Postfunctionalization of Porous Organic Polymers Based on Friedel-Crafts Acylation for CO2 and Hg2+ Capture

Melamine-based porous organic polymers (POPs) are promising for gas uptake and water treatment because of their unique and tunable porosity, high nitrogen (N) content, and high Brunauer-Emmett-Teller (BET) surface area (S-BET). However, it is difficult to construct ketone-based POPs by the Friedel-Crafts acylation reaction. Herein, the ketone-based POPs were post-functionalized with melamine (MA) by the Schiff-based reaction and the rigid triazine rings of MA were embedded in the polymer chains as rigid cross-linkers, resulting in the polymers with high S-BET (555 m(2).g(-1)) and total pore volume (0.72 cm(3).g(-1)). Moreover, plentiful imine, amino, and triazine functionalities were inserted in the polymers, providing the polymers with high N content of 41.83 wt %. The resulting polymers were promising for CO2 capture (145 mg. g(-1); 273 K, 1.0 bar) and Hg2+ removal (372 mg.g(-1)). This study offers a universal strategy to construct melamine-based POPs from various ketone-functionalized HCPs via a simple postfunctionalization.