苯甲醛低温氧化主导反应速率系数从头算:C6H5CO+O2加成反应  

Ab Initio Calculation of the Rate Coefficients for Low-Temperature Oxidation Dominated Reaction:C6H5CO+O2

作　　者：赵倩 张英佳[1] 黄佐华[1] Zhao Qian;Zhang Yingjia;Huang Zuohua(State Key Laboratory of Multiphase Flow in Power Engineering,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安交通大学动力工程多相流国家重点实验室,西安710049

出　　处：《燃烧科学与技术》2020年第6期521-528,共8页Journal of Combustion Science and Technology

基　　金：国家自然科学基金资助项目(91741115,51888103).

摘　　要：苯甲醛氢提取反应的主要产物为苯甲酰基(C6H5CO),以往研究几乎通过直接离解反应消耗该自由基,未考虑C6H5CO与氧气加成反应通道.为明晰酰基氧气加成反应在醛类组分低温氧化中的重要性,本文首先验证了CH3CO+O2之于乙醛低温氧化的主导性作用,再在DLPNO-CCSD(T)/cc-pVTZ//M06-2X/6-311++G(d,p)水平构建了C6H5CO+O2反应势能面.基于RRKM/ME方法,采用微正则变分过渡态理论,获得目标反应速率系数的温度和压力依赖关系,为苯甲醛低温氧化机理的完善提供重要依据.此外,考察了新计算反应通道对苯甲醛低温氧化机理的影响,发现新计算反应对于不同苯甲醛子机理的影响差异显著.结果显示,不同模型中苯甲醛氧化关键物种热力学参数差异是造成该现象的主要原因.Benzoyl radical(C6H5CO)is a primary intermediate of benzaldehyde oxidation,which is mainly decomposed in the previous studies without considering the oxygen addition reaction.In order to clarify the importance of acyl radical addition to oxygen in aldehydes oxidation particularly at low temperatures,the effect of acetyl addition to oxygen in acetaldehyde oxidation at low temperatures is examined at first.Then,the potential energy surface of C6H5ĊO+O2 is evaluated at the level of DLPNO-CCSD(T)/cc-pVTZ//M06-2X/6-311++G(d,p).Based on the RRKM/ME method,the micro-canonical variational transition state theory(VTST)is used to obtain the temperature and pressure dependent reaction rate coefficients,providing important reference for the improvement of benzaldehyde oxidation mechanism at low temperatures.In addition,the effect of newly calculated reaction channels on the oxidation mechanism of benzaldehyde is investigated,and it is revealed that the effects of newly calculated reactions on benzaldehyde sub-mechanisms differ significantly.The main cause is the difference in the thermodynamic parameters of key species involved in the benzaldehyde oxidation reactions of different models.

关 键 词：苯甲酰基 氧气加成反应 RRKM/ME 微正则变分过渡态理论 压力依赖 

分 类 号：TK16[动力工程及工程热物理—热能工程]