TiO-supported RuIr alloy as an efficient and CO-resistant catalyst for hydrogen oxidation

Ruthenium (Ru), with a hydrogen binding energy comparable to platinum (Pt) and stronger oxygen affinity, is a promising platform for designing hydrogen oxidation reaction (HOR) catalysts. Nevertheless, the practical application of Ru-based catalysts is still hampered by limited intrinsic activity and poor CO tolerance. In this work, a RuIr alloy supported on titanium oxide (RuIr/TiO) is obtained as an efficient and durable catalyst for alkaline HOR. The mass activity of RuIr/TiO reaches to 10.36 A mg −1 PGM at the overpotential of 50 mV, which is 4.84 times higher than that of commercial Pt/C. Under 1000 ppm CO/H 2 , RuIr/TiO shows only a 6.85 % drop in current density after a long-time electrolysis, outperforming commercial Pt/C (27.84 %). Experimental characterizations and density functional theory (DFT) calculations reveal that alloying and strong metal-support interaction can induce interfacial charge redistribution and modulate the electronic structure of the active Ru site, thereby accelerate the reaction kinetics of alkaline HOR, optimize H adsorption, and enhance OH binding, leading to the promoted oxidation of CO on the catalyst surface.