Sol-gel-derived perovskite-based sorbents for high-temperature air separation.

In this work, partial substitution or doping of SrCo_0.8Fe_0.2O_3-δ (SCF), which leads to the formation of La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ (LSCF) and La_0.6Sr_0.4Co_0.2Ni_0.8O_3-δ (LSCNi) were carried out using Pechini sol-gel technique. The perovskite oxides sol was then calcined at 850 °C for 4 h and their crystallinity, morphology and oxygen sorption/desorption behaviour were systematically compared. It was found that the synthesised perovskite oxides exhibit single-phase cubic perovskites. The O₂-TPD analysis indicates that LSCNi adsorbed the largest amount of oxygen and SCF only performed better at higher operating temperature. From the fixed bed test, LSCF and LSCNi are found to have high potential to be used as O₂ sorbent for high-temperature air separation because they required shorter time to achieve the breakthrough curve.Sol-gel derived perovskite-based sorbents were synthesised for high temperature air separation and the effects of partial substitution/doping on the structure and morphology of MIEC perovskite oxides were discussed. Doping of perovskite-based sorbents were successfully carried out using sol-gel technique.The O₂-TPD analysis indicates that LSCNi adsorbed the largest amount of oxygen.Doping of La³⁺ into A-site and Ni²⁺ into B-site ion has improved the oxygen sorption properties.LSCF and LSCNi can be used as O₂ sorbent as they have shorter breakthrough time. [ABSTRACT FROM AUTHOR]