Weakening the RuO covalency to promote the dominance of adsorbate evolution mechanism pathway by zirconium doping for ultra-stable proton exchange membrane water electrolysis.

In the anode catalytic systems of proton exchange membrane water electrolysis (PEMWEs), RuO emerges as a viable low-cost alternative for Ir in reducing hydrogen production costs. However, the high covalency of RuO bonds instigates lattice oxygen oxidation, resulting in a rapid decline in catalyst activity. Herein, we report Zr-doped RuO synthesized via hydrothermal reaction followed by heat treatment, which simultaneously enhances catalytic activity and suppresses lattice oxygen reactivity through synergistic structural and electronic modulation. Zr-doped RuO features an overpotential of only 221 mV at 10 mA cm and demonstrates remarkable durability over 1500 h in operation, displaying exceptional oxygen evolution reaction (OER) performance in acidic media. In situ Raman characterization and density functional theory (DFT) calculations indicate that Zr regulates the adsorption properties of Ru sites, weakens RuO covalency, suppresses the activity of lattice oxygen, and promotes the dominance of the adsorbate evolution mechanism (AEM) reaction pathway, thus increasing the service life in PEMWE systems. When evaluated in a PEMWE, this catalyst exhibits excellent catalytic performance with a voltage of only 1.38 V at 100 mA cm, demonstrating superior durability over 250 h under continuous operation. This strategy by suppressing the participation of lattice oxygen and the formation of oxygen vacancy in reaction provides an important reference value for the synthesis of efficient and stable RuO-based electrocatalysts for acidic water electrolysis.