Integrated Non‐Noble‐Metal‐Anode for Direct Ammonia Fuel Cells with High Activity and Long Stability Both in O ₂ and Air

ABSTRACT Ammonia is a promising carbon‐free energy carrier, offering advantages in storage, transport, and infrastructure compatibility. Its application in anion exchange membrane‐based direct ammonia fuel cells (AEM‐DAFCs) represents a promising approach to sustainable energy conversion. However, the development of AEM‐DAFCs is critically limited by noble‐metal dependence. Although powder‐based non‐noble metal catalysts have been widely investigated, devices assembled with them still deliver low power density and poor durability. Here, we present an activated nickel phosphorus on Ni foam (A‐Ni ₃ P@NF) as an efficient integrated non‐noble anode. Through a P doping strategy that introduces tunable defect centers, the electronic structure of nickel is tuned to regulate the adsorption of reaction intermediates. This modulation enables a new ammonia oxidation reaction (AOR) pathway, which is validated through in situ characterization, synchrotron Ni K ‐edge X‐ray absorption spectroscopy (XAS), and theoretical calculation. The optimized A‐Ni ₃ P@NF‐III exhibits outstanding ammonia oxidation activity, remarkable N ₂ selectivity (96.4%), and record‐long durability (>320 h). Integrated into AEM‐DAFCs, the catalyst achieves peak power densities of 166.83 in O ₂ and 123.69 mW cm ⁻² in air, the highest value reported for non‐noble anodes. This work establishes a universal strategy for non‐noble integrated anodes, advancing AEM‐DAFCs toward practical application.