Redox behaviors and structural characteristics of Mn0.1Ce0.9Ox and Mn0.1Ce0.6Zr0.3Ox
来源期刊:Journal of Rare Earths2008年第4期
论文作者:贾莉伟 沈美庆 王军 褚霞 王家明 胡志成
文章页码:523 - 527
摘 要:Mn0.1Ce0.9Ox 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.
贾莉伟,沈美庆,王军,褚霞,王家明,胡志成
Key Laboratory for Green Chemical Technology of State Education Ministry, School of Chemical Engineering and Technology, Tianjin UniversityWuxi Weifu Environmental Catalysts Co., Ltd.
摘 要:Mn0.1Ce0.9Ox 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.
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