Elucidating Reaction Kinetics with Time-Resolved Frequency Comb Spectroscopy

Author
Abstract
The kinetics of the hydroxyl radical (OH) + carbon monxide (CO) reaction, which is funda-mental to both atmospheric and combustion chemistry, are complex because of the formation of the hydrocarboxyl radical (HOCO) intermediate. Despite extensive studies of this reaction, HOCO has not been observed under thermal reaction conditions. In this thesis, we report the development of a sensitive and multiplexed technique, time-resolved frequency comb spectroscopy (TRFCS) for the observation of reactive chemical intermediates on the microsecond timescale. Using this technique, we observed deuteroxyl radical (OD) + CO reaction kinetics and detected all relevant reactants and products. By simultaneously measuring the time-dependent concentrations of the OD, trans-DOCO, cis-DOCO and CO2, we observed unambiguous low-pressure termolecular dependence of the reaction rate coe°cients for N2 and CO bath gases. These results con˝rm the HOCO for-mation mechanism and quantify its yield. Additionally, we observed cis-DOCO  trans-DOCO isomerization and quanti˝ed its rate.
Year of Publication
2017
Academic Department
Department of Physics
Degree
Ph.D.
Number of Pages
186
Date Published
2017-05
University
University of Colorado Boulder
City
Boulder
JILA PI Advisors
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