Impact of post-synthesis modification of nanoporous organic frameworks on small gas uptake and selective CO2 capture

摘要

Porous organic polymers containing nitrogen-rich building units are among the most promising materials for selective CO2 capture and separation applications that impact the environment and the quality of methane and hydrogen fuels. In this study, we report on post-synthesis modification of nanoporous organic frameworks (NPOFs) and its impact on gas storage (H2, CH4, CO2) and selective CO2 binding over N2 and CH4 under ambient conditions. The synthesis of NPOF-4 was accomplished via acid catalyzed cydotrimerization reaction of 1,3,5,7-tetrakis(4-acetylphenyl)adamantahe in ethanol/xylenes. NPOF-4 is microporous and has high surface area (SA_(BET) = 1249 m~2 g~(-1)). Post-synthesis modification of NPOF-4 by nitration afforded NPOF-4-NO2 and its subsequent reduction resulted in an aminefunctionalized framework NP0F-4-NH2 that exhibits improved gas storage capacities and very high CO2/N2 (139) and CO2/CH4 (15) selectivities compared to NPOF-4.