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 postfunctionalized 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 CO 2 capture (145 mg·g –1; 273 K, 1.0 bar) and Hg 2+ 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.