Chemical Transformation of α-Pinene derived Organosulfate via Heterogeneous OH Oxidation: Implications for Sources and Environmental Fates of Atmospheric Organosulfates

Abstract. Organosulfur compounds are found to be ubiquitous in atmospheric aerosols — a majority of which are expected to be organosulfates (OSs). Given the atmospheric abundance of OSs, and their potential to form a variety of reaction products upon ageing, it is imperative to study the transformation kinetics and chemistry of OSs to better elucidate their atmospheric fates and impacts. In this work, we investigated the chemical transformation of an α-pinene derived organosulfate (C10H17O5SNa, αpOS-249) through heterogeneous OH oxidation at a relative humidity of 50 % in an oxidation flow reactor (OFR). The aerosol-phase reaction products were characterized using the high-performance liquid chromatography-electrospray ionization-high resolution mass spectrometry and the ion chromatography. By monitoring the decay rates of αpOS-249, the effective heterogeneous OH reaction rate was measured to be (6.72 ± 0.55) × 10−13 cm3 molecule−1 s−1. This infers an atmospheric lifetime of about two weeks at an average OH concentration of 1.5 × 106 molecules cm–3. Product analysis shows that OH oxidation of αpOS-249 can yield more oxygenated OSs having a nominal mass-to-charge ratio (m/z) at 247 (C10H15O5S−), 263 (C10H15O6S−), 265 (C10H17O6S−), 277 (C10H13O7S−), 279 (C10H15O7S−), and 281 (C10H17O7S−). The formation of fragmentation products, including both small OSs (C < 10) and inorganic sulfates, is found to be insignificant. These observations suggest that functionalization reactions are likely the dominant processes and that multigenerational oxidation possibly leads to formation of products with one or two hydroxyl and carbonyl functional groups adding to αpOS-249. Furthermore, all product ions except m/z = 277 have been detected in laboratory generated α-pinene derived secondary organic aerosols as well as in atmospheric aerosols. Our results reveal that OSs freshly formed from the photochemical oxidation of α-pinene could react further to form OSs commonly detected in atmospheric aerosols through heterogeneous OH oxidation. Overall, this study provides more insights into the sources, transformation, and fate of atmospheric OSs.

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Chemical Composition of Gas and Particle Phase Products of Toluene Photooxidation Reaction under High OH Exposure Condition

Atmosphere ◽

10.3390/atmos12070915 ◽

2021 ◽

Vol 12 (7) ◽

pp. 915

Author(s):

Yik-Sze Lau ◽

Man-Nin Chan ◽

Hon-Yin Poon ◽

Yan Tan ◽

Shun-Cheng Lee ◽

...

Keyword(s):

Chemical Analysis ◽

Gas Phase ◽

Oxidation Reaction ◽

Particle Number ◽

Flow Reactor ◽

Exposure Condition ◽

Phase Reaction ◽

Reaction Products ◽

Toluene Photooxidation ◽

Photooxidation Reaction

In the current study, the photooxidation reaction of toluene (C7H8) was investigated in a Potential Aerosol Mass Oxidation Flow Reactor (PAM OFR). The hydroxyl radical (OH) exposure of toluene in the PAM OFR ranged from 0.4 to 1.4 × 1012 molec cm−3 s, which is equivalent to 3 to 12 days of atmospheric oxidation. A proton transfer reaction-mass spectrometer (PTR-MS) and a scanning mobility particle sizer (SMPS) were used to study the gas-phase products formed and particle number changes of the oxidation reaction in PAM OFR. The secondary organic aerosol (SOA) formed in the PAM OFR was also collected for off-line chemical analysis. Key gas-phase reaction products of toluene, including glyoxal, methyl glyoxal, unsaturated carbonyl compounds, and benzaldehyde, were identified by the PTR-MS. Second generation products, including acetic acid, formaldehyde, formic acid, and acetaldehyde, were also detected. By comparing the mass spectrums obtained under different OH exposures and relative humidity (RH), changes in the two parameters have minimal effects on the composition of gas-phase products formed, expect for the spectrum obtained at OH exposure of 0.4 × 1012 cm−3 s and RH = 17%, which is slightly different from other spectrums. SMPS results showed that particle mass concentration increases with increasing OH exposure, while particle number concentration first increases and then decreases with increasing OH exposure. This result probably suggests the formation of oligomers at high OH exposure conditions. Off-line chemical analysis of the SOA sample was dominated by C4 diacids, including malic acid, citramalic acid, and tartaric acid. The well-known toluene SOA marker 2,3-Dihydroxy-4-oxopentanoic acid, as well as 2,3-dihydroxyglutaric acid, which has not been identified in previous toluene photooxidation experiments, were also detected in the SOA sample. Our results showed good agreements with the results of previous smog chamber studies of toluene photooxidation reaction, and they suggested that using PAM OFR for studies of oxidation reaction of different VOCs can be atmospherically relevant.

