长光路FTIR研究HFC152a光化学反应

STUDY ON THE PHOTOCHEMICAL REACTIONS OF HFC152a USING LONG PATH FTIR

用长光路ＦＴＩＲ技术研究氟里昂替代物ＨＦＣ１５２ａ（ＣＨ＿３ＣＨＦ＿２）在对流层中的光化学反应，氯原子作反应的引发剂，用相对速度方法测定了ＨＦＣ１５２ａ与Ｃｌ原子反应速率常数为（２．３±０．５）×１０（－１３）ｃｍ￣３·ｍｏｌ（－１）·ｓ（－１）（２９８±Ｋ）．ＨＦＣ１５２ａ在对流层中的主要含氟光解产物为ＣＯＦ＿２，产率为８８％，有关反应机理进行了讨论。

HFC152a(CH3CHF3) has been proposed as an alternative for the fully halogenated chlorofluorocarbons. This papaer reports laboratory studies on photochemical reactions of HFC152a in the troposphere, using long path Fourier transform infrared abosorption spectroscopy and initiated by chlorine atoms. The reaction rate constant of HFC152a with chlorine atoms, measured by the relative technique, was (2. 3 ± 0. 5) ×10-13 cm￣3 mol-1·s-1 at 298±2 K. The main fluorine-contented product of HFC152a during tropospheric degradation was COF_2, with a yield of 88%. The reaction mechanism was discussed.