MIES-studies on size-selected clusters deposited on oxide surfaces

MIES 研究沉积在氧化物表面的选定尺寸团簇

• 批准号: 5404778
• 负责人: Professor Dr. Ulrich Heiz
• 金额: --
• 依托单位: Lehrstuhl für Physikalische Chemie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2003
• 资助国家: 德国
• 起止时间: 2002-12-31 至 2007-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5404778?language=en
• 关键词: MIES; studies; size; selected; clusters

This project aims to study the electronic structure of pure and ligated clusters on oxide surfaces by means of the metastable impact electron spectroscopy, MIES, in combination with the ultraviolet photoelectron spectroscopy, UPS, in order to understand their chemical properties. We focus in the first term of the project on well-defined metal clusters with well-known, different and specific chemical properties. The following systems will be investigated in detail spectroscopically: (a) Au3Sr, Au4 und Au8 supported on ultrathin MgO-films: In this example we first characterize the electronic states of the three clusters spectroscopically and compare the obtained results with existing ab initio calculations. Second, we study the binding behavior of 02 to these clusters and a possible activation of the adsorbant. These studies will give important information on the different chemical properties of the three clusters with respect to the oxidation of CO. (b) Pd-atoms supported on ultrathin Mg0-films: Here we study to what extent the oxidation of CO occurs via carbonate formation and/or coadsorption of CO and 02. In the first phase of the project a highly intense source for metastable He atoms will be built at the Technical University of Clausthal. This source will then be integrated into the analysis chamber of the existing cluster deposition experiment at the University of Ulm. In this experimental setup the hemispherical analyzer, necessary for the MIESS studies, is already available. In future these experiments will be extended to other systems. We will grow thin Ti02 and Si02 films onto Mo(110) and Mo(112), respectively, characterize existing defects of these surfaces and study the same cluster systems on these different support materials.

该项目旨在通过亚稳态撞击电子光谱法研究纯和连接簇在氧化物表面上的电子结构，MIES与紫外光光谱光谱，UPS结合使用，以了解其化学性质。我们将重点放在项目的第一学期上，这些金属簇具有众所周知的，不同和特定的化学特性。以下系统将详细研究：（a）Au3sr，Au4 und Au8在超薄MGO-FILMS上支持的AU8：在此示例中，我们首先以光谱群体的三个簇的电子状态进行了表征，并将所获得的结果与现有的AB Initio计算进行比较。其次，我们研究了02与这些簇的结合行为以及吸附剂的可能激活。这些研究将提供有关三个簇的不同化学特性的重要信息。然后，该来源将集成到ULM大学现有集群沉积实验的分析室中。在这个实验设置中，已经可以使用MIESS研究所需的半球分析仪。将来，这些实验将扩展到其他系统。我们将分别在MO（110）和MO（112）上种植薄薄的Ti02和Si02膜，分别表征了这些表面的现有缺陷，并在这些不同的支持材料上研究了相同的群集系统。