中的氧化还原诱导微观结构和相位动力学:在现场同步射线射线衍射的洞察
Shyam Bharatkumar Patel1, Jianyu Wang1, Xiaobo Chen1
1Department of Mechanical Engineering & Materials Science and Engineering Program, State University of New York at Binghamton, Binghamton, New York 13902, United States.
Journal of the American Chemical Society
|July 24, 2025
概括
氧化还原循环不可逆转地改变了的微观结构. 和水暴露会导致六角密封的相变,影响催化剂和储存.
科学领域:
- 材料科学
- 表面科学
- 电化学
背景情况:
- 多晶 (Ni) 对于催化和储存至关重要.
- 了解其在氧化还原循环过程中的微观结构和相位演变对于优化性能至关重要.
研究的目的:
- 在O2,H2和H2O环境中的氧化还原循环过程中研究Ni的微结构和相位演变.
- 阐明相变的机制及其动力学.
主要方法:
- 在现场使用同步射线衍射来监测Ni微结构变化.
- 使用约翰逊-梅尔-阿弗拉米-科尔莫戈罗夫模型进行了动力分析.
主要成果:
- 在O2中引起的氧化 (111) 纹理,在随后的减少和再氧化时丢失.
- H2暴露导致了质子溶解和从面中心立方 (FCC) 到六角密封 (HCP) Ni 的相位过渡.
- 由于质子透,H2O暴露导致了-NiOOH和HCP Ni的形成.
- 在预氧化和原始Ni表面上分别观察到NiO,gamma-NiOOH和HCP Ni的独特1D和3D生长动力学.
结论:
- 氧化还原循环导致Ni的不可逆转的微观结构变化.
- 和水在Ni相转换中起着至关重要的作用.
- 控制的微结构和相位演变是设计基于Ni的催化剂和储存系统的关键.
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