Microregulation of Pore Channels in Covalent-Organic Frameworks Used for the Selective and Efficient Separation of Ethane

Chaohui He; Yong Wang; Yang Chen; Xiaoqing Wang; Jiangfeng Yang; Libo Li; Jinping Li

doi:10.1021/acsami.0c16575

Microregulation of Pore Channels in Covalent-Organic Frameworks Used for the Selective and Efficient Separation of Ethane

ACS Appl Mater Interfaces. 2020 Nov 25;12(47):52819-52825. doi: 10.1021/acsami.0c16575. Epub 2020 Nov 13.

Authors

Chaohui He¹, Yong Wang¹, Yang Chen¹, Xiaoqing Wang¹, Jiangfeng Yang¹, Libo Li^{1

2}, Jinping Li^{1

2}

Affiliations

¹ College of Chemistry and Chemical Engineering, Shanxi Key Laboratory of Gas Energy Efficient and Clean Utilization, Taiyuan University of Technology, Taiyuan, 030024 Shanxi, P. R. China.
² Key Laboratory of Coal Science and Technology, Ministry of Education and Shanxi Province, Taiyuan University of Technology, Taiyuan, 030024 Shanxi, P. R. China.

PMID: 33185444
DOI: 10.1021/acsami.0c16575

Abstract

The removal of low content of ethane (C₂H₆) from ethylene (C₂H₄) using C₂H₆-selective adsorbents to reduce the energy consumption in the petrochemical industry is one of the meaningful and challenging tasks in separation research. Herein, we report for the first time the systematic research of covalent-organic frameworks (COFs) as a platform used for the separation of light hydrocarbons based on their specific topology. Benefiting from its richly distributed weakly polar surface and suitable pore cavities, COF-1 exhibits the highest adsorption selectivity (1.92 at 298 K and 1 bar) for the C₂H₆/C₂H₄ mixture among the COFs studied. Density functional theory calculations clearly revealed that COF-1 can exhibit multiple C-H···π interactions with ethane in its suitable pore environment and thus preferentially binds to ethane over ethylene. Finally, breakthrough experiments proved that COF-1 may be regarded as an effective porous adsorbent with polymer-grade C₂H₄ obtained directly from C₂H₆/C₂H₄ mixtures at 298 K and 1 bar.

Keywords: C2H6 selective adsorbent; covalent-organic frameworks; density functional theory calculations; microregulation; pore environment.