An electrochemical methodology for the cyclic CO2 "catch and release". The role of the electrogenerated N-heterocyclic carbene in BMIm-BF4

According to the property of N-heterocyclic carbenes (NHCs) to yield NHC-CO2 adducts, a solution of NHCs in the parent room temperature ionic liquid (RTIL) as solvent may act as a system able to catch and release carbon dioxide cyclically and in mild conditions. The system has been set up and analyzed via simple electrochemical methodologies. NHCs have been generated by electrolysis of BMIm-BF4 (as solvent and parent of NHC) in the absence of any base and organic solvent. CO2 has been caught and released in every cycle by bubbling of CO2 in the system at 60 °C, heating and stirring at 120 °C, and subsequently cooling down to 60 °C. In a single series of 10 cycles, performed as a preliminary control, the system is able to catch and release 4 mol of CO2 per Faraday consumed in the electrolysis. © 2013 Elsevier Ltd.