催化学报

催化学报 ›› 2026, Vol. 81: 310-318.DOI: 10.1016/S1872-2067(25)64915-1

• 论文 • 上一篇    下一篇

室温下直接电化学液氨分解实现现场产氢

石苗苗a,1, 何月轩a,1, 张宁b, 鲍迪b, 赵大明b, 钟海霞b(), 鄢俊敏a(), 蒋青a   

  1. a 吉林大学材料科学与工程学院, 汽车材料教育部重点实验室, 吉林长春 130022
    b 中国科学院长春应用化学研究所, 稀土资源利用国家重点实验室, 吉林长春 130022
  • 收稿日期:2025-08-07 接受日期:2025-10-11 出版日期:2026-02-18 发布日期:2025-12-26
  • 通讯作者: *电子信箱: junminyan@jlu.edu.cn (鄢俊敏),hxzhong@ciac.ac.cn (钟海霞).
  • 作者简介:1共同第一作者.
  • 基金资助:
    国家重点研发计划(2021YFB4000603);国家自然科学基金(52273277);国家自然科学基金(52072362);国家自然科学基金(52302094)

Direct electrochemical liquid ammonia splitting for onsite hydrogen generation under room temperature

Miao-Miao Shia,1, Yue-Xuan Hea,1, Ning Zhangb, Di Baob, Da-Ming Zhaob, Hai-Xia Zhongb(), Jun-Min Yana(), Qing Jianga   

  1. a Key Laboratory of Automobile Materials, Ministry of Education, School of Materials Science and Engineering, Jilin University, Changchun 130022, Jilin, China
    b State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, Jilin, China
  • Received:2025-08-07 Accepted:2025-10-11 Online:2026-02-18 Published:2025-12-26
  • Contact: *E-mail: junminyan@jlu.edu.cn (J. Yan),hxzhong@ciac.ac.cn (H. Zhong).
  • About author:1Contributed equally to this work.
  • Supported by:
    National Key Research and Development Program of China(2021YFB4000603);National Natural Science Foundation of China(52273277);National Natural Science Foundation of China(52072362);National Natural Science Foundation of China(52302094)

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摘要：

氨(NH3)因其高储氢密度(17.6 wt%)、易于液化运输及无碳排放等优势, 被视为极具潜力的氢能载体. 然而, 传统热催化氨分解制氢需在400-700 °C高温下进行, 能耗高、启动慢且伴随温室气体排放, 限制了其实际应用. 电化学液氨分解(ELADH)可在室温条件下实现氢气与氮气的生成, 理论电压仅为0.077 V, 远低于水电解的1.23 V, 具有更高的能量效率. 然而, 该技术长期以来受限于反应动力学缓慢、催化剂活性低及系统稳定性差等关键问题, 尤其是在强腐蚀性液氨电解液中, 多数催化剂在数小时内即失活. 因此, 开发高效、稳定的电催化剂及优化电解系统, 成为推动ELADH技术走向实用的关键.

本研究旨在通过理性设计电催化系统与开发高性能Ru基催化剂, 实现室温下高效、稳定的电化学液氨分解制氢. 首先通过密度泛函理论计算系统评估了Pt, Rh, Ir, Ru等贵金属及Ru单原子结构对NH3分解的催化潜力. 结果表明, Ru(101)晶面在N‒H键解离步骤中能垒最低(0.68 eV), 且对*H中间体的吸附能适中(‒0.74 eV), 兼具优异的NH3活化能力与高效的H2脱附动力学, 显著优于其他金属及其单原子构型. 基于此, 采用两步高温热解法制备了氮掺杂碳负载的Ru纳米颗粒(Ru NPs-CN)与Ru单原子(Ru SAs-CN)催化剂. 结构表征显示, Ru NPs-CN中Ru以平均粒径约8.5 nm的纳米颗粒形式均匀分布, 主要暴露(101)晶面, 比表面积达319.4 m2 g‒1, 具备丰富的介孔结构, 利于反应传质. 电化学测试在优化后的三电极体系中进行, 以石墨板为阳极、Ag/AgNO3为参比电极、NH4PF6为电解质. 性能评估表明, Ru NPs-CN在析氢反应中表现出优异的活性与稳定性: 在‒10 mA cm‒2电流密度下过电位仅为‒1.01 V (相对于NHE), 在‒1.47 V电位下电流密度高达‒910 mA cm‒2, 远优于Ru SAs-CN及商用Pt/C催化剂. 且塔菲尔斜率为101 mV dec‒1, 电荷转移电阻小, 表明其反应动力学更快. 此外, 在多级电流测试及长达100 h的恒电流电解中, Ru NPs-CN均表现出优异的稳定性与抗波动能力, 结构表征证实反应后催化剂形貌未发生明显变化. 同位素标记实验与气相色谱测试进一步验证了H2与N2的气体产物完全来源于液氨分解.

综上, 本工作成功构建了一种在室温、低压(<1 MPa)下高效、稳定运行的电化学液氨分解系统, 通过理论计算与实验相结合, 明确了Ru(101)晶面在促进N‒H键解离与氢脱附中的关键作用, 为设计高性能ELADH催化剂提供了新思路. 未来研究可聚焦于优化阳极材料以降低槽压、开发高效气体分离技术, 并开展系统经济性与全生命周期评估, 推动该技术向实际应用迈进. 本研究为室温下NH3作为安全、高效氢载体的现场制氢提供了可行的技术路径与理论支撑.

关键词: 液氨分解, 电催化, 钌基催化剂, 析氢反应, 稳定性

Abstract:

Ammonia (NH3) is seen to be promising hydrogen carrier, but its decomposition into hydrogen (H2) has been plagued by high operating temperature (400‒700 °C) and long start-up time. Here, we present that directly electrochemical liquid NH3 decomposition (ELADH) method could realize efficient onsite H2 generation at room-temperature, whereas active and stable electrocatalytic system is challenging. Through rationally optimizing the electrolysis system with Ru catalysts, we achieved an active and durable ELADH into H2 under ambient temperature. It was found that Ru nanoparticles (Ru NPs) with (101) facet could effectively promote the favorable N-H dissociation and hydrogen desorption, and thus accelerate the slow reaction kinetics. The as-prepared Ru NPs on nitrogen carbon exhibit lower potential of ‒1.01 V vs. NHE at ‒10 mA cm‒2 and larger current density of ‒910 mA cm‒2 at ‒1.47 V vs. NHE, superior to Ru single atoms and commercial Pt/C. Importantly, this system affords stable H2 evolution under 100 h continuous electrolysis without apparent degradation, far beyond the reported catalysts. This work paves the new way of room-temperature onsite H2 production and presents insightful understanding of the electrochemical liquid ammonia splitting process.

Key words: Liquid ammonia decomposition, Electrocatalysis, Ruthenium-based catalyst, Hydrogen evolution, Stability