Li Minzhang, Wang Wei, Liang Man, Yang Qingjie, Wang Yirong, Guo Lu, Yu Zixun, Chen Fuming, Chen Yuan
Guangdong Engineering Technology Research Center of Efficient Green Energy and Environment Protection Materials, School of Electronic Science and Engineering, South China Normal University, China.
Collaborative Innovation Center of Ecological Civilization, School of Chemistry and Chemical Engineering, Hainan University, Haikou, 570228, China.
Angew Chem Int Ed Engl. 2025 Jun 20:e202506712. doi: 10.1002/anie.202506712.
Freshwater scarcity and nitrate contamination in water sources are critical environmental sustainability challenges. We address these two challenges by coupling seawater desalination with electrochemical nitrate reduction (NORR) via bimetallic Fe/Zn polyphthalocyanine frameworks. They serve as high-performance catalysts for NORR toward ammonia (NH) production. The efficient NORR is integrated into an electrocatalytic desalination device, enabling the production of freshwater from seawater and the removal of nitrate from contaminated water. In situ spectroscopic studies and theoretical calculations show that Zn-N units incorporated into the Fe polyphthalocyanine framework modulate Fe-N sites' d-band center to enhance the adsorption of NO and the generation of *H, resulting in 3.22 times higher turnover frequency and highly selective reduction toward NH. The optimized FeZnPPc delivered NH Faradic efficiency (>97% over a wide potential range (-0.55 to -0.95 V vs. reversible hydrogen electrode (RHE)), the NH yield rate of 2.68 mmol h cm at -0.85 V versus RHE, and over 120 h of stable operation, outperforming previously reported Fe-based catalysts for NORR. The desalination device achieves the highest salt removal rates (1326.92 µg cm min) among various desalination methods. Ten cycles of natural seawater desalination to drinking water are demonstrated with 99% ion removal. This work presents an innovative solution for addressing sustainable water challenges.
淡水资源短缺和水源中的硝酸盐污染是关键的环境可持续性挑战。我们通过双金属铁/锌聚酞菁框架将海水淡化与电化学硝酸盐还原（NORR）相结合来应对这两个挑战。它们作为用于NORR制氨（NH）的高性能催化剂。高效的NORR被集成到电催化脱盐装置中，能够从海水中生产淡水并从受污染的水中去除硝酸盐。原位光谱研究和理论计算表明，掺入铁聚酞菁框架中的Zn-N单元调节Fe-N位点的d带中心，以增强对NO的吸附和*H的生成，导致周转频率提高3.22倍，并对NH具有高度选择性还原。优化后的FeZnPPc在宽电位范围（相对于可逆氢电极（RHE）为-0.55至-0.95 V）内提供了>97%的NH法拉第效率，在相对于RHE为-0.85 V时NH产率为2.68 mmol h cm，并且稳定运行超过120 h，优于先前报道的用于NORR的铁基催化剂。该脱盐装置在各种脱盐方法中实现了最高的除盐率（132 μg cm min）。展示了将天然海水脱盐十次转化为饮用水，离子去除率达到99%。这项工作提出了一种应对可持续水挑战的创新解决方案。
