scholarly journals Atmospheric fate of two relevant unsaturated ketoethers: kinetics, products and mechanisms for the reaction of hydroxyl radicals with (<i>E</i>)-4-methoxy-3-buten-2-one and (1<i>E</i>)-1-methoxy-2-methyl-1-penten-3-one

2020 ◽  
Vol 20 (14) ◽  
pp. 8939-8951
Author(s):  
Rodrigo Gastón Gibilisco ◽  
Ian Barnes ◽  
Iustinian Gabriel Bejan ◽  
Peter Wiesen
Keyword(s):  
Hydroxyl Radicals ◽  
Relative Rate ◽  
Reaction Chamber ◽  
Oxidation Products ◽  
Rate Coefficients ◽  
Main Reaction ◽  
Reaction Products ◽  
Gas Phase Reactions ◽  
Nitrogen Containing Compounds ