CH_3SH与H_2O_2气相反应机理的理论研究

Theoretical Study on the Mechanism of CH_3SH with H_2O_2 under Atmospheric Conditions

采用密度泛函理论的B3LYP方法,在6-311+G(d,p)基组水平上研究了CH3SH与H2O2的微观反应机理,全参数优化了反应势能面上各驻点的几何构型,振动分析和内禀反应坐标(IRC)分析结果证实了中间体和过渡态的真实性,计算所得的键鞍点电荷密度的变化情况也确认了反应过程.结果表明,反应共分三大步进行,包含两条反应通道,第二步由IM1到CH3SO2H的反应为决速步骤,其中的第一条通道是主要反应通道,相应活化能为157.3和109.7kJ/mol.

Density function theory （DFT） B3LYP method was employed to study the mechanism of the reaction of CH3SH and H2O2 with the 6-311＋G（d,p） basis sets. Geometries of the stationary points were completely optimized. The transition states were validated by the vibrational analysis and the internal reaction coordinate （IRC） calculations. The vibration analysis and the IRC analysis testified the authenticity of intermediates and transition states. The results indicate that the reaction can occur through three elementary steps which involve two paths. The second step IM1 to CH3SO2H constitutes the rate-determining step and the first path is the main path. The corresponding activation energies are 157.3 and 109.7 kJ/mol.