Creating free-access active sites and regulating their interaction with substrates are crucial for efficient catalysis, yet remain a grand challenge. Herein, naked Pd nanoparticles (NPs) have been encapsulated in a metal-organic framework (MOF), MIL-101-NH₂, to afford Pd@MIL-101-NH₂. The hydrophobic perfluoroalkyls were post-synthetically modified onto -NH₂ group to yield Pd@MIL-101-F_x (x = 3, 5, 7, 11, 15), which engineer the MOF pore walls to regulate Pd surrounding microenvironment and interaction with substrates. As a result, both the dehydrogenation coupling of organosilane and hydrogenation of halogenated nitrobenzenes show that their activity and selectivity can be greatly promoted upon hydrophobic modification due to the favorable substrate enrichment and regulated interactions between Pd and the modified MOF hosts, far surpassing the traditional supported or surfactant-protected Pd NPs. We envision metal NPs@MOF composites would be an ideal platform integrating the inherent activity of well-accessible metal sites with engineered microenvironment via readily tunable MOFs.

创建自由访问的活性位点并调节它们与底物的相互作用对于有效催化至关重要，但仍然是一个巨大的挑战。此处，裸露的Pd纳米颗粒（NPs）已封装在金属有机框架（MOF）MIL-101-NH _2中，得到Pd @ MIL-101-NH ₂。将疏水性全氟烷基后合成修饰到-NH ₂基上，得到Pd @ MIL-101-F _x（x = 3、5、7、11、15），可对MOF孔壁进行工程处理以调节Pd周围的微环境以及与底物的相互作用。结果，有机硅烷的脱氢偶联和卤代硝基苯的氢化都表明，由于Pd与改性的MOF主体之间的良好的底物富集和调节的相互作用，疏水改性后可以大大提高它们的活性和选择性，远远超过了传统方法。或表面活性剂保护的Pd NP。我们设想金属NPs @ MOF复合材料将是一个理想的平台，可通过易于调整的MOF将易于访问的金属位点的固有活动与工程化的微环境相结合。