Modeling secondary organic aerosol formation from xylene and aromatic mixtures using a dynamic partitioning approach incorporating particle aqueous-phase chemistry (II)

Parikh, Harshal M.; Carlton, Annmarie G.; Zhou, Yang; Zhang, Haofei; Kamens, Richard M.; Vizuete, William

doi:10.1016/j.atmosenv.2012.03.062

Cited by 8 publications

(6 citation statements)

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“…To our knowledge, a methylglyoxal uptake coefficient has been reported only on 55–85% H 2 SO 4 solutions . Modeling studies have adopted glyoxal uptake coefficients for methylglyoxal based on chemical similarity, ,,, even though the two molecules are very different in important aspects such as surface activities, − hydration equilibrium constants, , Henry’s law coefficients, − and oligomerization processes. , There is a clear need for measurements of methylglyoxal uptake coefficients onto aerosol and droplet surfaces that have atmospheric relevance. In this study, we extract methylglyoxal uptake coefficients from a series of chamber experiments performed on atmospherically relevant inorganic and organic seed aerosols at high relative humidity levels.…”

Section: Introductionmentioning

confidence: 99%

“…10,12 Glyoxal uptake coefficients have been found to depend on aerosol acidity, 13 relative humidity, 13,14 and ionic strength. 15 While the value of Liggio et al 13 (γ = 2.9 × 10 −3 on nonacidified aerosol) is most commonly used in modeling studies, 3,16,17 high-end values (γ = 16 × 10 −3 ) have been successfully used to model PM 2.5 levels in Mexico City. 5 For methylglyoxal, the situation is even more uncertain.…”

Section: Introductionmentioning

confidence: 99%

“…Glyoxal uptake coefficients measurements have ranged from γ = 1 × 10 –3 on aqueous droplets to a photochemically enhanced uptake of γ = 16 × 10 –3 on nonhygroscopic ammonium sulfate/fulvic acid aerosol. , Glyoxal uptake coefficients have been found to depend on aerosol acidity, relative humidity, , and ionic strength . While the value of Liggio et al (γ = 2.9 × 10 –3 on nonacidified aerosol) is most commonly used in modeling studies, ,, high-end values (γ = 16 × 10 –3 ) have been successfully used to model PM 2.5 levels in Mexico City …”

Section: Introductionmentioning

confidence: 99%

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Methylglyoxal Uptake Coefficients on Aqueous Aerosol Surfaces

et al. 2018

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In order to predict the amount of secondary organic aerosol formed by heterogeneous processing of methylglyoxal, uptake coefficients (γ) and estimates of uptake reversibility are needed. Here, uptake coefficients are extracted from chamber studies involving ammonium sulfate and glycine seed aerosol at high relative humidity (RH ≥ 72%). Methylglyoxal uptake coefficients on prereacted glycine aerosol particles had a strong dependence on RH, increasing from γ = 0.4 × 10 to 5.7 × 10 between 72 and 99% RH. Continuous methylglyoxal losses were also observed in the presence of aqueous ammonium sulfate at 95% RH (γ = 3.7 ± 0.8 × 10). Methylglyoxal uptake coefficients measured at ≥95% RH are larger than those reported for glyoxal on nonacidified, aqueous aerosol surfaces at 90% RH. Slight curvature in first-order uptake plots suggests that methylglyoxal uptake onto aqueous aerosol surfaces is not entirely irreversible after 20 min. Methylglyoxal uptake by cloud droplets was rapid and largely reversible, approaching equilibrium within the 1 min mixing time of the chamber. PTR-MS measurements showed that each cloud event extracted 3 to 8% of aerosol-phase methylglyoxal and returned it to the gas phase, likely by an oligomer hydrolysis mechanism.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Methylglyoxal Uptake Coefficients on Aqueous Aerosol Surfaces

et al. 2018

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“…This could be, at least in part, because derived empirical formulations do not include the potential for polar organic gases to partition to polar solvents such as water, and react in that medium to form low-volatility products. Parikh et al (2011Parikh et al ( , 2012 find that when an Odum 2-product or volatility basis set (VBS) SOA model is applied to independent smog chamber studies where relative humidity (RH) and particle-phase liquid water concentrations (H 2 O ptcl ) are more typical of general atmospheric conditions, SOA parameterizations cannot reproduce observed amounts or trends in SOA mass (Parikh et al, 2011(Parikh et al, , 2012. In a series of experiments conducted in an outdoor chamber, accounting for gas-phase formation of watersoluble gases followed by partitioning into aerosol water was necessary to describe observed SOA mass accurately (Parikh et al, 2011(Parikh et al, , 2012.…”

