Engineering Microporous Ethane-Trapping Metal-Organic Frameworks for Boosting Ethane/Ethylene Separation

Published

February 21, 2020

Author(s)

Jiyan Pei, Jia-Xin Wang, Kai Shao, Yu Yang, Yuanjing Cui, Hui Wu, Wei Zhou, Bin Li, Guodong Qian

Abstract

Realization of ethane-trapping materials for separating ethane (C₂H₆) from ethylene (C₂H₄) by adsorption, to potentially replace the energy-intensive cryogenic distillation technology, is of prime importance in the petrochemical industry. It is still very challenging to target C₂H₆-selective adsorbents with both high C₂H₆ capture capacity and gas selectivity. Herein, we report that a crystal engineering or reticular chemistry strategy enables the control of pore size and functionality in a family of isomorphic metal-organic frameworks (MOFs) for boosting the C₂H₆ uptake and selectivity simultaneously. By altering the carboxylic acid linker in Ni(bdc)(ted)_0.5, we developed two novel isoreticular MOFs, Ni(ndc)(ted)_0.5 and Ni(adc)(ted)_0.5 (termed as ZJU-120 and ZJU-121, respectively), in which the pore sizes and nonpolar aromatic rings can be finely engineered. We discover that the activated ZJU-120a with the optimized pore size (4.4 Å) and aromatic rings exhibits both very high C₂H₆ uptake (96 cm³ g^-1 at 0.5 bar and 296 K) and C₂H₆/C₂H₄ selectivity (2.74), outperforming most of the C₂H₆-selective MOFs reported. Computational studies indicate that the suitable pore size and more nonpolar aromatic rings on the pore surfaces of ZJU-120a mainly contribute to its exceptional C2H6 uptake and selectivity. The breakthrough experiments demonstrate that ZJU-120a can efficiently separate C₂H₆ from 50/50 and 10/90 C₂H₆/C₂H₄ mixtures at ambient conditions.

Citation

Journal of Materials Chemistry A

Volume

8

Issue

7

Pub Type

Journals

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Keywords

Porous materials, Gas separation

Citation

Pei, J. , Wang, J. , Shao, K. , Yang, Y. , Cui, Y. , Wu, H. , Zhou, W. , Li, B. and Qian, G. (2020), Engineering Microporous Ethane-Trapping Metal-Organic Frameworks for Boosting Ethane/Ethylene Separation, Journal of Materials Chemistry A, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=929307 (Accessed April 16, 2024)