Howes, NUM, Lockhart, JPA, Blitz, MA orcid.org/0000-0001-6710-4021 et al. (6 more authors) (2016) Observation of a New Channel, the Production of CH3, in the Abstraction Reaction of OH Radicals with Acetaldehyde. Physical Chemistry Chemical Physics, 18 (38). pp. 26423-26433. ISSN 1463-9076
Abstract
Using laser flash photolysis coupled to photo-ionization time-of-flight mass spectrometry (PIMS), methyl radicals (CH3) have been detected as primary products from the reaction of OH radicals with acetaldehyde (ethanal, CH3CHO) with a yield of ~15% at 1-2 Torr of helium bath gas. Supporting measurements based on laser induced fluorescence studies of OH recycling in the OH/CH3CHO/O2 system are consistent with the PIMS study. Master equation calculations suggest that the origin of the methyl radicals is from prompt dissociation of chemically activated acetyl products and hence is consistent with previous studies which have shown that abstraction, rather than addition/elimination, is the sole route for the OH + acetaldehyde reaction. However, the observation of a significant methyl product yield suggests that energy partitioning in the reaction is different from the typical early barrier mechanism where reaction exothermicity is channeled preferentially into the newly formed bond. The master equation calculations predict atmospheric yields of methyl radicals of ~ 14 %. The implications of the observations in atmospheric and combustion chemistry are briefly discussed.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © the Owner Societies 2016. This is an author produced version of a paper published in Physical Chemistry Chemical Physics. Uploaded in accordance with the publisher's self-archiving policy. |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemistry (Leeds) > Physical Chemistry (Leeds) |
Funding Information: | Funder Grant number NERC (Natural Environment Research Council) R8/H12/83/013 NERC (Natural Environment Research Council) NCAS 15/16 NERC (Natural Environment Research Council) NE/M002381/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 12 Sep 2016 13:28 |
Last Modified: | 22 Jan 2021 10:08 |
Published Version: | https://doi.org/10.1039/C6CP03970G |
Status: | Published |
Publisher: | Royal Society of Chemistry |
Identification Number: | 10.1039/C6CP03970G |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:104218 |