Oxygen-sorptive and -desorptive properties of perovskite-related oxides under temperature-swing conditions for oxygen enrichment

A group of A- and/or B-site partially substituted strontium cobaltites was investigated for oxygen-sorptive properties under temperature-swing conditions in air. The cobaltites with perovskite structure desorbed and absorbed significant amounts of oxygen quickly as well as reversibly on heating or cooling in the temperature range between 300 and 1000 °C, while those with brownmillerite or 2H-BaNiO3 structure either lacked oxygen-sorptive properties or showed retarded oxygen sorption with hysteresis, respectively. Under temperature-swing cycles between 300 and 550 °C at a heating or cooling rate of 30 °C/min, SrCo0.4Fe0.6O3−δ showed the largest mass change of 0.96%, or sorption and desorption of 7 cm3 oxygen (STP)/g oxide among the perovskite-type oxides tested. This result appears to indicate the potential of a new oxygen enriching method coupled with a temperature-swing technique.