Xu Mengqiu, Xie Qifan, Duan Delong, Zhang Ye, Zhou Yuhu, Zhou Haiqiao, Li Xiaoyu, Wang Yao, Gao Peng, Ye Wei
College of Material, Chemistry and Chemical Engineering Key Laboratory of Organosilicon Chemistry and Material Technology Ministry of Education, Hangzhou Normal University, Hangzhou, Zhejiang, 311121, P. R. China.
College of Materials Science and Engineering, Zhejiang University of Technology, Hangzhou, Zhejiang, 310014, P. R. China.
ChemSusChem. 2022 Jun 8;15(11):e202200231. doi: 10.1002/cssc.202200231. Epub 2022 Apr 29.
The industrial Haber-Bosch process for ammonia synthesis is extremely important in modern society. However, it is energy intensive and leads to severe pollution, which has motivated eco-friendly NH synthesis research. Electroreduction of contaminant nitrate ions back to NH is an effective complement but is still limited by low NH yields and nitrate-to-NH selectivities. In this study, the electrochemical nitrate reduction reaction (NTRR) is carried out over a single-atom Cu catalyst. Atomically dispersed Cu sites anchored on dual-mesoporous N-doped carbon framework display excellent NTRR performance with NH production rate of 13.8 mol g h and NO -to-NH faradaic efficiency (FE) of 95.5 % at -1.0 V. Cu-N-C catalyst can sustain continuous 120 h NTRR test in the simulated NH synthesis scenarios with large current density (about 200 mA cm ) and amplified volume of NO solution (9 times). Theoretical calculations reveal that atomically dispersed Cu -N sites reduce the energy barrier of potential-determining step in NTRR and promote the decomposition of primary intermediate in NO -to-N process. These findings provide a guideline for the rational design of highly active, selective and durable electrocatalysts for the NTRR.
工业上用于合成氨的哈伯-博施法在现代社会中极其重要。然而，该方法能源密集且会导致严重污染，这推动了对环境友好的氨合成研究。将污染物硝酸根离子电还原回氨是一种有效的补充，但仍受限于低氨产率和硝酸根到氨的选择性。在本研究中，电化学硝酸根还原反应（NTRR）在单原子铜催化剂上进行。锚定在双介孔氮掺杂碳骨架上的原子分散铜位点表现出优异的NTRR性能，在-1.0 V时氨产率为13.8 μmol g-1 h-1，硝酸根到氨的法拉第效率（FE）为95.5%。Cu-N-C催化剂在模拟氨合成场景中，在大电流密度（约200 mA cm-2）和放大体积（9倍）的硝酸根溶液下，能够维持连续120小时的NTRR测试。理论计算表明，原子分散的Cu-N位点降低了NTRR中决速步骤的能垒，并促进了硝酸根到氨过程中初级中间体的分解。这些发现为合理设计用于NTRR的高活性、选择性和耐用的电催化剂提供了指导。
