在CeO(2) 支持的Au纳米粒子上的CO氧化机制
Hyun You Kim1, Hyuck Mo Lee, Graeme Henkelman
1Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712-0165, USA. hykim8083@gmail.com
Journal of the American Chemical Society
|December 24, 2011
概括
在二氧化 (CeO2) 表面的氧气空缺显著增强金纳米粒子 (Au NP) 催化氧化一氧化碳 (CO) 的活性. 这些职位空缺创造了新的反应途径,改善了催化剂设计.
科学领域:
- 计算化学的计算化学
- 材料科学 材料科学 材料科学
- 表面科学是一门学科.
- 催化剂是一种催化剂.
背景情况:
- 二氧化 (CeO2) 是异质催化中的关键支材料,以其氧气储存能力而闻名.
- 黄金纳米粒子 (Au NPs) 具有独特的催化性能,特别适用于氧化反应.
- 在CeO2的表面氧空缺被实验观察并影响其反应性.
研究的目的:
- 调查氧气空缺对支持CeO2的AuNP的催化活性的影响,用于CO氧化.
- 为了阐明CO氧化过程中涉及的反应机制,在固态测量和富含氧气空隙的CeO2表面.
- 为设计改进的支持Au催化剂提供见解.
主要方法:
- 用密度函数理论 (DFT) 的计算来建模和分析催化过程.
- 对一个Au(13) 纳米颗粒在石化CeO2 (Au(13) @CeO2-STO上的CO氧化路径进行比较,与具有三个氧空位的CeO2 (Au(13) @CeO2-3VAC) 相比.
- 对三种拟议的CO氧化机制的分析:共吸收的O2,网状氧气和与Au-Ce ((3+) 点结合的O2.
主要成果:
- 在CeO2表面的氧气空隙创建了一个新的CO氧化路径,涉及O2与Au-Ce ((3+) 点结合.
- 职位空缺的存在显著改变了反应机制,增强了催化活性.
- DFT的计算揭示了空缺辅助路径的能量优势.
结论:
- 氧气空缺在增强CeO2支持的Au NP的CO氧化催化活性方面发挥着至关重要的作用.
- 一个设计策略涉及降低支的空隙形成能量,并使用可降解氧化物来创建O2的点.
- 这项研究为开发更高效的支持CO氧化金色催化剂提供了一条途径.
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