RUI: Aqueous-Phase Photochemistry of Atmospheric Hydrocarbon Oxidation Products

RUI：大气碳氢化合物氧化产物的水相光化学

• 批准号: 9407566
• 负责人: John Allen
• 金额: $ 14.63万
• 依托单位: Indiana State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-09-15 至 1998-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9407566&HistoricalAwards=false
• 关键词: RUI; Aqueous; Phase; Photochemistry; Atmospheric

A wide variety of hydrocarbons are emitted into the atmosphere from both natural and anthropogenic sources. Isoprene (2-methyl- 1,3-butadiene) is of particular interest because it has the largest global flux of any single hydrocarbon species with the possible exception of methane, Isoprene reacts rapidly with hydroxyl radical (OH) and ozone (O3) in the presence of NOx forming 3-buten-2 one( methyl vinyl ketone, MVK) and 2-methyl-2-propenal (methacrolein, MACR). Once formed, tropospheric MVK and MACR, as well as many other hydrocarbon oxidation products, may undergo a variety of reactions in the gas phase. It is likely that MVK, MACR and other hydrocarbon oxidation products can also partition into atmospheric water drops and undergo subsequent aqueous-phase reactions leading to the formation of peroxyl radicals (HO2/RO2) and other oxidant species, and there by, consuming MVK and MACR. Peroxyl radicals can destroy tropospheric O3 and form peroxides that rapidly oxidize sulfur dioxide (SO2) in the aqueous phase. The sulfate aerosol that is subsequently formed efficiently backscatters incoming solar radiation and exerts a significant cooling effect upon climate. These researchers therefore will study: 1) partitioning of MVK, MACR and other hydrocarbon oxidation products from the gas phase into water, 2) aqueous-phase photochemistry of MVK, MACR, and other hydrocarbon oxidation products under conditions that are typical of atmospheric water drops, and 3) aqueous-phase reactions of MVK, MACR and other hydrocarbon oxidation products with selected photochemical oxidants.

多种碳氢化合物从自然和人为来源排放到大气中。 异戊二烯（2-甲基-1,3-丁二烯）特别受关注，因为它在任何单一碳氢化合物中具有最大的全球通量（可能是甲烷除外），异戊二烯在环境中与羟基自由基 (OH) 和臭氧 (O3) 快速反应。 NOx 的存在形成 3-丁烯-2 酮（甲基乙烯基酮，MVK）和 2-甲基-2-丙烯醛（甲基丙烯醛，MACR）。 对流层 MVK 和 MACR 以及许多其他碳氢化合物氧化产物一旦形成，可能会在气相中发生各种反应。 MVK、MACR 和其他碳氢化合物氧化产物也可能分解到大气中的水滴中，并进行后续的水相反应，导致形成过氧自由基 (HO2/RO2) 和其他氧化剂物质，从而消耗 MVK 和MACR。 过氧自由基可以破坏对流层O3并形成过氧化物，快速氧化水相中的二氧化硫(SO2)。 随后形成的硫酸盐气溶胶有效地反向散射入射的太阳辐射，并对气候产生显着的冷却作用。 因此，这些研究人员将研究：1) MVK、MACR 和其他碳氢化合物氧化产物从气相到水中的分配，2) MVK、MACR 和其他碳氢化合物氧化产物在典型大气水滴条件下的水相光化学，和 3) MVK、MACR 和其他烃氧化产物与选定的光化学氧化剂的水相反应。