Zhang Hexin, Zhou Weichi, Hu Liangqing, Guo Yanming, Lu Yinpeng, Feng Jing
Key Laboratory of Superlight Materials & Surface Technology of Ministry of Education, Harbin Engineering University, Harbin 150001, PR China.
Key Laboratory of Superlight Materials & Surface Technology of Ministry of Education, Harbin Engineering University, Harbin 150001, PR China.
J Colloid Interface Sci. 2025 Jan;677(Pt A):264-272. doi: 10.1016/j.jcis.2024.07.226. Epub 2024 Jul 30.
The electrocatalytic nitrogen reduction reaction (NRR) is a crucial process in addressing energy shortages and environmental concerns by synthesizing the NH. However, the difficulty of N activation and fewer NRR active sites limit the application of NRR. Therefore, the NRR performance can be improved by rapid electron transport paths to participate in multi-electron reactions and N activation. Doping with transition metal element is a viable strategy to provide electrons and electronic channels in the NRR. This study focuses on the synthesis of Fe(MoO) (FeMo) and x%La-doped FeMo (x = 3, 5, 7, and 10) using the hydrothermal method. La-doping creates electron transport channels Fe-O-Fe and oxygen vacancies, achieving an equal molar ratio of Fe/Fe. This strategy enables the super-exchange in Fe-O-Fe, and then enhances electron transport speed for a rapid hydrogenation reaction. Therefore, the synergistic effect of Fe/Fe cycling and oxygen vacancies improves the NRR performance. Notably, 5%La-FeMo demonstrates the superior NRR performance (NH yield rate: 29.6 μg h mg, Faradaic efficiency: 5.8%) at -0.8 V (vs. RHE). This work analyzes the influence of the catalyst electronic environment on the NRR performance based on the effect on different valence states of ions on electron transport.
电催化氮还原反应（NRR）是通过合成NH₃来解决能源短缺和环境问题的关键过程。然而，氮活化的困难和较少的NRR活性位点限制了NRR的应用。因此，可以通过快速电子传输路径参与多电子反应和氮活化来提高NRR性能。掺杂过渡金属元素是在NRR中提供电子和电子通道的可行策略。本研究重点采用水热法合成Fe(MoO₄)₂（FeMo）和x%La掺杂的FeMo（x = 3、5、7和10）。La掺杂形成了Fe-O-Fe电子传输通道和氧空位，实现了Fe²⁺/Fe³⁺的等摩尔比。这种策略能够在Fe-O-Fe中实现超交换，进而提高电子传输速度以进行快速氢化反应。因此，Fe²⁺/Fe³⁺循环和氧空位的协同效应提高了NRR性能。值得注意的是，5%La-FeMo在-0.8 V（相对于可逆氢电极，RHE）时表现出优异的NRR性能（NH₃产率：29.6 μg h⁻¹ mg⁻¹，法拉第效率：5.8%）。这项工作基于离子不同价态对电子传输的影响，分析了催化剂电子环境对NRR性能的影响。
