New Molecular Materials for Direct Air Capture of Carbon Dioxide Using Electro-Swing Chemistry

The increasing amount of carbon dioxide (CO2) in the atmosphere is the main factor contributing to climate change. Recent studies have determined that simply reducing emissions is insufficient to restore the Earth’s atmospheric system—negative emissions are therefore necessary. Current carbon (i.e., CO2) capture technologies use thermal or pressure swings. These approaches suffer from low energy efficiency, high cost, and geographic constraints. Electro-swing chemistry-based carbon capture has emerged as a promising potential solution to these challenges. However, strong CO2-binding sorbents, not susceptible to oxygen interference, remain elusive. In this study, three electron-deficient quinones were designed and tested as CO2 capture molecular sorbents. Cyclic voltammetry (CV) on these novel quinones reveals that 2,3-dicyano-1,4-benzoquinone (DBQ) has a second reduction potential positive of that of oxygen reduction. Moreover, this sorbent binds to CO2 with a free energy ΔGbind of −5.39 kcal/mol when activated by electrochemical reduction. These results suggest that DBQ may be a sorbent candidate that can capture >70% of CO2 in the current atmosphere using electro-swing chemistry without the interference of oxygen in the air. This novel sorbent can be further developed for large-scale carbon capture and combating global warming and its associated impacts.