Incorporation of 1-ethyl-3-methyl-imidazolium acetate into UiO-66 as an efficient sorbent for carbon dioxide capture

Adjusting the internal porous environment of MOFs to enhance their adsorption properties is considered an effective strategy to improve their gas separation performance. Herein, 1-ethyl-3-methyl-imidazolium acetate ([Emim][Ac]) was encapsulated in UiO-66 by an impregnation method for the improvement of carbon dioxide (CO2) capture performance. The synthesis and detailed characterizations of the developed [Emim][Ac]@UiO-66 are reported, and the effect of the loading amount of [Emim][Ac] on the CO2 separation performance was also studied. The obtained [Emim][Ac]@UiO-66 could efficiently show the synergistic effect of the adsorption of CO2 between [Emim][Ac] and UiO-66. The optimized [Emim][Ac]@UiO-66 exhibited a much higher CO2 adsorption capacity at 298 K and 1.0 bar, affording 2 times the CO2 uptake than its original UiO-66. In addition, the CO2/N-2 selectivity and CO2/CH4 selectivity of [Emim][Ac]@UiO-66-3.5% are significantly higher than those of UiO-66. This study for designing various MOF-encapsulated ionic liquids potentially paves the way for the development of highly efficient absorbents for gas separations.

Automated summary

Adjusting the internal porous environment of MOFs to enhance their adsorption properties is considered an effective strategy to improve their gas separation performance. In this study, UiO-66 was encapsulated with 1-ethyl-3-methyl-imidazolium acetate ([Emim][Ac]) to improve CO2 capture performance. The [Emim][Ac]@UiO-66 exhibited higher CO2 adsorption capacity and selectivity compared to the original UiO-66, indicating its potential as an efficient absorbent for gas separations.