Flexible Layered Metal–Organic Framework for Temperature-Dependent Discrimination of Cyclic Hydrocarbons
Feng Xie, Liang Yu, Trevor Jenkins, Timo Thonhauser, Hao Wang, Jing Li
Abstract
The separation and purification of cyclic hydrocarbons such as benzene, cyclohexene, and cyclohexane represent a crucially important but challenging process in the petrochemical industry. In this study, we show a flexible two-dimensional metal–organic framework (MOF) acting as an efficient adsorbent for the adsorptive separation of C6 cyclic hydrocarbons via molecular-sieving. The 2D-MOF features fully reversible structure transformation upon the removal/recoordination of terminal H 2 O and solvent DMF, and between activated and hydrocarbon-loaded forms. The distinct temperature- and adsorbate-dependent adsorption behavior is accompanied by guest-induced expansion of the layered structure. Such behavior enables the full discrimination of the individual C6 cyclic hydrocarbons from their binary and ternary mixtures by temperature-programmed protocols, achieving the third and second highest uptake ratios for C 6 H 6 /C 6 H 12 and C 6 H 10 /C 6 H 12 among MOFs reported to date. This study represents the first example of using a flexible 2D layered MOF sorbent to separate ternary mixtures of C6 cyclic hydrocarbons via a temperature-dependent molecular-sieving mechanism.