在环境压力下Pt{557}表面的CO诱导团的热演变和不稳定性
Jeongjin Kim1,2, Myung Cheol Noh1,2, Won Hui Doh1,2
1Center for Nanomaterials and Chemical Reactions, Institute for Basic Science , Daejeon 34141, Republic of Korea.
Journal of the American Chemical Society
|January 20, 2016
概括
在催化剂上吸附一氧化碳 (CO) 会导致表面重组. 这项研究揭示了二氧化碳诱导的重组和集群形成,影响了催化活性.
科学领域:
- 表面科学
- 催化剂
- 材料科学
背景情况:
- 一氧化碳 (CO) 是工业化学反应中的关键分子,其在催化剂表面的吸附对反应动力学至关重要.
- 由于活性位点的密度高,如 (Pt) 等阶梯面具有增强的催化活性.
- 表面重组,特别是阶梯表面的粗化,与二氧化碳吸附行为有关.
研究的目的:
- 通过一氧化碳吸附诱导的阶段性催化剂Pt557表面重组的热演变.
- 了解二氧化碳吸附,表面形态变化和二氧化碳诱导的团的形成之间的关系.
主要方法:
- 使用扫描道显微镜 (STM) 来观察表面重组的动态.
- 研究一氧化碳 (CO) 在1.4 mbar的吸附对Pt557级表面的影响.
- 分析了CO诱导的团的热演变和行为.
主要成果:
- 观察到在Pt557表面上形成的断层形态和CO诱导的三角形Pt集群.
- 在CO诱导的Pt集群中记录了可逆的无序-有序过渡.
- 这些集群在高温下发现的热不稳定性,归因于排斥性CO-CO相互作用.
结论:
- CO吸附显著重组了阶段性表面,影响了催化性能.
- 由CO引起的Pt集群的形成和行为对温度和CO-CO相互作用敏感.
- 了解这些表面动态对于优化涉及二氧化碳的催化过程至关重要.
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