Ultramicroporous Metal-Organic Framework with Inert Pore Surfaces for Inversed Separation of Ethylene from C Hydrocarbons Mixtures.

The achievement of direct CH separation from C 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(μ-OH)(tipa)(bpy)]·3DMF·6HO (), 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 CH compared to CH and CH in the low-pressure region, which is further verified by adsorption heats and selectivities. The CH separation potential in one step for binary CH/CH (50/50 and 10/90) and ternary CH/CH/CH (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 CH and the framework.