Sorting of C₄ Olefins with Interpenetrated Hybrid Ultramicroporous Materials by Combining Molecular Recognition and Size‐Sieving

Abstract

C olefin separations present one of the great challenges in hydrocarbon purifications owing to their similar structures, thus a single separation mechanism often met with limited success. Herein we report a series of anion-pillared interpenetrated copper coordination for which the cavity and functional site disposition can be varied in 0.2 Å scale increments by altering the anion pillars and organic linkers (GeFSIX-2-Cu-i (ZU-32), NbFSIX-2-Cu-i (ZU-52), GeFSIX-14-Cu-i (ZU-33)), which enable selective recognition of different C olefins. In these materials the rotation of the organic linkers is controlled to create a contracted flexible pore window that enables the size-exclusion of specific C olefins, while still adsorbing significant amounts of 1,3-butadiene (C H ) or 1-butene (n-C H ). Combining the molecular recognition and size-sieving effect, these materials unexpectedly realized the sieving of C H /n-C H , C H /iso-C H , and n-C H /iso-C H with high capacity.

Halogen–C2H2 Binding in Ultramicroporous Metal–Organic Frameworks (MOFs) for Benchmark C2H2/CO2 Separation Selectivity

“…The energetic „sweet spot“ for C 2 H 2 capture under ambient conditions is controlled by sorbent–C 2 H 2 binding interactions, which result from pore size and pore chemistry. This is exemplified by the current benchmark sorbents for CO 2 /N 2 , CO 2 /CH 4 , C 2 H 2 /C 2 H 4 , C 2 H 4 /C 2 H 6 , C 2 H 6 /C 2 H 4, propadiene/propylene, propyne/propylene, ternary propyne/propadiene/propylene, and C 4 olefins . Interestingly, the leading sorbents are ultramicroporous with tight binding sites, in which sorbate binding is driven by pore chemistry: strong electrostatics, H‐bonding sites, or open metal sites .…”

Highly Selective, High‐Capacity Separation of o‐Xylene from C8 Aromatics by a Switching Adsorbent Layered Material

“…Metal-organic materials (MOMs), [8] also known as porous coordination polymers (PCPs) [9] or metal-organic frameworks (MOFs), [10] are ap romising class of porous materials that offer potential form utility in storage,separation, sensing, and catalysis. [11] Unlike traditional classes of porous materials they can offer exquisite control over pore size and pore chemistry as their modularity makes them amenable to crystal engineering. [12] Several MOMs have been investigated with respect to C 8 aromatics separation;h owever, they also lack ac ombination of strong selectivity and high adsorption capacity.…”

An Asymmetric Anion‐Pillared Metal–Organic Framework as a Multisite Adsorbent Enables Simultaneous Removal of Propyne and Propadiene from Propylene

“…It was hypothesized that the multisiteadsorbent of ZU-62 separately afforded am ore energy favorable binding site for the propadiene accommodation distinguished from that for the propyne,a nd thus the obviously improved propadiene capacity under ultra-low pressure.I nspiringly,t he similar aperture size of ZU-62 and ZU-32 (GeFSIX-2-Cu-i)(4.48 vs.4.5 )made it possible to eliminate the contribution from the contracted pore size. [12] Additionally,Z U-62 was also found to exhibit great potential in the separation of acetylene and ethylene (Supporting Information, Figure S14). Thef lexible phenomenon arisen in the initial adsorption curve of both propyne and propadiene on ZU-62 may attribute to its contracted pore window caused by the rotation of the pyridines (Supporting Information, Figure S5A).…”

“…Thei ntroduction of adsorbed molecules would prompt the pyridines to be parallel to each other, and therefore the accessible channel for the entry of guest molecules. [12] Additionally,Z U-62 was also found to exhibit great potential in the separation of acetylene and ethylene (Supporting Information, Figure S14).…”