Effect of CH_3OOH on the atmospheric concentration of OH radicals  

作　　者：WANG Caixia CHEN Zhongming 

机构地区：[1]The State Key Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences, Peking University, Beijing 100871, China

出　　处：《Progress in Natural Science:Materials International》2006年第11期1141-1149,共9页自然科学进展·国际材料（英文版）

基　　金：Supported by National Natural Science Foundation of China (Grant No .20107001) ,the Major State Basic Research Development Programof Chi-na (Grant No .2002CB410802) ,and the Excellent Yong Teachers Programof MOE, China

摘　　要：Methyl hydroperoxide （CH3OOH, MHP） is known to be a significant sink and reservoir of HOx and ROx radicals in the atmosphere. In order to investigate the impact of MHP on the concentration of atmospheric OH radicals, two key gas-phase reactions of MHP, i.e. the reactions with OH radicals and with UV photolysis, have been simulated at temperature of 293 ± 2 K and total pressure of 1.01 × 10^5 Pa, using the long path Fourier transform infrared （LP-FTIR） spectrometry. OH radicals are generated by the photolysis of 03 in the presence of water vapor. Combined with the relative rate method, the reaction rate constant of MHP with OH radicals is determined to be （3.99 ± 0.15） ×10^-12 cm^3. molecule^-1, s^-1, and thus the atmospheric lifetime of MHP is estimated at 2.9 days. Furthermore, from detailed analysis of the UV photolysis of MHP, the yield of OH radicals is obtained to be 0.91 ± 0.04. Based on the MHP atmospheric lifetime and the yield of OH radicals, it is concluded that MHP plays an essential role in the redistribution of OH radicals in the troposphere.Methyl hydroperoxide （CH<sub>3OOH, MHP） is known to be a significant sink and reservoir of HO<sub>x and RO<sub>x radicals in the atmosphere. In order to investigate the impact of MHP on the concentration of atmospheric OH radicals, two key gas-phase reactions of MHP, i.e. the reactions with OH radicals and with UV photolysis, have been simulated at temperature of 293±2 K and total pressure of 1.01×105 Pa, using the long path Fourier transform infrared （LP-FTIR） spectrometry. OH radicals are generated by the photolysis of O3 in the presence of water vapor. Combined with the relative rate method, the reaction rate constant of MHP with OH radicals is determined to be （3.99±0.15）×10 -12 cm3·molecule -1 ·s -1 , and thus the atmospheric lifetime of MHP is estimated at 2.9 days. Furthermore, from detailed analysis of the UV photolysis of MHP, the yield of OH radicals is obtained to be 0.91±0.04. Based on the MHP atmospheric lifetime and the yield of OH radicals, it is concluded that MHP plays an essential role in the redistribution of OH radicals in the troposphere.

关 键 词：OH radicals methyl hydroperoxide rate coefficient UV photolysis gas-phase reaction LP-FTIR 

分 类 号：O644[理学—物理化学]