Preferential Adsorption Performance of Ethane in a Robust Nickel-Based Metal-Organic Framework for Separating Ethane from Ethylene

Jingyao Zhang; Zewei Liu; Hongbin Liu; Feng Xu; Zhong Li; Xun Wang

doi:10.1021/acsomega.1c06309

Preferential Adsorption Performance of Ethane in a Robust Nickel-Based Metal-Organic Framework for Separating Ethane from Ethylene

ACS Omega. 2022 Feb 24;7(9):7648-7654. doi: 10.1021/acsomega.1c06309. eCollection 2022 Mar 8.

Authors

Jingyao Zhang¹, Zewei Liu¹, Hongbin Liu¹, Feng Xu², Zhong Li¹, Xun Wang¹

Affiliations

¹ School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, China.
² School of Environment and Chemical Engineering, Foshan University, Foshan 528225, China.

Abstract

Development of an ethane-selective adsorbent to separate ethane from ethylene is a challenging issue with great significance for ethylene purification. The adsorptive separation technique based on physical adsorption holds a great promise to address this issue. Herein, we report a robust ethane-selective metal-organic framework, Ni(BODC)(TED), and investigate its separation performance on C₂H₆/C₂H₄. The as-synthesized Ni(BODC)(TED) exhibits excellent water vapor stability and high capacity of C₂H₆ molecules with an uptake of 3.36 mmol/g at 298 K and 100 kPa, higher than those of many adsorbents reported in recent years. Its C₂H₆/C₂H₄ selectivity predicted by the ideal adsorbed solution theory (IAST) model reaches 1.79. A molecular simulation is applied to unveil the preferential adsorption mechanism of ethane. Calculation shows that five strong C-H···H interactions are formed between C₂H₆ and the framework of Ni(BODC)(TED), and the isosteric heat of ethane on Ni(BODC)(TED) is 27.02 kJ/mol, higher than that of ethylene, resulting in preferential adsorption of ethane. Ni(BODC)(TED) would become a promising member of the family of ethane-selective materials for the industrial separation of ethane from ethylene.