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运用密度泛函理论DFT-UB3LYP方法,对2Sr+、2Ba+采用相对论校正赝势基组SDD,对N、O、H采用6-311+G(2d,p)基组,计算研究了气相中碱土金属离子2Sr+、2Ba+介入N2O(1∑+)和H2(1∑g+)反应的微观机理,优化了二重态势能面上各反应物、中间体和过渡态的构型特征,用频率分析方法和内禀反应坐标方法(IRC)对过渡态进行了验证.运用Kozuch撰写的能量跨度模型(Energetic Span Model,δlE),确定了决定循环反应速率的决速过渡态(TDTS)和决速中间体(TDI),并利用转化频率(Turnover Fre-quency,TOF)评估了催化性能.结果表明:从热力学性质分析2Sr+、2Ba+离子对N2O(1∑+)和H2(1∑g+)反应很好的催化作用,可得到目标产物N2(1∑g+)和H2O(1 A1),却从动力学性质分析主要反应产物为N2、SrOH+(BaOH+)和H,最终动力学因素在反应中起决定性作用,以上结论与实验观测结果相符.
Using DFT-UB3LYP method, the relativistic pseudopotential group SDD was used for 2Sr + and 2Ba +, and the 6-311 + G (2d, p) group for N, O and H was used. The interaction between 2Sr +, 2Ba + and N2O (1Σ +) and H2 (1Σg +) reactions was investigated by using the microscopic mechanism. The configurational characteristics of reactants, intermediates and transition states on the potential surface of the doublet state were optimized. The transition state was validated by the intrinsic reaction coordinate method (IRC). Using the Energetic Span Model (δlE) written by Kozuch, the transition states (TDTS) and velocity-determining intermediate (TDI) ), And the catalytic performance was evaluated by using Turnover Fre-quency (TOF). The results showed that the catalytic effect of 2Sr + and 2Ba + ions on the reaction of N2O (1Σ +) and H2 (1Σg +) , The target products N2 (1Σg +) and H2O (1 A1) can be obtained, but the kinetic properties of the main reaction products N2, SrOH + (BaOH +) and H, the final kinetic factors play a decisive role in the reaction, the above conclusions Consistent with the experimental observations.