A core–shell nanostructure of gold nanoparticles@covalent organic framework (COF) loaded with palladium nanoparticles (AuNPs@COF-PdNPs) was designed for the rapid monitoring of catalytic reactions with surface-enhanced Raman spectroscopy (SERS). The nanostructure was prepared by coating the COF layer on AuNPs and then in situ synthesizing PdNPs within the COF shell. With the respective SERS activity and catalytic performance of the AuNP core and COF-PdNPs shell, the nanostructure can be directly used in the SERS study of the catalytic reaction processes. It was shown that the confinement effect of COF resulted in the high dispersity of PdNPs and outstanding catalytic activity of AuNPs@COF-PdNPs, thus improving the reaction rate constant of the AuNPs@COF-PdNPs-catalyzed hydrogenation reduction by 10 times higher than that obtained with Au/Pd NPs. In addition, the COF layer can serve as a protective shell to make AuNPs@COF-PdNPs possess excellent reusability. Moreover, the loading of PdNPs within the COF layer was found to be in favor of avoiding intermediate products to achieve a high total conversion rate. AuNPs@COF-PdNPs also showed great catalytic activities toward the Suzuki–Miyaura coupling reaction. Taken together, the proposed core–shell nanostructure has great potential in monitoring and exploring catalytic processes and interfacial reactions.

中文翻译：

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核壳金纳米颗粒@负载钯的共价有机框架用于催化反应的原位表面增强拉曼光谱监测


负载钯纳米粒子的金纳米粒子@共价有机框架（COF）的核壳纳米结构（AuNPs@COF-PdNPs）被设计用于通过表面增强拉曼光谱（SERS）快速监测催化反应。该纳米结构是通过在 AuNP 上涂覆 COF 层，然后在 COF 壳内原位合成 PdNP 来制备的。凭借AuNP核和COF-PdNPs壳各自的SERS活性和催化性能，该纳米结构可以直接用于催化反应过程的SERS研究。结果表明，COF的限域效应导致PdNPs的高分散性和AuNPs@COF-PdNPs优异的催化活性，从而将AuNPs@COF-PdNPs催化的加氢还原反应速率常数提高了10倍。用 Au/Pd NP 获得。此外，COF层可以作为保护壳，使AuNPs@COF-PdNPs具有优异的可重复使用性。此外，发现COF层内负载PdNP有利于避免中间产物，从而实现高总转化率。 AuNPs@COF-PdNPs 对 Suzuki-Miyaura 偶联反应也表现出良好的催化活性。综上所述，所提出的核壳纳米结构在监测和探索催化过程和界面反应方面具有巨大的潜力。