Direct frequency comb measurement of OD + CO → DOCO kinetics
Abstract
The kinetics of the hydroxyl radical (OH) + carbon monoxide (CO) reaction, which is fundamental 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. Exploiting the sensitive, broadband, and high-resolution capabilities of time-resolved cavity-enhanced direct frequency comb spectroscopy, we observed deuteroxyl radical (OD) + CO reaction kinetics and detected stabilized trans-DOCO, the deuterated analog of trans-HOCO. By simultaneously measuring the time-dependent concentrations of the trans-DOCO and OD species, we observed unambiguous low-pressure termolecular dependence of the reaction rate coefficients for N_2 and CO bath gases. These results confirm the HOCO formation mechanism and quantify its yield.
Additional Information
© 2016 American Association for the Advancement of Science. Received 20 May 2016; resubmitted 24 August 2016. Accepted 28 September 2016. Additional data supporting the conclusions are available in supplementary materials. We thank K. Sung of the NASA Jet Propulsion Laboratory (JPL) for providing a list of D2O mid-IR line positions and intensities measured by R. A. Toth of JPL. We acknowledge financial support from the Air Force Office of Scientific Research, the Defense Advanced Research Projects Agency (DARPA) Spectral Combs from UV to THz (SCOUT) program, the National Institute of Standards and Technology, NSF, and DARPA (grants FAA-9550-14-C-0030 and W31P4Q-16-C-0001). M.O. is supported by NSF grant CHE-1413712. T.Q.B. and B.S. are supported by the National Research Council Research Associate Fellowship, P.B.C. is supported by the NSF Graduate Research Fellowship Program, and O.H.H. is partially supported through a Humboldt Fellowship. P.H., D.F., and C.D. are employees of a startup company (Crystalline Mirror Solutions), cofounded by G.D.C. and M.A., and coinventors on a submitted patent focusing on the crystalline mirror technology applied in this Report.Attached Files
Supplemental Material - aag1862-Bjork-SM.pdf
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Additional details
- Eprint ID
- 71766
- Resolver ID
- CaltechAUTHORS:20161107-094113128
- Air Force Office of Scientific Research (AFOSR)
- National Institute of Standards and Technology (NIST)
- FAA-9550-14-C-0030
- Defense Advanced Research Projects Agency (DARPA)
- W31P4Q-16-C-0001
- Defense Advanced Research Projects Agency (DARPA)
- CHE-1413712
- NSF
- National Research Council
- NSF Graduate Research Fellowship
- Alexander von Humboldt Foundation
- Created
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2016-11-07Created from EPrint's datestamp field
- Updated
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2021-11-11Created from EPrint's last_modified field