减少TiO2状态对催化CO氧化对沉积大小选择的Pt集群的催化CO氧化的影响
Simon Bonanni1, Kamel Aït-Mansour, Wolfgang Harbich
1Institute of Condensed Matter Physics, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
Journal of the American Chemical Society
|January 12, 2012
概括
在二氧化上的白金集群显示了不同的CO氧化活性. 稍微减少的支增强了催化作用,而大幅减少的支由于扩散和TiO (x) 形成而使其失活.
科学领域:
- 不同质的催化剂.
- 表面科学是一门科学.
- 材料化学 材料化学
背景情况:
- 二氧化 (TiO2) 是异质催化剂中广泛使用的支材料.
- TiO2的表面特性,特别是其还原状态,可以显著影响支金属集群的催化性能.
- 了解这些支持效应对于设计高效的催化剂至关重要.
研究的目的:
- 研究TiO2支的减少状态对沉积 (Pt) 集群的催化活性的影响.
- 阐明CO氧化反应期间观察到的催化活性变化的机制.
主要方法:
- 研究了不同程度的降解在TiO2上支持的Pt(7) 集群上的CO氧化反应.
- 分析了支的减少状态和Pt集群的催化活性之间的关系.
主要成果:
- 略有减少的TiO2支持促进了Pt集群对CO氧化具有很高的催化活性.
- 强烈减少的TiO2支持导致CO氧化活性显著灭.
- 失活是由于TiO3+) 间位物从散体扩散到表面,形成TiOx) 结构并消耗吸附氧气.
结论:
- TiO2支的还原状态对支的Pt集群对CO氧化的催化性能进行了关键控制.
- 散装缺陷的热激活扩散到表面在催化剂停用中起着关键作用.
- 这些发现对设计和优化可降解氧化物支持的金属催化剂具有广泛的影响.
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