Yttrium-Doped Ru Nanoparticles Stabilized on Carbon Nanotubes as Bifunctional Catalysts for High-Efficiency Acidic Water Electrolysis

Ruthenium, a promising lower-cost, high-activity alternative to iridium for acidic PEMWE oxygen evolution, requires innovative stabilization and bifunctionality enhancement strategies due to its dissolution and nanoparticle instability under OER conditions and inferior HER activity compared to platinum. Herein, a novel strategy for bifunctional acidic water electrolysis catalysts integrates Y-doped Ru nanoparticles onto CNT-decorated carbon cloth (Y-Ru/CNT/CC), yielding high activity and stability. Introducing Y atom shifts the Ru d-band center negatively, reducing excessive adsorption of oxygen-containing intermediates and improving OER stability, while optimizing the hydrogen adsorption free energy (Δ<i>G</i>_H*) for enhanced HER activity. Furthermore, the CNT support provides a highly conductive network and abundant anchoring sites, which cooperate with Y-doping to inhibit Ru dissolution migration under acidic conditions. The catalyst exhibited excellent bifunctional activity in 0.5 M H₂SO₄ (HER: η₁₀ = 27 mV; OER: η₁₀ = 185 mV), which was significantly better than that of commercial Pt/C and RuO₂. This study presents a novel approach to designing a cost-effective acidic electrolytic water catalyst, promoting the practical application of PEMWE technology.