(600bf) Analysis of Perovskites and Layered Perovskite Oxides As Materials for Conversion of Carbon Dioxide to Carbon Monoxide in Thermochemical Cycles

More than 30,000 Mt are emitted each year to the atmosphere, yet less than 1% of the CO₂ produced is re-utilized in industrial processes such as urea and salicylic acid synthesis. Here, an alternative to CO₂ utilization is proposed, where CO₂ can be transformed to high-value chemicals that could be used as a source for C1 chemistry by thermochemical cycles (TC).

Perovskites (ABO₃) are ideal for TCs because they have the ability to form oxygen vacancies while maintaining its crystalline structure, at lower temperatures than similar oxides (~820 °C) such as ceria and spinels. Layered perovskite (A₂BO₄) have similar properties to perovskites and therefore could be potential candidates for adsorption and conversion of carbon dioxide. The goal of the study is to demonstrate an oxide that has equilibrium between adsorption strength and CO₂-conversion capabilities. The stability of the CO₂ molecule posses a challenge because of the energy needed to break the C=O bond.

In this work, different perovskites, layered perovskites and spinels (La_0.75Sr_0.25CoO₃, La_0.75Sr_0.25FeO₃, La_0.75Sr_0.25Co_0.5Fe_0.5O₃, LaSrCoO₄ and CeCo₂O₄) were studied for their oxygen formation capabilities under inert environment and their carbon dioxide adsorption strength properties. The material that can convert carbon dioxide to carbon monoxide on its oxygen vacancies with the minimal energy input will be used for further studies on light-induced thermochemical conversion of CO₂ to CO.