催化学报

催化学报 ›› 2025, Vol. 78: 343-353.DOI: 10.1016/S1872-2067(25)64813-3

• 论文 • 上一篇    

近邻调控钌单原子位点优化Fe-N4空间畸变增强酸性氧还原反应

殷述虎a,1, 程晓阳b,1, 韩瑜b, 朱挺a,*(), 于忠卫a, 黄蕊b,*(), 徐骏a,*(), 姜艳霞b,*(), 孙世刚b   

  1. a南通大学微电子学院(集成电路学院), 江苏省半导体设备和集成电路设计封装和测试重点实验室, 江苏南通 226019
    b厦门大学化学化工学院, 教育部电化学技术工程研究中心, 固体表面物理化学国家重点实验室, 福建厦门 361005
  • 收稿日期:2025-05-31 接受日期:2025-07-17 出版日期:2025-11-18 发布日期:2025-10-14
  • 通讯作者: *电子信箱: cmzhuting@ntu.edu.cn (朱挺), rhuang@xmu.edu.cn (黄蕊), xjun@ntu.edu.cn (徐骏), yxjiang@xmu.edu.cn (姜艳霞).
  • 作者简介:1共同第一作者.
  • 基金资助:
    国家自然科学基金(22502091);国家自然科学基金(22288102);国家自然科学基金(22172134);国家自然科学基金(22472143);中国工程院战略研究与咨询项目(22-HN-ZD-02);厦门市自然科学基金(20241302);南通大学大型仪器开放课题(KFJN2561)

Proximity-engineered Ru single-atom sites modulate Fe-N4 spatial distortion for enhanced acidic oxygen reduction reaction

Shu-Hu Yina,1, Xiao-Yang Chengb,1, Yu Hanb, Ting Zhua,*(), Zhong-Wei Yua, Rui Huangb,*(), Jun Xua,*(), Yan-Xia Jiangb,*(), Shi-Gang Sunb   

  1. aSchool of Microelectronics and Integrated Circuits, Jiangsu Key Laboratory of Semi. Dev. & IC Design, Package and Test, Nantong University, Nantong 226019, Jiangsu, China
    bState Key Laboratory of Physical Chemistry of Solid Surfaces, Engineering Research Center of Electrochemical Technologies of Ministry of Education, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China
  • Received:2025-05-31 Accepted:2025-07-17 Online:2025-11-18 Published:2025-10-14
  • Contact: *E-mail: cmzhuting@ntu.edu.cn (T. Zhu), rhuang@xmu.edu.cn (R. Huang), xjun@ntu.edu.cn (J. Xu), yxjiang@xmu.edu.cn (Y. Jiang).
  • About author:1Contributed equally to this work.
  • Supported by:
    National Natural Science Foundation of China(22502091);National Natural Science Foundation of China(22288102);National Natural Science Foundation of China(22172134);National Natural Science Foundation of China(22472143);Strategic Research and Consultancy Project of the Chinese Academy of Engineering(22-HN-ZD-02);Natural Science Foundation of Xiamen, China(20241302);Large Instruments Open Foundation of Nantong University(KFJN2561)

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摘要：

开发高效非贵金属氧还原(ORR)催化剂是降低质子交换膜燃料电池(PEMFCs)成本的关键. 目前, 单分散的铁-氮-碳(Fe-N-C)被认为是最有潜力替代贵金属Pt的非贵金属催化剂. 然而, 该类催化剂仍面临两大挑战: 一是其本征活性低, 导致在PEMFCs中活性低; 二是ORR过程中产生的活性氧物种(ROS)使得Fe-N-C发生严重的氧化降解, 导致工况稳定性差. 目前采用的策略是引入自由基清除剂(如二氧化铈, CeO2), 以抑制ROS引发的降解过程. 然而, 这类对ORR呈惰性的添加剂存在固有的权衡: 在提升稳定性的同时, 往往会导致催化活性下降; 且过高的添加量会进一步损害阴极催化剂层的导电性能. 因此, 发展一种能够协同缓解自由基氧化、优化非贵金属催化剂本征催化性能的方法, 已成为当前重要的研究方向.

