Systematic Investigation of Nitrile Based Ionic Liquids for CO2 Capture: A Combination of Molecular Simulation and ab Initio Calculation

• DOI: 10.1021/jp411434g
• Publication Date: 2014-01-17T13:41:24Z
• Authors: Krishna M. Gupta; Jianwen Jiang
• Keywords: Dicyanamide; Thiocyanate; Tetrafluoroborate; Interaction energy

Molecular simulation and ab initio calculation are performed to investigate CO2 capture in four nitrile (−CN) based ionic liquids (ILs), namely 1-n-butyl-3-methylimidazolium thiocyanate [BMIM][SCN], dicyanamide [BMIM][N(CN)2], tricyanomethane [BMIM][C(CN)3], tetracyanoborate [BMIM][B(CN)4]. In neat ILs, the simulated densities match well with experimental data, cation–anion interaction becomes weaker increasing number of −CN. CO2/IL systems, molecules preferentially located at interface, which is consistent observed minimum potential mean force. The solubility diffusivity ILs increase as [BMIM][SCN] < [BMIM][N(CN)2] [BMIM][C(CN)3] [BMIM][B(CN)4], thus −CN beneficial for capture. identified be governed by binding energy cation–anion, rather than CO2–anion. computational study provides quantitative microscopic insight into role sorption diffusion, it suggests that [BMIM][B(CN)4] might an interesting candidate