化学学报 上一篇    

综述

基于金属有机框架的中性介质硝酸盐电催化还原制氨:设计策略与机理研究

何乾龙, 胡洁颖, 钟礼匡*, 何军*   

  1. 轻工化工学院, 广东工业大学, 广州 510006, 广东省, 中国
  • 投稿日期:2026-01-31
  • 作者简介:框架材料化学”专辑

Metal-Organic Framework-Based Electrocatalysts for Neutral Nitrate-to-Ammonia Conversion: Design Strategies and Mechanistic Insights

He Qianlong, Hu Jieying, Chung Lai-Hon*, He Jun*   

  1. School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, Guang-dong, P. R. China
  • Received:2026-01-31
  • Contact: * E-mail: laihonchung@gdut.edu.cn; junhe@gdut.edu.cn
  • Supported by:
    National Natural Science Foundation of China (No. 22371054, 22301045), the Foundation of Basic and Applied Basic Research of Guangdong Province (No. 2024A1515012801, 2024B1515120009) and the Postdoctoral Fellowship Program of CPSF (GZC20240311).

随着农业与工业的不断发展,目前全球范围内水体中的硝酸盐(NO3-)污染仍然十分严重,并且呈现出多点分散的特点,使用硝酸根电化学还原(eNO3RR)技术,可以在常温常压下将NO3-废弃物还原成对人类有用的物质——氨(NH3)。然而,在接近实际水体环境的中性pH条件下,eNO3RR面临质子供给受限、析氢副反应竞争、亚硝酸盐(NO2-)累积风险以及催化剂寿命不足等多重瓶颈。近期备受关注的金属有机框架(MOF)材料潜力巨大,其可调的多孔结构与明确的活性位点有利于提高NO3⁻还原效率与选择性。这一领域近期取得了巨大的进展,卓越的MOF基材料已达到接近99%的NH3法拉第效率,在抑制NO2-累积的同时将NH3产率推高至>23000 μg h-1 mgcat-1,通过构建导电复合结构与衍生化策略,MOF基材料能在工业级电流密度(>950 mA cm-2)下保持>90%的法拉第效率和10小时以上的稳定性。本综述聚焦MOF基电催化剂,系统剖析了中性eNO3RR的机理,借助MOF的原子级可设计性,通过单原子/簇调控、多金属协同、导电复合以及衍生化策略,可精准克服中性条件下eNO3RR的质子供给、析氢竞争及稳定性瓶颈,实现从污染物到NH3的高效转化。但是目前距离这一目标仍存在许多挑战:催化过程中的活性中心动态识别不够清晰准确,真实水体中的长效稳定性有待验证,以及规模化合成等问题亟待解决。

关键词: 金属有机框架, MOF衍生物, 电催化硝酸根还原, 氨合成, 中性环境

With the continuous development of agriculture and industry, nitrate (NO3-) pollution in water bodies worldwide remains a serious issue, characterized by decentralized distribution across multiple sites. The electrocatalytic nitrate reduction reaction (eNO3RR) technology enables the reduction of NO3- waste into ammonia (NH3)—a substance useful to humans—under ambient temperature and pressure. However, under near-neutral pH conditions that mimic actual aquatic environments, eNO3RR faces multiple bottlenecks, including limited proton supply, competition from hydrogen evolution side reactions, risks of nitrite (NO2-) accumulation, and insufficient catalyst lifespan. Metal-organic framework (MOF) materials, which have attracted significant attention recently, hold tremendous potential. Their tunable porous structures and well-defined active sites are conducive to improving NO3- reduction efficiency and selectivity. Remarkable progress has been made in this field: advanced MOF-based materials have achieved an NH3 Faraday efficiency (FE) of nearly 99%, suppressed NO2- accumulation, and pushed the NH3 yield to >23000 μg h⁻1 mgcat1. By constructing conductive composite structures and employing derivatization strategies, MOF-based materials can maintain a FE of >90% and remain stable for over 10 hours at industrial-level current densities (>950 mA cm⁻2). This review focuses on MOF-based electrocatalysts and systematically analyzes the mechanism of neutral eNO3RR. Leveraging the atomic-level designability of MOFs, strategies such as single-atom/cluster regulation, multi-metal synergy, conductive composites, and derivatization can precisely overcome the bottlenecks of proton supply, hydrogen evolution competition, and stability in neutral eNO3RR, enabling efficient conversion of pollutants to NH3. Nevertheless, several challenges remain before this goal is fully achieved: the dynamic identification of active centers during catalysis is not sufficiently clear and accurate, long-term stability in real water bodies needs verification, and issues such as large-scale synthesis urgently require solutions.

Key words: Metal-organic frameworks, MOF derivatives, electrocatalytic nitrate reduction reaction, ammonia synthesis, neutral conditions