Pore channels play a decisive for mass transport in catalytic systems. However, the influences of the location of catalytic sites inside or outside of the pore walls on the performance were still under-explored due, because it is difficult to construct sites anchored in or outside of pore walls. Herein, one-dimensional covalent organic frameworks (COFs) with precisely anchored active sites were used to explore the effects of channels on a typical oxygen reduction reaction (ORR) catalysis. Electrocatalytic evaluations showed that single Pt sites located inside of the channels exhibited higher kinetic activity compared to those anchored outside. The in situ spectroscopic analysis revealed that local reconstruction of Pt–Cl breaking and potential-induced anion transport occurred more effectively inside the channels. The superior anion transportability and kinetic activity of the inside-channel active sites also facilitated *OH desorption during the ORR process outperforming their outside-channel counterparts. The results of this study provide strategies for designing active sites in porous catalysts for heterogeneous catalysis.

中文翻译：

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用于氧还原反应的一维共价有机框架中孔壁的内/外催化位点


孔通道对催化系统中的质量传输起着决定性的作用。然而，由于难以构建锚定在孔壁内部或外部的位点，因此孔壁内部或外部的催化位点位置对性能的影响仍未得到充分探索。在此，使用具有精确锚定活性位点的一维共价有机框架 （COF） 来探索通道对典型氧还原反应 （ORR） 催化的影响。电催化评估表明，与锚定在通道外部的 Pt 位点相比，位于通道内部的单个 Pt 位点表现出更高的动力学活性。原位光谱分析表明，Pt-Cl 断裂和电位诱导阴离子传输的局部重建在通道内发生得更有效。通道内活性位点卓越的阴离子转运性和动力学活性也促进了 ORR 过程中 *OH 的解吸，优于其通道外对应物。本研究的结果为多孔催化剂中用于非均相催化的活性位点设计提供了策略。