Computer‐Assisted Design of Imidazolate‐Based Ionic Liquids for Improving Sulfur Dioxide Capture, Carbon Dioxide Capture, and Sulfur Dioxide/Carbon Dioxide Selectivity. Issue 21 (11th October 2017)

• Record Type: Journal Article
• Authors: Cui, Guokai; Zhao, Ning; Wang, Jianji; Wang, Congmin
• Is Part Of: Chemistry, an Asian journal. Volume 12:Issue 21(2017)
• Page Start: 2863
• Page End: 2872
• Publication Date: 2017-10-11
• Subjects: absorption -- basicity -- carbon dioxide -- ionic liquids -- selectivity; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/asia.201701215
• Languages: English
• ISSNs: 1861-4728

Abstract

Abstract: A new strategy involving the computer‐assisted design of substituted imidazolate‐based ionic liquids (ILs) through tuning the absorption enthalpy as well as the basicity of the ILs to improve SO2 capture, CO2 capture, and SO2 /CO2 selectivity was explored. The best substituted imidazolate‐based ILs as absorbents for different applications were first predicted. During absorption, high SO2 capacities up to ≈5.3 and 2.4 mol SO 2 molIL −1 could be achieved by ILs with the methylimidazolate anions under 1.0 and 0.1 bar (1 bar=0.1 MPa), respectively, through tuning multiple N⋅⋅⋅ S interactions between SO2 and the N atoms in the imidazolate anion with different substituents. In addition, CO2 capture by the imidazolate‐based ILs could also be easily tuned through changing the substituents of the ILs, and 4‐bromoimidazolate IL showed a high CO2 capacity but a low absorption enthalpy. Furthermore, a high selectivity for SO2 /CO2 could be reached by IL with 4, 5‐dicyanoimidazolate anion owing to its high SO2 capacity but low CO2 capacity. The results put forward in this work are in good agreement with the predictions. Quantum‐chemical calculations and FTIR and NMR spectroscopy analysis methods were used to discuss the SO2 and CO2 absorption mechanisms. Abstract : Out of gas : A new strategy involving the computer‐assisted design of imidazolate‐based ionic liquids (ILs) through tuning the absorption enthalpy and the basicity of the ILs to improve SO2 capture, CO2 capture, and SO2 /CO2 selectivity is reported. This method may pave a new way to design materials for gas absorption and utilization.