Pore Space Partition within a Metal–Organic Framework for Highly Efficient C2H2/CO2 Separation

Abstract

The pore space partition (PSP) approach has been employed to realize a novel porous MOF ( FJU-90 ) with dual functionalities for the challenging C 2 H 2 /CO 2 separation under ambient conditions. By virtue of a triangular ligand (Tripp = 2,4,6-tris(4-pyridyl)pyridine), the cylindrical channels in the original FJU-88 have been partitioned into uniformly interconnected pore cavities, leading to the dramatically reduced pore apertures from 12.0 × 9.4 to 5.4 × 5.1 Å 2 . Narrowing down the pore sizes, the resulting activated FJU-90a takes up a very large amount of C 2 H 2 (180 cm 3 g –1 ) but much less of CO 2 (103 cm 3 g –1 ) at 298 K and 1 bar, demonstrating it to be the best porous MOF material for this C 2 H 2 /CO 2 (50%:50%) separation in terms of the C 2 H 2 gravimetric productivity. IAST calculations, molecular modeling studies, and simulated and experimental breakthrough experiments comprehensively demonstrate that the pore space partition strategy is a very powerful approach to constructing MOFs with dual functionality for challenging gas separation.