Melamine-functionalized aromatic carbonyl-based polymer with high surface area for efficient CO2 capture

Abstract

The development of efficient CO2 adsorbents is an industrially and environmentally crucial issue because fossil fuels will be actively used in the upcoming decades. Herein, we report the synthesis of a novel aromatic carbonyl polymer (ACP) with a large surface area (1461 m2/g) and hierarchical pores via a one-pot Friedel–Crafts reaction and its functionalization with two amine ligands, ethylene diamine (EDA) and melamine (MEL), on carbonyl groups. The resulting ACP-EDA and ACP-MEL polymers showed excellent CO2 uptake (132.8 and 134.1 mg/g, respectively) at 298 K and 1 bar. Owing to the higher density of amine and triazine sites, ACP-MEL exhibited stronger interactions with CO2 molecules, resulting in CO2/N2 and CO2/CH4 selectivities higher than those of ACP-EDA. ACP-MEL showed fairly high CO2/N2 (∼110) and CO2/CH4 (∼14) selectivities. Moreover, it retained selective CO2 adsorption performance for 5 cycles at ambient temperature. Covalent functionalization of a highly porous material, having a high density of carbonyl sites, with MEL groups, is a promising approach for developing efficient CO2 adsorbents.