Optimization of absorption/desorption parameters of Brownmillerite SrCoO2.5 for oxygen storage

The order-disorder transition of Brownmillerite (BM)-type oxides have gained attraction for oxygen enrichment applications. Herein, BM SrCoO2.5 is exploited for oxygen storage and separation across its order-disorder transition. Optimized temperature and duration of heat treatment in an oxygen atmosphere for obtaining maximum oxygen storage is explored. A maximum of 15.28 cm(3) of O-2 per gram of the material can be stored in the sample at STP by a heat-treatment at 673-693 K. A drastic increase in ionic conductivity of the sample above a certain temperature gave rise to a threshold temperature for oxygen absorption. Kinetics of oxygen release appeared to follow nucleation and growth model and the rate of desorption was found to increase with rise in temperature. The oxygen intake/release of BM SrCoO2.5 occurs within minutes in a completely reversible manner facilitating a low cost O-2 separation through vacuum swing adsorption