Utilisation of CO2 as "Structure Modifier" of Inorganic Solids. Issue 6 (21st December 2021)

• Record Type: Journal Article
• Authors: Bennett, M. J.; Dobson, I.; Benoit, D. M.; Francesconi, M. G.
• Is Part Of: Chemistry. Volume 28:Issue 6(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-12-21
• Subjects: carbon dioxide fixation -- intercalation -- main groups elements -- perovskite phases -- transition metals; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.202103608
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: Utilisation of CO2 as a chemical reagent is challenging, due to the molecule's inherent chemical stability. However, CO2 reacts promptly at high temperature (∼1000 °C) with alkaline‐earth oxides to form carbonates and such reactions are used towards capture and re‐utilisation. In this work, this concept is extended and CO2 is utilised as a reagent to modify the crystal structure of mixed‐metal inorganic solids. Modification of the crystal structure is a "tool" used by materials scientists to tailor the physical property of solids. CO2 gas was reacted with several isostructural mixed‐metal oxides Sr2 CuO3, Sr1.8 Ba0.2 CuO3 and Ba2 PdO3 . These oxides are carefully selected to show anion vacancies in their crystal structure, to act as host sites for CO2 molecules, leading to the formation of carbonate anions, (CO3 ) 2− . The corresponding oxide carbonates were formed successfully and the favourable formation of SrCO3 as secondary phase was minimised via an innovative, yet simple synthetic procedure involving alternating of CO2 and air. We also derived a simple model to predict the kinetics of the reactions for the cuprates, using first‐principles density functional theory and assimilating the reaction to a gas‐surface process. Abstract : CO2 is abundant and free but environmentally unfriendly. It is also unreactive, hence re‐purposing can be a challenge. This research article describes how CO2 can be used as a useful reagent towards the preparation and/or chemical and structural modification of inorganic solids. This approach is of wide application hence, in the future, it may become part of a toolbox of methods to reduce the environmental impact of CO2 .