甲烷等离子体偶联合成碳二烃反应过渡态和反应途径的理论研究

Theoretical Study of Transition States and Reaction Paths on the Coupling Reaction of Methane under Plasma

提出甲烷等离子体偶联合成碳二烃的主要基元反应是甲烷与甲基、亚甲基、次甲基的自由基反应 ,并用半经验量子化学的 PM3方法 ,对可能的反应途径进行了量子化学研究 ,得到了过渡态的构型 ,计算了反应热及活化能 .计算结果表明 :反应主产物为乙烷 。

The probable reactive paths for the coupling reaction of methane under plasma are proposed and computed by semi PM3 method. By searching for the location of the transition states and calculating the reaction heat and the activation energy, it was obtained that the activation barriers of paths 1 and 2 are much low comparatively among four reaction paths, so the major product of the reaction is C 2H 6, which agrees with the experimental result. IRC analysis was also carried out for possible reactive paths.