Temperature-dependent molecular sieving of fluorinated propane/propylene mixtures by a flexible-robust metal-organic framework
Wei Xia, Yisi Yang, Liangzheng Sheng, Zhijie Zhou, Lihang Chen, Zhangjing Zhang, Zhangjing Zhang, Zhiguo Zhang, Zhiguo Zhang, Qiwei Yang, Qilong Ren, Zongbi Bao
Abstract
The electronics industry necessitates highly selective adsorption separation of hexafluoropropylene (C 3 F 6 ) from perfluoropropane (C 3 F 8 ), which poses a challenge due to their similar physiochemical properties. In this work, we present a microporous flexible-robust metal-organic framework (Ca-tcpb) with thermoregulatory gate opening, a rare phenomenon that allows tunable sieving of C 3 F 8 /C 3 F 6 . Remarkably, the temperature-dependent adsorption behavior enhances the discrimination between the larger C 3 F 8 and the smaller C 3 F 6 , resulting in unprecedented C 3 F 6 /C 3 F 8 selectivity (over 10,000) compared to other well-known porous materials at an optimal temperature (298 K). Dynamic breakthrough experiments demonstrate that high-purity C 3 F 8 (over 99.999%) could be obtained from a C 3 F 6 /C 3 F 8 (10:90) mixture under ambient conditions. The unique attributes of this material encompass exceptional adsorption selectivity, remarkable structural stability, and outstanding separation performance, positioning it as a highly promising candidate for C 3 F 6 /C 3 F 8 separation. Single-crystal structural analysis of C 3 F 6 -loaded Ca-tcpb and theoretical calculations elucidate the host-guest interaction via multiple intermolecular interactions.