Ship in a bottle synthesis of ionic liquids in NaY supercages for CO2 capture

Abstract

CO₂ is the single most important anthropogenic greenhouse gas, contributing ∼64% to the global radiative forcing. And the rising concentration of CO₂ in the atmosphere will result in global climate change. In this study, 1-alkyl-3-methylimidazolium bromide ionic liquids (ILs) ([C_nMIM]Br, n = 4, 6, 8, 10) were ship in a bottle synthesized in NaY zeolite to get [C_nMIM]Br@NaY samples and applied for CO₂ capture. These samples were then characterized by elemental analysis, thermal gravimetric analysis (TGA), X-ray diffraction (XRD) and FT-Raman spectra. The results indicated that [C_nMIM]Br ILs were successfully encapsulated inside NaY and the encapsulated [C_nMIM]Br ILs were much more stable than their bulk analogues. And Raman spectra showed that the relative intensities of some peaks in the [C_nMIM]Br@NaY samples had good relationships with the side chain length of ILs. Then the breakthrough curves were recorded to evaluate the CO₂ adsorption capacity of these samples, and indicated that the highest adsorption capacity could reach up to 20.08 mL CO₂ per g [C₄MIM]Br@NaY. And the cyclic CO₂ adsorption results also illustrated that the [C_nMIM]Br@NaY samples were stable and effective with prolonged use. So these samples could be potential materials for CO₂ capture.