Efficient and reversible CO2 capture in bio-based ionic liquids solutions

Choline/amino acid-based ionic liquids were synthetized via ionic metathesis and their CO2 absorption performances evaluated by employing different experimental approaches. In order to overcome any viscosity-related problem, dimethyl sulfoxide (DMSO) was employed as solvent. IL-DMSO solutions with different IL concentrations were evaluated as absorbents for CO2, also investigating their good cyclability as desirable for real industrial CO2 capture technologies. 1 H-NMR and in-situ ATR-IR experiments were the toolbox to study the CO2 chemical fixation mechanism under different experimental conditions, proving the formation of distinct chemical species (carbamic acid and/or ammonium carbamate). In general, these ILs demonstrated molar uptakes higher than classical 0.5 mol CO2/mol IL and the capacity to release CO2 in extremely mild conditions. The possible biological adverse effects were also analyzed, for the first time, in zebrafish (Danio rerio) during the development, by assessing for different toxicological endpoints, proving the non-toxicity and high biocompatibility of these bio-inspired ILs.