The abundant triazine rings with the good affinity for CO₂ molecules in covalent triazine frameworks (CTFs) can capture and activate CO₂ molecules, making CTFs a potential candidate for CO₂ cycloaddition reaction. However, due to the single active site, the realization of high catalytic performance commonly requires the assistance of cocatalysts or harsh reaction conditions. In this study, several novel ionic covalent triazine frameworks (MCTFs, BCTFs and YCTFs) multifunctional heterogeneous catalysts were synthesized for CO₂ cycloaddition reactions. The prepared CTFs catalysts have outstanding pore structure and uniformly distributed active sites (N Lewis basic sites in triazine ring and Cl^– nucleophilic sites). The optimal catalyst MCTF-10 has good CO₂ enrichment capacity and high adsorption selectivity. In addition, the catalyst shows an outstanding catalytic performance for the coupling reaction of CO₂ and propylene oxide, with 96 % of yield and 99 % of selectivity for the product under metal-, solvent- and cocatalyst-free parameters (110 °C, initial CO₂ pressure 1 MPa, 4 h). Even under diluted CO₂ concentration (15 % CO₂, 85 % N₂) and mild conditions (80 °C, 0.1 MPa, 24 h), the synthetized CTFs exhibits an outstanding catalytic activity. The excellent catalytic performance, along with the good cycling stability and broad applicability of epoxides, make it a competitive catalyst for catalyzing the CO₂ cycloaddition reaction.

中文翻译：

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多功能离子共价三嗪骨架作为高效 CO2 环加成反应的非均相催化剂


在共价三嗪框架 （CTF） 中，丰富的三嗪环对 CO₂ 分子具有良好的亲和力，可以捕获和激活 CO₂ 分子，使 CTF 成为 CO₂ 环加成反应的潜在候选者。然而，由于活性位点单一，实现高催化性能通常需要助催化剂或苛刻反应条件的帮助。在本研究中，合成了几种用于 CO₂ 环加成反应的新型离子共价三嗪框架 （MCTFs、BCTFs 和 YCTFs） 多功能异相催化剂。制备的 CTFs 催化剂具有出色的孔隙结构和均匀分布的活性位点（三嗪环中的 N Lewis 碱性位点和 Cl^– 亲核位点）。最佳催化剂 MCTF-10 具有良好的 CO₂ 富集能力和较高的吸附选择性。此外，该催化剂对 CO₂ 和环氧丙烷的偶联反应表现出出色的催化性能，在无金属、溶剂和助催化剂的参数（110 °C，初始 CO₂ 压力 1 MPa，4 h）下，产物的产率为 96%，选择性为 99%。即使在稀释的 CO₂ 浓度（15 % CO 2,85 % N ₂）和温和条件（80 °C，0.1 MPa，24 h）下，合成的 CTF 也表现出出色的催化活性。优异的催化性能，以及良好的循环稳定性和环氧化物的广泛适用性，使其成为催化 CO₂ 环加成反应的有竞争力的催化剂。