Efficient Selective CO Composite Sorbent from Amino Acid Ionic Liquids and Silica Gel: H NMR Spectroscopy Provides Insight on the CO-Binding Mechanism and in-Pore Microscopic Viscosity.

A promising CO sorbent based on the [Emim][Gly] (1-ethyl-3-methylimidazolium glycinate)/silica gel composite has been studied. CO sorption experiments have shown that the optimum loading of [Emim][Gly] ionic liquid in silica gel is 40 wt.%. The 2-step process CO binding mechanism in [Emim][Gly] has been proposed based on the results of sorption experiments, H NMR spectroscopy and ab-initio calculations. The impact of CO on the microscopic viscosity and the dynamical melting of ionic liquid has been thoroughly investigated. H NMR spectroscopy has revealed that CO strongly binds cation and anion in [Emim][Gly], forcing them to move in a correlated fashion.