自由基HO_2与C_2H_2反应势能面的理论研究

Theoretical study on the potential energy surface of the HO_2 and C_2H_2 reaction

应用量子化学从头计算和密度泛函理论(DFT)对HO2+C2H2反应体系的反应机理进行了研究.在B3LYP/6-311G**和CCSD(T)/6-311G**水平上计算了HO2+C2H2反应的二重态反应势能面.计算结果表明,主要反应方式为自由基HO2的H原子和C2H2分子中的C原子结合,经过一系列异构化,最后分解得到主要产物P1(CH2O+HCO).此反应是放热反应,化学反应热为-321.99kJ.mol-1.次要产物为P2(CO2+CH3),也是放热反应.

The reaction mechanism of C2H2 with HO2 was investigated by ab initio and density functional theory（DFT）.The doublet potential energy surface of the C2H2 and HO2 reaction was calculated at the B3LYP/6-311G＊ ＊ and CCSD（T）/6-311G＊ ＊ level.The results of the calculation showed that the major reaction mode was H-atom of HO2 combination with C-atom of C2H2 to form the composite.Then thecomposite was subjected to isomerization process and decomposed to the main product P1（CH2O＋HCO）.The reaction process released large heat and the reaction heat was-321.99 kJ·mol-1.The secondary reaction was also exothermic reaction and produced the secondary product P2（CO2＋CH3）.