Shi Fei, Chen Zhong-ming
The State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences, Peking University, Beijing 100871, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2004 Jan;24(1):65-7.
Organic peroxides play an important role in chemistry of the atmosphere and in controlling urban air quality; however, accurate knowledge about their atmospheric reactions is lacking. In this paper, the experimental simulation was employed to study the atmospheric photo-oxidation of methyl hydroperoxide (CH3OOH, MHP), a key organic peroxide in the atmosphere. At the temperature of (292 +/- 2) K and pressure of 9.3 x 10(4) Pa (20% O2 + 80% N2), the MHP photo-oxidation was initiated by Cl-atom and the process of reaction was in-situ observed by long path Fourier transform infrared (Long Path FTIR) spectrometry. From FTIR spectra, the main products observed were formaldehyde (HCHO), formic acid (HCOOH), carbon monoxide (CO) and carbon dioxide (CO2), and minor methanol (CH3OH) was found as well. Within the reaction period of 60 min, yields were determined: 24% for HCOOH and 6% for CO; 50% for HCHO at its maximum concentration although its yield was varying with the reaction time. Finally, reaction mechanisms were discussed, which implied that MHP is a reservoir of odd-hydrogen radicals (HOx) and plays an important role in atmospheric photo-reactions.
有机过氧化物在大气化学和控制城市空气质量方面起着重要作用；然而，目前缺乏关于它们大气反应的准确认识。本文采用实验模拟方法研究了大气中关键有机过氧化物甲基过氧化氢（CH3OOH，MHP）的大气光氧化反应。在（292±2）K的温度和9.3×10（4）Pa（20% O2 + 80% N2）的压力下，MHP的光氧化反应由氯原子引发，反应过程通过长程傅里叶变换红外（Long Path FTIR）光谱进行原位观测。从FTIR光谱中观察到的主要产物有甲醛（HCHO）、甲酸（HCOOH）、一氧化碳（CO）和二氧化碳（CO2），还发现了少量甲醇（CH3OH）。在60分钟的反应期内，测定了产物产率：HCOOH为24%，CO为6%；HCHO在其最大浓度时为50%，尽管其产率随反应时间而变化。最后，对反应机理进行了讨论，这表明MHP是奇氢自由基（HOx）的储存库，在大气光反应中起着重要作用。
