly with Fe³⁺, locking the metal-oxygen network into a disordered yet stable architecture, suppressing phase segregation and ultimately enabling OER activity. The Fe_0.3Co_0.7O_x-SiWA achieves ultralow OER overpotentials of 277/330 mV at 10/100 mA cm^-2, a Tafel slope of 44.6 mV dec^-1, and an industrial-grade potential of 1.8 V (vs RHE) at 1000 mA cm^-2, surpassing commercial RuO₂ and most non-noble catalysts reported to date. Comprehensive mechanistic investigations employing ¹⁸O^- labeled differential electrochemical mass spectra (DEMS), in situ infrared, in situ Raman spectroscopy and density functional theory (DFT) calculations revealed a lattice oxygen-mediated (LOM) pathway that allows for direct O─O coupling, bypassing the rate-limiting OOH* formation step in conventional adsorbate evolution mechanism (AEM) pathways. Atomic disorder in the amorphous multi-metal oxides promotes lattice oxygen participation, as validated by both theoretical and experimental evidence. This work provides a paradigm for engineering cluster-stabilized amorphous oxides while advancing mechanistic understanding of high-current-density electrocatalysis through synergistic structure-property insights.