Encapsulated Amino-Acid-Based Ionic Liquids for CO2 Capture

Abstract

Ionic liquids have gathered special attention due to their potential for carbon dioxide capture, and their potential as solvents for mitigation of climate change. Following the scope of previous works, amino-acid-based ionic liquids encapsulated (ENILs) into carbonaceous submicrocapsules are here proposed as a novel material for CO2 capture. The ENILs prepared using tetrabutylphosphonium acetate ([P4,4,4,4][Ac]), used as reference, (2-hydroxyethyl)trimethylammonium l-phenylalaninate ([N1,1,1,2(OH)][L-Phe]), (2-hydroxyethyl)trimethylammonium l-prolinate ([N1,1,1,2(OH)][L-Pro]), and tetrabutylammonium l-prolinate ([N4,4,4,4][L-Pro]) were characterized by SEM, TEM, elemental analysis, TGA, and BET to assess their morphology, chemical composition, porous structure, and thermal stability. The absorption of CO2 on these materials was studied up to 0.5 MPa and 343 K. The desorption of CO2 from the saturated ENILs was evaluated, under mild conditions, evidencing these materials as promising agents for CO2 capture from post-combustion sources, with high sorption capacity and fast and complete regeneration.