Effect of NOx on 1,3,5-trimethylbenzene (TMB) oxidation product distribution and particle formation

Epameinondas Tsiligiannis, Julia Hammes, Christian Mark Salvador, Thomas F. Mentel, Mattias Hallquist

Research output: Contribution to journalArticlepeer-review

44 Scopus citations

Abstract

Secondary organic aerosol (SOA) represents a significant fraction of the tropospheric aerosol and its precursors are volatile organic compounds (VOCs). Anthropogenic VOCs (AVOC) dominate the VOC budget in many urban areas with 1,3,5-trimethylbenzene (TMB) being among the most reactive aromatic AVOCs. TMB formed highly oxygenated organic molecules (HOMs) in an NOx-free environment, which could contribute to new particle formation (NPF) depending on oxidation conditions where elevated OH oxidation enhanced particle formation. The experiments were performed in an oxidation flow reactor, the Go:PAM unit, under controlled OH oxidation conditions. By addition of NOx to the system we investigated the effect of NOx on particle formation and on the product distribution. We show that the formation of HOMs, and especially HOM accretion products, strongly varies with NOx conditions. We observe a suppression of HOM and particle formation with increasing NOx/1TMB ratio and an increase in the formation of organonitrates (ONs) mostly at the expense of HOM accretion products. We propose reaction mechanisms and pathways that explain the formation and observed product distributions with respect to oxidation conditions. We hypothesise that, based on our findings from TMB oxidation studies, aromatic AVOCs may not contribute significantly to NPF under typical NOx/AVOC conditions found in urban atmospheres.

Original languageEnglish
Pages (from-to)15073-15086
Number of pages14
JournalAtmospheric Chemistry and Physics
Volume19
Issue number23
DOIs
StatePublished - Dec 13 2019
Externally publishedYes

Funding

Financial support. This research has been supported by the Veten-skapsrådet (grant nos. 2014-05332 and 2013-06917) and the Sven-ska Forskningsrådet Formas (grant no. 2015-1537).

FundersFunder number
Veten-skapsrådet2013-06917, 2014-05332
Svenska Forskningsrådet Formas2015-1537

    Fingerprint

    Dive into the research topics of 'Effect of NOx on 1,3,5-trimethylbenzene (TMB) oxidation product distribution and particle formation'. Together they form a unique fingerprint.

    Cite this