School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China.
Jieyang Branch of Chemistry and Chemical Engineering Guangdong Laboratory (Rongjiang Laboratory), Jieyang 515200, China.
ACS Appl Mater Interfaces. 2023 Feb 15;15(6):8263-8274. doi: 10.1021/acsami.2c22824. Epub 2023 Feb 2.
Multifunctionalization of porous organic polymers toward synergistic CO catalysis has drawn much attention in recent decades, but it still faces many challenges. Herein, we develop a facile, simple, and efficient strategy to obtain a series of aluminum porphyrin-based ionic porous aromatic frameworks (iPAFs), which are considered excellent bifunctional catalysts for converting CO into cyclic carbonates without any cocatalyst under mild and solvent-free conditions. By increasing the amounts of tetraphenylmethane fragments in the porphyrin backbones, the cooperative effect between Lewis acidic metal centers and nucleophilic ionic sites has been enhanced and then the significant improvement of catalytic activity can be achieved owing to the high surface areas (up to 719 m·g), abundant hierarchical micro-mesopores, and prominent CO adsorption capacities (up to 1.8 mmol·g at 273 K) as well as highly dispersed dual-function sites. More fascinatingly, high-active AlPor-iPAF-3 enables CO cycloaddition to perform with diluted CO (15% CO in 85% N, v/v) or under ambient conditions. Therefore, this postsynthetic modification procedure in combination with the framework dilution strategy provides a new approach to fabricating high-surface-area metalloporphyrin-based porous ionic polymers (PIPs) with hierarchical structures, which is conducive to improving the accessibility of multiple active sites around substrates.
多孔有机聚合物的多功能化在协同 CO 催化方面引起了近几十年来的广泛关注，但仍面临许多挑战。在此，我们开发了一种简便、高效的策略，可获得一系列基于铝卟啉的离子型多孔芳香骨架（iPAFs），这些骨架被认为是在温和无溶剂条件下将 CO 转化为环状碳酸酯而无需任何助催化剂的优秀双功能催化剂。通过增加卟啉骨架中四苯甲烷片段的数量，可以增强路易斯酸性金属中心和亲核离子位点之间的协同作用，从而由于高比表面积（高达 719 m·g）、丰富的分级微孔、显著的 CO 吸附能力（在 273 K 时高达 1.8 mmol·g）以及高度分散的双功能位，实现催化活性的显著提高。更有趣的是，高活性的 AlPor-iPAF-3 可使 CO 环加成反应在稀释的 CO（15% CO 在 85% N，v/v）或环境条件下进行。因此，这种后合成修饰程序与骨架稀释策略相结合，为制造具有分级结构的高表面积金属卟啉基多孔离子聚合物（PIPs）提供了一种新方法，有利于提高底物周围多个活性位点的可及性。
