Transforming atmospheric CO2 into alternative fuels: a metal-free approach under ambient conditions

摘要

This work demonstrates the first-ever completely metal-free approach to the capture of CO _(2) from air followed by reduction to methoxyborane (which produces methanol on hydrolysis) or sodium formate (which produces formic acid on hydrolysis) under ambient conditions. This was accomplished using an abnormal N-heterocyclic carbene ( a NHC)–borane adduct. The intermediate involved in CO _(2) capture ( a NHC-H, HCOO, B(OH) _(3) ) was structurally characterized by single-crystal X-ray diffraction. Interestingly, the captured CO _(2) can be released by heating the intermediate, or by passing this compound through an ion-exchange resin. The capture of CO _(2) from air can even proceed in the solid state via the formation of a bicarbonate complex ( a NHC-H, HCO _(3) , B(OH) _(3) ), which was also structurally characterized. A detailed mechanism for this process is proposed based on tandem density functional theory calculations and experiments.