Insights into the thermodynamic-kinetic synergistic separation of propyne/propylene in anion pillared cage MOFs with entropy-enthalpy balanced adsorption sites

Yunjia Jiang; Lingyao Wang; Tongan Yan; Jianbo Hu; Wanqi Sun; Rajamani Krishna; Dongmei Wang; Zonglin Gu; Dahuan Liu; Xili Cui; Huabin Xing; Yuanbin Zhang

doi:10.1039/d2sc05742e

Insights into the thermodynamic-kinetic synergistic separation of propyne/propylene in anion pillared cage MOFs with entropy-enthalpy balanced adsorption sites

Chem Sci. 2022 Nov 28;14(2):298-309. doi: 10.1039/d2sc05742e. eCollection 2023 Jan 4.

Authors

Yunjia Jiang¹, Lingyao Wang¹, Tongan Yan², Jianbo Hu³, Wanqi Sun¹, Rajamani Krishna⁴, Dongmei Wang¹, Zonglin Gu⁵, Dahuan Liu², Xili Cui³, Huabin Xing³, Yuanbin Zhang¹

Affiliations

¹ Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, College of Chemistry and Life Sciences, Zhejiang Normal University Jinhua 321004 China ybzhang@zjnu.edu.cn.
² State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology Beijing 100029 China.
³ Department of Chemistry, Zhejiang University 38 Zheda Road 310027 Hangzhou P. R. China.
⁴ Van't Hoff Institute for Molecular Sciences, University of Amsterdam Science Park 904 1098 XH Amsterdam Netherlands.
⁵ College of Physical Science and Technology, Yangzhou University Jiangsu 225009 China.

Abstract

Propyne/propylene (C₃H₄/C₃H₆) separation is an important industrial process yet challenged by the trade-off of selectivity and capacity due to the molecular similarity. Herein, record C₃H₄/C₃H₆ separation performance is achieved by fine tuning the pore structure in anion pillared MOFs. SIFSIX-Cu-TPA (ZNU-2-Si) displays a benchmark C₃H₄ capacity (106/188 cm³ g^-1 at 0.01/1 bar and 298 K), excellent C₃H₄/C₃H₆ IAST selectivity (14.6-19.3) and kinetic selectivity, and record high C₃H₄/C₃H₆ (10/90) separation potential (36.2 mol kg^-1). The practical C₃H₄/C₃H₆ separation performance is fully demonstrated by breakthroughs under various conditions. 37.8 and 52.9 mol kg^-1 of polymer grade C₃H₆ can be produced from 10/90 and 1/99 C₃H₄/C₃H₆ mixtures. 4.7 mol kg^-1 of >99% purity C₃H₄ can be recovered by a stepped desorption process. Based on the in situ single crystal analysis and DFT calculation, an unprecedented entropy-enthalpy balanced adsorption pathway is discovered. MD simulation further confirmed the thermodynamic-kinetic synergistic separation of C₃H₄/C₃H₆ in ZNU-2-Si.