The Kinetics of the Decomposition of Gaseous Glyoxal

Steacie, E. W. R.; Hatcher, W. H.; Horwood, J. F.

doi:10.1063/1.1749655

Cited by 15 publications

(4 citation statements)

References 6 publications

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“…Glyoxal is also known to polymerize at the temperatures needed for volatilization. As an alternative, solid glyoxal trimeric dihydrate (Aldrich) was dehydrated as described elsewhere (32) to yield gas-phase, monomeric glyoxal, which was flushed directly into the chamber via a stream of clean air. Once exposed to the interior Teflon surface, the glyoxal formed a visible film on this surface which continuously off-gassed glyoxal in the free monomeric form.…”

Section: Methodsmentioning

confidence: 99%

Heterogeneous Reactions of Glyoxal on Particulate Matter: Identification of Acetals and Sulfate Esters

Liggio

McLaren

2005

Environ. Sci. Technol.

326

387

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Reactive uptake of glyoxal onto particulate matter has been studied in laboratory experiments in a 2 m3 Teflon reaction chamber. Inorganic seed particles of different composition were utilized, including (NH4)2SO4, (NH4)2SO4/ H2SO4, NaNO3, and simulated sea salt, while the relative humidity and acid concentration were varied. The organic composition of the growing particles was measured in situ with an aerosol mass spectrometer, providing particle mass spectra as a means of product identification. Aerosol physical characteristics were also measured with a differential mobility analyzer and condensation nucleus counter. Regardless of seed composition, particle growth was rapid and continuous over the course of several hours. Identification of several mass fragments greater than the glyoxal monomer suggested that heterogeneous reactionsto form glyoxal adducts of lowvolatility had occurred. Temporal analysis of the mass fragments was consistent with a proposed acid-catalyzed mechanism whereby glyoxal is first hydrated, followed by self-reaction to form cyclic acetal structures. Increased relative humidity slowed the formation of higher order oligomers, also consistent with the proposed mechanism. The relative contribution of various oligomers to the overall organic composition was strongly dependent on the relative humidity and hence the particulate water concentration. A mild acid catalysis was also observed upon increasing the acidity of the seed particles. Specific mass fragments were found that could only arise from sulfate esters and were not present on the non-sulfur-containing seed particles. This first evidence of the formation of organic sulfates in particles is presented together with a proposed mechanism and molecular structure. These results suggest that the formation of these products of glyoxal uptake can contribute significantly to secondary organic aerosol.

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Section: Methodsmentioning

confidence: 99%

Heterogeneous Reactions of Glyoxal on Particulate Matter: Identification of Acetals and Sulfate Esters

Liggio

McLaren

2005

Environ. Sci. Technol.

326

387

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“…[7] Gaseous glyoxal was produced by dehydration of the commercially available solid glyoxal trimeric dihydrate (Aldrich) as described elsewhere [Steacie et al, 1935]. This yielded gas phase monomeric glyoxal, which was flushed directly into the chamber via a stream of clean air.…”

Section: Experimental Descriptionmentioning

confidence: 99%

Reactive uptake of glyoxal by particulate matter

Li²,

2005

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[1] The uptake of gaseous glyoxal onto particulate matter has been studied in laboratory experiments under conditions relevant to the ambient atmosphere using an aerosol mass spectrometer. The growth rates and reactive uptake coefficients, g, were derived by fitting a model of particle growth to the experimental data. Organic growth rates varied from 1.05 Â 10 À11 to 23.1 Â 10 À11 mg particle À1 min À1 in the presence of $5 ppb glyoxal. Uptake coefficients (g) of glyoxal varied from 8.0 Â 10 À4 to 7.3 Â 10 À3 with a median g = 2.9 Â 10 À3 , observed for (NH 4 ) 2 SO 4 seed aerosols at 55% relative humidity.Increased g values were related to increased particle acidity, indicating that acid catalysis played a role in the heterogeneous mechanism. Experiments conducted at very low relative humidity, with the potential to be highly acidic, resulted in very low reactive uptake. These uptake coefficients indicated that the heterogeneous loss of glyoxal in the atmosphere is at least as important as gas phase loss mechanisms, including photolysis and reaction with hydroxyl radicals. Glyoxal lifetime due to heterogeneous reactions under typical ambient conditions was estimated to be t het = 5-287 min. In rural and remote areas the glyoxal uptake can lead to 5-257 ng m À3 of secondary organic aerosols in 8 hours, consistent with recent ambient measurements.Citation: Liggio, J., S.-M. Li, and R. McLaren (2005), Reactive uptake of glyoxal by particulate matter,

