Photoenhanced Uptake of NO<sub>2</sub> by Pyrene Solid Films

Brigante, Marcello; Cazoir, David; D’Anna, Barbara; George, Christian; Donaldson, D. J.

doi:10.1021/jp802324g

Cited by 75 publications

(96 citation statements)

References 42 publications

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“…The parameterization that led to the best description of HONO was based on a maximum reactive uptake coefficient at noon of 6 × 10 −5 that was scaled with the normalized spectral irradiance and 100 % yield of NO 2 to HONO. This uptake coefficient is larger than those found on organics and urban grime in laboratory studies (for example George et al, 2005;Brigante et al, 2008;Ammar et al, 2010). However, the true atmospheric surface area available for chemistry is likely larger than the geometric surface area used in the model, thus explaining the need for a larger uptake coefficient in the model.…”

Section: Discussionmentioning

confidence: 69%

Modeling of daytime HONO vertical gradients during SHARP 2009

et al. 2013

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Nitrous acid (HONO) acts as a major precursor of the hydroxyl radical (OH) in the urban atmospheric boundary layer in the morning and throughout the day. Despite its importance, HONO formation mechanisms are not yet completely understood. It is generally accepted that conversion of NO₂ on surfaces in the presence of water is responsible for the formation of HONO in the nocturnal boundary layer, although the type of surface on which the mechanism occurs is still under debate. Recent observations of higher than expected daytime HONO concentrations in both urban and rural areas indicate the presence of unknown daytime HONO source(s). Various formation pathways in the gas phase, and on aerosol and ground surfaces have been proposed to explain the presence of daytime HONO. However, it is unclear which mechanism dominates and, in the cases of heterogeneous mechanisms, on which surfaces they occur.

Vertical concentration profiles of HONO and its precursors can help in identifying the dominant HONO formation pathways. In this study, daytime HONO and NO₂ vertical profiles, measured in three different height intervals (20–70, 70–130, and 130–300 m) in Houston, TX, during the 2009 Study of Houston Atmospheric Radical Precursors (SHARP) are analyzed using a one-dimensional (1-D) chemistry and transport model. Model results with various HONO formation pathways suggested in the literature are compared to the the daytime HONO and HONO/NO₂ ratios observed during SHARP. The best agreement of HONO and HONO/NO₂ ratios between model and observations is achieved by including both a photolytic source of HONO at the ground and on the aerosol. Model sensitivity studies show that the observed diurnal variations of the HONO/NO₂ ratio are not reproduced by the model if there is only a photolytic HONO source on aerosol or in the gas phase from NO₂^* + H₂O. Further analysis of the formation and loss pathways of HONO shows a vertical dependence of HONO chemistry during the day. Photolytic HONO formation at the ground is the major formation pathway in the lowest 20 m, while a combination of gas-phase, photolytic formation on aerosol, and vertical transport is responsible for daytime HONO between 200–300 m a.g.l. HONO removal is dominated by vertical transport below 20 m and photolysis between 200–300 m a.g.l

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Section: Discussionmentioning

confidence: 69%

Modeling of daytime HONO vertical gradients during SHARP 2009

et al. 2013

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“…For example, no influence of RH has been observed for dark heterogeneous HONO formation on soot particles sampled on filters (Arens et al, 2001). No impact of humidity on NO 2 uptake coefficients on pyrene was detected (Brigante et al, 2008). For HONO formation on tannic acid coatings (both at dark and irradiated conditions) a linear but relatively weak dependence has been reported between 10 and 60 % RH, while below 10 % and above 60 % RH the correlation between HONO formation and RH was much stronger (Sosedova et al, 2011).…”

Section: Rh Dependencymentioning

confidence: 94%

Light-induced protein nitration and degradation with HONO emission

et al. 2017

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Abstract. Proteins can be nitrated by air pollutants (NO 2 ), enhancing their allergenic potential. This work provides insight into protein nitration and subsequent decomposition in the presence of solar radiation. We also investigated lightinduced formation of nitrous acid (HONO) from protein surfaces that were nitrated either online with instantaneous gas-phase exposure to NO 2 or offline by an efficient nitration agent (tetranitromethane, TNM). Bovine serum albumin (BSA) and ovalbumin (OVA) were used as model substances for proteins. Nitration degrees of about 1 % were derived applying NO 2 concentrations of 100 ppb under VIS/UV illuminated conditions, while simultaneous decomposition of (nitrated) proteins was also found during long-term (20 h) irradiation exposure. Measurements of gas exchange on TNMnitrated proteins revealed that HONO can be formed and released even without contribution of instantaneous heterogeneous NO 2 conversion. NO 2 exposure was found to increase HONO emissions substantially. In particular, a strong dependence of HONO emissions on light intensity, relative humidity, NO 2 concentrations and the applied coating thickness was found. The 20 h long-term studies revealed sustained HONO formation, even when concentrations of the intact (nitrated) proteins were too low to be detected after the gas exchange measurements. A reaction mechanism for the NO 2 conversion based on the Langmuir-Hinshelwood kinetics is proposed.

