Selective Ethane/Ethylene Separation in a Robust Microporous Hydrogen-Bonded Organic Framework

Published

January 8, 2020

Author(s)

Xu Zhang, Libo Li, Jia-Xin Wang, Hui-Min Wen, Rajamani Krishna, Hui Wu, Wei Zhou, Zhong-Ning Chen, Bin Li, Guodong Qian, Banglin Chen

Abstract

The separation of ethane (C₂H₆) from ethylene (C₂H₄) is of prime importance in the production of polymergrade C₂H₄ for industrial manufacturing. It is very challenging and still remains unexploited to fully realize efficient C₂H₆/C₂H₄ separation in the emerging hydrogen-bonded organic frameworks (HOFs) due to the weak nature of hydrogen bonds. We herein report the benchmark example of a novel ultra-robust HOF adsorbent (termed as HOF-76a) with a Brunauer-Emmett-Teller surface area exceeding 1100 m² g^-1, exhibiting the preferential binding of C₂H₆ over C₂H₄ and thus highly selective separation of C₂H₆/C₂H₄. Theoretical calculations indicate the key role of the non-polar surface and the suitable triangular channel-like pores in HOF-76a to sterically "match" better with the nonplanar C2H6 molecule than the planar C₂H₄, thus affording overall stronger multipoint van der Waals interactions with C2H6. The exceptional separation performance of HOF-76a for C₂H_{6/C2H4 separation was clearly demonstrated by gas adsorption isotherms, ideal adsorbed solution theory calculations, and simulated and experimental breakthrough curves. Breakthrough experiments on HOF-76a reveal that polymer-grade ethylene gas can be straightforwardly produced from 50/50 (v/v) C}d2^H₆/C₂H₄ mixtures during the first adsorption cycle with a high productivity of 7.2 L/kg (or 18.8 L/kg) at 298 K and 1 .01 bar (or 5.o bar).

Citation

Journal of American Chemical Society

Volume

142

Issue

1

Pub Type

Journals

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Keywords

Porous materials, Gas separation, Hydrogen bonding

Citation

Zhang, X. , Li, L. , Wang, J. , Wen, H. , Krishna, R. , Wu, H. , Zhou, W. , Chen, Z. , Li, B. , Qian, G. and Chen, B. (2020), Selective Ethane/Ethylene Separation in a Robust Microporous Hydrogen-Bonded Organic Framework, Journal of American Chemical Society, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=929393 (Accessed April 25, 2024)