Direct Air Capture and Integrated Conversion of Carbon Dioxide into Cyclic Carbonates with Basic Organic Salts.

Direct air capture and integrated conversion is a very attractive strategy to reduce CO 2 concentration in the atmosphere. However, the existing capturing processes are technologically challenging due to the costs of the processes and the low concentration of CO 2 . The efficient valorization of the CO 2 captured could help overcome many techno-economic limitations. Here, we present a novel economical methodology for direct air capture and conversion that is able to efficiently convert CO 2 from the air into cyclic carbonates. The new approach employs commercially available basic ionic liquids, works without the need for sophisticated and expensive co-catalysts or sorbents and under mild reaction conditions. The CO 2 from atmospheric air was efficiently captured by IL solution (0.98 molCO 2 /mol IL ) and, subsequently, completely converted into cyclic carbonates using epoxides or halohydrins potentially derived from biomass as substrates. A mechanism of conversion was evaluated, which helped to identify relevant reaction intermediates based on halohydrins, and consequently, a 100% selectivity was obtained using the new methodology.