Interactions between the Ionic Liquid and the ZrO2 Support in Supported Ionic Liquid Membranes for CO2 Separation

Abstract

This work reports the interaction study of two supported ionic liquid membranes (SILMs) based on 1-butyl-3-methylimidazolium hexafluorophosphate ([C 4 mim][PF 6 ]) and 1-butyl-3-methylimidazolium tetrafluoroborate ([C 4 mim][BF 4 ]), which were impregnated into porous zirconia supports with 20 nm average pore diameters. The interaction of ionic liquid-support observed from diffuse reflectance (DR), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy and energy dispersive spectroscopy (SEM/EDS) is reported. The IR spectrum in the 600 to 4000 cm −1 range showed a specific interaction of the ionic liquid with the support. The N 2 and CO 2 permeances in the SILMs with [C 4 mim][BF 4 ] were 8.7 × 10 −8 mol·s −1 ·m −2 ·Pa −1 and 9.6 × 10 −7 mol·s −1 ·m −2 ·Pa −1 , respectively. The separation factor through the ionic liquid in the membrane as a function of temperature showed that the SILMs studied here can be used for CO 2 separation at low temperatures.

CO2 separation using composites consisting of 1-butyl-3-methylimidazolium tetrafluoroborate/CdO/1-aminopyridinium iodide

“…Polymer-based membranes, especially with ether group in their chains, have contributed to strong coordination between CO and oxygen atoms of the polymer 14–17 . This strong coordination could enhance solubility of CO 2 molecules, resulting in the enhancement of CO 2 /airy gas selectivity 18 .…”