Preparation and property investigation of CeO2-ZrO2-Al2O3 oxygen-storage compounds
Preparation and property investigation of CeO2-ZrO2-Al2O3 oxygen-storage compounds
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DOI：
10.1016/j.jallcom.2007.01.060
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发表时间：
2008-05
影响因子：
6.2
通讯作者：
Zhenling Wei;Hongmei Li;Xiaoyu Zhang;Shenghui Yan;Zhenfei Lv;Yaoqiang Chen;M. Gong
中科院分区：
文献类型：
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作者：
Zhenling Wei;Hongmei Li;Xiaoyu Zhang;Shenghui Yan;Zhenfei Lv;Yaoqiang Chen;M. Gong
采用共沉淀法制备了CeO_2-ZrO_2-Al_2O_3（CZA）贮氧材料，其氧化铝含量分别为10，25，50，75和90wt%。为了与CeO 2-ZrO 2（CZ）的结果进行比较，采用BET法、X射线衍射（XRD）、拉曼光谱、程序升温还原（H2-TPR）和氧脉冲技术（OSC）对所制备的材料进行了表征。XRD和拉曼光谱结果表明，除90wt%氧化铝的样品外，其余样品分别在873和1273 K下煅烧5 h后，均能保持单一的CeO 2立方萤石结构。与新鲜样品相比，老化样品的颗粒尺寸增大，但没有发生相分离。根据BET和OSC的结果，在1273 K煅烧后，氧化铝掺杂可以使该体系材料保持较高的比表面积（114.5m2g-1）和较大的孔容（0.36mlg-1），而不失去CeO 2的特性。随着Al_2O_3含量的增加，铈的可利用率也增加，表明CZA的OSC比CZ更稳定。本工作制备的CZA材料为高度分散的复合固溶体。在1273 K下煅烧后，这些化合物仍能保持结构和织构的稳定性，同时保持优异的OSC和稳定的氧化还原性能。
Oxygen-storage materials CeO2–ZrO2–Al2O3(CZA), with alumina contents 10, 25, 50, 75 and 90wt%, respectively, were prepared by the co-precipitation method. To compare our results with those of CeO2–ZrO2(CZ), the prepared materials were characterized by Brunauer-Emmet Teller method (BET), X-ray diffraction (XRD), Raman spectrum, temperature-programmed reduction (H2-TPR) and oxygen pulsing technique (OSC). The XRD and Raman results show that all samples (except sample with 90wt% alumina) can keep the single CeO2cubic fluorite structure after calcination at 873 and 1273K for 5h, respectively. Compared with the fresh samples, the particle sizes of aged samples increase, but no phase separation occurs. According to the results of BET and OSC, after calcination at 1273K, alumina doped can make this system materials maintain higher specific surface area (114.5m2g−1) and larger pore volume (0.36mlg−1) without losing characteristics of CeO2. As Al2O3contents increase, the ratio of utilizable cerium also increases, indicating that the OSC of CZA is more stable than that of CZ. In this work, the prepared CZA materials are highly dispersed composite solid solutions. After calcination at 1273K, those compounds can still keep the structural and textural stability, and simultaneously hold excellent OSC and stable redox property.