表面替代在多元组件核心外结构中从原子混乱到秩序阶段过渡中的作用
Wencong Zhang1,2, Fan Li1, Yi Li1,2
1Center of Hydrogen Science & State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, People's Republic of China.
Nature communications
|November 11, 2024
概括
了解催化剂中的原子排序是关键. 这项研究揭示了Pt-Co纳米颗粒中的扩散如何降低过渡温度,从而使催化剂设计的可控相变成为可能.
科学领域:
- 材料科学 材料科学 材料科学
- 纳米技术纳米技术
- 催化剂是一种催化剂.
背景情况:
- 在金属间相中的原子排序增强了催化剂的活性和稳定性.
- 在多组件系统中,混乱到秩序阶段过渡的机制尚未完全理解.
- 控制相位转换对于设计先进的催化剂至关重要.
研究的目的:
- 在化过程中研究Pd@Pt-Co立方纳米粒子中的原子扩散和相位过渡机制.
- 阐明替代在Pt-Co系统中对相位过渡温度和动力学的作用.
- 为多元件催化系统的合理设计提供见解.
主要方法:
- 现场电子显微镜以实时观察相位过渡.
- 现场原子分辨率元素分析用于详细的结构和组成特征.
- 计算计算以确定相位过渡温度和激活能量.
主要成果:
- 在表面区域向外扩散的 (Pd) 替代了 (Pt),形成了一个 (Pt,Pd) -Co三元系统.
- 这种替代使得在400°C的低温下实现相位过渡,然后由有序相位的形状保存的向内传播.
- 在更高的温度下过度的相互扩散减少了原子的排序,改变了纳米粒子形态.
结论:
- 替代显著降低了Pt-Co合金中原子扩散的相位过渡温度和激活能量.
- 这项研究揭示了控制多组件纳米粒子相变的关键原子化机制.
- 这些发现对于未来设计高活性和稳定的多组分催化剂至关重要.
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