Room Temperature Kinetics of the Reaction of OH with Ethylene Oxide
The gas-phase oxidation of ethylene oxide (EtO, C<sub>2</sub>H<sub>4</sub>O) by the hydroxyl radical (OH) is the primary atmospheric pathway for removing this known carcinogen from the troposphere. The rate coefficient of the OH + EtO reaction was measured at room temperature (296 K) in a temperature- and pressure-controlled reactor using pulsed laser photolysis-laser-induced fluorescence (PLP-LIF). Time-resolved pseudo-first order OH decays, generated by photolyzing H<sub>2</sub>O<sub>2</sub>, HNO<sub>3</sub>, or (CH<sub>3</sub>)<sub>3</sub>COOH at 248 nm, were measured using LIF in EtO/N<sub>2</sub> mixtures at total pressures of 67 and 267 hPa. The observed rate coefficient, <i>k</i><sub>1</sub>(296 K) = (1.09 ± 0.10) × 10<sup>-13</sup> cm<sup>3</sup> molecule<sup>-1</sup> s<sup>-1</sup>, is approximately 25% faster than the current recommended value. These results are compared with previous room-temperature studies, and atmospheric lifetimes of EtO with respect to OH are discussed.
Authors
- Carl J. Percival (ORCID: https://orcid.org/0000-0003-2525-160X)
- Paul O. Wennberg (ORCID: https://orcid.org/0000-0002-6126-3854)
- Mitchio Okumura (ORCID: https://orcid.org/0000-0001-6874-1137)
- Megan Woods (ORCID: https://orcid.org/0000-0002-1367-0084)
- Frank A.F. Winiberg
- Xu Zhang
Institutions
- California Institute of Technology (US)
- Planetary Science Institute (US)
- Jet Propulsion Laboratory (US)
- Division of Chemistry (US)
Publication Details
- Journal
- The Journal of Physical Chemistry Letters
- Published
- 2026-01-06
- DOI
- https://doi.org/10.1021/acs.jpclett.5c03620
- Primary Topic
- Atmospheric chemistry and aerosols
- Type
- article
- Field-Weighted Citation Impact
- 0.00