Insensitivity of the extent of surface reduction of ceria on termination: comparison of (001), (110), and (111) faces
Insensitivity of the extent of surface reduction of ceria on termination: comparison of (001), (110), and (111) faces
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DOI：
10.1557/mrc.2020.73
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发表时间：
2020-12
影响因子：
1.9
通讯作者：
W. Yuan;S. Haile
中科院分区：
文献类型：
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作者：
W. Yuan;S. Haile
CeO_2表面相对于体相的还原能力增强早已得到证实。一些研究还表明，具有不同表面的CeO2纳米颗粒表现出不同的催化活性。尽管人们一致认为活性与表面Ce^3+浓度有关，但缺乏作为终止函数的这种浓度的实验测量。本文利用X射线吸收近边能谱(XANES)对具有(001)、(110)和(111)表面终止的薄膜中的Ce^3+浓度进行了定量研究。虽然在表面发现Ce^3+浓度增加，但它对薄膜取向的不敏感是令人惊讶的。
The enhanced reducibility of the surface of ceria relative to the bulk has long been established. Several studies also show that ceria nanoparticles with different facets exhibit different catalytic activities. Despite consensus that the activity is correlated with the surface Ce^3+ concentration, experimental measurements of this concentration as a function of termination are lacking. Here, X-ray absorption near-edge spectroscopy (XANES) is used to quantify the Ce^3+ concentration in films with (001), (110), and (111) surface terminations under reaction relevant conditions. While an enhanced Ce^3+ concentration is found at the surfaces, it is surprisingly insensitive to film orientation.