Toward Fast Proton Shuttling in Acidic Oxygen Evolution Reaction

초록

The acidic oxygen evolution reaction (OER) is a key bottleneck in proton exchange membrane water electrolysis due to sluggish proton-coupled electron transfer kinetics. While conventional approaches have focused on tuning adsorption energies of intermediates, Recent operando spectroscopic and theoretical studies indicates that sluggish deprotonation of oxygenated intermediates (*OH, *OOH) can influence acidic OER kinetics. This review establishes proton transfer dynamics as a descriptor governing acidic OER activity, moving beyond the kinetic constraints derived from the proton coupled electron transfer. We discuss how deprotonation governs classical mechanisms, including adsorbate evolution mechanism (AEM), lattice oxygen mechanism (LOM) and oxide path mechanism (OPM), while highlighting emerging pathways enabled by non-concerted proton-electron transfer. Recent advances in catalyst design-such as bridge oxygen-mediated proton shuttling, heteroatom modulation, high-entropy oxide, strain engineering, and support assisted proton transfer are typically analyzed for their role in accelerating proton removal and enhancing catalytic performance. In addition, operando and isotope-based techniques (ATR-SEIRAS, Raman, NAP-XPS, DEMS, and KIE) are summarized as a powerful tool for probing deprotonation pathways. This is a focused review offering a cohesive framework for the design of next-generation acidic OER catalysts through the rational modulation of proton transfer kinetics.

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