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“…The oxidation chemistry of glyoxal (OCHCHO) is of interest, partly because it is recognized as an intermediate in combustion of hydrocarbons and partly because glyoxal has been identified as a promising HCO high-temperature source for shock tube measurements. , Moreover, glyoxal is discussed as an important component in tropospheric chemistry. , Glyoxal can be formed from oxidation of C 2 H 2 at low to medium temperatures, − as well as in the atmosphere, − mostly through the chain-propagating sequence Previous studies of OCHCHO chemistry include thermal decomposition in static reactors and shock tubes , as well as low-temperature oxidation − and determination of explosion limits in static reactors . Also, data on the low-temperature oxidation of glyoxal by H 2 O 2 and NO 2 have been reported.…”

Section: Introductionmentioning

confidence: 99%

“…1,2 Moreover, glyoxal is discussed as an important component in tropospheric chemistry. 3,4 Glyoxal can be formed from oxidation of C 2 H 2 at low to medium temperatures, 5−9 as well as in the atmosphere, 10 Previous studies of OCHCHO chemistry include thermal decomposition in static reactors 17 and shock tubes 18,19 as well as low-temperature oxidation 20−22 and determination of explosion limits in static reactors. 23 Also, data on the lowtemperature oxidation of glyoxal by H 2 O 2 24 and NO 2 25 have been reported.…”

Section: ■ Introductionmentioning

confidence: 99%

Glyoxal Oxidation Mechanism: Implications for the Reactions HCO + O₂ and OCHCHO + HO₂

et al. 2015

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A detailed mechanism for the thermal decomposition and oxidation of the flame intermediate glyoxal (OCHCHO) has been assembled from available theoretical and experimental literature data. The modeling capabilities of this extensive mechanism have been tested by simulating experimental HCO profiles measured at intermediate and high temperatures in previous glyoxal photolysis and pyrolysis studies. Additionally, new experiments on glyoxal pyrolysis and oxidation have been performed with glyoxal and glyoxal/oxygen mixtures in Ar behind shock waves at temperatures of 1285−1760 K at two different total density ranges. HCO concentration−time profiles have been detected by frequency modulation spectroscopy at a wavelength of λ = 614.752 nm. The temperature range of available direct rate constant data of the hightemperature key reaction HCO + O 2 → CO + HO 2 has been extended up to 1705 K and confirms a temperature dependence consistent with a dominating direct abstraction channel. Taking into account available literature data obtained at lower temperatures, the following rate constant expression is recommended over the temperature range 295 K < T < 1705 K: k 1 /(cm 3 mol −1 s −1 ) = 6.92 × 10 6 × T 1.90 × exp(+5.73 kJ/mol/RT). At intermediate temperatures, the reaction OCHCHO + HO 2 becomes more important. A detailed reanalysis of previous experimental data as well as more recent theoretical predictions favor the formation of a recombination product in contrast to the formerly assumed dominating and fast OH-forming channel. Modeling results of the present study support the formation of HOCH(OO)CHO and provide a 2 orders of magnitude lower rate constant estimate for the OH channel. Hence, low-temperature generation of chain carriers has to be attributed to secondary reactions of HOCH(OO)CHO.

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The Kinetics of the Decomposition of Gaseous Glyoxal

Cited by 15 publications

References 6 publications

Heterogeneous Reactions of Glyoxal on Particulate Matter: Identification of Acetals and Sulfate Esters

Heterogeneous Reactions of Glyoxal on Particulate Matter: Identification of Acetals and Sulfate Esters

Reactive uptake of glyoxal by particulate matter

Glyoxal Oxidation Mechanism: Implications for the Reactions HCO + O₂ and OCHCHO + HO₂

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The Kinetics of the Decomposition of Gaseous Glyoxal

Cited by 15 publications

References 6 publications

Heterogeneous Reactions of Glyoxal on Particulate Matter: Identification of Acetals and Sulfate Esters

Heterogeneous Reactions of Glyoxal on Particulate Matter: Identification of Acetals and Sulfate Esters

Reactive uptake of glyoxal by particulate matter

Glyoxal Oxidation Mechanism: Implications for the Reactions HCO + O2 and OCHCHO + HO2

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Glyoxal Oxidation Mechanism: Implications for the Reactions HCO + O₂ and OCHCHO + HO₂