Oxygen Storage Capability of Brownmillerite-type Ca₂AlMnO_5+δ and Its Application to Oxygen Enrichment

Abstract

Ca2AlMnO5+δ with a brownmillerite‐type structure can topotactically store/release a large amount of excess oxygen (about 3.0 wt.%) depending on temperature and the surrounding atmosphere in a highly reversible manner.

Redox characteristics variations in the cation-ordered perovskite oxides BaLnMn2O5+δ(Ln = Y, Gd, Nd, and La) and Ca2Al1−xGaxMnO5+δ(0 ≤ x ≤ 1)

“…Our previous TG experiment indicated 6 temperature upon Ga-for-Al substitution. We point out that the much slower oxygen-intake rate for the fully Ga-substituted product is also attributed to the less strong chemical bonds between Ga and excess oxygen atoms.…”

“…The oxygen intake/release behavior essentially agrees with that in our previous report. 6 While the x = 0.1 product exhibits a similar behavior to x = 0, its onset temperatures of oxygen release (upon heating) and oxygen re-intake (upon cooling) are slightly lowered.…”

Solution combustion synthesis of Brownmillerite-type Ca2AlMnO5 as an oxygen storage material

“…Although various oxides have been investigated as oxygen storage materials, Ca 2 AlMnO 5, which consists only of rock forming materials [11], is very promising based on its large oxygen storage capacity. Ca 2 AlMnO 5 is classified as a Brownmillerite, which is an oxygen-deficient B-site ordered perovskite with a general formula of A 2 B 2 O 5 [11].…”

“…Ca 2 AlMnO 5 is classified as a Brownmillerite, which is an oxygen-deficient B-site ordered perovskite with a general formula of A 2 B 2 O 5 [11]. Motohashi et al [11] first reported that Ca 2 AlMnO 5 can be applied in oxygen enrichment.…”

“…Ca 2 AlMnO 5 is classified as a Brownmillerite, which is an oxygen-deficient B-site ordered perovskite with a general formula of A 2 B 2 O 5 [11]. Motohashi et al [11] first reported that Ca 2 AlMnO 5 can be applied in oxygen enrichment. They reported that this material can store/release about 3.0 wt% M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT oxygen topotactically in response to variations in temperature and the surrounding atmosphere in a highly reversible manner [11].…”