化学学报 ›› 2001, Vol. 59 ›› Issue (4): 610-614. 上一篇    下一篇

研究论文

甲烷-空气-H2O模拟光化学反应体系中CH3OO·自身复合反 应的研究

齐斌;苏克和;胡敏;陈忠明;张远航;唐孝炎   

  1. 陕西师范大学化学系.西安(710062);西北工业大学化工系;北京大学环境模拟 与污染控制国家重点联合实验室;北京大学环境科学中心.北京(100871)
  • 发布日期:2001-04-15

Studies on the self-reaction of CH3OO·radicals formed in the methane-ar-H2O photoreaction system

Qi Bin;Su Kehe;Hu Min;Chen Zhongming;Zhang Yuanhang;Tang Xiaoyan   

  1. Shanxi Normal Univ, Dept Chem.Xian(710062);Beijing Univ., Center of Environmental Sci..Beijing(100871)
  • Published:2001-04-15

在1.013×10^5Pa,(298±2)K及O2-N2气氛下,研究了羟基自由基·OH引发的甲烷光化学反应体系中过氧甲基自由基CH3OO·自身复合反应。反应物和产物采用长光路Fourier红外光谱(LP-FTIR)和高效液相色谱(HPLC)测定。证实产物中有甲基过氧化氢(CH3OOH,MHP)和过氧甲醚(CH3OOCH3,DMP)存在并首次在该体系中发现了羟甲基过氧化氢(HOCH2OOH,HMHP).HMHP的检出表明,CH3OO·自身复合的可能途径之一生成了Criegee中间体过氧次甲基双自由基·CH2OO·,采用G2,G2(MP2)和G2(ful)方法对一些反应的标准焓变和标准Gibbs自由能变化进行了理论计算。结果表明CH3OO·自身复合生成·CH2OO·及·CH2OO·与H2O反应生成HMHP的途径在热力学上是可能的。

关键词: 甲烷, 空气, 水, 光化学反应, 过氧化甲基, 自由基, 红外分光光度法, 高速液体色谱

The self-reaction of CH3OO· radicals in the presence of water has been studied at 298 K in 1.013×10^5 Pa of synthetic air . Reactants and products are detected by LP-FTIR absorption spectrometer and high-performance liguid chromatography (HPLC). CH3OOH and CH3OOCH3 are proved to be among the products of the self-reaction of CH3OO·. In addition, HOCH2OOH is identified for the first time in the reaction system. The finding of HOCH2OOH shows that the path to form Griegee intermediate ·CH2OO· is possible in the self-reaction of CH3OO·. Ab initio calculations at the G2, G2(MP2) and G2(ful) levels further indicate that it is favorable in thermodynamics for both the self reaction of CH3OO· to form·CH2OO· and the reaction of ·CH2OO· withwater to produce HMHP.

Key words: METHANE, AIR, WATER, PHOTOCHEMICAL REACTION, FREE RADICALS, INFRARED SPECTROPHOTOMETRY, HIGH SPEED LIQUID CHROMATOGRAPHY

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