Addition of Imidazolium-Based Ionic Liquid to Improve Methanol Production in Polyamine-Assisted CO 2 Capture and Conversion Systems Using Pincer Catalysts.

Ionic liquids have been studied as CO 2 capture agents. However, they are rarely used in combined CO 2 capture and conversion processes. Utilizing imidazolium-based ionic liquids, the conversion of CO 2 to methanol was greatly improved in polyamine assisted systems catalyzed by homogeneous pincer catalysts with Ru and Mn metal centers. Among the ionic liquids tested, [BMIM]OAc was found to perform the best under the given reaction conditions. Among the polyamine tested, pentaethylenehexamine (PEHA) led to the highest conversion rates. Ru-Macho and Ru-Macho-BH were the most active catalysts. Direct air capture utilizing PEHA as the capture material was also demonstrated and produced an 86 % conversion of the captured CO 2 to methanol in the presence of [BMIM]OAc.