Work

Dynamic hydroxyl mediated charge buffering stabilizes high valence ruthenium edge sites for acidic water oxidation

Year: 2026

Type: article

Abstract: High valence metal species are essential for driving electrocatalytic acidic water oxidation, but suffer from intrinsic thermodynamic instability. This activity-stability paradox is particularly severe for ruthenium-based catalysts, where highly active Ru(>IV) species are also precursors for rapid dissolution. Here we show that a cooperative host-guest architecture circumvents this trade-off through dynamic, hydroxyl-mediated charge buffering. By anchoring isolated ruthenium atoms at β-MnO2 edge sites, we demonstrate that host-derived surface hydroxyls govern both kinetics and robustness. These hydroxyls optimize intermediate binding to facilitate ideal O-O coupling, accelerating the reaction. Concurrently, the specific coordination environment allows the manganese host to reversibly accommodate excess oxidative charge, preventing irreversible structural degradation and ruthenium dissolution. The resulting Ru0.03Mn0.97O2 catalyst achieves a mass activity 223-fold higher than RuO2 and increases the stability number by three orders of magnitude. As an anode in a proton exchange membrane electrolyzer, it sustains an industrial-level current density of 1 A cm−2 for over 1000 h, comparing favorably to IrO2 while reducing precious metal usage by 80%. Highly active ruthenium-based catalysts for acidic water oxidation typically suffer from rapid dissolution. Here, the authors design a ruthenium-manganese host-guest architecture where surface hydroxyls buffer oxidative charge, enabling stable electrolysis at industrial currents.

Source: Nature Communications

DOI: 10.1038/s41467-026-74540-9