Urea-Based Hydrothermally Derived Homogeneous Nanostructured Ce1-xZrxO2 (x = 0−0.8) Solid Solutions: A Strong Correlation between Oxygen Storage Capacity and Lattice Strain
Urea-Based Hydrothermally Derived Homogeneous Nanostructured Ce1-xZrxO2 (x = 0−0.8) Solid Solutions: A Strong Correlation between Oxygen Storage Capacity and Lattice Strain
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DOI：
10.1021/jp048084b
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发表时间：
2004-07
影响因子：
3.3
通讯作者：
R. Si;Ya‐Wen Zhang;Shijie Li;B. Lin;Chunhua Yan
中科院分区：
文献类型：
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作者：
R. Si;Ya‐Wen Zhang;Shijie Li;B. Lin;Chunhua Yan
采用温和尿素水热法制备了Ce1-xZrxO2(x=0−0.8)纳米粉末，在413K下均匀成核，在773K和1173K下焙烧，X射线荧光和能谱分析表明，所得产物中Ce和Zr离子的化学计量均匀度较好。X射线光电子能谱(XPS)和紫外可见光电子能谱(UV−Vis)表明，Ce3+/Ce4+的表面积比和体积比均随x含量的增加而增大。粉末X射线衍射和拉曼光谱表明，所制备的Ce1-xZrxO2样品为单相固溶体，结构均匀，在1273K以下具有较高的热稳定性，而x=0.4ZrxO2的样品由于尺寸效应较小，保持了准立方结构(t‘’相)。−=0.6时，样品中Ce3+和Ce4+的体积比随x的增加而增大。透射电子显微镜(TEM)分析表明，所制备的CeO_2纳米粒子具有较好的抗氧化性。
Ce1-xZrxO2 (x = 0−0.8) nanoparticulate powders were prepared via a mild urea hydrolysis based hydrothermal method through homogeneous nucleation at 413 K followed by calcination at 773 or 1173 K. X-ray fluorescence (XRF) and energy-dispersive X-ray analysis (EDAX) measurements testify to the good stoichiometric homogeneity of Ce and Zr cations in the as-obtained Ce1-xZrxO2 products. X-ray photoelectron spectroscopy (XPS) and ultraviolet−visible (UV−vis) spectra exhibit that both surface and bulk ratios of Ce3+ to Ce4+ for the as-prepared Ce1-xZrxO2 nanocrystals increased with the zirconium content x. Powder X-ray diffraction (PXRD) patterns and Raman spectra demonstrate that the present Ce1-xZrxO2 samples were single-phase solid solutions with good structural homogeneity and high thermal stability up to 1273 K, and those with x = 0.4−0.6 retained a pseudocubic structure (t‘ ‘ phase) due to the small crystallite size effect. Transmission electron microscopy (TEM) micrographs reveal that the as-prepared CeO...