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“…Previous studies have observed that γ can have a linear dependence on VIS and UV photon flux, but some measurements were limited in the VIS photon flux intensity compared to the sun's total VIS irradiance (Stemmler et al, 2006;Jammoul et al, 2008;Brigante et al, 2008;D'Anna et al, 2009;Baduel et al, 2011;Sosedova et al, 2011;Zelenay et al, 2011). Previous studies have also shown that the uptake of gas phase oxidants may follow a Langmuir-Hinshelwood (LH) type reaction mechanism, where the oxidant first adsorbs on the organic substrate and subsequently reacts, yielding γ values that are reduced at high oxidant concentrations (Stemmler et al, 2007;Jammoul et al, 2008;Brigante et al, 2008;D'Anna et al, 2009;Net et al, 2010;Baduel et al, 2011;Sosedova et al, 2011;Zelenay et al, 2011).…”

Section: S M Forrester and D A Knopf: Photosensitised Kinetics Ofmentioning

confidence: 99%

“…It has been shown experimentally that phenols can efficiently quench the excited triplet state of a photosensitiser, such as an aromatic carbonyl compound, in solution (Canonica et al, 1995;Anastasio et al, 1997;Canonica et al, 2000). However, it is expected that these types of reactions may be even more efficient at the surface of aerosol particles due to enhanced light intensity at the surface (Nissenson et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

Photosensitised heterogeneous oxidation kinetics of biomass burning aerosol surrogates by ozone using an irradiated rectangular channel flow reactor

Forrester

Knopf

2013

Atmos. Chem. Phys.

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Abstract. Heterogeneous reaction kinetics involving organic aerosol and atmospheric oxidants such as ozone can be enhanced under visible or UV irradiation in the presence of a photosensitiser, with subsequent implications for the climate, cloud radiative properties, air quality, and source appointment. In this study we report the steady-state reactive uptake coefficient, γ, of O3 by levoglucosan and 5-nitroguaiacol acting as surrogates for biomass burning aerosol particles, with and without the presence of Pahokee peat acting as a photosensitiser. The reactive uptake has been determined in the dark and as a function of visible and UV-A irradiation and ozone concentration. In addition, γ was determined for 1 : 1, 1 : 10, and 1 : 100 by mass mixtures of Pahokee peat and 5-nitroguaiacol, and for a 10 : 1 : 3 mixture of levoglucosan, Pahokee peat, and 5-nitroguaiacol. We developed a novel irradiated rectangular channel flow reactor (I-RCFR) that was operated under low pressures of about 2–4 hPa, and allowed for uniform irradiation of the organic substrates. The I-RCFR was coupled to a chemical ionisation mass spectrometer and has been successfully validated by measuring the kinetics between various organic species and oxidants. γ of O3 and levoglucosan in the dark and under visible and UV-A irradiation was determined to be in the range of (2–11) × 10−6 and did not change in the presence of Pahokee peat. The determined γ of O3 and 5-nitroguaiacol in the dark was 5.7 × 10−6 and was only enhanced under UV-A irradiation, yielding a value of 3.6 × 10−5. γ of the 1 : 1 Pahokee peat/5-nitroguaiacol substrate was enhanced under visible and UV-A irradiation to 2.4 × 10−5 and 2.8 × 10−5, respectively. Decreasing the amount of Pahokee peat in the 5-nitroguaiacol/Pahokee peat substrate resulted in lower values of γ under visible irradiation, however, γ was consistent under UV-A irradiation regardless of the amount of Pahokee peat. The 10 : 1 : 3 mixture by mass of levoglucosan, Pahokee peat, and 5-nitroguaiacol, under both visible and UV-A irradiation yielded γ values of 2.8 × 10−5 and 1.4 × 10−5, respectively. γ was determined as a function of photon flux for O3 with the 1 : 1 Pahokee peat/5-nitroguaiacol substrate, yielding a linear relationship under both visible and UV-A irradiation. γ of O3 with the 1 : 1 Pahokee peat/5-nitroguaiacol substrate was determined as a function of ozone concentration and exhibited an inverse dependence of γ on ozone concentration, commonly interpreted as a Langmuir–Hinshelwood mechanism. The reactive uptake data have been represented by a Langmuir-type isotherm. From the O3 uptake data under visible irradiation, the following fit parameters have been derived: ks = (5.5 ± 2.7) × 10−19 cm2 s−1 molecule−1 and KO3 = (2.3 ± 2.0) × 10−12 cm3 molecule−1; and under UV-A irradiation: ks = (8.1 ± 2.0) × 10−19 cm2 s−1 molecule−1 and KO3 = (1.7 ± 0.7) × 10−12 cm3 molecule−1. The oxidative power, or the product of γ and [O3], was determined for O3 with the 1 : 1 Pahokee peat/5-nitroguaiacol substrate and was in the range of (1.2–26) × 106 molecule cm−3. Atmospheric particle lifetimes were estimated for a 0.4 μm 5-nitroguaiacol particle as a function of visible and UV-A irradiation and ozone concentration.

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Photoenhanced Uptake of NO₂ by Pyrene Solid Films

Cited by 75 publications

References 42 publications

Modeling of daytime HONO vertical gradients during SHARP 2009

Modeling of daytime HONO vertical gradients during SHARP 2009

Light-induced protein nitration and degradation with HONO emission

Photosensitised heterogeneous oxidation kinetics of biomass burning aerosol surrogates by ozone using an irradiated rectangular channel flow reactor

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Photoenhanced Uptake of NO2 by Pyrene Solid Films

Cited by 75 publications

References 42 publications

Modeling of daytime HONO vertical gradients during SHARP 2009

Modeling of daytime HONO vertical gradients during SHARP 2009

Light-induced protein nitration and degradation with HONO emission

Photosensitised heterogeneous oxidation kinetics of biomass burning aerosol surrogates by ozone using an irradiated rectangular channel flow reactor

Contact Info

Product

Resources

About

Photoenhanced Uptake of NO₂ by Pyrene Solid Films