The Interaction of Gas Phase Methyl Radicals with Surfaces

本项目属于分析化学和表面化学的一般领域以及表面化学反应动力学的子领域。将研究甲基自由基与铁和钼金属单晶表面的相互作用。这种自由基与多晶铁和钼氧化物表面的相互作用也将被研究。采用超高真空表面科学技术，在固体表面暴露于自由基之前对其进行表征，然后检测自由基的吸附和反应。所得到的表面和气相物质将被识别，它们的产率将被量化为时间和温度的函数。这些结果将有助于阐明自由基吸附、解吸和表面化学反应的动力学和机理。涉及自由基中间体的化学反应在化学中很重要，这些物质与表面的相互作用在许多技术中都很重要。甲基自由基是最简单、活性最强的烃类自由基之一，被认为是遵循自由基反应机制的许多烃类反应的中间产物。本研究项目所研究的氧化表面将为暴露于自由基反应环境中的工艺材料提供模型。

This project is in the general area of analytical and surface chemistry and in the subfield of surface chemical reaction dynamics. The interaction of methyl free radicals with well-defined surfaces of iron and molydenum metal single crystals chemically modified by adsorption of one atomic layer of oxygen will be investigated. Interactions of this radical species with polycrystalline iron and molybdenum oxide surfaces will also be studied. Ultrahigh vacuum surface science techniques will be employed to characterize the solid surfaces prior to their exposure to the radicals and then to detect radical adsorption and reaction. The resulting surface and gas-phase species will be identified and their yields quantified as a function of time and temperature. These results will enable the kinetics and mechanisms of radical adsorption, desorption and surface chemical reactions to be elucidated. Chemical reactions that involve free radical intermediates are important in chemistry and the interactions of these species with surfaces are important in many technologies. The methyl radical is one of the simplest and most reactive hydrocarbon radicals and is thought to be present as an intermediate in many hydrocarbon reactions that follow free radical reaction mechanisms. The oxygenated surfaces to be studied in this research project will provide models for technological materials exposed to free radical reaction environments.