Heterogeneous Photochemical Sources of Atomic Cl in the Troposphere

Zetzsch, Cornelius; Behnke, Wolfgang

doi:10.1002/bbpc.19920960351

Cited by 83 publications

(58 citation statements)

References 23 publications

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“…Similar reactions occur also on airborne aerosol surfaces [Behnke and Zetzsch, 1989b]. Further experiments showed that C1NO2 is produced from the reaction of N205 on moist NaC1 aerosol surfaces [Behnke and Zetzsch, 1990;Zetzsch and Behnke, 1992]. Here we describe smog chamber and wetted-wall flow tube experiments, which evaluate the uptake of N20 5 and C1NO2 on water and NaC1 solutions and the C1NO2 yield of the reaction of N20 5 on wet NaC1 aerosol and bulk surfaces.…”

Section: Introductionmentioning

confidence: 92%

Production and decay of ClNO₂ from the reaction of gaseous N₂O₅ with NaCl solution: Bulk and aerosol experiments

Behnke¹,

George²,

Scheer³

et al. 1997

J. Geophys. Res.

313

503

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Abstract. The chemistry of N20 5 on liquid NaC1 aerosols or bulk NaC1 solutions was studied at 291 K by aerosol smog chamber and wetted-wall flow tube experiments. The uptake of N20 5 on deliquescent aerosol was obtained to be (3.2 + 0.2) x 10 -2 (lrr error) from the aerosol experiments. In the wetted-wall flow tube we observed that nitryl chloride (C1NO2) is the main product of the reaction at NaC1 concentrations larger than approximately 0.5 M and almost the only product at concentrations larger than I M. The C1NO: yield does not depend linearly on the NaC1 concentration, especially at small sodium chloride concentrations (i.e., smaller than 1 M). It appeared that a simple C1-) is unable to explain the observed concentration dependence of the product yield. We propose that N20 s dissociates to NO•-and NO•-(rate constant k I > 10 • s -•) mainly. The directly hydrolysis of N20 s (k3[H20]) is less than 20% of the total reaction. NO•-reacts with water to form 2H + and NO• (ks) or with C1-to form C1NO 2 (k4).Neglecting the influence of ionic strength we evaluate k4/k s to be 836 __ 32 (lo-error). Using the wetted-wall flow tube technique, we studied the uptake of nitryl chloride by aqueous solutions containing NaC1. We observed that the uptake coetScient 3• decreased from (4.84 +_ 0.13) x 10 -6 on pure water to (0.27 _+ 0.02) x 10 -6 on a 4.6 M NaC1

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Section: Introductionmentioning

confidence: 92%

Production and decay of ClNO₂ from the reaction of gaseous N₂O₅ with NaCl solution: Bulk and aerosol experiments

Behnke¹,

George²,

Scheer³

et al. 1997

J. Geophys. Res.

313

503

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“…A multi-reflection cell (White-cell) coupled with DOAS was used to observe BrO levels directly. The concentrations of OH and Cl radicals were quantified indirectly by monitoring the decay of several hydrocarbons using the radical clock method (Zetzsch and Behnke, 1992). For details on the experimental setup, the analytical methods used and results about RHS release from the salt pan in the absence of SOA, see Buxmann et al (2012).…”

Section: Photochemical Activation Salt-pan Experimentsmentioning

confidence: 99%

“…The formation of even simpler molecules like phosgene, chloroacetone and 1,1-dichloroacetone after interaction of hydrocarbons with halogens released from NaCl aerosol was found by Zetzsch and Behnke (1992) in aerosol smogchamber experiments. A detailed review on these formation pathways is given by Behnke and Zetzsch (2005).…”

Section: Introductionmentioning

confidence: 96%

Halogenation processes of secondary organic aerosol and implications on halogen release mechanisms

et al. 2012

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Abstract. Reactive halogen species (RHS), such as X·, X 2 and HOX containing X = chlorine and/or bromine, are released by various sources like photo-activated sea-salt aerosol or from salt pans, and salt lakes. Despite many studies of RHS reactions, the potential of RHS reacting with secondary organic aerosol (SOA) and organic aerosol derived from biomass-burning (BBOA) has been neglected. Such reactions can constitute sources of gaseous organohalogen compounds or halogenated organic matter in the tropospheric boundary layer and can influence physicochemical properties of atmospheric aerosols.Model SOA from α-pinene, catechol, and guaiacol was used to study heterogeneous interactions with RHS. Particles were exposed to molecular chlorine and bromine in an aerosol smog-chamber in the presence of UV/VIS irradiation and to RHS, released from simulated natural halogen sources like salt pans. Subsequently, the aerosol was characterized in detail using a variety of physicochemical and spectroscopic methods. Fundamental features were correlated with heterogeneous halogenation, which results in new functional groups (FTIR spectroscopy), changes UV/VIS absorption, chemical composition (ultrahigh resolution mass spectroscopy (ICR-FT/MS)), or aerosol size distribution. However, the halogen release mechanisms were also found to be affected by the presence of organic aerosol. Those interaction processes, changing chemical and physical properties of the aerosol are likely to influence e.g. the ability of the aerosol to act as cloud condensation nuclei, its potential to adsorb other gases with low-volatility, or its contribution to radiative forcing and ultimately the Earth's radiation balance.

