Kinetics, SOA yields, and chemical composition of secondary organic aerosol from β-caryophyllene ozonolysis with and without nitrogen oxides between 213 and 313 K

• Verfasst von: Gao, Lingyun [VerfasserIn]
• Verfasst von: Song, Junwei [VerfasserIn]
• Verfasst von: Mohr, Claudia [VerfasserIn]
• Verfasst von: Huang, Wei [VerfasserIn]
• Verfasst von: Vallon, Magdalena [VerfasserIn]
• Verfasst von: Jiang, Feng [VerfasserIn]
• Verfasst von: Leisner, Thomas [VerfasserIn]
• Verfasst von: Saathoff, Harald [VerfasserIn]
• Titel: Kinetics, SOA yields, and chemical composition of secondary organic aerosol from β-caryophyllene ozonolysis with and without nitrogen oxides between 213 and 313 K
• Verf.angabe: Linyu Gao, Junwei Song, Claudia Mohr, Wei Huang, Magdalena Vallon, Feng Jiang, Thomas Leisner, and Harald Saathoff
• E-Jahr: 2022
• Jahr: 6 May 2022
• Umfang: 20 S.
• Fussnoten: Gesehen am 18.07.2022
• Titel Quelle: Enthalten in: Atmospheric chemistry and physics
• Ort Quelle: Katlenburg-Lindau : EGU, 2001
• Jahr Quelle: 2022
• Band/Heft Quelle: 22(2022), 9, Seite 6001-6020
• ISSN Quelle: 1680-7324
• DOI: doi:10.5194/acp-22-6001-2022
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1810707129

Abstract

<p><strong class="journal-contentHeaderColor">Abstract.</strong> <span class="inline-formula"><i>β</i></span>-caryophyllene (BCP) is one of the most important sesquiterpenes (SQTs) in the atmosphere, with a large potential contribution to secondary organic aerosol (SOA) formation mainly from reactions with ozone (O<span class="inline-formula">₃</span>) and nitrate radicals (NO<span class="inline-formula">₃</span>). In this work, we study the temperature dependence of the kinetics of BCP ozonolysis, SOA yields, and SOA chemical composition in the dark and in the absence and presence of nitrogen oxides including nitrate radicals (NO<span class="inline-formula">₃</span>). We cover a temperature range of 213-313 K, representative of tropospheric conditions. The oxidized components in both gas and particle phases were characterized on a molecular level by a chemical ionization mass spectrometer equipped with a filter inlet for gases and aerosols using iodide as the reagent ion (FIGAERO-iodide-CIMS). The batch mode experiments were conducted in the 84.5 m<span class="inline-formula">³</span> aluminium simulation chamber AIDA at the Karlsruhe Institute of Technology (KIT). In the absence of nitrogen oxides, the temperature-dependent rate coefficient of the endocyclic double bond in BCP reacting with ozone between 243-313 K is negatively correlated with temperature, corresponding to the following Arrhenius equation: <span class="inline-formula"><i>k</i>=</span> (1.6 <span class="inline-formula">±</span> 0.4) <span class="inline-formula">×</span> 10<span class="inline-formula">⁻¹⁵</span> <span class="inline-formula">×</span> exp((559 <span class="inline-formula">±</span> 97)<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M13" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>/</mo><mi>T</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="14pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="1817643d3376598401f9272685f497c2"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-22-6001-2022-ie00001.svg" width="14pt" height="14pt" src="acp-22-6001-2022-ie00001.png"/></svg:svg></span></span>). The SOA yields increase from 16 <span class="inline-formula">±</span> 5 % to 37 <span class="inline-formula">±</span> 11 %, with temperatures decreasing from 313 to 243 K at a total organic particle mass of 10 <span class="inline-formula">µg</span> m<span class="inline-formula">⁻³</span>. The variation in the ozonolysis temperature leads to a substantial impact on the abundance of individual organic molecules. In the absence of nitrogen oxides, monomers C<span class="inline-formula">₁₄₋₁₅</span>H<span class="inline-formula">₂₂₋₂₄</span>O<span class="inline-formula">₃₋₇</span> (37.4 %), dimers C<span class="inline-formula">₂₈₋₃₀</span>H<span class="inline-formula">₄₄₋₄₈</span>O<span class="inline-formula">₅₋₉</span> (53.7 %), and trimers C<span class="inline-formula">₄₁₋₄₄</span>H<span class="inline-formula">₆₂₋₆₆</span>O<span class="inline-formula">₉₋₁₁</span> (8.6 %) are abundant in the particle phase at 213 K. At 313 K, we observed more oxidized monomers (mainly C<span class="inline-formula">₁₄₋₁₅</span>H<span class="inline-formula">₂₂₋₂₄</span>O<span class="inline-formula">₆₋₉</span>, 67.5 %) and dimers (mainly C<span class="inline-formula">₂₇₋₂₉</span>H<span class="inline-formula">₄₂₋₄₄</span>O<span class="inline-formula">₉₋₁₁</span>, 27.6 %), including highly oxidized molecules (HOMs; C<span class="inline-formula">₁₄</span>H<span class="inline-formula">₂₂</span>O<span class="inline-formula">_7,9</span>, C<span class="inline-formula">₁₅</span>H<span class="inline-formula">₂₂</span>O<span class="inline-formula">_7,9</span>C<span class="inline-formula">₁₅</span>H<span class="inline-formula">₂₄</span>O<span class="inline-formula">_7,9</span>), which can be formed via hydrogen shift mechanisms, but no significant trimers. In the presence of nitrogen oxides, the organonitrate fraction increased from 3 % at 213 K to 12 % and 49 % at 243 and 313 K, respectively. Most of the organonitrates were monomers with C<span class="inline-formula">₁₅</span> skeletons and only one nitrate group. More highly oxygenated organonitrates were observed at higher temperatures, with their signal-weighted <span class="inline-formula">O:C</span> atomic ratio increasing from 0.41 to 0.51 from 213 to 313 K. New dimeric and trimeric organic species without nitrogen atoms (C<span class="inline-formula">₂₀</span>, C<span class="inline-formula">₃₅</span>) were formed in the presence of nitrogen oxides at 298-313 K, indicating potential new reaction pathways. Overall, our results show that increasing temperatures lead to a relatively small decrease in the rate coefficient of the endocyclic double bond in BCP reacting with ozone but to a strong decrease in SOA yields. In contrast, the formation of HOMs and organonitrates increases significantly with temperature.</p>