Phosphorization of α‐Fe2O3 boosts active hydrogen mediated electrochemical nitrate reduction to ammonia

Hou, ZhiangZhang, YixuanChen, HaoWang, JinnanLi, AiminCorvini, Philippe2025-01-202024-09-251613-68101613-682910.1002/smll.202406424https://irf.fhnw.ch/handle/11654/49818Inexpensive iron-based materials are considered promising electrocatalysts for nitrate (NO3−) reduction, but their catalytic activity and spontaneous corrosion remain challenges. Here, the α-Fe2O3 active surface is reconstructed by gradient phosphorization to obtain FePx with higher electrochemical activity. FeP2.0 optimizes the adsorption energy of NO3− and its reduction intermediates, meanwhile promote the generation of active hydrogen (*H) but inhibit its generation of H2. More importantly, Fe and P can serve as binding sites for NO3− and *H, respectively, which improves the electron utilization of NO3− deoxygenation and the efficiency of the subsequent hydrogenation for the selective synthesis of NH3. 91.7% NO3− conversion rate is achieved for the reduction of 100 mL 200 mg L−1 NO3−−N, 99.3% ammonia (NH3 selectivity (yield of 1.79 mg h−1 cm−2), and 91.4% Faraday efficiency in 3 h. The high-purity solid NH4Cl is finally extracted by gas extraction and vacuum distillation (81.4% recovery). This study provides new insights and strategies for the conversion of NO3− to NH3 products over iron-based electrocatalysts.en500 - NaturwissenschaftenPhosphorization of α‐Fe2O3 boosts active hydrogen mediated electrochemical nitrate reduction to ammonia01A - Beitrag in wissenschaftlicher Zeitschrift2406424