This paper aims to elucidate oxygen sorption/desorption behavior accompanying with phase transition for perovskite-type oxide of SrFeO3-delta, as a function of temperature and oxygen partial pressure. Oxygen desorption of SrFeO3-delta in the temperature range of 100-800 degrees C was examined in terms of oxygen non-stoichiometry and crystal structural change, by means of thermogravimetric analysis and Mossbauer spectroscopy. In the case of oxygen desorption in nitrogen, the oxygen content of SrFeO3-delta was reduced in a stepwise manner. Thus, three phases having oxygen-vacancy-ordered structures were observed, depending on temperature; Sr8Fe8O23 (SrFeO2.875) below 300 degrees C, Sr4Fe4O11(SrFeO2.75) at 300-400 degrees C, and Sr2Fe2O5 (SrFeO2.5) above 400 degrees C. In contrast, in the case of oxygen desorption in air, the oxygen content decreased monotonically with increasing temperature without appearance of any stable phases. Furthermore, the isothermal oxygen sorption/desorption behavior of SrFeO3-delta was examined to evaluate the capability as an oxygen sorbent for the high-temperature pressure-swing adsorption (HT-PSA) process. The sample sorbed oxygen in air and desorbed it in nitrogen reversibly at a constant temperature above 300 degrees C. The oxygen-storage capacity based on the reversible weight change exhibited rather large value above 400 degrees C, due to the large difference in its oxygen content between in air and in nitrogen. Actual oxygen separation from atmospheric air was performed at 600 degrees C by means of the small-scale HT-PSA apparatus loaded with the SrFeO3-delta pellet-sample. The result suggests that SrFeO3-delta is one of potential oxygen sorbents for the HT-PSA process. (C) 2016 Elsevier Ltd. All rights reserved.