Heterogeneous Reaction of Gaseous Ozone with Aqueous Iodide in the Presence of Aqueous Organic Species

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• 作者：Sayaka Hayase ; Akihiro Yabushita ; Masahiro Kawasaki ; Shinichi Enami ; Michael R. Hoffmann ; Agustn J. Colussi
• 刊名：Journal of Physical Chemistry A
• 出版年：2010
• 出版时间：May 20, 2010
• 年：2010
• 卷：114
• 期：19
• 页码：6016-6021
• 全文大小：246K
• 年卷期：v.114,no.19(May 20, 2010)
• ISSN：1520-5215

文摘

The fast reaction of gaseous ozone, O₃(g), with aqueous iodide, I⁻(aq), was found to be affected by environmentally relevant cosolutes in experiments using cavity ring-down spectroscopy (CRDS) and electrospray ionization mass spectrometry (ESIMS) for the detection of gaseous and interfacial products, respectively. Iodine, I₂(g), and iodine monoxide radical, IO(g), product yields were suppressed in the presence of a few millimolar phenol (pK_a = 10.0), p-methoxyphenol (10.2), or p-cresol (10.3) at pH ≥ 3 but unaffected by salicylic acid (pK_a2 = 13.6), tert-butanol, n-butanol, or malonic acid. We infer that reactive anionic phenolates inhibit I₂(g) and IO(g) emissions by competing with I⁻(aq) for O₃(g) at the air/water interface. ESIMS product analysis supports this mechanism. Atmospheric implications are discussed.