Encapsulation of cuprous/cobalt sites in metal organic framework for enhanced C2H4/C2H6 separation

Chunli Xu; Zhifeng Yang; Lei Shi; Yu Yin; Min Lu; Mengxuan Liu; Aihua Yuan; Hong Wu; Xiao-Ming Ren; Shaobin Wang; Hongqi Sun

doi:10.1016/j.jcis.2020.09.037

Encapsulation of cuprous/cobalt sites in metal organic framework for enhanced C₂H₄/C₂H₆ separation

J Colloid Interface Sci. 2021 Feb 1:583:605-613. doi: 10.1016/j.jcis.2020.09.037. Epub 2020 Sep 28.

Authors

Chunli Xu¹, Zhifeng Yang¹, Lei Shi², Yu Yin³, Min Lu¹, Mengxuan Liu¹, Aihua Yuan⁴, Hong Wu², Xiao-Ming Ren⁵, Shaobin Wang⁶, Hongqi Sun⁷

Affiliations

¹ School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China.
² School of Engineering, Edith Cowan University, Joondalup, WA 6027, Australia.
³ School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China. Electronic address: season_july@just.edu.cn.
⁴ School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China. Electronic address: aihua.yuan@just.edu.cn.
⁵ State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, China.
⁶ School of Chemical Engineering and Advanced Materials, The University of Adelaide, Adelaide, SA 5005, Australia.
⁷ School of Engineering, Edith Cowan University, Joondalup, WA 6027, Australia. Electronic address: h.sun@ecu.edu.au.

PMID: 33039859
DOI: 10.1016/j.jcis.2020.09.037

Abstract

Adsorbents based on Cu^I for π-complexative separation of C₂H₄/C₂H₆ have attracted widespread interests. However, they are still confronting some challenges, for example, (i) a low separation efficiency, resulted from the ineffective reduction of Cu^II to Cu^I along with aggregation, and (ii) poor stability due to the oxidation of Cu^I to inactive Cu^II. In this study, active Cu and auxiliary Co species are simultaneously encapsulated within the nanopores of MIL-101 using a double-solvent (DS) method to obtain CuCoM-DS. The Cu species at the interior of MIL-101 are homogeneously dispersed and can be completely reduced to Cu^I without any structural damage to MIL-101. The resulting CuCoM-DS exhibits a superior performance in C₂H₄/C₂H₆ separation not only to the pristine MIL-101, but to the counterpart samples of single Cu and/or Cu/Co at the exterior of MIL-101. The best sample of 1.5CuCoM-DS adsorbent is capable to adsorb 50.5 mL·g^-1 of C₂H₄, and the C₂H₄/C₂H₆ selectivity is 2.6 at 100 kPa. Both C₂H₄ uptake and C₂H₄/C₂H₆ selectivity are higher than those reference samples. Moreover, 1.5CuCoM-DS preserves over 90% of fresh C₂H₄ uptake after the exposure to atmospheric air for 12 days. This study provides new design ideas for confining bimetallic sites in MOFs for broad applications.

Keywords: Ethylene/ethane; Gas separation; IAST; Metal organic frameworks (MOFs); π-Complexation.