Spherical amine grafted silica aerogels for CO₂ capture

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Silica aerogels are promising porous materials.
• Developing efficient adsorbents for carbon dioxide (CO2) capture is crucial for mitigating climate change.
• Amine-functionalized materials offer high selectivity for CO2.

Purpose of the Study:

• To synthesize novel spherical amine grafted silica aerogels (SASAs) for CO2 capture.
• To investigate the effect of synthesis parameters on SASA structure and performance.
• To evaluate the CO2 adsorption capacity and regenerability of the developed material.

Main Methods:

• Spherical silica gel synthesis via sol-gel process in an oil bath.
• Amine grafting using 3-aminopropyltriethoxysilane.
• Vacuum drying to form spherical amine grafted silica aerogels (SASAs).
• Characterization of SASA structure (surface area, pore volume) and CO2 adsorption performance.

Main Results:

• SASAs were successfully synthesized with a proposed mechanism.
• Increased grafting time enhanced amine loading but decreased surface area and pore volume.
• Optimal CO2 adsorption capacity of 1.56 mmol g-1 was achieved at 35 °C with dry 1% CO2.
• Excessive amine loading negatively impacted CO2 adsorption capacity.

Conclusions:

• Spherical amine grafted silica aerogels are capable CO2 adsorbents.
• Synthesis conditions must be optimized to balance amine loading and porosity.
• This work presents a cost-effective and eco-friendly approach for designing regenerable adsorbent materials for CO2 capture.