@article{Wu2026, 
author = {Ruyan Wu and Yang Liu and Yongzhen Jin and Runze Chen and Yangfan Lin and Jianhui Wang},
title = {Enhancing electrocatalytic ammonia oxidation via surface concentration-gradient platinum alloying},
year = {2026},
journal = {Nano Research},
keywords = {electrocatalytic ammonia oxidation reaction, poisoning mechanism, platinum, surface compositional gradient alloy},
url = {https://www.sciopen.com/article/10.26599/NR.2026.94909171},
doi = {10.26599/NR.2026.94909171},
abstract = {Electrocatalytic ammonia oxidation reaction (EAOR) remains hindered by the lack of catalysts that simultaneously achieve high activity and long-term stability. Herein, we report a surface compositional gradient PtFe alloy catalyst (G-PtFe) consisting of a Pt-Fe gradient shell and a PtFe alloy core. The G-PtFe delivers an EAOR current density of 541.7 mA cm−2, representing an 8.7-fold improvement over pristine Pt, while exhibiting robust poisoning resistance across a wide potential range of 0.5−1.2 V vs. RHE. When employed as anode catalyst in direct ammonia fuel cells, the G-PtFe-based device achieves a peak power density 3.3 times higher than that of commercial Pt/C. Combined experimental analyses and density functional theory simulations reveal that EAOR deactivation on conventional Pt-based catalysts originates from potential-dependent adsorption imbalance: insufficient surface OH adsorption at low potentials promotes the accumulation of N-containing poisoning intermediates, whereas excessive OH binding at high potentials suppresses NH3 adsorption and induces surface passivation. The surface compositional gradient structure enables dynamically balanced OH and NH3 adsorption over a wide potential window, resulting in ultra-stable EAOR performance. This work provides mechanistic insights into potential-dependent catalyst poisoning and establishes a surface gradient alloy strategy for rational design of efficient and durable EAOR catalysts.}
}