催化学报 ›› 2026, Vol. 83: 258-270.DOI: 10.1016/S1872-2067(26)64989-3

• 论文 • 上一篇    下一篇

切换卟啉基共价有机框架中金属位点调控电催化亚硝酸盐还原反应的产物选择性

李冬华a, 胡洪寅a,b, 周锦烨a, 缪涵韵a, 武宇a, 王金艳a, 郭宝春c, 杜明亮a,d,*(), 陆双龙a,*()   

  1. a江南大学化学与材料工程学院, 合成与生物胶体教育部重点实验室, 江苏无锡 214122
    b清华大学深圳国际研究生院, 材料研究院, 广东深圳 518055
    c华南理工大学材料科学与工程学院, 广东广州 510640
    d浙江省现代纺织技术创新中心, 浙江绍兴 312000
  • 收稿日期:2025-08-06 接受日期:2025-09-28 出版日期:2026-04-18 发布日期:2026-03-04
  • 通讯作者: * 电子信箱: lushuanglong@jiangnan.edu.cn (陆双龙), du@jiangnan.edu.cn (杜明亮).
  • 基金资助:
    国家自然科学基金(52173201);国家自然科学基金(21905115);中央高校基本科研业务费(JUSRP622039)

Steering product selectivity via metallic site-dependent pathways in porphyrin-based covalent organic frameworks for electrocatalytic nitrite reduction

Donghua Lia, Hongyin Hua,b, Jinye Zhoua, Hanyun Miaoa, Yu Wua, Jinyan Wanga, Baochun Guoc, Mingliang Dua,d,*(), Shuanglong Lua,*()   

  1. aKey Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, Jiangsu, China
    bInstitute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, Guangdong, China
    cSchool of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, Guangdong, China
    dZhejiang Provincial Innovation Center of Advanced Textile Technology, Shaoxing 312000, Zhejiang, China
  • Received:2025-08-06 Accepted:2025-09-28 Online:2026-04-18 Published:2026-03-04
  • Contact: * E-mail: lushuanglong@jiangnan.edu.cn (S. Lu), du@jiangnan.edu.cn (M. Du).
  • Supported by:
    National Natural Science Foundation of China(52173201);National Natural Science Foundation of China(21905115);Fundamental Research Funds for the Central Universities(JUSRP622039)

摘要:

