Smog chamber study of secondary organic aerosol formation from gas- and particle-phase naphthalene ozonolysis

• Published in: Atmospheric environment (1994) Vol. 294; p. 119490
• Main Authors: Liu, Jixing, Zhu, Shuping, Guo, Teng, Jia, Bin, Xu, Li, Chen, Jun, Cheng, Ping
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2023
• Subjects: Homogeneous and heterogeneous reaction; Naphthalene; Ozonolysis; Secondary organic aerosol; Ozonolysis; Secondary organic aerosol; Naphthalene; Homogeneous and heterogeneous reaction
• ISSN: 1352-2310; 1873-2844
• DOI: 10.1016/j.atmosenv.2022.119490

Naphthalene (Nap), one of the most abundant PAHs in the atmosphere, has been shown to be an important secondary organic aerosol (SOA) precursor. In this study, the gas- and particle-phases (Suspended Nap-coated polystyrene latex spheres (PSLs) generated by vaporization condensation) Nap ozonolysis were investigated in a 1000 L volume cubic Teflon smog chamber. Gas-phase products and Nap-SOAs were observed from the gas- and particle-phase Nap ozonolysis via homogeneous and heterogeneous reactions, respectively. The time-dependent size distribution and mass concentration of Nap-SOAs were analyzed using a scanning mobility particle sizer and a laboratory-developed single-particle aerosol mass spectrometry (SPAMS) instrument. The chemical components of the homogeneous and heterogeneous reaction products were analyzed on-line by single photo ionization mass spectrometry (SPIMS), SPAMS, as well as by thermal desorption gas chromatograph-mass spectrometry. The results showed that the chemical components of the gas-and particle-phase Nap ozonolysis were essentially the same, with the dominant products being phthalaldehyde, phthalic anhydride, 2-carboxybenzaldehyde, and benzoic acid; Nap-SOA formation was attributed to the formation of new particles as well as the uptake of homogeneous and heterogeneous Nap oxidation products on the gas-phase or/and the particle surface. Based on the online measurement results, the reaction mechanism of Nap-ozonolysis also exhibits an initial carbon atom or double-bond attacks by O3, and kinetic analysis of Nap-coated PSLs ozonolysis shows a heterogeneous reaction rate constant of 2.55E-4 s−1 with R2 = 0.984. This study provides a systematic approach to characterize the chemical and physical properties of the gas- and particle-phase Nap ozonolysis in real time, which will deepen our understanding of the migration and transformation of PAHs in the atmosphere. •Gas- and particle-phases Nap ozonolysis were investigated in a smog chamber.•Gas-phase products and Nap-SOAs were observed via homogeneous and heterogeneous reactions.•Nap-ozonolysis reaction mechanism exhibits an initial carbon atom or double-bond attacks by O3.•Nap-coated PSLs ozonolysis shows a heterogeneous reaction rate constant of 2.55E-4 s−1 with R2 = 0.984.