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Hydrogenolysis of glucose and fructose in glycol solutions over CuO-MgO-ZrO2 catalyst

Catalysis and petrochemistry ◽

10.15407/kataliz2020.30.048 ◽

2020 ◽

pp. 48-55

Author(s):

M.E. Sharanda ◽

◽

E.A. Bondarenko ◽

Keyword(s):

Ethylene Glycol ◽

Propylene Glycol ◽

Flow Reactor ◽

General Trend ◽

Raw Materials ◽

Reaction Products ◽

Renewable Raw Materials ◽

High Partial Pressure ◽

Zro2 Catalyst ◽

Phase Process

Ethylene glycol and propylene glycol are important representatives of polyols. On an industrial scale, they are obtained from petrochemical raw materials. Within a decade, significant efforts were made for the producing of polyols from biologically renewable raw materials - carbohydrates. The general trend for carbohydrate hydrogenolysis includes application of liquid-phase process with the use of modified metal-oxide catalysts, at 120-120 ° C and pressure of 3MPa or above. So high pressure is used for the reason to increase hydrogen solubility, and also due to the high partial pressure of low boiling solvents. We supposed that usage of high boiling solvents could allow hydrogenolysis to be performed at the lower pressure. Ethylene glycol and propylene glycol are of particular interest as such kind of solvent since they are both the main products of glucose hydrogenolysis. In this work, the process of hydrogenolysis of glucose and fructose over Cu / MgO-ZrO2 catalyst have been studied at temperature range of 160-200 °C and a pressure of 0.1-0.3 MPa in a flow reactor. The solvents were simultaneously the target products of the reaction - ethylene glycol and / or propylene glycol. Gas chromatography and 13C NMR were used for the reaction products identification. It was found that the solubility of glucose in propylene glycol is 21 % by weight, and in ethylene glycol 62% by weight. It was pointed out that the process of hydrogenolysis can take place at a pressure close to atmospheric. Under these conditions, the conversion of hexoses reaches 96-100 %. The reaction products are preferably propylene glycol and ethylene glycol. The total selectivity for C3-2 polyols is 90-94 %, that is higher than in the hydrogenolysis of glucose in aqueous solution.

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Kinetics of the catalytic hydrodesulphurization reaction system; hydrogenolysis of thiophene

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19802728 ◽

1980 ◽

Vol 45 (10) ◽

pp. 2728-2741 ◽

Cited By ~ 7

Author(s):

Pavel Fott ◽

Petr Schneider

Keyword(s):

Atmospheric Pressure ◽

Active Sites ◽

Flow Reactor ◽

Kinetic Equations ◽

Reaction System ◽

Reaction Products ◽

Molybdenum Catalyst ◽

Cobalt Molybdenum Catalyst ◽

Kinetics Of ◽

Reaction Schemes

Kinetics have been studied of the reaction system taking place during the reaction of thiophene on the cobalt-molybdenum catalyst in a gradientless circulation flow reactor at 360 °C and atmospheric pressure. Butane has been found present in a small amount in the reaction products even at very low conversion. In view of this, consecutive and parallel-consecutive (triangular) reaction schemes have been proposed. In the former scheme the appearance of butane is accounted for by rate of desorption of butene being comparable with the rate of its hydrogenation. According to the latter scheme part of the butane originates from thiophene via a different route than through hydrogenation of butene. Analysis of the kinetic data has revealed that the reaction of thiophene should be considered to take place on other active sites than that of butene. Kinetic equations derived on this assumption for the consecutive and the triangular reaction schemes correlate experimental data with acceptable accuracy.

