Density functional theory kinetic assessment of hydrogen abstraction from hydrocarbons by O2

Marrouni, Karim El; Abou‐Rachid, Hakima; Kaliaguine, Serge

doi:10.1016/j.theochem.2004.04.037

Cited by 9 publications

(23 citation statements)

References 19 publications

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“…The total energy of the products is slightly higher than that of the corresponding transition states by ϳ7-9 kcal/mol and 1-3 kcal/mol at B3LYP/6-311G(d,p) and BH&HLYP/6-311G(d,p) levels, respectively (Table I). These results are in accordance with those obtained in previous works [6,7,14,15]. In fact, the reverse process consists of a recombination of two hot radicals having a very high energy.…”

Section: Molecular Structure Calculationssupporting

confidence: 93%

“…Moreover, divergent values provided from different experimental laboratories are often reported for the same compound. Our previous studies [6,7] show the establishment of a very good correlation between the computed rate constants for a great number of combustion initiation reactions and the experimental CN of pure compounds including alcohols and hydrocarbons. In these works, we have confirmed the fundamental hypothesis that the molecular structures of the activated complexes involved in the autoignition processes are correlated to the experimental CN data.…”

Section: Introduction Umentioning

confidence: 71%

“…Indeed ▪ The global rate constant for reaction (DME ϩ O 2 : Table VI) is higher than the one for reaction (propane ϩ O 2 : [7]) at B3LYP/6-311G(d,p) and BH&LYP/6-311G(d,p) levels of calculation. Hence, the six hydrogen atoms of the methyl groups in CH 3 OOOCH 3 are more reactive toward O 2 than the eight hydrogen atoms in CH 3 OCH 2 OCH 3 .…”

Section: Rate Constant Of the Ignition Reactions Of Linear Symmetricamentioning

confidence: 87%

“…▪ As for the earlier ignition reactions, similar observations were made about the ignition reactions of DPE and n-heptane. In fact (k_global (DPE ϩ O 2 ): Table VI Ͼ k_global (n-heptane ϩ O 2 ): [7]). …”

Section: Rate Constant Of the Ignition Reactions Of Linear Symmetricamentioning

confidence: 99%

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Theoretical study of ignition reactions of linear symmetrical monoethers as potential diesel fuel additives: DFT calculations

Marrouni

Abou‐Rachid

Kaliaguine

2007

Int J of Quantum Chemistry

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This work investigates the chemical reactivity of four linear symmetrical monoethers with molecular oxygen. Such oxygenated compounds may be considered as potential diesel fuel additives in order to reduce the ignition delay in diesel fuel engines. For this purpose, a kinetic study is proposed to clarify the relation between the molecular structure of the fuel molecule and its ignition properties. To this end, DFT calculations were performed for these reactions using B3LYP/6-311G(d,p) and BH&HLYP/6-311G(d,p) to determine structures, energies, and vibrational frequencies of stationary points as well as activated complexes involved in each gas-phase combustion initiation reaction of the monoethers CH 3 OCH 3 , C 2 H 5 OC 2 H 5 , C 3 H 7 OC 3 H 7 , or C 4 H 9 OC 4 H 9 with molecular oxygen. This theoretical kinetic study was carried out using electronic structure results and the transition state theory, to assess the rate constants for all studied combustion reactions. As it has been shown in our previous work [AbouRachid et al., J Mol Struct (Theochem) 2003, 621, 293], the cetane number (CN) of a pure organic molecule depends on the initiation rate of its homogeneous gas-phase reaction with molecular oxygen. Indeed, the calculated initiation rate constants of the Habstraction process of linear monoethers with O 2 show a very good correlation with experimental CN data of these pure compounds at T ϭ 1,000 K. This temperature is representative of the operating conditions of a diesel fuel engine.

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Section: Molecular Structure Calculationssupporting

confidence: 93%

Section: Introduction Umentioning

confidence: 71%

Section: Rate Constant Of the Ignition Reactions Of Linear Symmetricamentioning

confidence: 87%

Section: Rate Constant Of the Ignition Reactions Of Linear Symmetricamentioning

confidence: 99%

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Theoretical study of ignition reactions of linear symmetrical monoethers as potential diesel fuel additives: DFT calculations

Marrouni

Abou‐Rachid

Kaliaguine

2007

Int J of Quantum Chemistry

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“…The molecular fragments named MDA, NAD a , NAD b , NADC a–d , and BTDE (Figure and ) were chosen carefully so that the electronic environment of the region near the reaction center is mimicked well. The pathways used to model the oxidation of these fragments are based on well‐documented radical mechanisms that are initiated by O 2 or

\dot{normalO} H

\dot{normalO} O H

. Formation of oxidation layer and radicals on the polymer on exposure to flowing air and high temperature also supports the initiation of oxidation by O 2 and radicals.…”

Section: Introductionmentioning

confidence: 99%

Quantum Mechanical Computations and Microkinetic Modeling to Obtain Mechanism and Kinetics of Oxidative Degradation of a Polyimide

Kunnikuruvan

Parandekar²,

Prakash³

et al. 2015

Macro Theory & Simulations

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Improving the high-temperature long-term thermo-oxidative stability of high-performance polymers is crucial for their applications in aerospace industry. For designing novel polymers with improved oxidative stability, it is vital to identify the most reactive moiety of the polyimide toward oxidation and understand the mechanism of oxidation. Quantum chemical calculations and microkinetic analysis have been carried out here to obtain the molecular level details of the oxidative degradation of a commercially important polyimide, PMR-15, at high temperatures. This study identifies the most vulnerable moiety of PMR-15 toward oxidation. Moreover, the rate-determining step in the oxidative degradation is also scrutinized. Mechanistic understanding of the reaction leads us to propose new modifications of PMR-15 with a better thermo-oxidative stability.

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Kinetics of the hydrogen abstraction alkane + O2 → alkyl + HO2 reaction class: an application of the reaction class transition state theory

Baradyn

Ratkiewicz

2019

Struct Chem

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Density functional theory kinetic assessment of hydrogen abstraction from hydrocarbons by O2

Cited by 9 publications

References 19 publications

Theoretical study of ignition reactions of linear symmetrical monoethers as potential diesel fuel additives: DFT calculations

Theoretical study of ignition reactions of linear symmetrical monoethers as potential diesel fuel additives: DFT calculations

Quantum Mechanical Computations and Microkinetic Modeling to Obtain Mechanism and Kinetics of Oxidative Degradation of a Polyimide

Kinetics of the hydrogen abstraction alkane + O2 → alkyl + HO2 reaction class: an application of the reaction class transition state theory

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