摘要
对CH_4+H(?)CH_3+H_2的非绝热trapping型的动力学进行了研究.采用量子化学从头算方法在QCISD/6-311G水平上计算了该反应的内禀反应坐标(IRC)和IRC上各构型点的振动分析,利用各构型点的信息,计算得到了共线型模型反应和真实热反应沿反应坐标不同能量下的微正则反应通量.计算结果表明共线型反应具有非绝热trapping型的特征,而真实热反应则不是非绝热trapping型.采用统一统计理论计算了300K～1500K的共线型反应的速率常数,由微正则变分过渡态计算了热反应的速率常数,得到与实验一致的结果.
The kinetics of nonadabatic trapping models of CH4 + H CH3 + H2 was studied. On the basis of the Intrinsic Reaction Coordinate (IRC) and IRC information computed by the ab initio method at QCISD/6 - 311g* * level, the flux integrals for collinear system and thermal system of the title reaction were calculated, respectively. The results show that the collinear system of the title reaction is a nonadiabatic trapping model but the thermal reaction is not. Using unified statistical theory (UST) and microcanonical variational transition state theory, rate constants were calculated. The thermal rate constants from 300K to 1500K are in excellent agreement with the experiment results.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
1999年第6期590-595,共6页
Acta Chimica Sinica
基金
国家博士点基金(9502710)资助项目
关键词
甲烷
氢抽提反应
共线反应
非绝热
tapping型
nonadiabatic trapping model, unified statistical theory, Intrinsic Reaction Coordinate, thermal reaction rate, flux integral