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New Insights into the Kinetics of the Gas-Phase Oxidation of Hexafluoropropene

Progress in Reaction Kinetics and Mechanism ◽

10.3184/174751916x14764433065222 ◽

2016 ◽

Vol 41 (4) ◽

pp. 418-427 ◽

Cited By ~ 1

Author(s):

David Lokhat ◽

Maciej Starzak ◽

Deresh Ramjugernath

Keyword(s):

Gas Phase ◽

Oxidation Process ◽

Flow Reactor ◽

Packed Column ◽

Phase Reaction ◽

Analytical Technique ◽

Tubular Flow Reactor ◽

Gas Phase Oxidation ◽

Tubular Flow ◽

Kinetics Of

The gas-phase reaction of hexafluoropropene and molecular oxygen was investigated in a tubular flow reactor at 450 kPa and within a temperature range of 463–493 K using HFP/O2 mixtures containing 20–67% HFP on a molar basis. Capillary and packed column chromatography served as the main analytical technique. The reaction yielded HFPO, COF2, CF3COF, C2F4 and c-C3F6 as gas-phase products. High molecular weight oligomers were also formed. The oligomers were found to have a polyoxadifluoromethylene structure according to elemental and 19F NMR analysis. At 493 K HFP is proposed to undergo oxygen-mediated decomposition to difluorocarbene radicals, yielding greater quantities of difluorocarbene recombination products. Kinetic parameters for a revised model of the oxidation process were identified through least squares analysis of the experimental data.

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Pressure dependent low temperature kinetics for CN + CH3CN: competition between chemical reaction and van der Waals complex formation

Physical Chemistry Chemical Physics ◽

10.1039/c6cp01982j ◽

2016 ◽

Vol 18 (22) ◽

pp. 15118-15132 ◽

Cited By ~ 14

Author(s):

Chantal Sleiman ◽

Sergio González ◽

Stephen J. Klippenstein ◽

Dahbia Talbi ◽

Gisèle El Dib ◽

...

Keyword(s):

Low Temperature ◽

Complex Formation ◽

Gas Phase ◽

Rate Coefficient ◽

Flow Reactor ◽

Slow Flow ◽

Phase Reaction ◽

Gas Phase Reaction ◽

Low Temperature Kinetics ◽

Temperature And Pressure

The gas phase reaction between the CN radical and acetonitrile CH3CN was investigated experimentally with a CRESU apparatus and a slow flow reactor as well as theoretically to explore the temperature and pressure dependence of its rate coefficient from 354 K down to 23 K.

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Gas-phase reaction products and yields of terpinolene with ozone and nitric oxide using a new derivatization agent

Atmospheric Environment ◽

10.1016/j.atmosenv.2015.10.015 ◽

2015 ◽

Vol 122 ◽

pp. 513-520 ◽

Cited By ~ 7

Author(s):

Jason E. Ham ◽

Stephen R. Jackson ◽

Joel C. Harrison ◽

J.R. Wells

Keyword(s):

Nitric Oxide ◽

Gas Phase ◽

Phase Reaction ◽

Reaction Products ◽

Gas Phase Reaction

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Heterogeneous oxidation of saturated organic aerosols by hydroxyl radicals: Uptake kinetics and condensed-phase products

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-7-6803-2007 ◽

2007 ◽

Vol 7 (3) ◽

pp. 6803-6842 ◽

Cited By ~ 2

Author(s):

I. J. George ◽

A. Vlasenko ◽

J. G. Slowik ◽

J. P. D. Abbatt

Keyword(s):

