我們計畫建立一個可以執行分子束散射實驗的超高真空系統。表面科學研究的動機有很大一部分來自於想要對催化現象有原子層級的了解,然而實際的催化反應和基礎表面科學研究有兩個重大的落差:材料複雜性的落差與氣壓的落差。氣壓的落差來自於表面實驗技術需要高真空,但是真實的觸媒反應是在大氣或是更高的氣壓下發生。分子束實驗可以減小這氣壓的落差,並且讓我們了解微觀尺度的反應動力特性。我們將使用分子束方法來研究氧化薄膜上奈米金屬粒子的催化特性。這樣的實驗具有獨特的優勢。首先,這樣的模型系統具有真實觸媒在結構與化學上的複雜性,讓我們能夠調整其催化能力與選擇性,以達成我們所需的反應。再者,這樣的實驗也能使我們了解結構與反應動力之間的相關性。 We propose to construct a molecular beam source coupled with an ultrahigh-vacuum system for surface analysis, in order to conduct molecular beam scattering experiments. Surface science has to a large extent been driven by the knowledge of catalysis at atomic level, whereas there are two major gaps between applied heterogeneous catalysis and fundamental surface science research: the materials gap and the pressure gap. The pressure gap originates from the need of most surface sensitive techniques of a high vacuum environment, in contrast to real catalysed reactions that are carried out at atmospheric pressure or higher. The molecular beam methods can reduce the pressure gap and extend our study to understanding of reaction kinetics at the microscopic level. We plan to apply the molecular beam methods to metal nanoclusters on the well-defined oxides. The combined approach provides unique advantages: first, such model systems possess structural or chemical complexity of catalyst surfaces, which allows one to tune their properties to maximize the selectivity and activity with respect to the desired reaction; second, molecular beam methods can provide the correlation of structural information to quantitative and detailed kinetic data. 研究期間:10008 ~ 10107