Velasco Ever, Xian Shikai, Wang Hao, Teat Simon J, Olson David H, Tan Kui, Ullah Saif, Osborn Popp Thomas M, Bernstein Ashley D, Oyekan Kolade A, Nieuwkoop Andrew J, Thonhauser Timo, Li Jing
Department of Chemistry and Chemical Biology, Rutgers University, 123 Bevier Road, Piscataway, New Jersey 08854, United States.
Hoffmann Institute of Advanced Materials, Shenzhen Polytechnic, 7098 Liuxian Boulevard., Shenzhen, Guangdong 518055, China.
ACS Appl Mater Interfaces. 2021 Nov 10;13(44):51997-52005. doi: 10.1021/acsami.1c08678. Epub 2021 Jul 20.
Adsorptive separation by porous solids provides an energy-efficient alternative for the purification of important chemical species compared to energy-intensive distillations. Particularly, the separation of linear hexane isomers from its branched counterparts is crucial to produce premium grade gasoline with high research octane number (RON). Herein, we report the synthesis of a new, flexible zinc-based metal-organic framework, [Zn(μ-OH)(adtb)(HO)·5 DMA] (Zn-adtb), constructed from a butterfly shaped carboxylate linker with underlying (4,8)-connected topology capable of separating the C6 isomers HEX, 3MP, and 23DMB. The sorbate-sorbent interactions and separation mechanisms were investigated and analyzed through in situ FTIR, solid state NMR measurements and computational modeling. These studies reveal that Zn-adtb discriminates the HEX/3MP isomer pair through a kinetic separation mechanism and the HEX/23DMB isomer pair through a molecular sieving mechanism. Column breakthrough measurements further demonstrate the efficient separation of linear HEX from the mono- and dibranched isomers.
与能源密集型蒸馏相比，多孔固体的吸附分离为重要化学物质的提纯提供了一种节能替代方法。特别是，从支链异构体中分离出线性己烷异构体对于生产具有高研究法辛烷值（RON）的优质汽油至关重要。在此，我们报道了一种新型柔性锌基金属有机框架[Zn(μ-OH)(adtb)(HO)·5 DMA]（Zn-adtb）的合成，它由具有潜在（4,8）连接拓扑结构的蝴蝶形羧酸盐连接体构建而成，能够分离C6异构体己烷（HEX）、3-甲基戊烷（3MP）和2,3-二甲基丁烷（23DMB）。通过原位傅里叶变换红外光谱（FTIR）、固态核磁共振（NMR）测量和计算模拟研究并分析了吸附质与吸附剂之间的相互作用及分离机制。这些研究表明，Zn-adtb通过动力学分离机制区分HEX/3MP异构体对，并通过分子筛机制区分HEX/23DMB异构体对。柱穿透测量进一步证明了从单支链和双支链异构体中有效分离线性己烷。
