Weak Acids Enhance Halogen Activation on Atmospheric Water鈥檚 Surfaces

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• 作者：Sayaka Hayase ; Akihiro Yabushita ; Masahiro Kawasaki ; Shinichi Enami ; Michael R. Hoffmann ; Agusti虂n J. Colussi
• 刊名：Journal of Physical Chemistry A
• 出版年：2011
• 出版时间：May 19, 2011
• 年：2011
• 卷：115
• 期：19
• 页码：4935-4940
• 全文大小：858K
• 年卷期：v.115,no.19(May 19, 2011)
• ISSN：1520-5215

文摘

We report that rates of I₂(g) emissions, measured via cavity ring-down spectroscopy, during the heterogeneous ozonation of interfacial iodide: I^{鈥?/sup>(surface, s) + O₃(g) + H+(s) 鈫掆啋 I₂(g), are enhanced several-fold, whereas those of IO路(g) are unaffected, by the presence of undissociated alkanoic acids on water. The amphiphilic weak carboxylic acids appear to promote I₂(g) emissions by supplying the requisite interfacial protons H+(s) more efficiently than water itself, at pH values representative of submicrometer marine aerosol particles. We infer that the organic acids coating aerosol particles ejected from ocean鈥檚 topmost films should enhance I₂(g) production in marine boundary layers.}