Electronic modulation and interfacial cooperation promoting electrocatalytic ammonia oxidation reaction on platinum nanocubes supported on CeO2-modified carbon

Ammonia is a promising energy carrier for overcoming hydrogen storage and transportation challenges. Although platinum (Pt) exhibits high activity for the electrocatalytic ammonia oxidation reaction (AOR), particularly on the Pt(100) facet, single-component Pt catalysts suffer from competitive adsorption between surface hydroxyl species and ammonia-derived intermediates. To address this limitation, we designed and synthesized a composite catalyst (Pt/CeO 2 /XC) featuring abundant Pt–CeO 2 interfaces. Oxygen-philic CeO 2 preferentially adsorbs surface hydroxyls, while the formation of interfacial Pt–O–Ce linkages modulates the electronic structure of Pt, optimizing the adsorption and coupling of nitrogen-containing intermediates. This dual-functional interfacial strategy enhances intrinsic activity, with Pt/CeO 2 /XC exhibiting a specific activity 15.8 times higher than that of commercial Pt/C, ranking among the most active AOR electrocatalysts reported to date. When employed as the anode catalyst in a direct ammonia fuel cell (DAFC), Pt/CeO 2 /XC delivers a peak power density of 32.3 mW/cm 2 . This work elucidates the critical role of metal-support interfacial regulation and electronic structure modulation in governing AOR performance, providing general design principles for high performance ammonia oxidation catalysts.