Computational study of Capturing CO2 and SO2 gases using imidazolium based ionic liquids

The objective of this study was to capture toxic gases like CO2 and SO2 using imidazolium based ionic liquids,1-butyl 3-methyl-imidazoliumbis(trifluoromethylsulfonyl)imide) and 1-ethyl 3-methyl-imidazolium acetate. In this work, the density functional theory (DFT) method of hybrid correlation functional with B3LYP/6-31++G (d, p) basis set was used to analyze the mechanism of interaction between toxic gases and ionic liquids. It has been founded that the [Bmim][Tf2N]-SO2 has greater binding energy than [Bmim][Tf2N]-CO2 . Therefore, the ionic liquid [Bmim][Tf2N] seems to be the most suitable option for SO2 gas capture. Similarly, The ionic liquid [Emim][Ac] has high efficiency to capture the toxic gas SO2 and has high affinity for this gas relative to CO2. The types of absorption observed in [Bmim][Tf2N]-SO2 interaction was Chemisorption while, [Bmim]Tf2N]-CO2 interaction was physisorption. To sum up, [Bmim][Tf2N] and [Emim][Ac] seems to be the most suitable option and has high efficiency to capture SO2 gas relative to CO2. Bangladesh J. Sci. Ind. Res. 59(2), 73-86, 2024