Bio-based 1,3-diisobutyl imidazolium hydrogen oxalate [iBu(2)IM](HC2O4) as CO2 shuttle

This manuscript describes the using of biosourced L-valine, oxalic acid and glyoxal to produce a biobased imidazolium hydrogen oxalate [iBu(2)IM](HC2O4) which is converted to its related hydrogen carbonate salt by a simple electrolysis without using strong base. The addition of weak protic acids to the latter compound leads to a rapid and quantitative CO2 release with formation of the starting hydrogen oxalate salt or a new halide free bio-based ionic liquid [iBu(2)IM](AcO) which is able to adsorb reversibly the CO2 at room temperature. The protonation reactions, combined with electrolysis, could then be a promising alternative solution for storage and transport of CO2. They are indeed fast and use a thermally and air stable material produced from sustainable resources which are easily recycled by a low energy consuming process using non-expensive and corrosion-resistant equipment.