Section: Introductionmentioning

confidence: 99%

“…Parikh et al (2011Parikh et al ( , 2012 find that when an Odum 2-product or volatility basis set (VBS) SOA model is applied to independent smog chamber studies where relative humidity (RH) and particle-phase liquid water concentrations (H 2 O ptcl ) are more typical of general atmospheric conditions, SOA parameterizations cannot reproduce observed amounts or trends in SOA mass (Parikh et al, 2011(Parikh et al, , 2012. In a series of experiments conducted in an outdoor chamber, accounting for gas-phase formation of watersoluble gases followed by partitioning into aerosol water was necessary to describe observed SOA mass accurately (Parikh et al, 2011(Parikh et al, , 2012. It is important to note available H 2 O ptcl is a function not only of RH but also of particle concentration and hygroscopicity (Zhou et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

Particle partitioning potential of organic compounds is highest in the Eastern US and driven by anthropogenic water

2013

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Gas-phase water-soluble organic matter (WSOM_g) is ubiquitous in the troposphere. In the summertime, the potential for these gases to partition to particle-phase liquid water (H₂O_ptcl) where they can form secondary organic aerosol (SOA_AQ) is high in the Eastern US and low elsewhere, with the exception of an area near Los Angeles, CA. This spatial pattern is driven by mass concentrations of H₂O_ptcl, not WSOM_g. H₂O_ptcl mass concentrations are predicted to be high in the Eastern US, largely due to sulfate. The ability of sulfate to increase H₂O_ptcl is well established and routinely included in atmospheric models; however WSOM_g partitioning to this water and subsequent SOA formation is not. The high mass concentrations of H₂O_ptcl in the southeast (SE) US but not the Amazon may help explain why biogenic SOA mass concentrations are high in the SE US but low in the Amazon. Furthermore, during the summertime in the Eastern US, the potential for organic gases to partition into liquid water is greater than their potential to partition into organic matter (OM) because concentrations of WSOM_g and H₂O_ptcl are higher than semi-volatile gases and OM. Thus, unless condensed phase yields are substantially different (> ~ order of magnitude), we expect that SOA formed through aqueous-phase pathways (SOA_AQ) will dominate in the Eastern US. These findings also suggest that H₂O_ptcl is largely anthropogenic and provide a previously unrecognized mechanism by which anthropogenic pollutants impact the amount of SOA mass formed from biogenic organic emissions. The previously reported estimate of the controllable fraction of biogenic SOA in the Eastern US (50%) is likely too low

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Insight into the Role of Pd State on Pd‐Based Catalysts in o‐Xylene Oxidation at Low Temperature

Zhang

2018

ChemCatChem

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Pd‐based catalysts are long known to be efficient for catalytic oxidation of volatile organic compounds (VOCs), but the effect of the Pd state on the activity remains controversial. In this study, we prepared a series of Pd supported on Co3O4, MnO2, CeO2, TiO2, Al2O3, SiO2 catalysts. The as‐prepared catalysts were pretreated by NaBH4 and H2 reduction, respectively, and then tested towards o‐xylene oxidation. The samples were next characterized to investigate how the Pd state and the support type affect the catalytic activity. The test and characterization results clearly show that the metallic Pd species is much more active than the Pd oxide species for o‐xylene oxidation at low temperatures, independent of the presence of reducible oxides as supports. Furthermore, NaBH4 pretreatment could avoid undesired support reduction; thus, it is a more appropriate method than H2 reduction for the preparation of supported metallic noble‐metal catalysts.

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Modeling secondary organic aerosol formation from xylene and aromatic mixtures using a dynamic partitioning approach incorporating particle aqueous-phase chemistry (II)

Cited by 8 publications

References 37 publications

Methylglyoxal Uptake Coefficients on Aqueous Aerosol Surfaces

Methylglyoxal Uptake Coefficients on Aqueous Aerosol Surfaces

Particle partitioning potential of organic compounds is highest in the Eastern US and driven by anthropogenic water

Insight into the Role of Pd State on Pd‐Based Catalysts in o‐Xylene Oxidation at Low Temperature

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