A novel phenolic ionic liquid for 1.5 molar CO2 capture: combined experimental and DFT studies

A phenolic-based ionic liquid (IL), 1-(2-hydroxyethyl)-2,3-dimethylimidazolium phenoxide has been introduced for 1.5 molar carbon dioxide (CO2) absorption at ambient conditions without using special methodologies or precautions. The structure of the IL was characterized by various methods such as FT-IR, H-1 NMR, C-13 NMR, elemental analysis (EA) and thermogravimetric analysis (TGA). The ability of this IL for CO2 uptake reaches to its maximum value after 2 h. The IL has been reused fr several times with constant efficiency. Density functional theory (DFT) calculations at the B3LYP/6-311++G** level of calculation have been carried out to gain more structural knowledge about the interaction of CO2 with IL. Based on the results of experimental and theoretical investigations, a reasonable mechanism is proposed for CO2 absorption.