Oxygen Storage Capability of Brownmillerite-type Ca 2 AlMnO 5+δ and Its Application to Oxygen Enrichment
2013; American Chemical Society; Volume: 25; Issue: 3 Linguagem: Inglês
10.1021/cm303156n
ISSN1520-5002
AutoresTeruki Motohashi, Yuka Hirano, Yuji Masubuchi, Kazunori Oshima, Tohru Setoyama, Shinichi Kikkawa,
Tópico(s)Electronic and Structural Properties of Oxides
ResumoThe oxygen storage capability was investigated for Ca2(AlxMn1–x)2O5+δ (0.50 ≤ x ≤ 0.67) with a Brownmillerite-type structure. This oxide can store/release a large amount of excess oxygen (∼3.0 wt %) topotactically in response to variations in temperature and the surrounding atmosphere in a highly reversible manner. The capacity and response of oxygen storage are remarkable only in the vicinity of x = 0.50, that is, Ca2AlMnO5+δ, and rapidly deteriorated as the Al content increases. Owing to the high sensitivity in terms of oxygen nonstoichiometry, Ca2AlMnO5+δ exhibits oxygen intake/release ability when temperature swing between 500 and 700 °C is applied. With this characteristic feature of this oxide, a facile method for oxygen enrichment is demonstrated.
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