气相中Fe+催化CO与N2O循环反应的理论计算研究

采用密度泛函UB3LYP/6–311+G(2d)方法计算研究了Fe+在基态和激发态与CO与N2O反应的反应机理。全参数优化了反应势能面上各驻点的几何构型，用频率分析方法和内禀反应坐标（IRC）方法对过渡态进行了验证，并用UB3LYP/6–311++G(3df,3pd)、单点垂直激发等方法分别进行各驻点单点能校正，四重态和六重态反应势能面交叉点CP确定，计算结果表明，该反应为两步反应，且反应机理都为插入—消去反应，势能面上的两个交叉点能够有效的降低反应的活化能，这在动力学和热力学上都是有利的。

Theoretical study of catalytic oxidation cycles of CO with N2O by Fe+ in gas phase

The reaction mechanism between Fe+ in the ground state and the excited state with CO and N2O has been studied using the density functional theory (DFT) at UB3LYP/6-311+G(2d) level. The geometries for reactants, the transition states and the products were completely optimized. All the transition states were verified by the vibrational analysis and the intrinsic reaction coordinate calculations. For each stationary point, the single-point energy calculations were carried out by UB3LYP/6-311++G(3df,3pd) method. The potential energy curve-crossing diagrams were investigated for the state correlation between quartet and sextet states in the reaction of Fe+ with CO and N2O. The results showed that this reaction is a two-step reaction and the reaction mechanism is an insertion-elimination mechanism. There are two crossing points between the quartet and the sextet potential energy surfaces (PESs), which would effectively reduce the activation energy and play a significant and beneficial role in the kinetic and thermodynamic aspects of this catalytic reaction.