基于ReaxFF模拟的正戊烷热分解机理研究

Thermal Decomposition Mechanism of n-Pentane by ReaxFF Simulations

采用密度泛函理论和ReaxFF力场对正戊烷的热分解机理进行研究,分析了热分解的起始反应路径、温度对热分解的影响,并对正戊烷热分解进行了一级动力学研究。结果表明正戊烷热分解的起始反应主要分为两类:一类为碳碳单键断裂,另一类为碳氢键断裂,其中C2-C3键断裂是主要的起始反应路径。正戊烷热分解的主要产物为氢气、甲烷、乙烷、乙烯、乙炔、丙烷和丙烯。经过一级动力学计算得到表观活化能和指前因子分别为224.4 kJ·mol^-1和3.1324×10^14 s^-1。

Density functional thoery(DFT) and ReaxFF simulations were employed to investigate the thermal decomposition mechanism of n-pentane.The initial decomposition reactions,the effect of temperature on the n-pentane thermal decomposition and the first-order kinetic were investigated in this work.The results showed that the initial reactions of n-pentane thermal decomposition can be divided into two types,one was the breakage of C-C bonds and the other was the fracture of C-H bonds.Among them,the breakage of C2-C3 bond was the dominant route in the initial reactions.The main products of n-pentane thermal decomposition were hydrogen,methane,ethane,ethylene,acetylene,propane and propylene.Based on the kinetic analysis of n-pentane thermal decomposition,the apparent activation energy and pre-exponential factor were 224.4 kJ mol^-1 and 3.1324×10^14 s^-1,respectively.