中国科学技术大学江海龙团队报道了共价有机框架孔壁工程对包封Pt纳米颗粒的裁剪催化作用。相关研究成果发表在2024年7月2日出版的《德国应用化学》。

尽管负载型金属纳米颗粒（NPs）在多相催化中显示出了巨大的前景，但精确控制其与载体的相互作用仍然是一个重大挑战，这将深刻影响其催化性能。

该文中，Pt NPs被掺入硫醚官能化的共价有机框架（表示为COF-Sx）中，通过调节悬挂在COF孔壁上的硫醚密度，能够精确控制Pt NPs的尺寸和电子状态。值得注意的是Pt@COF-Sx在对氯硝基苯催化加氢制备对氯苯胺的过程中表现出非凡的选择性（>99%），这与嵌入无硫醚的COFs中的Pt NPs的低选择性形成鲜明对比。

此外，随着硫醚密度的增加，Pt@COF-Sx上的转换呈现火山型曲线。

该项工作提供了一种有效的方法，通过合理设计和精确剪裁载体结构，通过金属纳米粒子的微环境调节来调节其催化作用。

附：英文原文

Title: Tailoring Catalysis of Encapsulated Pt Nanoparticles by Pore Wall Engineering of Covalent Organic Frameworks

Author: Mingchun Guo, Xinyu Guan, Qiangqiang Meng, Ming-Liang Gao, Qunxiang Li, Hai-Long Jiang

Issue&Volume: 2024-07-02

Abstract: While supported metal nanoparticles (NPs) have shown significant promise in heterogeneous catalysis, precise control over their interaction with the support, which profoundly impacts their catalytic performance, remains a significant challenge. In this study, Pt NPs are incorporated into thioether-functionalized covalent organic frameworks (denoted COF-Sx), enabling precise control over the size and electronic state of Pt NPs by adjusting the thioether density dangling on the COF pore walls. Notably, the resulting Pt@COF-Sx demonstrate exceptional selectivity (>99%) in catalytic hydrogenation of p-chloronitrobenzene to p-chloroaniline, in sharp contrast to the poor selectivity of Pt NPs embedded in thioether-free COFs. Furthermore, the conversion over Pt@COF-Sx exhibits a volcano-type curve as the thioether density increases, due to the corresponding change of accessible Pt sites. This work provides an effective approach to regulating the catalysis of metal NPs via their microenvironment modulation, with the aid of rational design and precise tailoring of support structure.

DOI: 10.1002/anie.202410097

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202410097