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

Abstract

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, ¹H NMR, ¹³C 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.