Kim Seongwoo, Lee Jooyeon, Jeoung Sungeun, Moon Hoi Ri, Kim Min
Department of Chemistry and BK21Plus Research Team, Chungbuk National University, Cheongju, 28644, Republic of Korea.
Department of Chemistry, Ulsan National Institute of, Science and Technology, Ulsan, 44919, Republic of Korea.
Chemistry. 2020 Jun 18;26(34):7568-7572. doi: 10.1002/chem.202000933. Epub 2020 May 15.
Metal-organic frameworks (MOFs) are an attractive catalyst support for stable immobilization of the active sites in their scaffold due to the high tunability of organic ligands. The active site-functionalized ligands can be easily employed to construct MOFs as porous heterogeneous catalysts. However, the existence of active sites on the external surfaces as well as internal pores of MOFs seriously impedes the selective reaction in the pore. Herein, through a simple post-synthetic ligand exchange (PSE) method we synthesized surface-deactivated (only core-active) core-shell-type MOF catalysts, which contain 2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) groups on the ligand as active sites for aerobic oxidation of alcohols. The porous but catalytically inactive shell ensured the size-selective permeability by sieving effects and induced all reactions to take place in the pores of the catalytically active core. Because PSE is a facile and universal approach, this can be rapidly applied to a variety of MOF-based catalysts for enhancing reaction selectivity.
金属有机框架（MOFs）由于有机配体具有高度可调性，是一种用于在其支架中稳定固定活性位点的有吸引力的催化剂载体。活性位点功能化的配体可轻松用于构建作为多孔多相催化剂的MOFs。然而，MOFs外表面以及内部孔中活性位点的存在严重阻碍了孔内的选择性反应。在此，通过一种简单的后合成配体交换（PSE）方法，我们合成了表面失活（仅核心活性）的核壳型MOF催化剂，其配体上含有2,2,6,6-四甲基哌啶-1-氧基（TEMPO）基团作为醇类有氧氧化的活性位点。多孔但无催化活性的壳通过筛分效应确保了尺寸选择性渗透性，并促使所有反应在催化活性核心的孔中发生。由于PSE是一种简便且通用的方法，因此可快速应用于各种基于MOF的催化剂以提高反应选择性。
