Experimental Investigation of the Atmospheric Chemistry of Aromatic Hydrocarbonsand Long-Chain Alkanes

摘要

The interaction of volatile organic compounds (VOCs) and oxides of nitrogen inthe presence of sunlight leads to the formation of ozone and other manifestations of photochemical air pollution. There are, however, significant uncertainties in our knowledge of the products and mechanisms of the atmospheric reactions of alkanes and aromatic hydrocarbons, important constituents of ambient air in urban areas, with the hydroxyl (OH) radical. A series of product studies of the OH radical-initiated reactions of selected alkanes, ketones and alcohols have been carried out to obtain further insights into alkoxy radical isomerization. Product studies of the OH radical reaction with 4-methyl-2-pentanone, 2,6-dimethyl-4-heptanone, 2,4-dimethyl-2-pentanol and 3,5-dimethyl-3-hexanol in the presence of NOx have provided unambiguous evidence for alkoxy radical isomerization and these studies have provided rate constant ratios for the isomerization reaction versus alkoxy radical decomposition and reaction with O2.