TY - JOUR
T1 - A theoretical kinetics study on low-temperature oxidation of n-C4H9 radicals
AU - Duan, Junrui
AU - Ji, Jie
AU - Ye, Lili
AU - Zhai, Yitong
AU - Zhang, Lidong
N1 - KAUST Repository Item: Exported on 2020-10-12
Acknowledgements: This work was supported by National Natural Science Foundation of China (NSFC, Grant nos. 52036009, 51676176).
PY - 2020/9/25
Y1 - 2020/9/25
N2 - The low-temperature oxidation mechanism of n butyl radicals (n-C4H9) has been investigated by high level quantum chemical calculations coupled with the Rice-Ramsperger-Kassel-Marcus/Master Equation (RRKM/ME) theory. The potential energy surfaces (PES) were explored at the QCISD(T)/CBS//B3LYP/6-311++G(d,p) level. The temperature- and pressure-dependent rate constants were computed and fitted in modified Arrhenius parameters. The major reaction channels were discussed to more deeply understand the competing relationships between chain branching, chain propagation and termination reactions. The results show that the 1,5 H-shift reaction is more competitive than the 1,6 H-shift and 1,4 H-shift for isomerization reactions of n butyl peroxy radicals, and the concerted HO2 elimination channel to form butene becomes more important at high temperatures. Furthermore, based on our calculations, a revised kinetic model was developed to describe n-butane oxidation. Good consistency between model predictions and experimental data was shown. This study enhances our understanding of the combustion mechanism of n-butane and can be used as a reliable reference for mechanistic understanding of larger alkanes.
AB - The low-temperature oxidation mechanism of n butyl radicals (n-C4H9) has been investigated by high level quantum chemical calculations coupled with the Rice-Ramsperger-Kassel-Marcus/Master Equation (RRKM/ME) theory. The potential energy surfaces (PES) were explored at the QCISD(T)/CBS//B3LYP/6-311++G(d,p) level. The temperature- and pressure-dependent rate constants were computed and fitted in modified Arrhenius parameters. The major reaction channels were discussed to more deeply understand the competing relationships between chain branching, chain propagation and termination reactions. The results show that the 1,5 H-shift reaction is more competitive than the 1,6 H-shift and 1,4 H-shift for isomerization reactions of n butyl peroxy radicals, and the concerted HO2 elimination channel to form butene becomes more important at high temperatures. Furthermore, based on our calculations, a revised kinetic model was developed to describe n-butane oxidation. Good consistency between model predictions and experimental data was shown. This study enhances our understanding of the combustion mechanism of n-butane and can be used as a reliable reference for mechanistic understanding of larger alkanes.
UR - http://hdl.handle.net/10754/665530
UR - https://linkinghub.elsevier.com/retrieve/pii/S154074892030571X
UR - http://www.scopus.com/inward/record.url?scp=85091869200&partnerID=8YFLogxK
U2 - 10.1016/j.proci.2020.07.120
DO - 10.1016/j.proci.2020.07.120
M3 - Article
SN - 1540-7489
JO - Proceedings of the Combustion Institute
JF - Proceedings of the Combustion Institute
ER -