Expediting Kinetics and CO-Resistant of Alkaline Hydrogen Oxidation Reaction on Medium-Entropy Alloys through Engineering Oxophilicity

The pursuit of highly efficient and CO-tolerant Pt-based electrocatalysts for the hydrogen oxidation reaction (HOR) under alkaline conditions is imperative for the practical implementation of anion exchange membrane fuel cells. Unfortunately, Pt-based electrocatalysts for alkaline HOR face dual challenges of excessive Pt consumption and conflicting intermediate adsorption requirements. Herein, we incorporate oxophilic Ce and Mo elements into the Pt system to obtain carbon-supported PtCeMo medium-entropy alloys (PtCeMo/C), achieving maximal catalytic efficiency with reduced Pt loading. Systematic mechanistic investigations reveal that interfacial PtCeMo interactions induce charge redistribution at heterojunctions, creating an unconventional electron transfer pathway from the Pt to Mo/Ce species. This electronic configuration synergistically strengthens hydroxide adsorption while attenuating *H/*CO binding on Pt active sites, a critical dual modulation that overcomes conventional trade-offs in intermediate management. The optimized catalyst demonstrates 2.6 times enhanced mass activity compared to commercial Pt/C, with accelerated H₂/CO oxidation kinetics through promoted *H/*CO-OH coupling, and boosted resistance to CO poisoning. This work pioneers an electronic-structure engineering strategy leveraging multicomponent interfacial synergy for advanced Pt-based HOR electrocatalysts.