A Computational Study of Dicationic Ionic Liquids/CO2 Interfaces

摘要: Recent studies on CO2 capture using dicationic ionic liquids (DILs) demonstrated that DILs are promising absorbents for uptake especially compared with monocationic (MILs) analogues, in which each cation carries single positive charge contrast to two unit charges of a dication. However, DILs/CO2 interfacial properties at the molecular level still unknown. This work investigated absorption representative DILs, 1-alkyl-3-dimethylimidazolium bis(trifluoromethylsulfonyl)imide, [Cn(mim)2](Tf2N)2 (n = 3, 6, 12), dynamics (MD) simulations. The higher density DIL than MIL interfaces suggests increased interaction sites DILs. also exhibits an alkyl chain length dependence decreases elongation and proportionally correlates content fluorine atoms interfaces. Different orientations were illustrated those MILs; both inside exhibit lower diffusivity MILs, agreement stronger cation-anion binding energy Moreover, show H2O N2 from flue gas implicating CO2/H2O CO2/N2 selectivity.