High‐Efficiency Separation ofn‐Hexane by a Dynamic Metal‐Organic Framework with Reduced Energy Consumption

Abstract

The separation of n‐alkanes from their branched isomers is vitally important to improve octane rating of gasoline. To facilitate mass transfer, adsorptive separation is usually operated under high temperatures in industry, which require considerable energy. Herein, we present a kind of dynamic pillar‐layered MOF that exhibits self‐adjustable structure and pore space, a behavior induced by guest molecules. A combination of the flexibility of the framework with the commensurate adsorption for n‐hexane results in exceptional performance in separating hexane isomers. More significantly, lower temperature prompts the guest molecules to open the dynamic pores, which may provide a new perspective for optimized separation performance at lower temperatures with less energy consumption.

Flexible Zn-MOF with Rare Underlying scu Topology for Effective Separation of C6 Alkane Isomers

“…In contrast, n HEX was retained in the column for ∼30 min before it broke out. These results suggest that Zn-adtb represents another and rare MOF adsorbents that is capable of full separation of linear C6 isomer from the branched ones. ,, …”

“…The organic linker H 4 adtb takes on a bowl-shaped, highly distorted geometry (Figure 1b) and each of its four carboxylate groups coordinate to a different Zn cluster, resulting in a 3D extended network (Figure 1c−e). The organic linkers in the structure are overall four-connected and topological analysis with TOPOS reveals that Zn-adtb packs in the (4,8)-connected scu topology with the Schlaefli symbol {4 16 • 6 12 }{4 4 • 6 2 } 2 (Figure 1f). However, late-transition metal and post-transition metal based MOFs featuring scu topology have been rarely reported, especially for Zn-MOFs (Table S1).…”

“…These results suggest that Zn-adtb represents another and rare MOF adsorbents that is capable of full separation of linear C6 isomer from the branched ones. 16,39,40 Solid-State NMR (ssNMR). To investigate the interactions between Zn-adtb and the C6 isomers in more detail, we turned to solid-state NMR (ssNMR) spectroscopy.…”

“…Metal–organic frameworks (MOFs) have been extensively studied for gas storage, − separation, − capture of hazardous chemical species, − catalysis, , conductivity, − luminescence sensing, − and lighting − applications because of their permanent porosity and ease of tunability with regards to their pore shape, size, and chemistry . The facile functionalization of MOFs makes them versatile and attractive materials for numerous applications.…”

“…Materials for the separation of isomers through a molecular sieving effect for C6 isomers are quite rare. Currently, there are only four MOFs reported for the molecular sieving of C6 isomers. ,− …”