Synergistic Lewis acid-base pair engineering enables efficient low-concentration nitric oxide-to-ammonia conversion over iron-palladium bimetallene

Compared to traditional "consumptive treatment" denitrification technologies, the electrocatalytic nitric oxide reduction reaction (NORR) simultaneously achieves nitrogen removal from flue gas and resource recovery under ambient temperature and pressure. However, because of the extremely low solubility of nitric oxide (NO) in neutral electrolytes and its low concentration in industrial flue gas, NO mass transfer and adsorption are limited and hydrogenation kinetics are relatively sluggish. In this study, a pyrolysis-in situ electrochemical deposition strategy is employed to controllably transform the molecular precursors into atomically ordered intermetallic FePd₃ bimetallene (FePd). The strong FePd interaction regulates the local electronic structure and constructs a synergistic Lewis acid-base pair. The electron-deficient Fe centers enhance NO adsorption and mass transfer, while the electron-rich Pd centers enable efficient active hydrogen storage and facilitate the hydrogenation reaction. An integrated scalable electrolyzer ammonia recovery system is developed. The modular multi-unit system achieved a high ammonia yield of 24.6 μmol h^-1 cm^-2 with 81.7% NH₃ selectivity at low specific energy consumption of 18.3 kWh kg^-1 NH₃. This work paves a new pathway for transitioning NO from end-of-pipe treatment to resource recovery.