Fe_2与SO_2反应的密度泛函理论研究

Density functional theory study of two state reactivity of SO_2 activation on iron dimer

采用密度泛函理论-Density Functional Theory(DFT)中的B3LYP方法在6-311+G(d,p)的计算水平上研究了Fe_2+SO_2→2FeO+S反应的相关微观机理.全参数优化了七重态以及九重态反应势能面上各驻点的几何结构,用频率分析法以及内禀反应坐标-Intrinsic Reaction Coordinate(IRC)方法对过渡态进行了验证,得到了该反应的微观反应路径和反应势能面-Potential Energy Surface(PES),并用两态反应分析其反应机理.通过对反应过程的分析发现,反应在七重态以及九重态势能面上的反应路径是相似的,势能面上的两个交叉点能增加反应放热,有效地降低反应的活化能,为整个反应体系提供了一条能量较低的反应路径.

The mechanism of Fe2 ＋ SO2→2FeO ＋ S was studied by the density functional theory （DFT） with the B3LYP methods combined with the 6 -311 ＋ G （d, p） basis set. The geometry optimizations of reactants, tran- sition states, intermediates and products of the reactions of septet and nonet states were also completely studied, and all the transition states were discussed by means of vibration analysis and the intrinsic reaction coordinate. The ＂Two State Reactivity （TSR）＂ was used to analyze the reaction mechanism. The result showed that the two crossing points can effectively lower the activation energy of reaction, which provides a low energy reaction path for the whole reaction system.