Hydroxyl Radicals ◽

Particle Density ◽

Organic Aerosols ◽

Oxidation Products ◽

Photochemical Oxidation ◽

Mass Spectrometry Analysis ◽

Oh Radicals ◽

Ionization Mass ◽

Phase Reaction ◽

Heterogeneous Oxidation

Abstract. The kinetics and reaction mechanism for the heterogeneous oxidation of saturated organic aerosols by gas-phase OH radicals were investigated under NOx-free conditions. The reaction of 150 nm diameter Bis(2-ethylhexyl) sebacate (BES) particles with OH was studied as a proxy for chemical aging of atmospheric aerosols containing saturated organic matter. An aerosol reactor flow tube combined with an Aerodyne time-of-flight aerosol mass spectrometer (ToF-AMS) and scanning mobility particle sizer (SMPS) was used to study this system. Hydroxyl radicals were produced by 254 nm photolysis of O3 in the presence of water vapour. The kinetics of the heterogeneous oxidation of the BES particles was studied by monitoring the loss of a mass fragment of BES with the ToF-AMS as a function of OH exposure. We measured an initial OH uptake coefficient of γ0 = 1.26 (±0.04), confirming that this reaction is highly efficient. The density of BES particles increased by up to 20% of the original BES particle density at the highest OH exposure studied, consistent with the particle becoming more oxidized. Electrospray ionization mass spectrometry analysis showed that the major particle-phase reaction products are multifunctional carbonyls and alcohols with higher molecular weights than the starting material. Volatilization of oxidation products accounted for a maximum of 17% decrease of the particle volume at the highest OH exposure studied. Tropospheric organic aerosols will become more oxidized from heterogeneous photochemical oxidation, which may affect not only their physical and chemical properties, but also their hygroscopicity and cloud nucleation activity.

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Preparation of isocyanates by carbamates thermolysis on the example of butyl isocyanate

Butlerov Communications ◽

10.37952/roi-jbc-01/19-58-4-40 ◽

2019 ◽

Vol 58 (4) ◽

pp. 40-47

Author(s):

Ratmir R. Dashkin ◽

◽

Dmitry A. Gordeev ◽

Khusrav Kh. Gafurov ◽

Sergey N. Mantrov ◽

...

Keyword(s):

Gas Phase ◽

High Performance ◽

Gas Flow ◽

Flow Reactor ◽

Packed Column ◽

Biologically Active ◽

Dibutyltin Dilaurate ◽

Reaction Products ◽

Uv Detector ◽

Laboratory Setup

Butyl isocyanate is widely distributed as a precursor for the production of a number of biologically active substances: fungicides, preservatives, insecticides, personal care products, etc. Nowadays, there are a number of methods for the preparation of isocyanates, which can be divided into liquid phase and gas phase. One of the perspective methods for the production of isocyanates is the thermolysis of carbamate and/or the actions of various reaction activating agents, accompanied by the elimination of alcohol, but this process is reversible, which greatly complicates its use in industry. The paper presents the results of studies of non-catalytic thermal decomposition of N-alkylcarbamates with the formation of alkylisocyanates on the example of butylisocyanate in the gas phase, flow reactor in a wide temperature range (200 to 450 °C). In addition, a series of experiments was carried out using a catalyst, dibutyltin dilaurate, in order to reduce the thermolysis temperature and increase the yield of the final product. To implement the isocyanate production process, an experimental laboratory setup, consisting of a gas flow meter (argon) regulator, a packed column (for heating) and a sorption solution tank, was developed and tested. The thermolysis of N-n-butylcarbamate was carried out in two variations: the preparation of an individual n-butylisocyanate and the passage of reaction products through a sorption solution linking the n-butyl isocyanate to N-n-butyl-N '-(1-phenylethyl)urea, which allows to estimate the yield of the target n-butylisocyanate without additional losses. The analysis of the obtained substances was carried out by high performance liquid chromatography with a UV detector (target product) and a mass detector (analysis of by-products). According to the results of research, a modification of the laboratory facility was proposed, as well as n-butylisocyanate was obtained with a yield of 49% on the basis of a new technique.

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Volatility and lifetime against OH heterogeneous reaction of ambient Isoprene Epoxydiols-Derived Secondary Organic Aerosol (IEPOX-SOA)

10.5194/acp-2016-418 ◽

2016 ◽

Cited By ~ 2

Author(s):

Weiwei Hu ◽

Brett B. Palm ◽

Douglas A. Day ◽

Pedro Campuzano-Jost ◽

Jordan E. Krechmer ◽

...

