Gong Zhiheng, Xiang Xuepeng, Zhong Wenye, Jia Chenghao, Chen Peiyan, Zhang Nian, Zhao Shijun, Liu Weizhen, Chen Yan, Lin Zhang
Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, School of Environment and Energy, South China University of Technology, Guangzhou, 510006, P. R. China.
Department of Mechanical Engineering, City University of Hong Kong, Hong Kong, 999077, P. R. China.
Angew Chem Int Ed Engl. 2023 Sep 18;62(38):e202308775. doi: 10.1002/anie.202308775. Epub 2023 Aug 10.
The complexes of metal center and nitrogen ligands are the most representative systems for catalyzing hydrogenation reactions in small molecule conversion. Developing heterogeneous catalysts with similar active metal-nitrogen functional centers, nevertheless, still remains challenging. In this work, we demonstrate that the metal-nitrogen coupling in anti-perovskite Co N can be effective modulated by Cu doping to form Co CuN, leading to strongly promoted hydrogenation process during electrochemical reduction of nitrate (NO RR) to ammonia. The combination of advanced spectroscopic techniques and density functional theory calculations reveal that Cu dopants strengthen the Co-N bond and upshifted the metal d-band towards the Fermi level, promoting the adsorption of NO and *H and facilitating the transition from *NO /*NO to *NO H/*NOH. Consequently, the Co CuN delivers noticeably better NO RR activity than the pristine Co N, with optimal Faradaic efficiency of 97 % and ammonia yield of 455.3 mmol h cm at -0.3 V vs. RHE. This work provides an effective strategy for developing high-performance heterogeneous catalyst for electrochemical synthesis.
金属中心与氮配体的配合物是小分子转化中催化氢化反应最具代表性的体系。然而，开发具有类似活性金属-氮功能中心的非均相催化剂仍然具有挑战性。在这项工作中，我们证明了通过铜掺杂可以有效地调节反钙钛矿CoN中的金属-氮耦合，形成CoCuN，从而在电化学硝酸盐还原（NO RR）制氨过程中显著促进氢化过程。先进的光谱技术和密度泛函理论计算相结合表明，铜掺杂剂增强了Co-N键，并使金属d带向费米能级上移，促进了NO和H的吸附，并促进了从NO/NO到NOH/*NOH的转变。因此，CoCuN的NO RR活性明显优于原始CoN，在相对于可逆氢电极（RHE）为-0.3 V时，最佳法拉第效率为97%，氨产率为455.3 mmol h cm。这项工作为开发用于电化学合成的高性能非均相催化剂提供了一种有效策略。
