Lv Jiabao, Cao Ang, Zhong Yunhao, Lin Qingyang, Li Xiaodong, Wu Hao Bin, Yan Jianhua, Wu Angjian
State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, P. R. China.
Baima Lake Laboratory, Hangzhou, P. R. China.
Nat Commun. 2024 Aug 6;15(1):6675. doi: 10.1038/s41467-024-50988-5.
Renewable-driven electrocatalytic nitrate conversion offers a promising alternative to alleviate nitrate pollution and simultaneously harvest green ammonia. However, due to the complex proton-electron transfer processes, the reaction mechanism remains elusive, thereby limiting energy efficiency. Here, we adopt Ni(OH)₂ as a model catalyst to investigate the dynamic evolution of the reaction interface. A proposed OH cycle mechanism involves the formation of a locally OH-enriched microenvironment to promote the hydrogenation process, which is identified through in-situ spectroscopy and isotopic labelling. By further activating the dynamic state through the implementation of surface vacancies via plasma, we achieve a high Faradaic efficiency of almost 100%. The activated interface accelerates the OH cycle by enhancing dehydroxylation, water dissociation, and OH adsorption, thereby promoting nitrate electroreduction and inhibiting hydrogen evolution. We anticipate that rational activation of the dynamic interfacial state can facilitate electrocatalytic interface activity and improve reaction efficiency.
可再生能源驱动的电催化硝酸盐转化为缓解硝酸盐污染并同时获取绿色氨提供了一种有前景的替代方法。然而，由于复杂的质子 - 电子转移过程，反应机理仍然难以捉摸，从而限制了能源效率。在此，我们采用氢氧化镍作为模型催化剂来研究反应界面的动态演变。提出的氢氧根循环机制涉及形成局部富氢氧根的微环境以促进氢化过程，这通过原位光谱和同位素标记得以确定。通过等离子体在表面引入空位进一步激活动态状态，我们实现了近100%的高法拉第效率。活化的界面通过增强脱羟基、水离解和氢氧根吸附来加速氢氧根循环，从而促进硝酸盐电还原并抑制析氢。我们预计合理激活动态界面状态能够促进电催化界面活性并提高反应效率。