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“…However, if chloride ions are present, there is a competition between the reactions of NO 2 + with water and Cl À , and ClNO 2 is generated: 3,5,8,[10][11][12][13][14][15][16] …”

Section: Introductionmentioning

confidence: 99%

“…In the former case, the HNO 3 product can react further with NaCl [11][12][13][14][15][16][17][18]20,[22][23][24][25][26][27][28][29][30][31][32][33][34] to generate HCl.…”

Section: Introductionmentioning

confidence: 99%

Knudsen cell studies of the reactions of N2O5 and ClONO2 with NaCl: development and application of a model for estimating available surface areas and corrected uptake coefficients

Hoffman

Gebel

Fox

et al. 2003

Phys. Chem. Chem. Phys.

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The reaction of gaseous N 2 O 5 with sea salt and its components is a potential source of halogen atoms in the marine boundary layer. There are two possible reaction paths when water is present on the salt surface. Reaction with the chloride ion forms nitryl chloride (ClNO 2 ), a photolyzable compound: N 2 O 5 + NaCl ! ClNO 2 + NaNO 3 , while hydrolysis of N 2 O 5 generates HNO 3 that can react further with NaCl to form gaseous HCl: N 2 O 5 + H 2 O (on NaCl) ! 2 HNO 3 , HNO 3 + NaCl ! HCl + NaNO 3 . We report here Knudsen cell studies at 23 C of the reaction of N 2 O 5 with NaCl, using less than one layer of salt particles. A model, which takes into account the effective salt surface area exposed to the gas, was applied, allowing for the determination of uptake coefficients without introducing uncertainties associated with diffusion into multiple layers of salt particles. The net uptake coefficient for the sum of both channels for the N 2 O 5 reaction was measured to be g N 2 O 5 ¼ (2.9 AE 1.7) Â 10 À3, where the error cited is the 2s statistical error. The cumulative error is estimated to be better than a factor of three. Both ClNO 2 and HCl were observed as gaseous products from the N 2 O 5 -salt reaction and the branching ratio for ClNO 2 was 0.73 AE 0.28 (2s). A limited number of experiments were carried out for the reaction with synthetic sea salt, resulting in an uptake coefficient of about an order of magnitude larger than for NaCl, and a ClNO 2 yield of 100%. We propose a mechanism for this reaction in which surfaceadsorbed water plays a key role in the competition between hydrolysis of N 2 O 5 to generate HNO 3 and the reaction with NaCl to generate ClNO 2 . Reaction with NaCl is shown to be a potentially important source of ClNO 2 , and thus, of highly reactive chlorine atoms in urban marine regions at dawn. Application of our model to previous data from this laboratory for the reaction of chlorine nitrate (ClONO 2 ) with fractional layers of NaCl gives a corrected uptake coefficient of g ClONO 2 ¼ (2.4 AE 1.2) Â 10 À2 (2s), which suggests that the ClONO 2 -NaCl reaction may contribute significantly to the observed concentrations of Cl 2 in the marine boundary layer.

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Heterogeneous Photochemical Sources of Atomic Cl in the Troposphere

Cited by 83 publications

References 23 publications

Production and decay of ClNO₂ from the reaction of gaseous N₂O₅ with NaCl solution: Bulk and aerosol experiments

Production and decay of ClNO₂ from the reaction of gaseous N₂O₅ with NaCl solution: Bulk and aerosol experiments

Halogenation processes of secondary organic aerosol and implications on halogen release mechanisms

Knudsen cell studies of the reactions of N2O5 and ClONO2 with NaCl: development and application of a model for estimating available surface areas and corrected uptake coefficients

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Heterogeneous Photochemical Sources of Atomic Cl in the Troposphere

Cited by 83 publications

References 23 publications

Production and decay of ClNO2 from the reaction of gaseous N2O5 with NaCl solution: Bulk and aerosol experiments

Production and decay of ClNO2 from the reaction of gaseous N2O5 with NaCl solution: Bulk and aerosol experiments

Halogenation processes of secondary organic aerosol and implications on halogen release mechanisms

Knudsen cell studies of the reactions of N2O5 and ClONO2 with NaCl: development and application of a model for estimating available surface areas and corrected uptake coefficients

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Production and decay of ClNO₂ from the reaction of gaseous N₂O₅ with NaCl solution: Bulk and aerosol experiments

Production and decay of ClNO₂ from the reaction of gaseous N₂O₅ with NaCl solution: Bulk and aerosol experiments