CO₂ capture using silica-immobilized dicationic ionic liquids with magnetic and non-magnetic properties

Area of Science:

• Chemical Engineering
• Materials Science
• Environmental Science

Background:

• Aqueous amine solutions are traditional but face challenges in CO2 capture.
• Developing alternative materials is crucial for efficient post-combustion carbon capture technologies.

Purpose of the Study:

• To assess the CO2 sorption capacity and CO2/N2 selectivity of dicationic ionic liquids immobilized on mesoporous silica (SBA-15).
• To evaluate the stability and potential of these novel materials for industrial CO2 capture.

Main Methods:

• Synthesis and characterization of ionic liquids immobilized on SBA-15 using techniques like FTIR, NMR, SEM, TEM, TGA, VSM, BET, and BJH.
• Measurement of CO2 sorption capacity and CO2/N2 selectivity under specific conditions (1 bar, 25 °C).
• Evaluation of material stability through multiple sorption/desorption cycles.

Main Results:

• SBA@DIL_2FeCl4 exhibited the highest CO2 sorption capacity (57.31 mg/g) and CO2/N2 selectivity (12.27 mg/g).
• Immobilized ionic liquids did not significantly alter the silica's inherent CO2 sorption capacity.
• Selectivity for CO2 was enhanced approximately 3.8 times compared to pristine silica, indicating strong CO2 affinity.

Conclusions:

• The developed material demonstrates high CO2 sorption capacity and selectivity, outperforming pristine silica.
• The material shows excellent stability over multiple cycles, making it a viable candidate for industrial CO2 capture.
• Ionic liquid-functionalized silica presents a promising alternative to conventional aqueous amine solutions for post-combustion carbon capture.