Possibility of Morphological Control To Improve the Activity of Oxygen Carriers for Chemical Looping Combustion

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• 作者：Wu Qin ; Yang Wang ; Changfeng Lin ; Xueqing Hu ; Changqing Dong
• 刊名：Energy & Fuels
• 出版年：2015
• 出版时间：February 19, 2015
• 年：2015
• 卷：29
• 期：2
• 页码：1210-1218
• 全文大小：719K
• ISSN：1520-5029

文摘

Morphological control of transition-metal oxides has received great attention for the preferential exposure of catalytically active sites. However, in contrast to catalytic processes, structural damage and relaxation of metal-oxide-based oxygen carriers (OCs) occur during the chemical looping combustion (CLC) processes. To answer the doubt whether surface-controlled preparation to obtain active and efficient OCs for CLC is practical, we supported Fe₂O₃ with the high-index [104] surface on Al₂O₃ (denoted as Fe₂O₃[104]/Al₂O₃) as an OC via surface-controlled preparation and experimentally detected the reaction behavior between the probe model fuel gas CO and Fe₂O₃[104]/Al₂O₃ during CLC processes. The results showed that Fe₂O₃[104]/Al₂O₃ is more efficient than the reference Fe₂O₃/Al₂O₃ prepared via the traditional method of precipitation, as less carbon was deposited on the reduced Fe₂O₃[104]/Al₂O₃ than on the reduced Fe₂O₃/Al₂O₃. Then we theoretically revealed the detailed mechanisms of reactions between CO and different surfaces of Fe₂O₃ to further confirm the high activity and behavior of Fe₂O₃[104] as an oxygen carrier for CLC. Finally, the results of structural characterizations and reuse experiments verified the regeneration ability of Fe₂O₃[104]. These findings indicate that morphological control of oxygen carriers is very rewarding for CLC.