Title :

Insights into the Reactions of Hydroxyl Radical with Diolefins from Atmospheric to Combustion Environments

Author(s) :

Khaled, Fethi [Auteur]
King Abdullah University of Science and Technology [Saudi Arabia] [KAUST]
Giri, Binod Raj [Auteur]
King Abdullah University of Science and Technology [Saudi Arabia] [KAUST]
Liu, Dapeng [Auteur]
King Abdullah University of Science and Technology [Saudi Arabia] [KAUST]
Assaf, Emmanuel [Auteur]
Physicochimie des Processus de Combustion et de l’Atmosphère - UMR 8522 [PC2A]
Fittschen, Christa [Auteur]
Physicochimie des Processus de Combustion et de l’Atmosphère - UMR 8522 [PC2A]
Farooq, Aamir [Auteur]
King Abdullah University of Science and Technology [Saudi Arabia] [KAUST]

Journal title :

The Journal of Physical Chemistry A

Abbreviated title :

J. Phys. Chem. A

Volume number :

123

Pages :

2261-2271

Publisher :

American Chemical Society (ACS)

Publication date :

2019-02-15

English keyword(s) :

Hydroxyls
Redox reactions

HAL domain(s) :

Physique [physics]/Physique [physics]/Chimie-Physique [physics.chem-ph]
Chimie/Chimie théorique et/ou physique

English abstract : [en]

Hydroxyl radicals and olefins are quite important from a combustion and an atmospheric chemistry standpoint. Large amounts of olefinic compounds are emitted into the earth’s atmosphere from both biogenic and anthropogenic ...
Show more >Hydroxyl radicals and olefins are quite important from a combustion and an atmospheric chemistry standpoint. Large amounts of olefinic compounds are emitted into the earth’s atmosphere from both biogenic and anthropogenic sources. Olefins make a significant share in transportation fuels (e.g., up to 20% by volume in gasoline), and they appear as important intermediates during hydrocarbon oxidation. As olefins inhibit low-temperature heat release, they have caught some attention for their applicability in future advanced combustion engine technology. Despite their importance, the literature data for the reactions of olefins are quite scarce. In this work, we have measured the rate coefficients for the reaction of hydroxyl radicals (OH) with several diolefins, namely 1,3-butadiene, cis-1,3-pentadiene, trans-1,3-pentadiene, and 1,4-pentadiene, over a wide range of experimental conditions (T = 294–468 K and p ∼ 53 mbar; T = 881–1348 K and p ∼ 1–2.5 bar). We obtained the low-T data in a flow reactor using laser flash photolysis and laser-induced fluorescence (LPFR/LIF), and the high-T data were obtained with a shock tube and UV laser-absorption (ST/LA). At low temperatures, we observed differences in the reactivity of cis- and trans-1,3-pentadiene, but these molecules exhibited similar reactivity at high temperatures. Similar to monoolefins + OH reactions, we observed negative temperature dependence for dienes + OH reactions at low temperatures–revealing that OH-addition channels prevail at low temperatures. Except for the 1,4-pentadiene + OH reaction, which shows evidence of significant H-abstraction reactions even at low-temperatures, other diolefins studied here almost exclusively undergo addition reaction with OH radicals at the low-temperature end of our experiments; whereas the reactions mainly switch to hydrogen abstraction at high temperatures. These reactions show complex Arrhenius behavior as a result of many possible chemical pathways in such a convoluted system.Show less >

Language :

Anglais

Peer reviewed article :

Oui

Audience :

Non spécifiée

Administrative institution(s) :

Université de Lille
CNRS

Collections :

• Physicochimie des Processus de Combustion et de l'Atmosphère (PC2A) - UMR 8522

Research team(s) :

PhysicoChimie de l'Atmosphère (PCA)

Submission date :

2020-10-07T13:02:23Z
2020-10-15T10:47:53Z
2020-10-15T10:56:22Z