Unlocking Enhanced Catalysis Stability in Acidic Oxygen Evolution: Structural Insights for PEM Applications under High‐Current Density

Abstract In proton exchange membrane water electrolysis (PEMWE), catalysts for acidic oxygen evolution reaction (OER) that demonstrate high current density and stability are essential. Herein, we synthesized La‐doped RuO 2 (La‐RuO 2 @TM) nanorod composite catalysts in situ on titanium mesh (TM) using a one‐step low‐temperature pyrolysis method. La‐RuO 2 @TM displays excellent catalytic performance (1.533 V at 100 mA cm −2 ) and remarkable stability, showing no significant degradation in performance over 450 hours of operation. Density functional theory (DFT) calculations indicate that the formation of the La‐O−Ru local structure modulates the adsorption strength of reaction intermediates, alleviates metal (Ru) leaching, and reduces oxygen loss, significantly enhancing the material‘s durability in acidic OER. The PEM electrolyzer utilizing La‐RuO 2 @TM operates at 1.815 V with a current density of 1.0 A cm −2 , maintaining stable performance for 120 h at 60 °C. This study offers valuable insights for designing efficient and durable acidic OER catalysts.