The Interaction of Gas Phase Methyl Radicals with Surfaces

气相甲基自由基与表面的相互作用

• 批准号: 8821781
• 负责人: Peter Stair
• 金额: $ 31.54万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-08-01 至 1993-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8821781&HistoricalAwards=false
• 关键词: Interaction; Gas; Phase; Methyl; Radicals

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.

该项目属于分析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。甲基自由基与铁和钼金属单晶的明确表面的相互作用将被研究，这些单晶通过一个氧原子层的吸附进行化学修饰。这种自由基物种与多晶铁和氧化钼表面的相互作用也将被研究。超高真空表面科学技术将被用来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。由此产生的表面和气相物种将被识别，它们的产量将作为时间和温度的函数进行量化。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，这些物种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和活性最强的碳氢化合物自由基之一，被认为是许多遵循自由基反应机理的碳氢化合物反应的中间体。本研究项目中将要研究的含氧表面将为暴露在自由基反应环境中的技术材料提供模型。