Photodegradation of (CH₃CH₂)₂S and CH₃CH₂SCH₃ initiated by OH radicals at atmospheric pressure. Product yields and mechanism in NOx free air

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• 作者：Gabriela Oksdath-Mansilla^a ; Alicia B. Peñ ; é ; ñ ; ory^a ; Ian Barnes^b ; Peter Wiesen^b ; Mariano A. Teruel^a ; ^{mteruel@fcq.unc.edu.ar}
• 关键词：Alkyl sulfides ; Product distribution ; Atmospheric mechanism ; Gas-phase photooxidation ; Simulation chambers
• 刊名：Atmospheric Environment
• 出版年：2012
• 期刊代码：11_13522310
• 类别：env
• 出版时间：August, 2012
• 卷：55
• 期：Complete
• 页码：263-270
• 文件大小：544 K

摘要

The product distribution of the gas-phase reactions of OH radicals with diethyl sulfide (CH₃CH₂)₂S and ethyl methyl sulfide, CH₃CH₂SCH₃, determined in the absence of NOx, is presented. The experiments were performed in a 1080 L quartz-glass photoreactor and a 405 L borosilicate glass photoreactor in synthetic air at (298 卤 2) K using long path 鈥渋n situ鈥?FTIR spectroscopy for the analysis of the reactants and products. SO₂ and CH₃CHO were identified as major primary products for both title reactions together with HCHO as a co-product in the photodegradation of CH₃CH₂SCH₃.

Formation of CO and HCOOH was observed, however, the concentration-time behavior of these products show that they are secondary in origin and are produced from the further oxidation of major primary products. Traces of OCS were observed; its concentration-time behavior suggests that it is a minor primary product. The yields of the products obtained for the reaction of OH radicals with (CH₃CH₂)₂S were the following: (50 卤 3)%and (91 卤 3)%for SO₂ and CH₃CHO, respectively. While, for the reaction of OH radicals with CH₃CH₂SCH₃ yields of (51 卤 2)%, (57 卤 3)%and (46 卤 4)%were obtained for SO₂, CH₃CHO and HCHO, respectively.

The present results are compared with previous results for the well studied reaction of dimethyl sulfide, CH₃SCH₃, with OH radicals and simple atmospheric degradation mechanisms are postulated to explain the formation of the observed products.