Journal article
Isolating α-Pinene Ozonolysis Pathways Reveals New Insights into Peroxy Radical Chemistry and Secondary Organic Aerosol Formation
Environmental science & technology, Vol.55(10), pp.6700-6709
04/29/2021
DOI: 10.1021/acs.est.1c02107
PMID: 33913707
Abstract
α-Pinene ozonolysis is a key process that impacts the formation of new particles and secondary organic aerosol (SOA) in the atmosphere. The mechanistic understanding of this chemistry has been inconclusive despite extensive research, hindering accurate simulations of atmospheric processes. In this work, we examine the ozonolysis of two synthesized unsaturated carbonyl isomers (C
H
O) which separately produce the two Criegee intermediates (CIs) that would form simultaneously in α-pinene ozonolysis. Direct gas-phase measurements of peroxy radicals (RO
) from flowtube ozonolysis experiments by an iodide-adduct chemical ionization mass spectrometer suggest that the initial C
H
O
RO
from the CI with a terminal methyl ketone undergo autoxidation 20-fold faster than the CI with a terminal aldehyde and always outcompete the bimolecular reactions under typical laboratory and atmospheric conditions. These results provide experimental constraints on the detailed RO
autoxidation mechanisms for understanding new particle formation in the atmosphere. Further, isomer-resolved characterization of the SOA formed from a continuous-flow stirred tank reactor using ion mobility spectrometry mass spectrometry suggests that the two structurally different CIs predominantly and unexpectedly form constituents with identical structures. These results open up possibilities of diverse isomerization pathways that the two CIs may undergo that form mutual products to a large extent toward their way forming the SOA. This work highlights new insights into α-pinene ozonolysis pathways and call for future studies to uncover the detailed mechanisms.
Details
- Title: Subtitle
- Isolating α-Pinene Ozonolysis Pathways Reveals New Insights into Peroxy Radical Chemistry and Secondary Organic Aerosol Formation
- Creators
- Zixu Zhao - Department of Chemistry, University of California, Riverside, California 92521, United StatesWen Zhang - Department of Chemistry, University of California, Riverside, California 92521, United StatesTaylor Alexander - Department of Chemistry, University of California, Riverside, California 92521, United StatesXuan Zhang - Department of Life and Environmental Sciences, University of California, Merced, California 95343, United StatesDavid B C Martin - Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, United StatesHaofei Zhang - Department of Chemistry, University of California, Riverside, California 92521, United States
- Resource Type
- Journal article
- Publication Details
- Environmental science & technology, Vol.55(10), pp.6700-6709
- DOI
- 10.1021/acs.est.1c02107
- PMID
- 33913707
- NLM abbreviation
- Environ Sci Technol
- eISSN
- 1520-5851
- Publisher
- United States
- Grant note
- DOI: 10.13039/100000165, name: Division of Chemistry, award: CHE-2002413; DOI: 10.13039/100005595, name: University of California; DOI: 10.13039/100000001, name: National Science Foundation, award: AGS-1953905
- Language
- English
- Date published
- 04/29/2021
- Academic Unit
- Iowa Neuroscience Institute; Chemistry
- Record Identifier
- 9984077780602771
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