Redox behaviors and structural characteristics of Mn0.1Ce0.90Ox and Mn0.1Ce0.6Zr0.3Ox
Redox behaviors and structural characteristics of Mn0.1Ce0.90Ox and Mn0.1Ce0.6Zr0.3Ox
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DOI：
10.1016/s1002-0721(08)60130-1
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发表时间：
2008-08-01
影响因子：
4.9
通讯作者：
Hu Zhichang
中科院分区：
文献类型：
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作者：
Jia Liwei;Shen Meiqing;Hu Zhichang
用动态储氧法测试了用溶胶凝胶法合成的Mn0.1Ce0.90和Mn0.1Ce0.6Zr0.3Ox样品的氧化还原性能，并用X射线衍射仪、BET、电子顺磁共振和X射线光电子能谱对其进行了表征。结果表明，Mn-O和Ce-O之间的协同作用可以提高氧化还原性能。新鲜样品和陈化样品均具有类似于CeO2的萤石型立方结构，此外，通过引入一些Zr原子，提高了材料的热稳定性。X射线光电子能谱分析表明，Mn0.1Ce0.9Ox和Mn0.1Ce0.6Zr0.3Ox样品表面存在Mn2+/Mn3+氧化还原对。电子顺磁共振研究表明，样品中存在三种类型的Mn2+：立方对称晶格中孤立的Mn2+替代Ce4+，非立方对称的缺陷Mn2+，以及样品表面的Mn2+。
Mn0.1Ce0.90, and Mn0.1Ce0.6Zr0.3Ox samples synthesized by sol-gel method were tested for redox properties through the dynamic oxygen storage measurement and characterized using X-ray diffraction, BET, electron paramagnetic resonance, and X-ray photoelectron spectroscopy. The results showed that redox performances of ceria-based materials could be enhanced by synergetic effects between Mn-O and Ce-O. Fresh and aged samples were characterized with the fluorite-type cubic structure similar to CeO2, and furthermore, the thermal stability of Mn0.1Ce0.9Ox materials was improved by the introduction of some Zr atoms. From XPS, it could be concluded that Mn2+/Mn3+ redox couples existed on the surface of Mn0.1Ce0.9Ox and Mn0.1Ce0.6Zr0.3Ox samples. Electron paramagnetic resonance researches revealed that there were three types of Mn2+ species: isolated Mn2+ substituting for Ce4+ ions in the lattice with a cubic symmetry, ones in defect with a noncubic symmetry, and at the surface of samples.