In:
Atmospheric Chemistry and Physics, Copernicus GmbH, Vol. 19, No. 6 ( 2019-04-02), p. 4075-4091
Abstract:
Abstract. Although secondary organic aerosol (SOA) is a major component of PM2.5
and organic aerosol (OA) particles and therefore profoundly influences air
quality, climate forcing, and human health, the mechanism of SOA formation
via Criegee chemistry is poorly understood. Herein, we perform high-level
theoretical calculations to study the gas-phase reaction mechanism and
kinetics of four Criegee intermediate (CI) reactions with four
hydroxyalkyl hydroperoxides (HHPs) for the first time. The calculated
results show that the consecutive reactions of CIs with HHPs are both
thermochemically and kinetically favored, and the oligomers contain CIs
as chain units. The addition of an −OOH group in HHPs to the central carbon
atom of CIs is identified as the most energetically favorable channel, with
a barrier height strongly dependent on both CI substituent number (one or
two) and position (syn- or anti-). In particular, the introduction of a methyl
group into the anti-position significantly increases the rate
coefficient, and a
dramatic decrease is observed when the methyl group is introduced into the
syn-position. These findings are expected to broaden the reactivity profile and
deepen our understanding of atmospheric SOA formation processes.
Type of Medium:
Online Resource
ISSN:
1680-7324
DOI:
10.5194/acp-19-4075-2019
DOI:
10.5194/acp-19-4075-2019-supplement
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2019
detail.hit.zdb_id:
2092549-9
detail.hit.zdb_id:
2069847-1
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