阳性电荷状态和可能的金纳米集群的多态化在减少的
Changjun Zhang1, Angelos Michaelides, David A King
1Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom.
Journal of the American Chemical Society
|January 28, 2010
概括
这项研究使用密度函数理论揭示了二氧化 (CeO2) 表面上小金 (Au) 纳米集群的新型结构和方面. 这些发现提供了对催化作用至关重要的原子级细节的见解.
科学领域:
- 材料科学 材料科学 材料科学
- 表面科学是一门学科.
- 计算化学的计算化学
背景情况:
- 黄金 (Au) 对二氧化 (CeO2) 的催化性能取决于Au集群的原子结构.
- 对CeO2上小型Au星团的详细原子层次理解仍然有限.
研究的目的:
- 在减少的CeO2{111}表面上研究小金纳米集群的核和结构特征.
- 使用计算方法探索这些纳米集群的几何和电子特性.
主要方法:
- 使用密度函数理论 (DFT) 的计算.
- 在减少的CeO2{111}表面上模拟了黄金原子 (高达Au11) 的连续沉积.
- 分析核化模式,集群几何,面体和电子结构.
主要成果:
- 确定了小Au纳米集群的面中心立方 (fcc) 几何体旁边的新型六角密封 (hcp) 结构.
- 观察到不同的方面,包括{111}/{100}对于fcc和{1011}/{0001}对于hcp集群.
- 发现与二氧化表面接触的金原子表现出正电荷.
结论:
- 在CeO2上的小金纳米集群表现出独特的结构多样性,超出了散装式fcc安排.
- 在接口上的电子电荷分布表明了增强催化活性的潜力.
- 这些原子规模的洞察力对于设计先进的Au/CeO2催化剂至关重要.
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