Utilisation of CO₂ as "Structure Modifier" of Inorganic Solids.

Area of Science:

• Solid-state chemistry
• Materials science
• Inorganic chemistry

Background:

• Carbon dioxide (CO2) is chemically stable, making its utilization as a reagent challenging.
• Reactions of CO2 with alkaline-earth oxides at high temperatures form carbonates, relevant for CO2 capture and reuse.
• Modifying crystal structures is key to tailoring material properties.

Purpose of the Study:

• To explore the use of CO2 as a reagent to alter the crystal structure of mixed-metal inorganic solids.
• To investigate the reaction of CO2 with specific isostructural mixed-metal oxides (Sr2CuO3, Sr1.8Ba0.2CuO3, Ba2PdO3).
• To form novel oxide carbonates by incorporating CO2 into oxide anion vacancies.

Main Methods:

• Reaction of CO2 gas with Sr2CuO3, Sr1.8Ba0.2CuO3, and Ba2PdO3 at high temperatures.
• Utilizing a synthetic procedure involving alternating CO2 and air exposure to minimize secondary phase formation.
• Employing first-principles density functional theory to model reaction kinetics.

Main Results:

• Successfully synthesized novel oxide carbonates by reacting CO2 with the selected mixed-metal oxides.
• Minimized the formation of SrCO3 as a secondary phase through an optimized synthetic approach.
• Developed a predictive model for reaction kinetics in cuprates using density functional theory.

Conclusions:

• CO2 can be effectively utilized as a reagent to modify the crystal structure of specific mixed-metal oxides.
• The developed synthetic strategy enables controlled formation of oxide carbonates.
• First-principles modeling provides insights into the reaction mechanisms and kinetics.