Key Laboratory of Cluster Science Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, P. R. China.
Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun, 130023, P. R. China.
Angew Chem Int Ed Engl. 2023 May 22;62(22):e202302036. doi: 10.1002/anie.202302036. Epub 2023 Apr 25.
Developing porous sorbents represents a potential energy-efficient way for industrial gas separation. However, a bottleneck for reducing the energy penalty is the trade-off between dynamic adsorption capacity and selectivity. Herein, we showed this problem can be overcome by modulating the kinetic and thermodynamic separation behaviours in metal-organic frameworks for sieving 2-butene geometric isomers, which are desired for upgrading the raffinates to higher value-added end products. We found that the iron-triazolate framework can realize the selective shape screening of 2-butene isomers assisted by electrostatic interactions at the pore apertures. Further introducing uncoordinated N binding sites by ligand substitution lowered the gas diffusion barrier and greatly boosted the dynamic separation performance. In breakthrough tests under ambient conditions, trans-2-C H can be efficiently separated from cis-2-C H with a record capacity of 2.10 mmol g with high dynamic selectivity of 2.39.
开发多孔吸附剂是实现工业气体分离的一种有潜力的节能方法。然而，降低能耗的一个瓶颈是在动力学吸附容量和选择性之间的权衡。在此，我们表明通过调节金属有机骨架中的动力学和热力学分离行为，可以克服这个问题，从而对 2-丁烯几何异构体进行筛分，这对于将抽余液升级为更高附加值的最终产品是很有必要的。我们发现，铁-三唑骨架可以通过在孔径处的静电相互作用辅助实现 2-丁烯异构体的选择性形状筛分。进一步通过配体取代引入未配位的 N 结合位点，降低了气体扩散势垒，并极大地提高了动态分离性能。在环境条件下的突破测试中，反式-2-C H 可以与顺式-2-C H 高效分离，记录容量为 2.10 mmol·g，动态选择性高达 2.39。
