Visualizing Anisotropic Oxygen Diffusion in Ceria under Activated Conditions
Visualizing Anisotropic Oxygen Diffusion in Ceria under Activated Conditions
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活化条件下二氧化铈中各向异性氧扩散的可视化
DOI：
10.1103/physrevlett.124.056002
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发表时间：
2020
影响因子：
8.6
通讯作者：
Lifen Wang
中科院分区：
文献类型：
--
作者：
Liang Zhu;Xin Jin;Yu-Yang Zhang;Hong-Jun Gao;Lei Liu;Tijana Rajh;Zhi Xu;Wenlong Wang;Xuedong Bai;Jianguo Wen;Lifen Wang
氧反应性在氧化铈基催化剂的性能中起着关键作用。采用像差校正透射电子显微镜和分子动力学模拟研究了活化条件下氧化铈中氧原子的扩散。实现了活性氧及其实时扩散的可视化。铈和氧原子之间的相互作用源于库仑相互作用揭示了与氧的运输相关的铈原子的面外屈曲。发现了依赖于晶体取向的各向异性氧原子扩散，证明了优先的[001]晶体学扩散途径。这些发现揭示了各向异性取向相关的萤石结构氧化物的应用前景。
Oxygen reactivity plays a key role in the performance of ceria-based catalysts. Aberration-corrected transmission electron microscopy and molecular dynamics simulations were used to study the oxygen atom diffusion in ceria under activated conditions. Reactive oxygen atom and its real-time diffusion were visualized. The interplay between cerium and oxygen atoms originating from a Coulomb interaction was revealed by the out-of-plane buckling of cerium atoms associated with oxygen transport. Anisotropic oxygen atom diffusion that depends on crystal orientations was discovered, demonstrating a preferential [001 crystallographic diffusion pathway. These findings reveal prospects for applications of anisotropic orientation-relevant fluorite-structured oxides.