本文通过两步热解法成功合成钌-铁双位点催化剂(RuFe-N-C). 先进表征技术证实, Ru单原子位点与Fe-N4位点形成原子级邻近结构, 投影距离约1.7 Å. 这种Ru-Fe配对诱导了显著的结构扰动: Fe-N键长拉伸, Fe-N4位点空间畸变率达2.5%. 优化后的RuFe-N-C催化剂在ORR中展现出卓越性能: 在150 kPa绝对氢氧条件下, 半波电位(E1/2)达0.840 V, 峰值功率密度(Pmax)高达938 mW cm-2. 相较于Fe-N-C催化剂(E1/2 = 0.819 V, Pmax = 662 mW cm-2), 实现21 mV半波电位和42%功率密度的的性能提升. 同时, 该催化剂具备优异稳定性, 经历10000次加速衰减测试(ADT)后, 电位衰减仅17 mV, 远低于Fe-N-C (ΔE1/2 = -38 mV). 实验研究揭示了双功能协同效应: (1)本征活性提升——邻近Ru位点使Fe-N4活性中心的本征活性显著增强, 在0.85 V电位下的转换频率达17.86 e site-1 s-1, 较文献报道的先进Fe-N-C催化剂(< 1 e site-1 s-1)提升1‒2个数量级; (2)自由基清除机制——Ru中心作为高效电子中继站, 有效清除反应中产生的有害ROS, 经ADT和质子交换膜燃料电池耐久性测试证实, 该机制显著缓解了自由基诱导的催化剂降解.

综上, 本文通过精准的协同电子调控策略, 构建了高性能双金属单原子催化剂新范式: 在Fe-N4位点邻近引入Ru辅助位点, 同步优化催化活性与长期稳定性, 突破了传统Fe-N-C体系的瓶颈, 为能源转换技术中的先进催化剂设计开辟了新路径.

关键词: 氧还原反应, 非贵金属催化剂, Ru-Fe双位点, 空间畸变, 燃料电池

Abstract:

Fe-N-C catalysts are promising substitutes for precious-metal platinum in acidic oxygen reduction reactions (ORR), yet their moderate intrinsic activity and susceptibility to reactive oxygen species (ROS)-induced degradation hinder practical implementation. Herein, we fabricate a Ru-Fe dual-site catalyst (RuFe-N-C) through a two-step pyrolysis strategy. Structural characterization reveals atomic-scale proximity between Ru single atoms and Fe-N4 moieties, exhibiting a projected distance of ~1.7 Å. This configuration induces Fe-N bond elongation accompanied by 2.5% lattice distortion. The optimized RuFe-N-C catalyst exhibits high ORR performance, with a half-wave potential (E1/2) of 0.840 V and peak power density (Pmax) of 938 mW cm-2 under 150 kPa absolute H2-O2. These metrics signify substantial enhancements relative to conventional Fe-N-C benchmarks (+21 mV in E1/2 and +42% in Pmax). Moreover, the catalyst maintains outstanding stability, showing merely 17 mV E1/2 decay after 10000 accelerated durability test (ADT) cycles. Experimental analyses reveal a bifunctional mechanism: (1) Adjacent Ru sites substantially enhance the intrinsic ORR activity of Fe-N4 moieties, delivering a notable turnover frequency (TOF = 17.86 e site-1 s-1 at 0.85 V vs. RHE) that exceeds state-of-the-art Fe-N-C benchmarks by 1-2 orders of magnitude (< 1 e site-1 s-1); (2) Ru centers function as electron relays that facilitate ROS scavenging, thus suppressing degradation. This work establishes a paradigm for engineering bimetallic single-atom catalysts through synergistic electronic modulation to concurrently enhance activity and stability.

Key words: Oxygen reduction reaction, PGM-free catalyst, Ru-Fe dual site, Spatial distortion, Fuel cells