One Ca²⁺ Site in CaNaY Zeolite Can Attach Three CO₂ Molecules

Area of Science:

• Materials Science
• Chemistry
• Environmental Science

Background:

• Efficient carbon dioxide (CO2) capture materials are crucial for mitigating climate change.
• Previous research showed NaY zeolite captured two CO2 molecules per Na+ site, but only at low temperatures.
• A need exists for CO2 capture materials effective at ambient temperatures.

Purpose of the Study:

• To investigate the CO2 adsorption capacity of CaNaY zeolites at ambient temperatures.
• To demonstrate the potential of CaY zeolites as efficient CO2 capture materials.

Main Methods:

• Infrared (IR) spectroscopy was used to monitor CO2 adsorption.
• The study utilized natural 13C abundance for IR analysis of CO2 complexes.
• CO2 adsorption was studied at varying pressures and ambient temperature.

Main Results:

• One Ca2+ site in CaNaY zeolites can adsorb up to three CO2 molecules.
• Ca2+ (CO2)2 complexes are predominant at >1 mbar CO2.
• Triligand species (Ca2+ (CO2)3) begin to form at 65 mbar CO2.
• Vibrational interactions between 12CO2 molecules in polyligand complexes were observed.

Conclusions:

• CaY zeolites exhibit high CO2 adsorption capacity at ambient temperatures.
• CaY zeolites are promising candidates for practical CO2 capture applications.
• The observed high adsorption capacity makes CaY zeolites a viable solution for carbon capture.