A highly connected metal–organic framework with a specific nonpolar nanotrap for inverse ethane/ethylene separation

时间:2023-11-23浏览:10

论文题目:A highly connected metal–organic framework with a specific nonpolar nanotrap for inverse ethane/ethylene separation

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发表期刊:Inorg. Chem. Front., 2023, Advance Article


Abstract

Efficient separation of ethylene (C2H4) from ethane (C2H6) via a one-step adsorption process is desirable yet challenging. In this work, we report a C2H6-selective polynuclear Tb-MOF [Tb93-O)23-OH)12(H2O)9(TCPE)3]·[H3O]+·(solvents)x (TCPE = tetrakis(4-carboxyphenyl)ethylene acid), NKU-200-Tb, assembled via  the reticular chemistry principle. The resulting (4,12)-connected  framework critically features a high density of nonpolar aromatic rings  on the pore surface and forms a specific nanotrap for C2H6 with multiple C–H⋯π interaction sites. As a result, NKU-200-Tb exhibits an inverse adsorption behavior with a high C2H6/C2H4 selectivity of 2.06 and a large uptake ratio of 151% (60.27/39.95 cm3 g−1) at 298 K and 1 bar. The superior adsorption properties of NKU-200-Tb, combined with great structural stability, place it among the most promising stable C2H6-selective MOFs. Dynamic breakthrough experiments demonstrate that polymer-grade C2H4 (>99.9%) can be harvested in one step from a binary mixture of C2H6/C2H4 (10/90, v/v). This work signifies the synergy of pore surface chemistry and space confinement in promoting the challenging C2H6/C2H4 separation.