用于烯烃/烷烃分离的核碱基-高核金属簇MOFs材料的设计合成

The separation of olefins / paraffins is classified as one of the seven chemical separations to change the world. In this project, we plan to design and synthesize some nucleobase-metal cluster based MOFs (NMC-MOFs) for olefins capture and separation from paraffins. Double bonds in olefin molecules can be recognized by open metal sites, functional organic groups and guest molecules through the cooperative host-guest and/or guest-guest interactions. Based on this principle, we intend to use the as-synthesized NMC-MOFs to achieve cost- and energy-efficient separation. The main research includes the following aspects: 1) Design and synthesis of NMC-MOFs. According to the coordination steric hindrance, metal-cluster based MOFs has less connections than coordination numbers and always coordinated with more solvent molecules, which can get more metal active sites to enhance the adsorption selectivity. 2) Improvement of the gas adsorption capacity of NMC-MOFs using two strategies, including different metal ions doping and increase the ligand substitution to generate coordination defects. 3) Controlling of the framework charge and accommodating suitable guest molecules into the framework using oxidation-reduction methods. Synergistically improve the adsorption selectivity of the material with uncoordinated amino groups of the nucleobases. 4) Identification of the adsorption sites and adsorption configurations of olefin molecules in the NMC-MOFs, combining IAST calculations, breakthrough measuerments and single-crystal X-ray diffraction, to investigate the relationships between structure and adsorption selectivity of the NMC-MOFs.

烯烃/烷烃的分离被列为改变世界的七项化学分离技术之一。本项目将开展用于烯烃/烷烃分离的核碱基-高核金属簇MOFs材料的设计合成。根据金属活性位点对烯烃双键的识别作用， 有机配体功能基团以及客体活性位点的协同作用，从核碱基-金属簇出发设计主体结构，以实现高效率、低能耗的烯烃/烷烃分离为目的，开展以下研究: 1）设计合成高核金属簇基MOFs材料，根据配位位阻原理，连接数远小于配位数，更多的溶剂分子参与配位，可以实现材料的高金属活性位点数；2）进行不同金属离子掺杂以及增加配体取代基形成配位缺陷两种方式提高气体吸附容量；3）对金属簇进行氧化还原后处理调控框架电荷，实现特定结构中客体作用位点的引入，协同核碱基中不参与配位的氨基，提高材料对烯烃的吸附选择性；4）结合IAST法理论计算、气体突破曲线测试以及单晶X-射线衍射，研究材料中的烯烃分子的吸附位点和吸附构型，探索结构与吸附选择性之间的关系。

乙烯和丙烯是石油化工行业最重要的基础原料，本项目针对烯烃烷烃分离难、分离能耗高等问题，制备了系列基于金属簇基的配位材料进行低碳烃分离性能和机理的研究。主要研究内容包括：1）根据金属活性位点对烯烃双键的识别作用，进行了高核金属簇基多孔材料的构筑方法研究；2）采用异金属策略、孔道分割策略、超微孔构筑等策略来提高材料对烯烃的吸附选择性; 3)IAST和DFT计算、气体突破曲线测试以及单晶X-射线衍射，研究材料中的烯烃分子的吸附位点和吸附构型，进行金属活性位点与有机配体功能基团以及客体活性位点的协同作用研究，探索结构与吸附选择性之间的关系。. 经过三年的努力，构建了较为合理的此类金属簇基多孔材料的制备规律，初步探索了结构与选择性之间的构效关系。整体项目取得的成果对金属簇基配位材料的组装技术领域具有较为重要的科学意义。项目共发表SCI文章10篇，申请发明专利1项，达到项目考核指标要求。