在中偏好的CO氧化:核心外纳米粒子的反应性
Anand Udaykumar Nilekar1, Selim Alayoglu, Bryan Eichhorn
1Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
Journal of the American Chemical Society
|May 13, 2010
概括
我们设计了新的核心外纳米粒子 (NP) 催化剂,其活性提高了中偏好的CO氧化 (PROX) 的活性. Ru@Pt核心外NP显示了最高的性能,在低温下表现出高效的CO氧化.
科学领域:
- 材料科学 材料科学 材料科学
- 催化剂是一种催化剂.
- 纳米技术 纳米技术
背景情况:
- 在燃料电池应用中,开发用于中首选CO氧化 (PROX) 的高效催化剂至关重要.
- 核心外纳米粒子通过控制界面效应提供可调节的催化性能.
研究的目的:
- 设计,合成和描述新的M@Pt核心外纳米粒子 (NP) 催化剂.
- 为了研究它们对PROX反应的催化性能.
- 用密度函数理论 (DFT) 阐明控制它们反应性的基本机制.
主要方法:
- 第一原则指导了M@Pt核心外NP的设计和合成 (M = Ru, Rh, Ir, Pd, Au).
- 使用X射线衍射,FTIR,HRTEM和温度编程反应进行表征.
- 对PROX的催化活性和选择性的评估.
- 使用DFT计算的机制研究.
主要成果:
- 合成的M@Pt核心外NP与受控的Pt外厚度 (~1-2个单层).
- 与单金属和双金属纳米合金相比,观察到几个M@Pt NP的PROX活性和选择性显著改善.
- Ru@Pt核心外NP表现出最高的活动,达到30°C的完全CO氧化.
- DFT的研究表明,增强的活性源于可用的没有CO的Pt位点,用于O2激活,以及独特的介导CO氧化途径.
结论:
- M@Pt核心外NP代表了设计具有低含量,高活性和选择性PROX催化剂的有希望的策略.
- 核心金属显著影响Pt外的催化性能.
- 了解反应机制为未来的催化剂开发提供了洞察力.
相关概念视频
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