Direct air capture and integrated conversion is a very
attractive
strategy to reduce CO2concentration in the atmosphere.
However, the existing capturing processes are technologically challenging
due to the costs of the processes and the low concentration of CO2. The efficient valorization of the CO2captured
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 CO2from 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 CO2from atmospheric air was efficiently captured by
IL solution (0.98 molCO2/molIL) 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.