Structural characterization of ceria-zirconia powder catalysts prepared by high-energy mechanical milling: A neutron diffraction study
Structural characterization of ceria-zirconia powder catalysts prepared by high-energy mechanical milling: A neutron diffraction study
复制标题
DOI：
10.1557/jmr.2000.0220
复制
发表时间：
2000-07-01
影响因子：
2.7
通讯作者：
Trovarelli, A
中科院分区：
文献类型：
--
作者：
Enzo, S;Delogu, F;Trovarelli, A
对高能机械研磨制备的CeO2-ZrO2粉末催化剂样品进行中子衍射测量。在所检查的整个组成范围内都证明了固溶体的形成。 Rietveld 方法的定量相评估表明，低 CeO2 含量时形成四方结构，而立方固溶体在高 CeO2 负载量下是稳定形式。此外，在中间成分（50 mol% CeO2）中观察到轴比一致且氧亚晶格内部变形的赝立方或四方 t" 晶胞。高达 1000 ℃ 的热退火表明晶胞参数膨胀；对于组合物 CexZr1-xO2 (x < 0.5)，观察到以立方相和单斜相为代价的四方性程度。
Neutron diffraction measurements were carried out on samples of CeO2-ZrO2 powder catalysts prepared by high-energy mechanical milling. The formation of solid solution was evidenced across the entire composition range examined. Quantitative phase evaluation by the Rietveld method indicated formation of tetragonal structure for low CeO2 content, whereas cubic solid solutions were the stable form at high CeO2 loading, In addition, a pseudocubic or tetragonal t " cell with axial ratio of unity and with internal deformation of the oxygen sublattice was observed at intermediate composition (50 mol% CeO2). Thermal annealing up to 1000 degrees C showed expansion of the unit cell parameters; an increase in the degree of tetragonality at the expense of cubic and monoclinic phase was observed for composition CexZr1-xO2 (x < 0.5).