State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
J Environ Sci (China). 2025 Mar;149:374-385. doi: 10.1016/j.jes.2024.01.046. Epub 2024 Feb 10.
Electrocatalytic reduction of nitrate to ammonia has been considered a promising and sustainable pathway for pollutant treatment and ammonia has significant potential as a clean energy. Therefore, the method has received much attention. In this work, Cu/Fe 2D bimetallic metal-organic frameworks were synthesized by a facile method applied as cathode materials without high-temperature carbonization. Bimetallic centers (Cu, Fe) with enhanced intrinsic activity demonstrated higher removal efficiency. Meanwhile, the 2D nanosheet reduced the mass transfer barrier between the catalyst and nitrate and increased the reaction kinetics. Therefore, the catalysts with a 2D structure showed much better removal efficiency than other structures (3D MOFs and Bulk MOFs). Under optimal conditions, Cu/Fe-2D MOF exhibited high nitrate removal efficiency (87.8%) and ammonium selectivity (89.3%) simultaneously. The ammonium yielded up to significantly 907.2 µg/(hr·mg) (7793.8 µg/(hr·mg)) with Faradaic efficiency of 62.8% at an initial 100 mg N/L. The catalyst was proved to have good stability and was recycled 15 times with excellent effect. DFT simulations confirm the reduced Gibbs free energy of Cu/Fe-2D MOF. This study demonstrates the promising application of Cu/Fe-2D MOF in nitrate reduction to ammonia and provides new insights for the design of efficient electrode materials.
电化学还原硝酸盐为氨被认为是一种有前途和可持续的污染物处理方法，氨作为清洁能源具有很大的潜力。因此，该方法受到了广泛关注。在这项工作中，通过一种简单的方法合成了 Cu/Fe 二维双金属金属有机骨架，无需高温碳化即可用作阴极材料。具有增强内在活性的双金属中心（Cu、Fe）表现出更高的去除效率。同时，二维纳米片降低了催化剂和硝酸盐之间的传质障碍，并增加了反应动力学。因此，二维结构的催化剂比其他结构（3D MOFs 和块状 MOFs）具有更好的去除效率。在最佳条件下，Cu/Fe-2D MOF 同时表现出高的硝酸盐去除效率（87.8%）和铵选择性（89.3%）。在初始浓度为 100 mg N/L 时，催化剂的铵产率高达 907.2 µg/(hr·mg)（7793.8 µg/(hr·mg)），法拉第效率为 62.8%。催化剂被证明具有良好的稳定性，可循环使用 15 次，效果良好。DFT 模拟证实了 Cu/Fe-2D MOF 的还原吉布斯自由能降低。本研究证明了 Cu/Fe-2D MOF 在硝酸盐还原为氨方面具有广阔的应用前景，并为高效电极材料的设计提供了新的思路。
