## 摘要

Ketenyl radical (HCCO) is an important hydrocarbon combustion intermediate. The mechanisms and kinetics for the reaction of HCCO (X^{2}A″) with H(^{2}S) occurring on both singlet and triplet surfaces have been studied by a combination of ab initio calculations and rate constant predictions at the CCSD(T)/6-311++G(3df,2p)//CCSD/6-311++G(d,p) level of theory. The kinetics and product branching ratios have been investigated in the temperature range of 297–3000 K by variational transition state and Rice–Ramsperger–Kassel–Marcus (RRKM) theories for the production of CH_{2}(a^{1}A_{1}) + CO(X^{1}Σ^{+}) and CH_{2}(X^{3}B_{1}) + CO(X^{1}Σ^{+}). Our prediction for the primary product CH_{2}(a^{1}A_{1}) + CO(X^{1}Σ^{+}) formation is in good agreement with earlier experimental results. The pressure independent rate constant for this channel can be expressed by k_{1}(T) = 8.62 × 10^{–11}T^{0}^{.16}exp(–20/T) cm^{3} molecule^{–1} s^{–1}. For the production of CH_{2}(X^{3}B_{1}) + CO(X^{1}Σ^{+}), the rate constant k_{2} can be represented as k_{2}(T) = 7.63 × 10^{–16}T^{1.56}exp(–386/T) cm^{3} molecule^{–1} s^{–1}. The predicted product branching ratios for the reaction are in close agreement with experimental data as well. We also predicted the heat of formation at 0 K for ^{2}HCCO, ^{3}CCO, and ^{1}CCO by CCSD(T)/6-311++G(3df,2p), CBS-QB3, and G2M; the values are in good agreement among one another. Specifically, the CCSD(T) values are: Δ_{f}H°(HCCO, X^{2}A″) = 42.52 ± 0.70; Δ_{f}H°(CCO, X^{3}Σ_{g}) = 91.50 ± 0.54; and Δ_{f}H°(CCO, a^{1}Δ) = 110.22 ± 0.54 kcal/mol.

原文 | English |
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頁（從 - 到） | 1095-1114 |

頁數 | 20 |

期刊 | Combustion science and technology |

卷 | 188 |

發行號 | 7 |

DOIs | |

出版狀態 | Published - 2 7月 2016 |