Temperature-dependent molecular sieving of fluorinated propane/propylene mixtures by a flexible-robust metal-organic framework | Science Advances
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.