Xu Shenying, Liang Jinhu, Cao Shutong, He Ruining, Yin Guoliang, Wang Quan-De
Faculty of Materials and Chemical Engineering, Yibin University, Yibin, Sichuan 644000, People's Republic of China.
School of Environment and Safety Engineering, North University of China, Taiyuan 030051, People's Republic of China.
ACS Omega. 2022 Mar 1;7(10):8675-8685. doi: 10.1021/acsomega.1c06683. eCollection 2022 Mar 15.
The hydrogen atom abstraction by the methyl peroxy radical (CHO) is an important reaction class in detailed chemical kinetic modeling of the autoignition properties of hydrocarbon fuels. Systematic theoretical studies are performed on this reaction class for H/C-C fuels, which is critical in the development of a base model for large fuels. The molecules include hydrogen, alkanes, alkenes, and alkynes with a carbon number from 1 to 4. The B2PLYP-D3/cc-pVTZ level of theory is employed to optimize the geometries of all of the reactants, transition states, and products and also the treatments of hindered rotation for lower frequency modes. Accurate benchmark calculations for abstraction reactions of hydrogen, methane, and ethylene with CHO are performed by using the coupled cluster method with explicit inclusion of single and double electron excitations and perturbative inclusion of triple electron excitations (CCSD(T)), the domain-based local pair-natural orbital coupled cluster method (DLPNO-CCSD(T)), and the explicitly correlated CCSD(T)-F12 method with large basis sets. Reaction rate constants are computed via conventional transition state theory with quantum tunneling corrections. The computed rate constants are compared with literature values and those employed in detailed chemical kinetic mechanisms. The calculated rate constants are implemented into the recently developed NUIGMECH1.1 base model for kinetic modeling of ignition properties.
在烃类燃料自燃特性的详细化学动力学建模中，甲基过氧自由基（CHO）夺取氢原子是一类重要的反应。针对H/C-C燃料的这一反应类别开展了系统的理论研究，这对于开发大型燃料的基础模型至关重要。这些分子包括氢、碳数为1至4的烷烃、烯烃和炔烃。采用B2PLYP-D3/cc-pVTZ理论水平来优化所有反应物、过渡态和产物的几何结构，以及对低频模式的受阻旋转进行处理。通过使用明确包含单电子和双电子激发以及微扰包含三电子激发的耦合簇方法（CCSD(T)）、基于域的局部对自然轨道耦合簇方法（DLPNO-CCSD(T)）以及具有大基组的显式相关CCSD(T)-F12方法，对氢、甲烷和乙烯与CHO的夺取反应进行了精确的基准计算。反应速率常数通过带有量子隧穿校正的传统过渡态理论进行计算。将计算得到的速率常数与文献值以及详细化学动力学机制中使用的值进行比较。计算得到的速率常数被应用于最近开发的用于点火特性动力学建模的NUIGMECH1.1基础模型中。
