Research on micro-structure and catalysis properties of nanosized Ce_1−x(Fe_0.5Eu_0.5)_xO_2−δ solid solutions

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• 作者：Guofang ZHANG (张国芳)^a ; ^b ; ^{afang1001@126.com} ; Jianyi XU (许剑轶)^a ; Zhonghui HOU (侯忠辉)^a ; Qingchun WANG (王青春)^a
• 关键词：solid solution ; hydrothermal ; Mg2Ni ; catalysis effect ; electrochemistry property ; rare earths
• 刊名：Journal of Rare Earths
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：35
• 期：1
• 页码：63-70
• 全文大小：3248 K
• 卷排序：35

文摘

Nanosized Fe3+ and Eu3+ codoped CeO2 solid solutions were synthesized via hydrothermal method. The crystalline structure of Ce1−x(Fe0.5Eu0.5)xO2−δ (x=0.00–0.30) solid solutions was carried out by the X–ray diffraction technique, and the spectrum features were identified by UV–Vis and Raman spectroscopy, respectively. It was observed that the cell parameters were first increased then decreased by increasing the doped ions content. The phase separation was detected when the dopant concentration reached to x=0.30. UV–Vis spectrum showed that the width of the band gap gradually reduced by increasing the doped content, and the solid solubility was determined to be x=0.20. The Raman technique displayed that the peak position of F2g mode gradually shifted to lower frequencies from 465 cm−1 for x=0.00 to 440 cm−1 for x=0.20. The catalytic effects of Ce1−x(Fe0.5Eu0.5)xO2−δ solid solutions on the electrochemistry properties of Mg2Ni/Ni were measured by mixing them together via ball milling technique. The electrochemical properties of the Mg2Ni/Ni–Ce1–x(Fe0.5Eu0.5)xO2−δ composites showed that the maximum discharge capability Cmax and the cycle stability were improved obviously. Meanwhile, the EIS characteristic also indicated that the doped solid solutions could enhance the rate of charge transfer on the surface of alloy. The catalytic effect of the solid solutions was speculated to rely on both the concentration of oxygen vacancies and the cell volumes of the solid solutions.