Oxygen storage capability of brownmillerite-type Ca2(AlxMn1-x)2O5+d (x = 0.50-0.67)

Abstract

The oxygen storage capability was investigate for Ca2(AlxMn1-x)2O5+d (x = 0.50-0.67) with a brownmillerite-type structure. This oxide was found to store/release a large amount of excess oxygen reversibly in response to variations in temperature and the surrounding atmosphere. The oxygen storage capacity at 400°C reached 2.9 wt% for x = 0.50, while it rapidly decreased with increasing x. Owing to the strong temperature dependence of excess oxygen amount, this oxide showed remarkable ability to intake/release oxygen when temperature swinging between 500°C and 700°C is applied.