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 900C under different CO2 or CO2-O-2 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.