Electron‐Donating Zr Induces Suppressed Ru Over‐Oxidation and Accelerated Deprotonation Process Toward Efficient and Durable Water Electrolysis

The scarcity of cost-effective and durable iridium-free anode electrocatalysts for the oxygen evolution reaction (OER) poses a significant challenge to the widespread application of the proton exchange membrane water electrolyzer (PEMWE). To address the electrochemical oxidation and dissolution issues of Ru-based electrocatalysts, an electron-donating modification strategy is developed to stabilize WRuO_x under harsh oxidative conditions. The optimized catalyst with a low Zirconium doping (Zr, 1 wt.%) enhances durability noticeably, with a 77% reduction in degradation rate in the durability test of 10 mA cm^-2 in 0.5 m H₂SO₄. When integrated into a homemade PEMWE device, the Zr-doped catalyst achieves excellent long-term stability, lasting up to 650 h at 100 mA cm⁻². Additionally, the electronic modulation from the Zr modification leads to superior activity with a low overpotential of 208 mV at 10 mA cm^-2. Theoretical calculation results further reveal that electron-donating Zr modification effectively suppresses Ru overoxidation and lattice oxygen participation, maintaining a robust structure during acidic OER. This modification also promotes deprotonation through stronger Brønsted acid sites, significantly improving both long-term stability and activity.