Ultramicroporous Metal–Organic Framework with Inert Pore Surfaces for Inversed Separation of Ethylene from C<sub>2</sub> Hydrocarbons Mixtures
Hai-Yu Duan, Xiu‐Yuan Li, Rajamani Krishna, Chaozheng He
Abstract
The achievement of direct C 2 H 4 separation from C 2 hydrocarbons is very challenging in the petrochemical industry due to their similar molecular sizes, boiling points, and physicochemical properties. In this work, a nonpolar/inert ultramicroporous metal–organic framework (MOF), [Co 3 (μ 3 -OH)(tipa)(bpy) 1.5 ]·3DMF·6H 2 O ( 1 ), with stand-alone one-dimensional square tubular channels was successfully constructed, its pore enriched with plenty of aromatic rings causing nonpolar/inert pore surfaces. The MOF shows preferential adsorption of C 2 H 6 compared to C 2 H 4 and C 2 H 2 in the low-pressure region, which is further verified by adsorption heats and selectivities. The C 2 H 4 separation potential in one step for binary C 2 H 6 /C 2 H 4 (50/50 and 10/90) and ternary C 2 H 4 /C 2 H 6 /C 2 H 2 (89/10/1) is also examined by transient breakthrough simulations. Moreover, grand canonical Monte Carlo simulations demonstrate that the unique reversed adsorption mechanism is due to the shortest and most number of C–H···π interactions between C 2 H 6 and the framework.