Liu Yi, Li Shuangjiang, Chen Ying, Hu Tianding, Pudukudy Manoj, Shi Lan, Shan Shaoyun, Zhi Yunfei
Faculty of Chemical Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650500, PR China.
Faculty of Chemical Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650500, PR China; Sichuan Vocational College of Chemical Technology, Luzhou, Sichuan 646300, PR China.
J Colloid Interface Sci. 2023 Dec 15;652(Pt A):737-748. doi: 10.1016/j.jcis.2023.07.127. Epub 2023 Jul 21.
The chemical conversion of carbon dioxide (CO) into highly value-added products not only alleviates the environmental issues caused by global warming but also makes an impact on economic benefits in the world. The synthesis of cyclic carbonates by the cycloaddition of CO with epoxides is one of the most attractive methods for CO conversion. However, the development of green and highly efficient heterogeneous catalysts is considered to be a great challenge in catalysis. In this work, alkenyl-modified melamine-based porous organic polymer (MPOP-4A) was firstly synthesized by a one-pot polycondensation method, and it was again modified with imidazolium-based ionic liquids to obtain final modified catalyst (MPOP-4A-IL). Various analytical techniques were used to confirm structure and chemical composition of the prepared materials. The MPOP-4A-IL catalyst synthesized by the post-modification strategy with imidazolium-based ionic liquids exhibited enhanced catalytic activity for CO cycloaddition reaction. The enhanced catalytic performance could be attributed to the presence of abundant active sites in their structure such as hydrogen bond donors (HBD), nitrogen (N) sites, and nucleophilic groups for an effective chemical reaction. The MPOP-4A-IL catalyst was found to be metal-free, easy to recycle and reuse, and has good versatility for a series of different epoxides. The interaction of MPOP-4A-IL catalyst with epoxide and CO was further verified by density functional theory (DFT) calculations, and the possible mechanism of the CO cycloaddition reaction was proposed.
将二氧化碳（CO₂）化学转化为高附加值产品，不仅能缓解全球变暖所引发的环境问题，还会对全球经济效益产生影响。通过CO₂与环氧化物环加成反应合成环状碳酸酯，是CO₂转化最具吸引力的方法之一。然而，开发绿色高效的多相催化剂被认为是催化领域的一项巨大挑战。在本工作中，首先通过一锅法缩聚反应合成了烯基修饰的三聚氰胺基多孔有机聚合物（MPOP-4A），然后用咪唑基离子液体对其再次修饰，得到最终的修饰催化剂（MPOP-4A-IL）。采用各种分析技术来确定所制备材料的结构和化学成分。通过用咪唑基离子液体进行后修饰策略合成的MPOP-4A-IL催化剂，对CO₂环加成反应表现出增强的催化活性。催化性能的增强可归因于其结构中存在丰富的活性位点，如氢键供体（HBD）、氮（N）位点以及用于有效化学反应的亲核基团。发现MPOP-4A-IL催化剂不含金属，易于回收和再利用，并且对一系列不同的环氧化物具有良好的通用性。通过密度泛函理论（DFT）计算进一步验证了MPOP-4A-IL催化剂与环氧化物和CO₂之间的相互作用，并提出了CO₂环加成反应的可能机理。
