Investigating the Role of CH2 Radicals in the HACA Mechanism

被引：43

作者：

Liu, Peng ^{[1
]}

Lin, He ^{[1
]}

Yang, Yang ^{[1
]}

Shao, Can ^{[1
]}

Guan, Bin ^{[1
]}

Huang, Zhen ^{[1
]}

机构：

[1] Shanghai Jiao Tong Univ, Key Lab Power Machinery & Engn, Minist Educ, Sch Mech Engn, Shanghai 200240, Peoples R China

来源：

JOURNAL OF PHYSICAL CHEMISTRY A | 2015年 / 119卷 / 13期

基金：

中国国家自然科学基金;

关键词：

POLYCYCLIC AROMATIC-HYDROCARBONS; PARTICLE-SIZE DISTRIBUTION; WELL MASTER EQUATION; THERMAL-DECOMPOSITION; NUMERICAL-SIMULATION; RATE COEFFICIENTS; SOOT FORMATION; GROWTH; METHANE; PAH;

D O I：

10.1021/jp5124162

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Detailed mechanisms of PAH growth involving methylene (CH2) were studied using accurate ab initio density functional theory B3LYP/6-311+G(d,p) calculations, as well as approximate QCISD(T,full)/6-311++G(3df,2pd) calculations. The PAH growth can be divided into five essential reaction steps, namely, addition C2H2 -> intramolecular hydrogen migration -> addition CH2 -> cyclization -> H-elimination. The aliphatic species of indene and 1H-phenalene are found in the pathways of PAH growth, which is in accord with the experimental results that reveal the formation of aliphatic species in flames. It was found that the simultaneous removal of two H atoms in one reaction step is feasible in PAH evolution, and this can reasonably interpret the absence of a H atom in the post-flame region. The corresponding rate coefficients at 1 atm were evaluated by using TST and RRKM theory by solving the master equations in the temperature range of 500-2500 K. The calculated branching ratios suggest that the pathways involving CH2 are competitive in PAH growth.

引用

页码：3261 / 3268

页数：8

共 57 条

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