Pore Aperture Control Toward Size‐Exclusion‐Based Hydrocarbon Separations

Abstract

Metal-organic frameworks (MOFs) have been proposed as a promising material for non-thermal chemical separations owing to their high structural diversity and tunability. Here, we report the synthesis of a zinc-based MOF containing a three-dimensional (3D) linker, bicyclo[2.2.2]octane-1,4-dicarboxylic acid, with high thermal stability towards the separation of hexane isomers. The incorporation of the 3D linker enhances the structural stability and provides well-defined pore apertures/channels with sub-Ångstrom precision. This precision allowed for the separation of similarly sized hexane isomers based on subtle differences in their kinetic diameters. Multi-component liquid phase batch experiments confirmed the separation of hexanes mixture into linear, monobranched, and dibranched isomers. This work represents a significant milestone in the construction of stable Zn-based MOFs and the incorporation of 3D linkers as a potential solution to challenging separations.

Efficient separation of xylene isomers by nonporous adaptive crystals of hybrid[3]arene in both vapor and liquid phases

“…The industrial separation of xylene isomers is achieved by distillation and crystallization. [11][12][13][14] However, these methods are energy-intensive, accounting for a large proportion of global energy consumption. 15,16 Moreover, the separation effect is not satisfied due to the close boiling points of xylene isomers (Table S1, ESI †).…”