Structure and Redox Properties of CexTi1-xO2 Solid Solution
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- 作者：Mengfei Luo ; Jun Chen ; Linshen Chen ; Jiqing Lu ; Zhaochi Feng ; and Can Li
- 刊名：Chemistry of Materials
- 出版年：2001
- 出版时间：January 2001
- 年：2001
- 卷：13
- 期：1
- 页码：197 - 202
- 全文大小：96K
- 年卷期：v.13,no.1(January 2001)
- ISSN：1520-5002
文摘
A series of CexTi1-xO2 mixed oxide materials was synthesized by a sol-gel method with xvarying from 0.1 to 0.9 and characterized by XRD, Raman, and TPR techniques. The structureof the mixed oxides changes with the Ce/Ti ratio. When the x value is decreased from 1.0 to0.6 for CexTi1-xO2, only a cubic phase is detected, and the lattice parameter of the cubicphase decreases because of the formation of a solid solution by substituting Ti atoms into aCeO2 lattice. When x = 0.3, a new phase is observed. The structure of this new phase wascharacterized by Rietveld refinement of X-ray diffraction data. This mixed oxide adopts themonoclinic symmetry with the space group C2/m and a = 0.9811(8) nm, b = 0.3726(3) nm,c = 0.6831(6) nm, and 
= 118.84
. When x = 0.4 and 0.5, a mixed phase region is detected.The addition of Ti atoms into CeO2 significantly improves the storage capacity of mobileoxygen of CeO2 by increasing the reduction extent of the mixed oxides. When x = 0.3-0.6,the valence value of Ce after a TPR run is estimated to be close to +3, which obviously issmaller than that for reduced CeO2 alone. The Ce0.5Ti0.5O2 sample shows the highest capacityof storage oxygen among CexTi1-xO2 mixed oxides. The capacity for reoxidation of the reducedCeO2-rich solid solution is higher than that of CeO2-lean mixed oxides. CexTi1-xO2 mixedoxides are promising materials for oxygen storage as well as catalysts for many reactionsinvolving oxygen, such as the catalysts for a three-way reaction to reduce the pollutantemissions or combustion of volatile organic compounds.
= 118.84. When x = 0.4 and 0.5, a mixed phase region is detected.The addition of Ti atoms into CeO2 significantly improves the storage capacity of mobileoxygen of CeO2 by increasing the reduction extent of the mixed oxides. When x = 0.3-0.6,the valence value of Ce after a TPR run is estimated to be close to +3, which obviously issmaller than that for reduced CeO2 alone. The Ce0.5Ti0.5O2 sample shows the highest capacityof storage oxygen among CexTi1-xO2 mixed oxides. The capacity for reoxidation of the reducedCeO2-rich solid solution is higher than that of CeO2-lean mixed oxides. CexTi1-xO2 mixedoxides are promising materials for oxygen storage as well as catalysts for many reactionsinvolving oxygen, such as the catalysts for a three-way reaction to reduce the pollutantemissions or combustion of volatile organic compounds.