Liu Hongfei, Qin Jiangzhou, Mu Jincheng, Liu Baojun
College of Resource and Environmental Engineering, Guizhou University, Guiyang 550025, China.
Department of Environmental Engineering, Peking University, The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, China.
J Colloid Interface Sci. 2023 Apr 15;636:134-140. doi: 10.1016/j.jcis.2023.01.014. Epub 2023 Jan 6.
Electrocatalytic nitrate (NO) reduction to ammonia (NH) is a promising alternative approach for simultaneous NH green synthesis and NO contaminants removal. However, the complex eight-electron reaction requires catalysts with superb performance due to the low NH selectivity and yield. In this work, the Co nanoparticles decorated N-doped carbon (NC) by in situ interface engineering were prepared by deriving ZIF-67 at 800 ℃ (Co/NC-800) for the selective NH synthesis. This catalyst exhibits a remarkable performance and excellent cycle stability, achieving a great NH yield of 1352.5 μg h mg at -1.7 V vs Ag/AgCl, with a high NH selectivity of up to 98.2 %, and a maximum Faradic efficiency of 81.2 % at -1.2 V vs Ag/AgCl. Moreover, DFT calculation results indicate that the interfacial effect between Co nanoparticle and NC could enhance electron transfer, and the composite Co/NC-800 shows a lower adsorption and conversion free energy, which promotes the production of ammonia.
电催化硝酸盐（NO）还原为氨（NH₃）是一种很有前景的同时实现NH₃绿色合成和去除NO污染物的替代方法。然而，由于NH₃的选择性和产率较低，复杂的八电子反应需要具有卓越性能的催化剂。在这项工作中，通过在800℃下衍生ZIF-67制备了原位界面工程修饰的钴纳米颗粒负载氮掺杂碳（NC）催化剂（Co/NC-800）用于选择性合成NH₃。该催化剂表现出卓越的性能和出色的循环稳定性，在相对于Ag/AgCl为-1.7V时实现了1352.5μg h⁻¹ mg⁻¹的高NH₃产率，NH₃选择性高达98.2%，在相对于Ag/AgCl为-1.2V时最大法拉第效率为81.2%。此外，密度泛函理论（DFT）计算结果表明，钴纳米颗粒与NC之间的界面效应可增强电子转移，复合催化剂Co/NC-800表现出较低的吸附和转化自由能，从而促进氨的生成。
