Analysis of the CO₂ Chemisorption in Li₅FeO₄, a New High Temperature CO₂ Captor Material. Effect of the CO₂ and O₂ Partial Pressures

Pentalithium ferrite (Li₅FeO₄) was tested as possible CO₂ captor, both by theoretical calculations and experimental measurements. The pristine Li₅FeO₄ compound with orthorhombic structure was synthesized via solid-state reaction and it was structural and microstructurally characterized. Later, sample was heat-treated at temperatures from room temperature to 900°C under different CO₂ or CO₂-O₂ atmospheres. Li₅FeO₄ exhibits excellent CO₂ chemisorption abilities with a capture capacity about 12.9 mmol/g, which is outstanding in comparison to other previously reported ceramic captors. This material is able to react with CO₂ from 200°C to approximately 715°C showing a high kinetic of reaction even at CO₂ partial pressure values as low as 0.2. Additionally, results suggest that oxygen addition does enhance the CO₂ chemisorption on Li₅FeO₄ at temperatures below 700°C, although oxygen addition seems to favor the desorption process at higher temperatures. (Graph Presented).