催化学报 ›› 2026, Vol. 84: 314-323.DOI: 10.1016/S1872-2067(26)65013-9

• 论文 • 上一篇    下一篇

MOFs中单金属位点到双金属位点的动态配位转变和塑料的级联光重整制CO

李健a,b,c,d, 吴振发a,c, 张欣茹a,b, 颜同安a,b(), 罗金f, 薛文娟a,b, 吕照临e, 黄宏亮a,b,c(), 仲崇立a()   

  1. a 天津工业大学先进分离膜材料国家重点实验室, 天津 300387
    b 天津工业大学化学工程与技术学院, 天津 300387
    c 天津工业大学材料科学与工程学院, 天津 300387
    d 天津工业大学沧州研究院, 河北沧州 061000
    e 中国科学院青岛生物能源与过程研究所, 山东青岛 266101
    f 岭南师范学院化学化工学院, 广东湛江 524048
  • 收稿日期:2025-10-22 接受日期:2025-12-08 出版日期:2026-05-18 发布日期:2026-04-16
  • 通讯作者: *电子信箱: huanghongliang@tiangong.edu.cn (黄宏亮),
    yantongan@tiangong.edu.cn (颜同安),
    zhongchongli@tiangong.edu.cn (仲崇立).
  • 基金资助:
    国家自然科学基金(22578327);国家自然科学基金(22208244);国家自然科学基金(22578328);国家自然科学基金(22508302);国家自然科学基金(22038010);山东省自然科学基金(ZR2022QE005);山东省自然科学基金(ZR2023QB208);河北省自然科学基金(B2025110012)

Dynamic coordination transformation from single-to dual-metal sites in MOFs for cascaded photoreforming of plastics into CO

Jian Lia,b,c,d, Zhenfa Wua,c, Xinru Zhanga,b, Tongan Yana,b(), Jin Luof, Wenjuan Xuea,b, Zhaolin Lve, Hongliang Huanga,b,c(), Chongli Zhonga()   

  1. a State Key Laboratory of Advanced Separation Membrane Materials, Tiangong University, Tianjin 300387, China
    b School of Chemical Engineering and Technology, Tiangong University, Tianjin 300387, China
    c School of Materials Science and Engineering, Tiangong University, Tianjin 300387, China
    d Cangzhou Institute of Tiangong University, Cangzhou 061000, Hebei, China
    e Qingdao New Energy Shandong Laboratory, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, Shandong, China
    f School of Chemistry and Chemical Engineering, Lingnan Normal University, Zhanjiang 524048, Guangdong, China
  • Received:2025-10-22 Accepted:2025-12-08 Online:2026-05-18 Published:2026-04-16
  • Contact: *E-mail: huanghongliang@tiangong.edu.cn (H. Huang),
    yantongan@tiangong.edu.cn (T. Yan),
    zhongchongli@tiangong.edu.cn (C. Zhong).
  • Supported by:
    National Natural Science Foundation of China(22578327);National Natural Science Foundation of China(22208244);National Natural Science Foundation of China(22578328);National Natural Science Foundation of China(22508302);National Natural Science Foundation of China(22038010);Natural Science Foundation of Shandong Province(ZR2022QE005);Natural Science Foundation of Shandong Province(ZR2023QB208);Natural Science Foundation of Hebei(B2025110012)

摘要:

废弃塑料的高效资源化是当前环境与能源领域的一项关键挑战. 传统光催化受限于单金属位点(SMSs)难以协同驱动多步反应, 导致塑料降解与产物定向转化效率低下. 双金属位点(DMSs)催化剂通过相邻位点的电子与空间协同效应, 为塑料的“切割-转化”级联过程提供了新方案. 金属有机框架(MOFs)是构建DMSs的理想平台, 然而, 如何从热力学更稳定的SMSs前驱体出发, 通过动态配位化学实现向DMSs的可控转变, 并以此驱动塑料完全转化为单一产物的研究仍属空白. 因此, 开发一种基于MOFs动态结构转变的SMSs-to-DMSs转化策略, 对于突破现有催化体系瓶颈、实现塑料高选择性光催化升级具有重要的科学价值与应用前景.