电催化亚硝酸盐还原(NO2RR)已成为可持续制备羟胺(NH2OH)和氨(NH3)的一种前景广阔的策略. 在这一背景下, 单原子催化剂(SACs)因其能够提供具有高活性、可调的原子精确的催化位点, 是NO2RR的理想催化剂. SACs的活性中心在于金属中心, 其在调控产物分布和反应途径中起着关键作用. 通过合理选择并调控金属中心, 可实现对羟胺与氨选择性的调节, 从而设计出能有效调控特定反应途径的催化剂. 这些研究强调了金属位点特性在决定产物选择性方面的关键作用, 不仅为深入理解NO2RR机制提供了参考, 更为通过合理设计SACs以在该反应中获得目标产物提供了重要的机理层面指导. 共价有机框架(COF)作为一种设计依赖于金属位点的催化途径的理想平台, 可精确控制金属中心和官能团以提高催化活性. 这种多功能性不仅能为NOxRR等反应开发出多样化的SACs, 还凸显了基于COF的催化剂在未来应用中的巨大潜力.
本文合成了一系列高结晶度金属-卟啉基共价有机框架(M-TAPP-TTF COF, M = Zn, Fe), 用于研究NO2RR反应过程中不同金属中心-产物选择性的相关性及其反应机制. X射线衍射、透射电镜、X射线光电子能谱、红外光谱等结果表明, 成功合成了M-TAPP-TTF COF, 且Zn/Fe均匀分布在COF中. 以这些COF材料为催化剂, 在H-型电解池中, 进行NO2RR测试; 实验结果表明, COF中的锌卟啉能有效抑制NO2向NH3的深度还原. 在整个测试电压范围内, NH2OH是最主要的产物, 在电压为-1.5 V vs. Ag/AgCl时, NH2OH的最大法拉第效率为71.4%, -2.0 V时的产率为542.3 μmol h-1 mgCOF-1. 相反, 当Fe作为金属活性中心时, 主要产物为NH3, NH3的选择性显著提高. NH3的最大法拉第效率为72.6%, -2.0 V时的产率为867.2 μmol h-1 mgCOF-1. 实验结果表明, 金属配位的TAPP-TTF COF中, 不同的金属中心在NO2RR过程中具有不同的选择性. 为了进一步说明活性位点与其相应的NO2RR性能之间的关系, 进行了密度泛函理论计算和原位拉曼光谱分析. Zn-TAPP-TTF COF中的Zn中心有利于*NO加氢为*NHO路径, 从而导致NH2OH的选择性提高. 与此相反, Fe-TAPP-TTF COF中的Fe中心倾向于*NO到*NOH的途径, 然后通过N-O键裂解将*NOH进一步还原为NH3. 这些发现有助于加深对金属位点依赖性反应机制的理解, 为合理设计具有可调选择性NO2RR催化剂奠定了基础.
综上, 本文成功合成了金属-卟啉基COF催化剂, 揭示了金属位点在调节产物选择性和反应路径中的关键作用, 为深入理解NO2RR反应机制提供了理论指导. 本研究不仅为设计具有可调选择性的NO2RR催化剂提供了新的思路, 也为基于COF平台, 面向NOxRR等反应, 设计开发高效催化剂, 提供了理论支持.

关键词: 共价有机框架, 亚硝酸盐还原反应, 金属位点, 电催化, 羟胺/氨

Abstract:

Electrocatalytic nitrite reduction represents a sustainable and efficient alternative to conventional routes for the production of hydroxylamine and ammonia. A comprehensive understanding of the correlation between the nature of catalytic active sites and their electrocatalytic performance is essential, particularly in steering product selectivity. Herein, we report the synthesis of a series of highly crystalline metalated porphyrin-based covalent organic frameworks (M-TAPP-TTF COFs, M = Zn, Fe), enabling systematic investigation of the structure-selectivity relationships and mechanistic pathways dictated by distinct metallic centers during NO2RR. Experimental evaluations reveal that fully metalated Zn-porphyrins in COFs could efficiently inhibit the deep reduction of NO2- to NH3 even at higher potentials, with NH2OH as the major product throughout the entire voltage window. The maximum Faradaic efficiency of NH2OH (FENH2OH) is 71.4% and its yield rate could reach up to 542.3 μmol h-1 mgCOF-1 at -2.0 V vs. Ag/AgCl. Meanwhile, when the metallic centers in the porphyrins were switched to Fe ions, it exhibits superior selectivity toward NH3 formation, achieving a maximum FENH3 of 72.6% and a yield rate of 867.2 μmol h-1 mgCOF-1 at -2.0 V vs. Ag/AgCl. Complementary density functional theory calculations and in-situ Raman spectroscopy reveal that the Zn active sites in Zn-TAPP-TTF COF promote the preferential hydrogenation of *NO to *NHO, followed by the thermodynamically favorable desorption of NH2OH, thereby enhancing selectivity toward NH2OH. In contrast, Fe active sites in Fe-TAPP-TTF COF favor the *NO to *NOH pathway, in which *NOH undergoes further reduction via N‒O bond cleavage with following favorable desorption of NH3. These insights into metallic site-dependent reaction pathways offer a mechanistic basis for the rational design of single-atom catalysts with tunable selectivity in electrocatalytic NO2RR.

Key words: Covalent organic frameworks, Nitrite reduction reaction, Metallic sites, Electrocatalysts, Hydroxylamine and ammonia