Bu Yongguang, Yu Wenjing, Zhang Wenkai, Wang Chao, Ding Jie, Gao Guandao
State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, China.
Research Center of Environmental Science and Engineering, School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing 100083, China.
Nano Lett. 2024 Mar 6;24(9):2812-2820. doi: 10.1021/acs.nanolett.3c04920. Epub 2024 Feb 24.
Electroreduction of waste nitrate to valuable ammonia offers a green solution for environmental restoration and energy storage. However, the electrochemical self-reconstruction of catalysts remains a huge challenge in terms of maintaining their stability, achieving the desired active sites, and managing metal leaching. Herein, we present an electrical pulse-driven Co surface reconstruction-coupled Co shuttle strategy for the precise regulation of the Co(II)/Co(III) redox cycle on the Co-based working electrode and guiding the dissolution and redeposition of Co-based particles on the counter electrode. As result, the ammonia synthesis performance and stability are significantly promoted while cathodic hydrogen evolution and anodic ammonia oxidation in a membrane-free configuration are effectively blocked. A high rate of ammonia production of 1.4 ± 0.03 mmol cm h is achieved at -0.8 V in a pulsed system, and the corresponding nitrate-to-ammonia Faraday efficiency is 91.7 ± 1.0%. This work holds promise for the regulation of catalyst reactivity and selectivity by engineering controllable structural and chemical transformations.
将废硝酸盐电还原为有价值的氨为环境修复和能量存储提供了一种绿色解决方案。然而，就维持催化剂稳定性、实现所需活性位点以及控制金属浸出而言，催化剂的电化学自重构仍然是一个巨大挑战。在此，我们提出一种电脉冲驱动的钴表面重构耦合钴穿梭策略，用于精确调节钴基工作电极上的Co(II)/Co(III)氧化还原循环，并引导钴基颗粒在对电极上的溶解和再沉积。结果，氨合成性能和稳定性得到显著提升，同时在无膜配置中有效抑制了阴极析氢和阳极氨氧化。在脉冲系统中，-0.8 V时氨产率高达1.4±0.03 mmol cm⁻² h⁻¹，相应的硝酸盐到氨的法拉第效率为91.7±1.0%。这项工作有望通过设计可控的结构和化学转变来调节催化剂的反应性和选择性。
