金属功能基元序构的新型有序多孔材料及突破气体分离trade-off的新机制研究

烯烃/烷烃分离是世界七大重要分离之一，基于多孔材料的吸附分离技术是最具潜力的节能高效分离技术之一。然而，多孔材料通常存在分离选择性和气体吸附量难以兼具的科学难题（trade-off效应），简单的结构调控或功能基元导入都难以解决。对此，本项目提出了一种金属功能基元序构的协同强化分离新机理，即设计与烯烃易形成π-配位键的金属功能基元（Ag+、Cu+等），自组装序构生成一类全新的三维金属化SIFSIX有序多孔结构，基于功能基元的π-络合作用、孔道结构调控和基元有序分布的协同强化效应，实现同时高的分离选择性和烯烃吸附量。本项目将系统研究金属功能基元的本征分离特性，明晰序构引发的孔道效应和基元有序分布对分离性能的增强作用规律；揭示功能基元+序构的协同强化机理及与宏观分离性能的关联模型。本项目的研究既为气体高效分离提供了一种新的材料体系和设计范式，也是功能基元序构研究在气体分离领域的一个新应用和突破。

Alkene/alkane (C2H4/C2H6 and C3H6/C3H8) separation has been highlighted as one of the most important industrial separation tasks. Adsorptive separation technology based on porous materials has been considered as a viable alternative to potentially replace traditional costly and energy-intensive cryogenic distillation. However, most of porous materials reported so far suffer from the trade-off between gas selectivity and uptake capacity. Recent studies demonstrate that simple control of pore sizes or incorporation of functional units cannot fully address this trade-off issue. This project proposes a new strategy that is sequenced construction of metalated functional units into porous materials to provide triple enhancement effect for boosting gas separation performance. By incorporating the specific metalated functional units (Ag+, Cu+, Pd2+, etc.) into SIFSIX materials, we design and synthesize a series of novel metalated SIFSIX porous materials. This material system can provide a strong π-complexation with alkene molecules, tunable pore sizes and ordered distribution of functional units for targeting both high selectivity and uptake capacity, thus addressing the trade-off issue. A series of metalated and ordered porous SIFSIX materials were prepared via pre- or post-metalation strategy. We will reveal the basic laws of using metalated functional units to orderly construct porous materials with fine-tuned pore size, shape, and functionality. We will also systematically investigate the principle of metalated functional units, order construction, and their synergistic effect on boosting gas separation performance, and establish a new method to design functional units for building target high-performance separating materials. On this basis, the selectivity and alkene adsorption capacity can be well modulated to achieve high values simultaneously. We hope that this project can not only provide a new method to design high-performance porous materials, but also offer a new application of using the sequenced construction concept for gas separation.