Structural defects in a nano-scale powder of CeO2 studied by pulsed neutron diffraction

被引:105
作者
Mamontov, E [1 ]
Egami, T [1 ]
机构
[1] Univ Penn, Dept Mat Sci & Engn, Philadelphia, PA 19104 USA
基金
美国国家科学基金会;
关键词
oxides; neutron scattering; defects;
D O I
10.1016/S0022-3697(00)00003-2
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
Pulsed neutron diffraction measurements on nano-scale powder of ceria, CeO2, uncovered new structural features which appear to be intimately related to the function of this material as an oxygen storage medium in automotive three-way catalytic converters. The results of the pair-distribution function (PDF) analysis and the Rietveld refinement of the neutron diffraction data indicate the presence of interstitial oxygen defects in the octahedral sites of the fluorite structure. The defects were found to disappear following high-temperature treatment. It is suggested that these weakly bound interstitial oxygen defects provide oxygen mobility that facilitates the oxygen storage capacity of ceria in the catalytic converters. (C) 2000 Elsevier Science Ltd. All rights reserved.
引用
收藏
页码:1345 / 1356
页数:12
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