Cooperative multimetal molybdate reconstruction activates lattice oxygen reactivity for durable alkaline water electrolysis

This is the authors' abstract. We don't add key points for this paper.

Dynamic reconstruction is central to the activity of transition-metal oxygen-evolution catalysts. However, controlling the reconstructed active phase remains challenging. Here we report a highly efficient OER multimetal catalyst (CoFeNi)MoO 4 , that undergoes rapid and extensive reconstruction to generate a compositionally homogeneous NiOOH-like multimetal oxyhydroxide phase with enhanced electronic conductivity and oxygen reactivity. The reconstructed catalyst requires an overpotential of only 237 mV to deliver 10 mA cm −2 in 1 M KOH and maintains stable operation at 1 A cm −2 for 1000 h in an anion-exchange-membrane water electrolyzer. In situ Raman spectra and isotope-labeling differential electrochemical mass spectrometry consistently indicate substantial lattice oxygen participation during OER. Density functional theory calculations reveal that multimetal coupling narrows the band gap, upshifts the O-2p band center, and lowers the energy barrier for the lattice-oxygen-mediated pathway. This work establishes multimetal molybdate reconstruction as an effective strategy for designing durable oxygen-redox-active water-oxidation catalysts.