Pt‐Sn/Sb Interaction Induces Reversed Charge Transfer and Selective Hydroxyl Adsorption for Enhanced Hydrogen Electro‐Oxidation

Abstract The challenges encountered by Pt‐based electrocatalysts in alkaline hydrogen oxidation reaction include high Pt dosage and conflicting demands for modulating adsorption strengths among diverse intermediates. Here, an ultrasmall Pt cluster grafted on antimony tin oxide nanocrystalline with strong electron donor ability to minimal Pt dosage yet maximized electrocatalytic performance is developed. Mechanism studies show that the formation of Pt–Sn/Sb interaction at the heterointerface and the resultant reversed electron transfer selectively enhance the adsorption for OH ‐ while concurrently weakening the binding strength for *H and CO toward Pt clusters. This accelerates the kinetics of H 2 /CO oxidation by promoting the binding of OH species with *H/*CO, yielding the catalyst with up to 5.7‐fold higher mass‐specific activity than benchmark Pt/C and increased resistance to CO poisoning. This work demonstrates the rational design of the synergistic multi‐site interactions towards advanced Pt‐based catalysts.