Engineering interfacial electronic reconstruction of Pt clusters on TiN for efficient alkaline hydrogen electro-oxidation

The sluggish kinetics of the alkaline hydrogen oxidation reaction (HOR) hinders the large-scale deployment of anion exchange membrane fuel cells (AEMFCs). Engineering the interfacial electronic reconstruction of electrocatalysts represents a critical pathway to overcome this bottleneck. Herein, we report a solvent-free vapor-phase sublimation strategy to synthesize ultra-small Pt clusters (∼2.5 nm) anchored on conductive titanium nitride (TiN) supports. By eliminating surfactant contamination and severe metal agglomeration inherent to wet-chemical methods, this approach ensures the pristine spatial confinement of Pt clusters and induces a robust interfacial electronic reconstruction at the Pt-TiN boundary. Consequently, the engineered catalyst delivers a mass activity of 776.8 A g Pt -1 , which is 2.1 times higher than that of commercial Pt/C, alongside superior CO tolerance. Moreover, the catalyst demonstrates outstanding durability with a mere 3.2% activity decay under continuous operation, outperforming the severe 76.0% degradation observed in commercial Pt/C. Mechanistic analyses indicate that electron transfer from TiN to Pt shifts the Pt d-band center downward to moderate *H adsorption, while adjacent TiN sites promote local *OH adsorption to facilitate the Volmer step. This study establishes a universal paradigm for leveraging interfacial electronic engineering to design high-performance electrocatalysts for AEMFCs.