Wang Jinyan, Sun Huimin, Huang Shaoda, Duan Fang, Gu Hongwei, Du Mingliang, Lu Shuanglong
Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, P. R. China.
Key Laboratory of Carbon Materials of Zhejiang Province, Wenzhou University, Wenzhou 325000, P. R. China.
ACS Appl Mater Interfaces. 2024 Oct 23;16(42):56459-56468. doi: 10.1021/acsami.4c11479. Epub 2024 Oct 8.
Covalent-organic frameworks (COFs) are promising electrocatalysts for the selective synthesis of HO through the two-electron oxygen reduction reaction (2e ORR). However, the design and synthesis of efficient and stable COF-based electrocatalysts is still challenging. In this work, a predesigned 1,10-phenanthroline-based one-dimensional COF (PYTA-PTDE-COF) was constructed to anchor main group metal (In, Sn, and Sb) as electrocatalysts toward 2e ORR. The catalysts are featured with fully exposed metalated side chains. Structural characterization revealed that PYTA-PTDE-M's (M = In, Sn, and Sb) are all quite similar, except for the coordinated metal ions with the maintenance of good crystallinity. They all exhibited satisfying activity and selectivity toward 2e ORR under alkaline conditions. Among them, PYTA-PTDE-Sb exhibited the best performance ( is 0.765 V, the HO selectivity is 96%, and the yield rate is 209.2 mmol g h). Moreover, it also delivered superior stability with almost no attenuation of current density during the long-time test. Theoretical calculations revealed that the Sb metal site in the COFs has the lowest adsorption strength of *OOH, which could be the main reason for its superior selectivity. The PYTA-PTDE-Sb assembled zinc-air battery realizes not only the supply of clean energy but also the production of green chemicals, showing it is highly promising in practical applications. This work offers an example for designing main group metal-coordinated 1D COFs and reveals fundamental structure-activity relationship toward 2e ORR.
共价有机框架（COFs）是通过两电子氧还原反应（2e ORR）选择性合成H₂O₂的有前景的电催化剂。然而，设计和合成高效且稳定的基于COF的电催化剂仍然具有挑战性。在这项工作中，构建了一种预先设计的基于1,10-菲咯啉的一维COF（PYTA-PTDE-COF），以锚定主族金属（In、Sn和Sb）作为2e ORR的电催化剂。这些催化剂的特点是金属化侧链完全暴露。结构表征表明，除了配位金属离子外，PYTA-PTDE-M（M = In、Sn和Sb）都非常相似，并且保持了良好的结晶度。它们在碱性条件下对2e ORR均表现出令人满意的活性和选择性。其中，PYTA-PTDE-Sb表现出最佳性能（E₁/₂为0.765 V，H₂O₂选择性为96%，产率为209.2 mmol g⁻¹ h⁻¹）。此外，在长时间测试中，它还具有卓越的稳定性，电流密度几乎没有衰减。理论计算表明，COFs中的Sb金属位点对*OOH的吸附强度最低，这可能是其具有卓越选择性的主要原因。PYTA-PTDE-Sb组装的锌空气电池不仅实现了清洁能源的供应，还实现了绿色化学品的生产，表明其在实际应用中具有很高的前景。这项工作为设计主族金属配位的一维COFs提供了一个例子，并揭示了2e ORR的基本构效关系。
