对于CO氧化反应的Pd (n) / TiO2 (n) / TiO2 (n) / TiO2 (n) / TiO2 (n) / TiO2 (n) / TiO2 (n) / TiO2 (n) / TiO2 (n) / TiO2 (n) /
William E Kaden1, William A Kunkel, Matt D Kane
1Department of Chemistry, University of Utah, 315 South 1400 East, Room 2020, Salt Lake City, Utah 84112-0850, USA.
Journal of the American Chemical Society
|September 3, 2010
概括
的团大小在TiO(2)(110) 上显著影响氧气激活. Pd(20) 显示出高效率,与较小的集群不同,影响CO氧化机制.
科学领域:
- 表面科学是一门科学.
- 不同质的催化剂.
- 纳米材料是一种纳米材料.
背景情况:
- 了解金属氧化物支上的氧气激活对于催化非常重要.
- 在TiO{2}{110) 上的团是研究大小依赖的催化性质的模型系统.
- 这些表面上的氧和一氧化碳 (CO) 之间的相互作用决定了反应路径.
研究的目的:
- 调查氧气在Pd{n}/TiO{2}{110) 集群上的解离性结合效率.
- 为了确定团大小 (n=4,7,10,20) 对氧激活和CO氧化的影响.
- 为了将电子特性与催化活性和反应机制相关联.
主要方法:
- 温度编程反应 (TPR) 质谱学.温度编程反应 (TPR) 质谱学.
- 射线光辐射光谱学 (XPS).X射线光辐射光谱学 (XPS).
- 在不同剂量和温度下对O2和CO的受控暴露.
主要成果:
- 与较小的Pd(n) 集群相比,Pd(20)/TiO(2)(110) 的氧气激活效率更高.
- 对于较小的集群,CO氧化活性受到O(2) 激活的限制,但在低O(2) 剂量下,Pd(20) 受到CO结合的限制.
- 一个特定的CO结合部位被确定为对CO2产生有反应性的.
结论:
- 的集群大小决定了氧气激活和CO氧化在TiO上的机制{2}{110}.
- Pd集群的电子特性是它们大小依赖的催化性能的关键.
- 识别反应性结合点对于设计高效的催化系统至关重要.
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