Electron Spectroscopic Studies of the Electronic and Geometric Structure of, and Chemisorption on, Transition Metal Oxide Surfaces

过渡金属氧化物表面的电子和几何结构及其化学吸附的电子光谱研究

• 批准号: 8711423
• 负责人: Victor Henrich
• 金额: $ 54.22万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-07-01 至 1991-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8711423&HistoricalAwards=false
• 关键词: Electron; Spectroscopic; Studies; Electronic; Geometric

During the past few years the Surface Science Laboratory at Yale has become established as the world's foremost research center for the study of the fundamental properties of oxide surfaces. Professor Henrich's approach is to use single crystal samples, prepared and studied in an ultrahigh vacuum environment or under controlled chemisorption conditions, and to measure their geometric and electronic structure by using a wide range of surface sensitive electron spectroscopic techniques. Particular attention has been given to the transition metal oxides, whose cations can have any of several different valence states depending upon their ligand environment; these oxides are the most important ones in catalysis and surface chemistry. Measurements on nearly perfect, vacuum cleaved surfaces are a necessary starting point, particularly for comparison with theoretical calculations. However, his primary interest is in the properties of surface defects and their interaction with adsorbed molecules. Surface defects have been shown to be the active sites for chemisorption on almost all oxides that have been studied, with nearly perfect surfaces being relatively inert. Professor Henrich proposes here a three-year research program consisting both of a continuation of the most productive research areas that are currently being pursued and of several new directions that will address some of the important questions that research to date has left unanswered. Empty electronic states on oxide surfaces will be examined by using inverse photoelectron spectroscopy, and a newly acquired high resolution electron energy loss spectrometer will be used to study the subtleties of the interaction of molecules of catalytic interest with oxides. A collaborative effort with the IBM Watson Research Center will use scanning tunneling microscopy to determine the geometry of both perfect and defect oxide surfaces and to measure the spectra of their filled and empty electronic levels.

在过去的几年中，耶鲁大学的地表科学实验室已成为世界上最重要的研究中心研究氧化物表面基本特性的研究中心。 亨利奇教授的方法是使用单晶样品，在超高真空环境或受控化学吸附条件下制备和研究，并通过使用广泛的表面敏感电子光谱技术来测量其几何和电子结构。 特别注意过渡金属氧化物，其阳离子可以根据其配体环境具有几种不同的价状态。这些氧化物是催化和表面化学中最重要的氧化物。 对几乎完美的真空裂解表面的测量是必要的起点，尤其是与理论计算进行比较。 但是，他的主要兴趣是表面缺陷的特性及其与吸附分子的相互作用。 表面缺陷已被证明是几乎所有研究的氧化物上化学吸附的活性位点，几乎完美的表面相对惰性。 亨利希教授在这里提出了一项为期三年的研究计划，其中包括目前正在追求的最有生产力的研究领域的延续，以及几个新的方向，这些方向将解决迄今为止研究尚未解决的一些重要问题。 氧化物表面上的空电子状态将通过使用逆光电子光谱法检查，新获得的高分辨率电子能量损耗光谱仪将用于研究催化兴趣与氧化物的催化兴趣分子相互作用的微妙之处。 与IBM Watson Research Center的合作努力将使用扫描隧道显微镜确定氧化物表面和缺陷的几何形状，并测量其填充和空电子水平的光谱。