Development of Borate-Based Basic Ionic Liquid for Room Temperature CO₂ Capture.

Area of Science:

• Chemical Engineering
• Materials Science
• Environmental Science

Background:

• Ionic liquids (ILs) are explored as advanced CO2 absorbents due to their tunable properties, aiming to reduce energy costs in carbon capture.
• Developing cost-effective and efficient CO2 capture technologies is crucial for mitigating climate change.

Purpose of the Study:

• To synthesize and investigate novel borate-based nonamine functionalized ionic liquids (ILs) incorporated with magnesium acetylacetonate for CO2 capture.
• To evaluate the CO2 uptake capacity, stability, and absorption mechanism of these ILs under moderate temperature and ambient pressure.

Main Methods:

• Synthesis of functionalized lithium borate ionic liquids with magnesium acetylacetonate.
• Characterization using Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared (FTIR) spectroscopy.
• Evaluation of CO2 capture capability, physical properties, thermochemical stability, and absorption enthalpy via Differential Scanning Calorimetry (DSC).

Main Results:

• Successful incorporation of acetylacetonate ligands into fluorinated-lithium borate ILs confirmed by spectroscopic methods.
• Synthesized ILs exhibit stability below 200 °C, retaining their structural integrity.
• ILs functionalized with fluorinated alcohol and magnesium acetylacetonate demonstrated a 55% increase in CO2 uptake compared to unmodified ILs.
• CO2 capture occurs via physical absorption with low enthalpy of absorption (-12.4 to -18.9 kJ mol⁻¹), significantly lower than conventional amines and amine-based ILs.

Conclusions:

• Lithium borate-acetylacetonate ILs present a promising, low-energy pathway for CO2 capture under ambient conditions.
• The enhanced CO2 uptake is attributed to cooperative interactions facilitated by the functionalized structure.
• These findings support the potential of tailored ionic liquids for more efficient and economical carbon capture strategies.