Investigations of the Photochemical HONO Formation Reactions of Atmospheric Importance

对大气重要性的光化学 HONO 形成反应的研究

• 批准号: 1405610
• 负责人: Lei Zhu
• 金额: $ 70.99万
• 依托单位: Health Research Incorporated/New York State Department of Health
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2019-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1405610&HistoricalAwards=false
• 关键词: Investigations; Photochemical; HONO; Formation; Reactions

This research is focused on determining the sources of nitrous acid to the atmosphere. Nitrous acid can form hydroxyl radical, an important compound responsible for creating the air pollutant ozone. Nitrous acid can be produced on some environmental surfaces, in the presence of water and nitrogen dioxide. Quantifying the relative importance of the sources of nitrous acid to the atmosphere will improve the understanding of some of the causes of air pollution and climate change.The objective of this research is to characterize and quantify photochemical sources of nitrous acid (HONO), an important precursor to the hydroxyl radical (OH). The photolysis of HONO significantly influences atmospheric pollutant oxidation and ozone production. Recent laboratory studies have shown that nitrophenols formed from the dark reaction of nitrogen dioxide (NO2) with surface adsorbed polyphenolic compounds and the subsequent photolysis of surface-adsorbed nitrophenols may be a substantial source of HONO. But wavelength-dependent HONO yields, from the photolysis of the adsorbed nitrophenols, have not been characterized. This work will quantify photochemical HONO and the OH quantum yields from heterogeneous and gas phase photolysis reactions using laser photolysis combined with cavity ring-down spectroscopy and determine the UV/visible absorption cross sections of surface-adsorbed NO3 and nitrophenols as a function of wavelength using Brewster angle cavity ringdown spectroscopy. Additional experiments will provide data on the absorption cross sections of gas phase nitrophenols and HONO yields from nitrate and 2-nitrophenol adsorbed on surfaces that serve as surrogates for various environmentally relevant surfaces.

这项研究的重点是确定大气中亚硝酸的来源。亚硝酸可以形成羟基自由基，这是一种产生空气污染物臭氧的重要化合物。在水和二氧化氮存在的情况下，亚硝酸可以在一些环境表面上产生。量化亚硝酸源对大气的相对重要性将有助于更好地理解空气污染和气候变化的一些原因。本研究的目的是表征和量化亚硝酸(HONO)的光化学来源，亚硝酸是羟基自由基(OH)的重要前体。HONO的光解对大气污染物的氧化和臭氧的产生有重要影响。最近的实验室研究表明，二氧化氮(NO2)与表面吸附的多酚化合物发生暗反应生成的硝基酚，以及随后表面吸附的硝基酚的光解可能是HONO的一个重要来源。但是，由吸附的硝基苯酚的光解产生的与波长相关的HONO产量还没有被表征。这项工作将使用激光光解结合腔衰荡光谱来量化多相和气相光解反应中的光化学HONO和OH的量子产率，并使用布鲁斯特角腔衰荡光谱来确定表面吸附的NO3和硝基酚的紫外/可见吸收截面作为波长的函数。其他实验将提供关于气相硝基苯酚的吸收截面以及硝酸盐和2-硝基苯酚在各种环境相关表面的替代物表面上的HONO产率的数据。