A Space-Charge Treatment of the Increased Concentration of Reactive Species at the Surface of a Ceria Solid Solution
A Space-Charge Treatment of the Increased Concentration of Reactive Species at the Surface of a Ceria Solid Solution
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二氧化铈固溶体表面活性物质浓度增加的空间电荷处理
DOI：
10.1002/ange.201708118
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发表时间：
2017
影响因子：
--
通讯作者：
De Souza, Roger A.
中科院分区：
文献类型：
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作者：
Zurhelle, Alexander F.;Tong, Xiaorui;Klein, Andreas;Mebane, David S.;De Souza, Roger A.
应用适用于浓固溶体的空间电荷理论（Poisson-Cahn理论）来定量描述通过原位X射线光电子能谱（XPS）获得的氧化物催化剂Ce0.8Sm0.2O1.9表面的Ce 3+（反应性物种）浓度的公布数据作为温度和氧分压的函数。 与以前的理论处理相反，这些计算清楚地表明表面带正电，并由伴随的负空间电荷区补偿。由于空间电荷层的范围较短，在表面处产生的高空间电荷电位（>0.8 V）被证明难以通过XPS测量检测到。这种方法强调在考虑氧化物催化剂表面时需要考虑缺陷相互作用并允许偏离局部电荷中性。
A space‐charge theory applicable to concentrated solid solutions (Poisson–Cahn theory) was applied to describe quantitatively as a function of temperature and oxygen partial pressure published data obtained by in situ X‐ray photoelectron spectroscopy (XPS) for the concentration of Ce3+(the reactive species) at the surface of the oxide catalyst Ce0.8Sm0.2O1.9. In contrast to previous theoretical treatments, these calculations clearly indicate that the surface is positively charged and compensated by an attendant negative space‐charge zone. The high space‐charge potential that develops at the surface (>0.8 V) is demonstrated to be hardly detectable by XPS measurements because of the short extent of the space‐charge layer. This approach emphasizes the need to take into account defect interactions and to allow deviations from local charge neutrality when considering the surfaces of oxide catalysts.