In Situ Multiscale Study of Iron Oxidation at High Temperatures

作者：Wei Tu, Zhen Zeng, Yongjian Zhao, Zhenghao Jia, Caixia Meng, Wei Liu, Xianhu Sun, Jianyu Huang · 发表于：Nano Letters · 年份：2025 · DOI：10.1021/acs.nanolett.5c00025 · 被引用次数：10 · 研究领域：Catalytic Processes in Materials Science、Electrocatalysts for Energy Conversion、Catalysts for Methane Reforming

Although high-temperature oxidation of metals results in significant failure of structure materials, in situ understanding of these processes and developing improved strategies are still very limited. Herein, using environmental scanning electron microscopy (ESEM), environmental transmission electron microscopy (ETEM), and X-ray photoelectron spectroscopy (XPS), we report the in situ dynamic high-temperature oxidation behaviors of iron in O 2, H 2 O, and O 2 + H 2 O atmospheres, respectively. The results demonstrate that an oxygen-rich environment (1.6 mbar) leads to transient formation of polycrystalline Fe 3 O 4 without passivation effects on further oxidation, while sparse oxygen environments (10 –3 mbar) promote formation of a uniform thin passivation layer of Fe 3 O 4, protecting itself from further oxidation in ambient air. In contrast to O 2, the H 2 O vapor accelerates oxidation, and the products consist of Fe 3 O 4 and FeOOH. These in situ results give insights into designing technically universal antioxidation strategies.