Tuning the Surface Polarity of Microporous Organic Polymers for CO Capture.

CO capture is very important to reduce the CO concentration in atmosphere. Herein, we report the preparation of microporous polymers with tunable surface polarity for CO capture. Porous polymers functionalized with -NH , -SO H, and -SO Li have been successfully prepared by using a post-synthesis modification of microporous polymers (P-PhPh prepared with 1,3,5-triphenylbenzene as the monomer and AlCl as the catalyst) by chemical transformations, such as nitration-reduction, sulfonation, and cationic exchange. The CO adsorption selectivity (CO /N and CO /H ) and isosteric heats of the microporous polymers increase markedly after modification, P-PhPh -NH and P-PhPh -SO Li afford higher CO uptake capacity than P-PhPh at pressures of less than 0.15 bar due to the enhanced interaction between CO and the -NH and -SO Li functional groups. Moreover, functionalized porous polymers could be stably used for CO capture. Surface modification is an efficient approach to tune the CO capture properties of porous polymers.