Geng Wei, Xiong Yang-Yang, Chen Cheng-Xia, Ning Shunlian, Xiong Zhuo, Deng Songlin, Tan Yuxuan, Song Xianmeng, Pan Mei, Mayor Marcel, Su Cheng-Yong
Lehn Institute of Functional Materials, GBRCE for Functional Molecular Engineering, IGCME, School of Chemistry, Sun Yat-Sen University, Guangzhou, 510006, China.
State Key Laboratory of Physical Chemistry of Solid Surfaces, IChEM, College of Chemistry and Chemical, Engineering, Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen, 361005, China.
Angew Chem Int Ed Engl. 2025 Jun 17;64(25):e202505546. doi: 10.1002/anie.202505546. Epub 2025 Apr 21.
Developing multifunctional photocatalysts with efficient synergistic effects for selective photocatalytic CO reduction is sought-after yet challenging. Herein, a tandem photocatalytic strategy has been developed through sequential post-synthetic metalation (SPSM) of variable Ru/Co-sites into a trinuclear Cu-based COF, Cu-BPY-COF, to construct a series of tri-metallized covalent-organic frameworks (COFs), Cu-BPY-COF(Ru/Co)-X (X = 1, 2, or 3, corresponding to the Ru:Co molar ratios of 1/39.6, 1/19.6, or 1/12.7, respectively), for photocatalytic CO methanation in high selectivity. The introduction of a small fraction of Ru-sites confers the framework with enhanced visible-light response, while the Co-sites immobilized in the bipyridine units significantly boost the generation of CO to enrich its concentration around the active trinuclear Cu-sites, which enables dramatically improved photocatalytic CO reduction activity toward CH. Significantly, the optimized Cu-BPY-COF(Ru/Co)-2 showcases exceptional photocatalytic activity with a CH evolution rate of 31.5 µmol g h and selectivity of 95%, 15.0 times higher than that of Cu-BPY-COF(Ru) merely introducing Ru-photosensitizer. The underlying photocatalytic mechanism has been studied to unveil how the ternary Ru/Co/Cu-sites collaborate to result in highly efficient and selective CO-to-CH reduction, shedding light on the design of highly selective CO methanation photocatalysts by leveraging the synergistic effect of multiple active centers within heterometallic covalent-organic frameworks (HM-COFs).
开发具有高效协同效应的多功能光催化剂用于选择性光催化 CO 还原备受关注但具有挑战性。在此，通过将可变的 Ru/Co 位点顺序后合成金属化（SPSM）到三核铜基 COF（Cu-BPY-COF）中，开发了一种串联光催化策略，以构建一系列三金属化共价有机框架（COF），即 Cu-BPY-COF(Ru/Co)-X（X = 1、2 或 3，分别对应 Ru:Co 摩尔比为 1/39.6、1/19.6 或 1/12.7），用于高选择性光催化 CO 甲烷化。引入一小部分 Ru 位点赋予框架增强的可见光响应，而固定在联吡啶单元中的 Co 位点显著促进 CO 的生成，以富集其在活性三核 Cu 位点周围的浓度，这使得光催化 CO 还原为 CH 的活性显著提高。值得注意的是，优化后的 Cu-BPY-COF(Ru/Co)-2 展现出卓越的光催化活性，CH 生成速率为 31.5 µmol g⁻¹ h⁻¹，选择性为 95%，比仅引入 Ru 光敏剂的 Cu-BPY-COF(Ru)高 15.0 倍。已研究了潜在的光催化机理，以揭示三元 Ru/Co/Cu 位点如何协同作用导致高效且选择性的 CO 到 CH 还原，为通过利用异金属共价有机框架（HM-COF）内多个活性中心的协同效应设计高选择性 CO 甲烷化光催化剂提供了思路。