本文创新性地提出无溶剂策略, 借助MOF的动态配位化学特性, 通过体相Cu1-SMSs/MOF的热驱动相变, 成功构建了二维Cu2-DMSs/MOF催化剂, 并实现了聚乙烯到CO的高效级联光重整. 综合运用原位傅里叶变换红外光谱、原位透射电镜及密度泛函理论计算, 系统阐明了相转变机理: 热处理下, Cu1-SMSs/MOF中Cu‒N键与Cl···H氢键的动态平衡被打破, 伴随HCl及副产物(C3N6H7)Cl的挥发, 促使孤立Cu原子迁移并重构, 最终形成稳定的Cu-Cu双金属配位单元(Cu2-N4结构). 球差校正电镜和X-射线吸收精细结构谱证实了金属在两种材料中均为原子级分散, 且Cu2-DMSs/MOF中形成了约1.94 Å的Cu‒Cu配位键. 所制备的Cu2-DMSs/MOF催化剂在无需任何牺牲剂的条件下, 展现出卓越的级联光催化性能. 其可将聚乙烯通过“氧化降解—还原转化”两步法高效转化为CO: 首先, 光激发产生的空穴与电子分别活化H2O和O2, 产生·OH和·O2活性自由基, 协同断裂聚乙烯的C‒C和C‒H键, 将其完全氧化为CO2, 产率高达2.32 mmol·g‒1·h‒1; 随后, 生成的CO2在双Cu位点上被原位光还原为CO, 产率达0.29 mmol·g‒1·h‒1, 且选择性为100%. 该综合性能相较于Cu1-SMSs/MOF及文献报道的氧化物等催化剂实现了数量级的提升. 循环使用后, 催化剂的晶体结构、化学组成及微观形貌无明显变化, 稳定性优异. 密度泛函理论计算证实, 双Cu位点向CO2的电子转移数(0.134 e)高于单Cu位点(0.076 e), 对CO2的吸附能(0.23 eV)更低, 且COOH中间体在双位点上的吸附能(‒1.73 eV)强于单位点(‒1.11 eV), 高效电荷转移与双位点协同作用是性能提升的核心原因.

综上, 本文发现了MOF中的动态配位化学可实现SMSs向DMSs的转化, 为双金属位点催化剂的开发开辟了新途径. 这种塑料转化为燃料的级联光催化转化策略, 为同时缓解白色污染危机和生产高价值化学品提供了极具前景的解决方案.

关键词: 金属有机框架, 双金属位点, 相变, 光级联反应, 塑料制燃料

Abstract:

Building on the success of catalytic single-metal sites (SMSs) in various model reaction systems, dual-metal sites (DMSs) could provide further breakthrough on catalysing complex reactions especially for those involving multiple cascading steps. Specifically, photocatalytic waste plastic conversion requires bond cleavage into small molecules followed by site-dependent transformations, where DMSs photocatalysts can, in principle, be highly active and selective through efficient charge separation and dual-site synergy. However, related studies remain rare since difficulty on efficient waste plastic photodegradation usually hinders subsequent catalytic conversion. Herein, we report for the first time that dual-metal sites are developed in a two-dimensional metal-organic framework (MOF) (Cu2-DMSs/MOF) derived from single-metal sites in bulk MOF (Cu1-SMSs/MOF) via dynamic coordination-driven transformation. The Cu2-DMSs/MOF catalyst exhibits enhanced photocatalytic performance without sacrificial agents, catalysing the cascading polyethylene-to-CO2 and CO2-to-CO reactions in one step. The polyethylene-to-CO2 degradation rate is 2.32 mmol·g‒1·h‒1 and the subsequent CO2-to-CO conversion proceeds at 0.29 mmol·g‒1·h‒1 with 100% selectivity, representing an order-of-magnitude enhancement compared with previous reports. The *O2 and *OH radicals formed from O2 and H2O oxidative cleave C‒C and C‒H bonds in polyethylene to CO2, which is subsequentially selective reduced to CO via multi-electron proton-coupling. This work offers a conceptual advance in designing dual-metal site catalysts, opening new avenues for cascading photocatalytic conversion of white pollution into valuable chemicals.

Key words: Metal-organic framework, Dual-metal sites, Phase transformation, Photocascade, Plastic-to-fuel conversion