乙烯乙炔分离是石化中重要环节和关键技术,工业分离技术和多孔MOF基吸附技术有过度催化、高成本、高能耗、分离效果差等问题。HOF本质是有机小分子,易溶易制膜、可重结晶回收,但稳定性差且未实现烯炔分离。本项目基于Lewis碱位点既是框架节点又是乙炔吸附位点的特点、和咔唑的分叉结构特征,创新性地利用“碎片化”合成方法构建高密度Lewis碱位点的“多臂多触角”咔唑基HOF,增强骨架稳定性,实现乙炔吸附的高选择性、高识别性和低再生能。拟开展:1.以含氮芳香环、胺或有机酸为触角、以多连接数的刚性芳香环或POSS簇为中心核,合成不同Lewis碱位点的咔唑臂基单体,组装成HOF;2.孔性和吸附分离性能测试;3.用单晶技术探究构效关系和分离机理;4.通过三个碎片一体化设计,调控骨架结构和氢键节点连接方式,增加触角间氢键数和HC≡C-H...O/N密度,优化材料综合性能。发表高质量论文6-8篇,专利2-3件。

The highly selective separation of ethylene and acetylene is very important but challenging in petrochemical industry. However, the problems such as excessive catalysis, high cost, high energy consumption and poor separation effect cannot be solved in industrial separation technology and MOF-based porous adsorption technology. Microporous hydrogen bonded organic frameworks (HOF) are essentially organic molecules with solution processability and characterization, easy purification and healing by simple recrystallization. But HOF shows poor stabilities, and the selective adsorption of acetylene from ethylene has not been realized. Based on the fact that Lewis bases act as hydrogen bonding node of framework and adsorption sites of acetylene, as well as the double-connection nature of carbazole, we proposed the synthesis of carbazole-based HOFs with "multi-hydrogen binding sites" by "Fragmented" method for the highly selective separation of ethylene and acetylene. The project includes: 1. To obtained carbazole-armed ligands containing different Lewis base sites, by using nitrogen-containing aromatic rings, amines or organic acids as antennas, and by using rigid aromatic rings with multiple binding sites or POSS clusters as cores. And then to fabricate stable HOF materials with multiple hydrogen bonding sites; 2. To study the porosity and the separation performance of ethylene and acetylene; 3. To explore the relationship between porosity and the separation performance of ethylene and acetylene by using single crystal technology, and then to perform feedback syntheses and to achieve performance optimization; 4. Through integrated design of three fragments, the HOF skeleton structure and the hydrogen bonding node are regulated to increase the number of hydrogen bonds and the density of HC≡C-H...O/N, thereby obtaining optimized performance.