Oxygen-diffusion-driven oxidation behavior and tracking areas visualized by X-ray spectro-ptychography with unsupervised learning
Oxygen-diffusion-driven oxidation behavior and tracking areas visualized by X-ray spectro-ptychography with unsupervised learning
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DOI：
10.1038/s42004-019-0147-y
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发表时间：
2019-04-26
影响因子：
5.9
通讯作者：
Takahashi, Yukio
中科院分区：
文献类型：
--
作者：
Hirose, Makoto;Ishiguro, Nozomu;Takahashi, Yukio
具有原子有序排列的铈和锆原子的铈锆固溶体氧化物Ce2Zr2Ox (x = 7-8)中的储氧和氧扩散释放是三效排气催化的关键。储氧通过异质氧扩散到 Ce2Zr2O7 颗粒的空位中进行，但在 Ce2Zr2Ox 块体中储氧后，异质氧扩散轨迹被消除。在这里，我们展示了三维硬X射线光谱法，以清晰地可视化Ce2Zr2Ox颗粒中的三维铈价图，无监督学习揭示了隐藏的氧扩散驱动的三维纳米级铈氧化行为，并在储氧过程中跟踪单个混合氧化物颗粒内部的区域。所描述的方法可以允许对固体材料中的反应跟踪区域进行纳米级化学成像。
Oxygen storage and release with oxygen diffusion in the bulk of the cerium-zirconium solid solution oxide Ce2Zr2Ox (x = 7-8), which possesses an atomically ordered arrangement of cerium and zirconium atoms, is the key to three-way exhaust catalysis. Oxygen storage proceeds via heterogeneous oxygen diffusion into the vacant sites of Ce2Zr2O7 particles, but the heterogeneous oxygen diffusion track is erased after oxygen storage in the Ce2Zr2Ox bulk. Here we show three-dimensional hard X-ray spectro-ptychography to clearly visualize the three-dimensional cerium valence map in Ce2Zr2Ox particles, and unsupervised learning reveals the concealed oxygen-diffusion-driven three-dimensional nanoscale cerium oxidation behavior and tracking areas inside individual mixed-oxide particles during the oxygen storage process. The described approach may permit the nanoscale chemical imaging of reaction tracking areas in solid materials.