Functionalized Ionic Liquids for CO₂ Capture under Ambient Pressure

Area of Science:

• Green Chemistry
• Materials Science
• Chemical Engineering

Background:

• Ionic liquids (ILs) are investigated for carbon dioxide (CO2) capture and utilization.
• High-pressure requirements for current IL-based CO2 capture processes limit scalability and increase costs.

Purpose of the Study:

• To design novel glycol ether-functionalized ionic liquids for efficient CO2 capture at ambient pressure.
• To evaluate the compatibility of these ionic liquids with enzymatic CO2 conversion pathways.

Main Methods:

• Synthesis of functionalized imidazolium, phosphonium, and ammonium ILs with acetate (OAc-) or Tf2N- anions.
• Measurement of CO2 solubility in ILs at room temperature and atmospheric pressure.
• Assessment of IL compatibility with alcohol dehydrogenase (ADH) for CO2 conversion.

Main Results:

• Task-specific ILs achieved high CO2 solubilization (up to 0.55 mol/mol IL or 5.9 wt%).
• Acetate anions enhanced CO2 capture, while Tf2N- anions showed better compatibility with ADH.
• Demonstrated potential for ambient pressure CO2 capture and subsequent enzymatic conversion to methanol.

Conclusions:

• Developed novel ionic liquids for efficient CO2 capture under ambient conditions.
• Identified ILs suitable for integrated CO2 capture and enzymatic conversion processes.
• Showcased a promising pathway for sustainable CO2 utilization and valuable chemical production.