LAUSR

The metal-free and solvent-free capture and reduction of large amounts of CO2 to formate under ambient conditions is achieved by combining a pyrrolidinium-based ionic liquid with a borohydride anion. This material demonstrates one of the highest CO2 capacities at room temperature and 1 bar with up to 1 gCO2/gIL. CO2 gas reacts with the BH4- anion to give triformatoborohydride ([HB(OCHO)3]-. The reaction occurs without loss in capacity at low CO2 concentration (6 vol% diluted with N2).The thermodynamics and kinetics of the reaction were monitored using a magnetic suspended balance. In addition, more than 1 molCO2/mol[EMPY][BH4] is captured and reduced when air is used as a carbon dioxide source. The product can be then treated with HCl to give formic acid and the corresponding chloride ionic liquid, which can be recycled to form new material. This new usage of ionic liquid borohydrides demonstrates great potential as a CO2 absorber and reducer to alternative fuels.