Pt3Ni纳米框架电催化剂的原子结构
Nigel Becknell1, Yijin Kang2, Chen Chen1
1Department of Chemistry, University of California , Berkeley, California 94720, United States.
Journal of the American Chemical Society
|December 15, 2015
概括
在现场研究催化剂结构是性能的关键. 对于Pt3Ni纳米框架,高氧降解反应 (ORR) 活性依赖于形成保护性皮表面.
科学领域:
- 材料科学
- 电化学
- 催化剂
背景情况:
- 催化剂的性能与其原子结构密切相关.
- 催化剂在反应条件下经常发生变化,因此需要进行现场研究.
- Pt-Ni 催化剂对氧减少反应 (ORR) 是有希望的,但它们的表面行为需要详细的调查.
研究的目的:
- 研究Pt3Ni纳米框架电催化剂的现场原子结构.
- 将表面结构与氧降解反应 (ORR) 的性能相关联.
- 了解Pt皮形成的机制及其对ORR活动的影响.
主要方法:
- 在现场X射线吸收光谱 (XAS) 以探测反应条件下的催化剂结构.
- 电化学低电位沉积和一氧化碳电氧化,以评估表面结合性质.
- 现场和现场XAS分析以比较催化剂状态.
主要成果:
- 纳米框架表面对吸附物具有不同的结合强度,与结构差异相关.
- 由于不完整的Pt分离和Ni溶解,更强的吸附物结合与更粗的Pt表面有关.
- 高ORR活性与显著的Pt分离相关,形成有益的Pt皮层.
结论:
- Pt3Ni空心纳米框架的高ORR活性严重依赖于Pt皮肤表面结构的形成.
- 在现场表征对于理解动态催化剂行为至关重要.
- 控制Pt分离和Ni溶解是优化ORR电催化剂的关键.
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