Metal Atoms and Particles on Oxide Supports: Probing Structure and Charge by Infrared Spectroscopy
Metal Atoms and Particles on Oxide Supports: Probing Structure and Charge by Infrared Spectroscopy
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DOI：
10.1021/jp010724c
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发表时间：
2001-08
影响因子：
3.3
通讯作者：
M. Frank;M. Bäumer;R. Kühnemuth;H. Freund
中科院分区：
文献类型：
--
作者：
M. Frank;M. Bäumer;R. Kühnemuth;H. Freund
负载的金属颗粒可以表现出与相应的块体材料根本不同的性质。为了深入了解大小和结构相关现象的基本原理，在原子水平上对小聚集体进行结构表征是至关重要的，但远非简单。在负载团簇和金属-氧化物界面的研究中，一个长期存在的问题是金属-氧化物的电荷转移程度。我们表明，红外光谱，利用一氧化碳作为探针分子，可以提供有价值的信息的超小金属聚集体和单个金属原子的结构和电荷。为了产生仅含有几个原子或甚至单个原子的支撑粒子，将亚单层量的过渡金属钯、铑和铱在低基底温度下气相沉积到薄的有序氧化铝膜上。扫描隧道显微镜用于表征成核行为和平均粒径。尖锐，离散的特征...
Supported metal particles may exhibit properties fundamentally different from the corresponding bulk materials. To gain insight into principles underlying size- and structure-dependent phenomena, a structural characterization of small aggregates at the atomic level is crucial, while far from straightforward. A long-standing question in the study of supported clusters and metal-oxide interfaces concerns the extent of metal-oxide charge transfer. We show that infrared spectroscopy, utilizing carbon monoxide as a probe molecule, may provide valuable information on both structure and charge of ultrasmall metal aggregates and single metal atoms. To create supported particles containing only few atoms or even a single atom, submonolayer amounts of the transition metals palladium, rhodium, and iridium were vapor-deposited onto a thin, well-ordered alumina film at low substrate temperatures. Scanning tunneling microscopy served to characterize nucleation behavior and average particle size. Sharp, discrete feature...