Smart Ionic Devices of Iron-based Ionic Liquids for Carbon Dioxide Capturing and Fixation

Resumo

The reduction of carcinogenic carbon dioxide can be achieved by the integration of its capturing and transformations into value added chemicals and fuels. One of the effective strategies is the production of cyclic carbonates from CO2 and epoxides, combining atomic efficiency with environmental benefits. In this study, we prepared an iron-based ionic liquid (IL) that represented a remarkable activity for the efficient chemical fixation of CO2 in various aromatic and aliphatic epoxides. The prepared Tris-butyl-3-methylimidazolium ferricyanide [BMIm]3[Fe(CN)6] IL showed conversions ranging from 20 to 100% with maximum selectivity to their corresponding cyclic carbonated. Our IL formed ionic containers is akin to the catalytic active membrane with confined spaces that significantly controlled the diffusion of reactants, intermediates and products. Aliphatic small sized epoxides exhibit higher conversion and selectivity to cyclic carbonate compared to bulkier ones. This suggests that larger epoxide substrates faced diffusion limitations within the confined spaces of IL, thereby restricting the reactants access to the catalytic active sites.