Chemical Engineering Journal, Vol.373, 338-344, 2019
Engineering pore surface and morphology of microporous organic polymers for improved affinity towards CO2
The increasing carbon dioxide (CO2) emissions from coal-fired power plants exacerbates the need for polymeric sorbents that can preferentially capture CO2 over nitrogen (N-2). Herein we report two amine-functionalized microporous organic polymers (PTPNHs) through one-step facile modification of carboxyl-rich microporous organic polymers (PTPMA) that was prepared from a classic Friedel-Crafts coupling of commercially available monomers. The amidation chemistry enables an unprecedented morphology evolution of the microporous organic polymer from nanospheres to uniform nanorods and the choice of amidation agents allows a good control on the diameter and length of the as-made nanorods. More interestingly, the amine-appended PTPNHs show enhanced CO2 adsorption per unit surface area (0.281 mg/m(2), at 273 K/1.0 bar) and exceptionally high ideal selectivity (CO2: N-2 = 123) with high affinity towards CO2, despite of their decreased Brunauer-Emmett-Teller (BET) surface areas (554 m(2) g(-1)). The CO2 adsorption per unit surface area of the nanorods is about 1.6 folds of that of pristine PTPMA. This study constitutes a step on regulating channel surface polarity and morphology control, and offers the prospect for low-cost direct CO2 capture technologies.