Pt_n^(+/-)(n=1,2,3)与N_2O反应机理的理论研究

DFT studies on the reaction mechanism of Pt_n^(+/-)(n=1,2,3) and N_2O

为更清晰地揭示Pt_n^(+/-)(n=1,2,3)与N_2O反应的机理,采用密度泛函UB3LYP方法,计算研究了Pt_n^(+/-)(n=1,2,3)在基态和激发态与N_2O微观反应的机理,对比探讨了铂团簇及单个铂原子对N_2O催化机理和催化效果.同时又对比研究了带有不同电荷的铂团簇对N_2O的催化作用,即:Pt_n^(+/-)(n=1,2,3)对N_2O的催化作用,从而探讨了电荷对N2O催化作用的影响.又对反应势能面上各驻点的几何构型进行了全参数优化,并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.为了进一步研究Pt_n^(+/-)(n=1,2,3)与N_2O反应过程中可能存在的"系间窜越"行为,计算研究了基态和第1激发态的2个反应势能面,其结果表明,Pt^+和Pt_3^+与N_2O的反应是典型的自旋禁阻反应,在能量交叉点(CP)附近可能存在着系间窜越现象.

To more clearly reveal the reaction mechanism of Ptn^＋/-（n=1,2,3） and N2 O, we used the density functional theoretical UB3LYP method to calculate the reaction mechanism of the reaction, and to learn the differ- ent between the platinum dusters and single platinum.At the same time ,we compared the effect on the reaction, Ptn^＋/-（n=1,2,3）＋N2O, by positive and negative charge.We have fully optimized all the geometry, and the intrinsic reaction coordinate （IRC） was then calculated to probe the reaction path and check if the correct transition state was located.The results showed that N20 activation mediated by Pt＋ and Pt＋ were a typical spin-forbidden process, and the involving crossing between the ground state and the first excited state energy surfaces has been discussed.