Light-Driven CO₂ Fixation into Epoxides Using an Al₂O₃/CoAl₂O₄ Composite Photocatalyst

Area of Science:

• Materials Science
• Catalysis
• Green Chemistry

Background:

• Utilizing carbon dioxide (CO2) as a C1 feedstock for synthesizing value-added chemicals is crucial for carbon neutrality.
• Developing catalysts from earth-abundant elements that operate under mild conditions remains a significant challenge.
• Photocatalytic conversion of epoxides using CO2 offers a promising pathway for producing cyclic carbonates.

Purpose of the Study:

• To develop a novel CoAl2O4/Al2O3 composite catalyst for light-driven CO2 fixation.
• To investigate the catalytic performance for converting epoxides into value-added cyclic carbonates under mild conditions.
• To establish a sustainable and efficient method for CO2 utilization.

Main Methods:

• Preparation of CoAl2O4/Al2O3 composite catalysts by calcining cobalt-incorporated Al-oxy-hydroxide.
• Photothermal conversion experiments using a 300 W xenon lamp under 1 atm CO2 pressure and solvent-free conditions.
• Characterization of catalyst performance, selectivity, and stability over multiple cycles.

Main Results:

• The 15% Co-Al2O3 composite catalyst exhibited the highest photothermal conversion efficiency (η = 66%).
• High selectivity (>95%) and good yield were achieved for cyclic carbonate synthesis using CO2 fixation.
• The catalyst demonstrated excellent stability, retaining activity over 8 catalytic cycles without degradation.

Conclusions:

• The developed CoAl2O4/Al2O3 photocatalyst provides an efficient and sustainable method for CO2 conversion into cyclic carbonates.
• The use of earth-abundant materials and mild reaction conditions aligns with green chemistry principles.
• This approach contributes to the development of a CO2 economy through effective carbon capture and utilization.