Boosting Ethane/Ethylene Separation within Isoreticular Ultramicroporous Metal-Organic Frameworks

Published

October 11, 2018

Author(s)

Rui-Biao Lin, Hui Wu, Libo Li, Xiao-Liang Tang, Zhiqiang Li, Junkuo Gao, Hui Cui, Wei Zhou, Banglin Chen

Abstract

The separation of ethane from its analogous ethylene is of great importance in the petrochemical industry, but very challenging and energy-intensive. Adsorptive separation using C_cH₆-selective porous materials can directly produce high purity C₂H₄ in a single operation but suffer from poor selectivity. Here, we report an approach to boost the separation of C₂H₆ over C₂H₄, involving the control of port structures in two isoreticular ultramicroporous metal-organic framework materials with weakly polar pore surface for strengthened binding affinity toward C₂H₆ over C₂H₄. Under ambient conditions, the prototypical compound shows a very small uptake difference and selectivity for C₂H₆/C₂H₄, whereas its smaller-pore isoreticular analogue exhibits a quite large uptake ration of 237% (60.0/25.3 cm³ cm^-3), remarkably increasing the C₂H₆/C₂H₄ selectivity. Neutron powder diffraction studies clearly reveal that the later material shows self-adapative sorption behavior for C₂H₆, which enables it to continuously maintain close van der Waals contacts with C₂H₆ molecules in its optimized pore structure, thus preferentially bind C₂H₆ over C₂H₄. Gas sorption isotherms, crystallographic analyses, molecular modeling, selectivity calculation and breakthrough experiment comprehensively demonstrate this unique MOF material as an efficient C₂H₆-selective adsorbent for C₂H₆-selective adsorbent for C₂H₄ purification.

Citation

Journal of American Chemical Society

Volume

2

Issue

3

Pub Type

Journals

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Keywords

Porous Materials, Gas Separation

Citation

Lin, R. , Wu, H. , Li, L. , Tang, X. , Li, Z. , Gao, J. , Cui, H. , Zhou, W. and Chen, B. (2018), Boosting Ethane/Ethylene Separation within Isoreticular Ultramicroporous Metal-Organic Frameworks, Journal of American Chemical Society, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=926732 (Accessed April 25, 2024)