No abstract

Three cuprous-based composite ionic liquids (ILs) [EimH][OAc]-xCuOAc (x = 0.5, 0.6, 0.7) were prepared and employed for efficient absorption of CO. It is shown that the cuprous composite IL [EimH][OAc]-0.6CuOAc exhibited the largest absorption capacity for CO (0.031 g/g at 293.15 K and 1 bar) and had a record CO/N 2 selectivity of 967, which is better than most of common ILs and solvents reported in the literature. The results of Fourier transform infrared (FTIR) spectra, electrospray ionization mass spectrometry (ESI-MS) analysis, and theoretical calculations reveal that such superior CO capacity mainly resulted from two kinds of chemical interaction between CO and the active anionic species [Cu(OAc) 2 ] À in [EimH][OAc]-0.6CuOAc. Furthermore, a "deactivated IL model" was further proposed to accurately describe the absorption behavior of CO in [EimH][OAc]-0.6CuOAc, in which the thermodynamic parameters including Henry's law constants, reaction equilibrium constants, and absorption enthalpies were estimated by the correlation of the experimental solubilities of CO.