Recent Advances in CO2 Capture by Functionalized Ionic Liquids

CO2 capture and storage (CCS) receives wordwide attention because the rising emission of CO2 from fossil fuels is threatening economies, environments, and human health. Ionic liquids address new opportunities for carbon capture because of their promising and unique properties, such as negligible vapor pressures, high thermal stabilities, excellent CO2 solubilities, and tunable properties. In this review, we summerized the recent advances in the chemisorption of CO2 using functionalized ionic liquids. It is of great importance to tune the anion structures, including amino acid anions, azole anions, and phenol anions because the anion moieties of ionic liquids usually play a dominant role in the absorption performance of CO2. Strategies for efficient CO2 capture, energy-saving release, and rapid absorption kinetics are present. The absorption mechanism was studied through a combination of spectroscopic investigation, and theoretical calculation. The recent developments in carbon capture by non-amino anion-functionalized ionic liquids present limitless potential to enhance the absorption performance of CO2. Some new concepts, such as multiple site cooperative interactions, the effect of enthalpy, and phase-change ionic liquids, open a door for improving CO2 capture by tuning the specific structure of the ionic liquid.