"Heterogeneous" Reactions of Chloride Salts in the Atmosphere: A Surface Science Approach

大气中氯化物盐的“非均相”反应：表面科学方法

• 批准号: 9222769
• 负责人: John Hemminger
• 金额: $ 33.5万
• 依托单位: University of California-Irvine
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-06-15 至 1997-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9222769&HistoricalAwards=false
• 关键词: Heterogeneous; Reactions; Chloride; Salts; Atmosphere

It is becoming increasingly evident that reactions of gases at solid interfaces play a key role in atmospheric chemistry. However, at the present time, our understanding of the fundamental kinetics and mechanisms of such reactions at interfaces in the atmosphere is rudimentary, at best. However, such data are essential to elucidate the role of these processes in the chemistry of both the stratosphere and troposphere. This research will explore the fundamental kinetics and dynamics of the reactions of solid NaCl, the major component of sea salt particles found in marine areas, with gases such as HNO3 and N2O5 using surface science techniques including X-ray photoelectron spectroscopy, high resolution electron energy loss spectroscopy and laser-induced desorption mass spectrometry. These reactions are believed to contribute to the formation of HCl and ClNO2 respectively. The latter is of particular importance since its photolysis produces chlorine atoms which may compete with OH in initiating the oxidation of organics in the troposphere. These studies will result in a much better understanding of the fundamental parameters controlling these gas-solid processes, which can than be input to models to provide a more realistic and accurate assessment of the role played by such reactions in the atmosphere. In addition, it will establish the utility of modern surface science methodology in elucidating the fundamentals of reactions occurring at interfaces in the atmosphere.

越来越明显的是，气体在固体界面上的反应在大气化学中起着关键作用。然而，目前，我们对大气中界面上这种反应的基本动力学和机制的了解充其量也是最基本的。然而，这些数据对于阐明这些过程在平流层和对流层化学中的作用至关重要。这项研究将利用表面科学技术，包括X射线光电子能谱、高分辨率电子能量损失谱和激光诱导解吸质谱，探索固体氯化钠(海洋中发现的海盐颗粒的主要成分)与HNO3和N2O5等气体反应的基本动力学和动力学。这些反应被认为分别促成了HCl和ClNO2的形成。后者特别重要，因为它的光解产生氯原子，在对流层中，氯原子可能会与OH竞争，引发有机物的氧化。这些研究将使人们更好地了解控制这些气固过程的基本参数，这些参数可以输入到模型中，以提供对大气中此类反应所起作用的更现实和更准确的评估。此外，它还将确立现代表面科学方法论在阐明大气中界面上发生的反应的基本原理方面的效用。