Constructing Electron-Deficient Ruthenium Sites for Stable Hydrogen Oxidation by Weakening OH Adsorption

Developing robust and efficient Pt-free catalysts for the alkaline hydrogen oxidation reaction (HOR) is essential for advancing anion exchange membrane-based fuel cells (AEMFCs), which demonstrates significant cost advantages and great resistance to CO poisoning. Although Ru exhibits high electrochemical activity for the HOR in alkaline media, its practical application in AEMFCs is hindered by the activity decline at high anodic potentials. Herein, we constructed Ru nanoparticles on buckminsterfullerene (Ru/C₆₀-PDA), which demonstrated enhanced stability compared to conventional Ru-based catalysts during the HOR and retained activity up to 0.9 V (vs RHE). Physical characterization and density functional theory (DFT) calculations confirm that Ru on C₆₀ is in an electron-deficient state, which weakens OH adsorption strength during the HOR, thereby improving the stability of the catalyst. In addition, Ru/C₆₀-PDA demonstrates significantly greater resistance to CO poisoning due to its weaker CO affinity, enabling it to maintain HOR activity even in the presence of 10 vol % CO. Furthermore, an AEMFC using Ru/C₆₀-PDA as the anode catalyst achieved a peak power density of 510 mW cm^-2 under zero backpressure conditions, outperforming both Pt/C and unmodified Ru particles. This study offers valuable insights for the rational design of highly stable HOR catalysts based on carbon supports.