Reducing the hydrogen transfer barrier by the introduction of Ru via a constructed Ir–Ru–WO2.72 bridge for highly CO-tolerant hydrogen oxidation

Hydrogen spillover effect-based active catalyst design is an effective strategy to enhance the hydrogen oxidation reaction (HOR) performance, which, unfortunately, still suffers from the high hydrogen spillover energy barrier. Here, a strategy alloying Ir with Ru is proposed to modulate the electronic structure of Ir to accelerate the H* transfer by a novel Ir–Ru–WO2.72 bridge, thus significantly reducing the hydrogen spillover energy barrier from Ir to WO2.72. The IrRu nanoclusters were deposited on a three-dimensional ordered macroporous WO2.72–C framework, and thus the constructed IrRu–WO2.72–C (1.16 wt% Ir and 1.09 wt% Ru) catalyst exhibits excellent HOR and CO-tolerance performance, rather high cell power density, and especially, 4 times higher mass activity than that of Pt/C. The modulation of Ru largely decreases the work function difference between the IrRu clusters and substrate, resulting in a reduced hydrogen spillover barrier via the Ir–Ru–WO2.72 bridge, weakened CO adsorption and fast removal of the adsorbed CO.