Solvothermal synthesis of hierarchically nanoporous organic polymers with tunable nitrogen functionality for highly selective capture of CO2

A series of porous organic polymers (POPs) with tunable nitrogen functionality and hierarchical porosity were successfully synthesized from the one-step copolymerization of divinylbenzene with 4-vinylpyridine or 1-vinylimidazolate under solvothermal conditions. The FTIR results, XPS spectra, and elemental analysis validated the incorporation of different kinds and contents of nitrogen species into the framework-synthesized POPs. The N-2 adsorption isotherms at -196 degrees C and SEM and TEM images revealed that the synthesized POPs have large surface areas and abundant meso-macropores. The CO2 and N-2 adsorption experiments demonstrated that the synthesized POPs have competitive capacity for CO2 at a relatively low pressure of 0.15 bar (0.64-1.47 mmol g(-1) at 0 degrees C and 0.49-0.87 mmol g(-1) at 25 degrees C) and exceptionally high IAST selectivity for CO2/N-2 (0.15/0.85) at 1 bar (74.9-154.8 at 0 degrees C and 91.8-224.5 at 25 degrees C). The CO2/N-2 selectivity is superior to that of most other reported physical adsorbents. This work provides a facile approach to the targeted synthesis of nitrogen-functionalized POPs with potential applications in the selective capture of CO2 from flue gas.