Atomically Engineered RuW@IrRuW Nanocatalysts for Superior Alkaline Hydrogen Oxidation Reactions.

The slow kinetics and poor stability of the hydrogen oxidation reaction (HOR) critically hinder anion exchange membrane fuel cells (AEMFCs). To address this, we engineered a RuW@IrRuW nanocatalyst on N-doped hollow carbon nanospheres (NHCSs) via wet-chemical impregnation and atomic substitution, featuring atomically dispersed IrRuW shell layers on RuW cores anchored within the porous NHCS framework. The unique architecture delivers exceptional HOR activity in 0.1 M KOH, achieving a mass activity of 3257.57 mA mg-1 and a specific activity of 2.85 mA cm-2, representing 8.1-fold and 7.9-fold enhancements over commercial Pt/C, respectively. Moreover, RuW@IrRuW/NHCSs exhibits outstanding stability (negligible decay after 40,000 s) and superior CO tolerance (85.9% activity after 2,900 s in CO). Combined experimental and theoretical studies reveal that the atomically layered IrRuW shell enables dual active sites for H* and OH* adsorption, mitigating competitive binding. Incorporating Ir modulates the electronic structure of the nanoparticle surface, optimizing H* and OH* adsorption and suppressing CO adsorption. Concurrently, the NHCS support enhances metal-carrier interactions, provides spatial confinement, and improves mass transfer. This work demonstrates a viable strategy to overcome the activity-stability trade-off for efficient, durable, and CO-tolerant HOR electrocatalysis.