CO2 adsorption and catalytic application of imidazole ionic liquid functionalized porous organic polymers

Abstract

A series of imidazole ionic liquid (IL) functionalized porous organic polymers (POPs) with high surface areas has been successfully prepared based on p-dichloroxylene (p-DCX) and N-methylimidazole (N-MI) as fundamental building blocks through the FeCl₃-catalyzed Friedel–Crafts alkylation reaction. The IL-functionalized POPs show CO₂ uptake up to 73.6 cm³ g⁻¹ (273 K, 1 bar). Their isosteric heat of adsorption can be increased from 7.84 to 17.35 kJ mol⁻¹ by adjusting the molar ratios of N-MI to p-DCX. These materials could also be used as reusable acid catalysts in the syntheses of benzimidazole derivatives from aromatic aldehydes and o-phenylene diamine in good yields (87–91%).