DIRECT MEASUREMENT OF OD+CO→ cis-DOCO, trans-DOCO, AND D+CO2 BRANCHING KINETICS USING TIME-RESOLVED FREQUENCY COMB SPECTROSCOPY

Bjork, Bryce J.

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https://hdl.handle.net/2142/97073 Copy

Description

Title

DIRECT MEASUREMENT OF OD+CO→ cis-DOCO, trans-DOCO, AND D+CO2 BRANCHING KINETICS USING TIME-RESOLVED FREQUENCY COMB SPECTROSCOPY

Author(s)

Bjork, Bryce J.

Contributor(s)

• Ye, Jun
• Iwakuni, Kana
• Spaun, Ben
• Changala, Bryan
• Bui, Thinh Quoc

Issue Date

6/21/2017

Keyword(s)

Dynamics and kinetics

Abstract

The kinetics of the reaction OH+CO$rightarrow$H+CO$_2$ has attracted experimental and theoretical studies for more than 40 years due to its importance in atmospheric and combustion environments. This reaction proceeds on a rich potential energy landscape, first by forming vibrationally excited HOCO*; subsequently, HOCO* either back reacts to OH+CO, dissociates to H+CO$_2$, or is stabilized to ground state HOCO by collisions with a third body. Due to the formation of the HOCO intermediate, the rate coefficient displays anomalous temperature and strong pressure dependences. Time-resolved Frequency Comb Spectroscopy (TRFCS) combines a mid-IR mode-locked femtosecond laser, a broadband optical enhancement cavity, and spatially dispersive detection system to simultaneously provide broad spectral bandwidth, high spectral resolution, high absorption sensitivity, and microsecond time resolution. We have applied this powerful technique to identify the deuterated analogues of HOCO isomers, {it trans}-DOCO and {it cis}-DOCO, for the first time in the reaction OD+CO under ambient conditions. By directly monitoring the concentrations of OD (reactant), {it trans}-DOCO, {it cis}-DOCO (intermediates), and CO$_2$(product), we unambiguously measure all pressure-dependent branching rates of the OD+CO reaction.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

English

Permalink

http://hdl.handle.net/2142/97073

DOI

10.15278/isms.2017.WH01

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