Strong Built‐in Electric Field in Pt/TiN Heterostructures for High‐Performance Ammonia Oxidation Electrocatalysis

ABSTRACT Herein, we report a built‐in electric field (BEF) construction strategy using Pt nanoparticles anchored on TiN supports, which drives electron redistribution at the Pt/TiN heterojunction interface, optimizing the electronic structure and enhancing charge transfer efficiency to regulate the adsorption energies of reaction intermediates (particularly NO x, ad species), ultimately boosting the intrinsic catalytic activity. Notably, Pt/TiN catalyst achieved a peak current of nearly 120 A g −1 during AOR, which is more than twice that of commercial Pt/C and approximately four times that of Pt/TiO 2 . Furthermore, both experimental and theoretical results indicate that the work function differences induce a pronounced BEF, which drives interfacial electron transfer, leading to Fermi level alignment and the formation of Pt regions characterized by electron accumulation. More importantly, a rechargeable Zn─NH 3 battery was constructed, delivering a Faradaic efficiency as high as 94.2% and enabling continuous NH 3 ‐mediated H 2 production for 30 h at 8 mA cm −2 , thereby laying a solid foundation for practical applications. This work introduces an innovative approach to BEF construction for regulating the electronic structure of Pt, thereby advancing electrocatalysis in energy conversion.