Reactive capture and electrochemical conversion of CO₂ with ionic liquids and deep eutectic solvents

Area of Science:

• Electrochemistry
• Materials Science
• Chemical Engineering

Background:

• Ionic liquids (ILs) and deep eutectic solvents (DESs) show potential for CO2 capture and conversion due to favorable properties like low volatility and high CO2 solubility.
• Conventional aqueous electrolytes for electrochemical CO2 conversion suffer from low CO2 solubility and high energy demands, alongside competing hydrogen evolution.

Purpose of the Study:

• To review the tuning of ILs and DESs for reactive capture and conversion (RCC) of CO2.
• To elucidate the CO2 chemisorption and electroreduction mechanisms within these novel solvent systems.
• To present a techno-economic evaluation of ILs and DESs for CO2 utilization.

Main Methods:

• Literature review focusing on the design and application of ILs and DESs for CO2 separation and electrochemical conversion.
• Analysis of bulk and interfacial properties of ILs and DESs relevant to CO2 reactive capture and conversion.
• Techno-economic assessment of IL and DES-based processes for CO2 utilization.

Main Results:

• ILs and DESs can be effectively tuned for efficient CO2 capture and electrochemical conversion, overcoming limitations of aqueous systems.
• Understanding the complex speciation at electrode-electrolyte interfaces is crucial for optimizing RCC processes.
• The review highlights the potential of ILs and DESs for direct CO2 utilization in electrified, modular systems.

Conclusions:

• ILs and DESs represent a significant advancement for CO2 reactive capture and conversion, offering sustainable alternatives to conventional methods.
• Further research into interfacial phenomena and process optimization is needed to fully realize the techno-economic potential of these electrolytes for CO2 utilization.