Construction of a Stable Crystalline Polyimide Porous Organic Framework for C2H2/C2H4 and CO2/N2 Separation

Graphical Lapping it up : A thermally and chemically stable, crystalline polyimide porous organic framework, was constructed by imidization of linear naphthalene-1,4,5,8-tetracarboxylic dianhydride with triangular 1,3,5-tris(4-aminophenyl)benzene. This material is capable of selective adsorption of C 2 H 2 over C 2 H 4 and CO 2 over N 2 (see figure). Utilization of porous materials for gas capture and separation is a hot research topic. Removal of acetylene (C 2 H 2 ) from ethylene (C 2 H 4 ) is important in the oil refining and petrochemical industries, since C 2 H 2 impurities deactivate the catalysts and terminate the polymerization of C 2 H 4 . Carbon dioxide (CO 2 ) emission from power plants contributes to global climate change and threatens the survival of life on this planet. Herein, 2D crystalline polyimide porous organic framework PAF-120, which was constructed by imidization of linear naphthalene-1,4,5,8-tetracarboxylic dianhydride and triangular 1,3,5-tris(4-aminophenyl)benzene, showed significant thermal and chemical stability. Low-pressure gas adsorption isotherms revealed that PAF-120 exhibits good selective adsorption of C 2 H 2 over C 2 H 4 and CO 2 over N 2 . At 298 K and 1 bar, its C 2 H 2 and CO 2 selectivities were predicted to be 4.1 and 68.7, respectively. More importantly, PAF-120 exhibits the highest selectivity for C 2 H 2 /C 2 H 4 separation among porous organic frameworks. Thus PAF-120 could be a suitable candidate for selective separation of C 2 H 2 over C 2 H 4 and CO 2 over N 2 .