2024-03-28T11:42:04Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/622532022-11-17T02:08:08Zhdl_2115_20045hdl_2115_139Redox characteristics variations in the cation-ordered perovskite oxides BaLnMn(2)O(5+delta) (Ln = Y, Gd, Nd, and La) and Ca2Al1-xGaxMnO5+delta (0 <= x <= 1)Motohashi, TerukiKimura, MakotoInayoshi, TakeruUeda, TakuMasubuchi, YujiKikkawa, Shinichi430Two series of manganese-based oxygen storage materials, BaLnMn(2)O(5+delta) (Ln = Y, Gd, Nd, and La) and Ca2Al1-xGaxMnO5+delta (0 <= x <= 1), were synthesized and characterized to clarify cationic substitution effects on the oxygen intake/release behaviors of these materials. The thermogravimetric data revealed that the isovalent substitutions neighboring the active sites for oxygen intake/release are very effective. For BaLnMn(2)O(5+)delta, fully-reduced delta approximate to 0 products with larger Ln ions showed oxygen intake starting at lower temperatures in flowing O-2 gas, resulting in a systematic relationship between the onset temperature and the ionic radius of Ln(3+). Furthermore, the delta vs. P(O-2) plots at 700 degrees C indicated a systematic trend: the larger the ionic size of Ln(3+) is, the larger oxygen contents the Ln-products exhibit. For Ca2Al1-x-GaxMnO5+delta , on the other hand, the temperature-induced oxygen intake/release characteristics appeared to be influenced by Ga-for-Al substitution, where the onset temperatures of oxygen release (upon heating) and oxygen intake (upon cooling) are decreased with the increasing Ga content (x).Royal Society of Chemistry (RSC)Journal Articleapplication/pdfhttp://hdl.handle.net/2115/62253https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/62253/1/Motohashi.pdf1477-9226Dalton transactions442310746107522015enginfo:pmid/25688832info:doi/10.1039/c4dt03863kauthor