Two-dimensional metal-containing covalent organic frameworks (COFs) have been employed as electrocatalysts. However, the metal sites were stacked within the layers with strong interactions, which hindered mass transport to them in the catalytic process. Herein, we constructed a pore-confined catalyst in a vinylene-linked COF for the oxygen reduction reaction (ORR) via the Katritzky reaction. By anchoring the catalytic sites along the pore walls with covalent bonds, the catalytic units were well-exposed during the catalytic process and retained crystallinity and porosity, facilitating mass access to the metal sites. In addition, the electron/charge transported from the framework to the metal units modulated the electronic states, thus improving the catalytic activity. The catalytic COF exhibited a half-wave potential of 0.85 V and a mass activity of 109.7 A g^–1, which are better than those of other reported COFs. Theoretical calculations revealed that the interaction between the framework and metal sites contributed to the easy formation of OOH* and OH*, resulting in high activity. This work provides insights into designing catalytic COFs based on C═C linkages.

中文翻译：

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在乙烯基连接的共价有机框架中构建孔域限制催化剂进行氧还原反应


二维含金属共价有机框架 （COF） 已被用作电催化剂。然而，金属位点堆叠在层内，具有很强的相互作用，这阻碍了催化过程中向它们的质量传输。在此，我们在乙烯基连接的 COF 中构建了一种孔域限制催化剂，用于通过 Katritzky 反应进行氧还原反应 （ORR）。通过用共价键沿孔壁锚定催化位点，催化单元在催化过程中暴露良好，并保持结晶度和孔隙率，便于大量进入金属位点。此外，从框架传输到金属单元的电子/电荷调节了电子态，从而提高了催化活性。催化 COF 表现出 0.85 V 的半波电位和 109.7 A g^–1 的质量活性，优于其他已报道的 COFs。理论计算表明，框架和金属位点之间的相互作用有助于 OOH* 和 OH* 的容易形成，从而导致高活性。这项工作为基于 C═C 键的设计催化 COF 提供了见解。