Keyword(s):

Flow Reactor ◽

Secondary Organic Aerosol ◽

Heterogeneous Reaction ◽

Ambient Air ◽

Organic Aerosol ◽

Amazon Forest ◽

Reaction Products ◽

Ambient Conditions ◽

Forested Areas ◽

Humidity Dependence

Abstract. Isoprene epoxydiols-derived secondary organic aerosol (IEPOX-SOA) can contribute substantially to organic aerosol (OA) concentrations in forested areas under low NO conditions, hence significantly influencing the regional and global OA budgets, accounting for example for 16–36 % of the submicron OA in the SE US summer. Particle evaporation measurements from a thermodenuder show that the volatility of ambient IEPOX-SOA is lower than that of bulk OA and also much lower than that of known monomer IEPOX-SOA tracer species, indicating that IEPOX-SOA likely exists mostly as oligomers in the aerosol phase. The OH aging process of ambient IEPOX-SOA was investigated with an oxidation flow reactor (OFR). New IEPOX-SOA formation in the reactor was negligible, as the OFR cannot accelerate processes such as aerosol uptake and reactions that do not scale with OH. Simulation results indicate that adding ~ 100 µg m−3 of pure H2SO4 to the ambient air allows to efficiently form IEPOX-SOA in the reactor. The heterogeneous reaction rate coefficient of ambient IEPOX-SOA with OH radical (kOH) was estimated as 4.0 ± 2.0 × 10−13 cm3 molec−1 s−1, which is equivalent to more than a 2-week lifetime. A similar kOH was found for measurements of OH oxidation of ambient Amazon forest air in an OFR. At higher OH exposures in the reactor (> 1 × 1012 molec. cm−3 s), the mass loss of IEPOX-SOA due to heterogeneous reaction was mainly due to revolatilization of fragmented reaction products. We report for the first time OH reactive uptake coefficients (γOH = 0.59 ± 0.33 in SE US and γOH = 0.68 ± 0.38 in Amazon) for SOA under ambient conditions. A relative humidity dependence of kOH and γOH was observed, consistent with surface area-limited OH uptake. No decrease of kOH was observed as OH concentrations increased. These observation of physicochemical properties of IEPOX-SOA can help to constrain OA impact on air quality and climate.

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Oxidative Dehydrogenation of Propane over Vanadium-Containing Faujasite Zeolite

Molecules ◽

10.3390/molecules25081961 ◽

2020 ◽

Vol 25 (8) ◽

pp. 1961 ◽

Cited By ~ 3

Author(s):

Małgorzata Smoliło ◽

Katarzyna Samson ◽

Ting Zhou ◽

Dorota Duraczyńska ◽

Małgorzata Ruggiero-Mikołajczyk ◽

...

Keyword(s):

Oxidative Dehydrogenation ◽

Gas Flow ◽

Flow Reactor ◽

Fixed Bed ◽

Oxidative Dehydrogenation Of Propane ◽

Reaction Products ◽

Promising Alternative ◽

Vis Spectroscopy ◽

Gas Flow Reactor ◽

Faujasite Zeolite

Oxidative dehydrogenation (ODH) of light alkanes to olefins—in particular, using vanadium-based catalysts—is a promising alternative to the dehydrogenation process. Here, we investigate how the activity of the vanadium phase in ODH is related to its dispersion in porous matrices. An attempt was made to synthesize catalysts in which vanadium was deposited on a microporous faujasite zeolite (FAU) with the hierarchical (desilicated) FAU as supports. These yielded different catalysts with varying amounts and types of vanadium phase and the porosity of the support. The phase composition of the catalysts was confirmed by X-ray diffraction (XRD); low temperature nitrogen sorption experiments resulted in their surface area and pore volumes, and reducibility was measured with a temperature-programmed reduction with a hydrogen (H2-TPR) method. The character of vanadium was studied by UV-VIS spectroscopy. The obtained samples were subjected to catalytic tests in the oxidative dehydrogenation of propane in a fixed-bed gas flow reactor with a gas chromatograph to detect subtract and reaction products at a temperature range from 400–500 °C, with varying contact times. The sample containing 6 wt% of vanadium deposited on the desilicated FAU appeared the most active. The activity was ascribed to the presence of the dispersed vanadium ions in the tetragonal coordination environment and support mesoporosity.

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