Understanding the fundamental interaction mechanism of hazardous gases and imidazolium based ionic liquids for efficient gas adsorption

In this study we present an investigation on the adsorption mechanism of hazardous gases (CO, CO2, H2S and SO2) on the ILs having the 1-Ethyl-3-methylimidazolium cation (C(2)mim(+)) and halide anions (Cl-, Br-, I- and BF4-), employing the first principles-based density functional theory (DFT). Adsorption energy data reveals that the C(2)mim Cl and C(2)mim Br ILs demonstrate a relatively higher adsorption energy value for all the gasses. Strong interactions between gases and ILs can be identified by nu(C-2-H) mode of cation, 786 cm(-1) and 1390 cm(-1) vibrational bands of CO2 and SO2 gases, respectively, as marker bands. Electronic structure calculation and AIM analysis confirm that all the gas molecules are more favorable to interact with the cation. Our present findings may be the prototype investigation to govern the exper-imental realization for the adsorption of such dangerous gases on the imidazolium-based ILs. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

This study investigates the adsorption mechanism of hazardous gases on ionic liquids with different cations and anions using density functional theory. It is found that ILs with C(2)mim Cl and C(2)mim Br cations have higher adsorption energy values for various gases. Vibrational bands and electronic structure calculations confirm the strong interactions between gases and cations in the ILs.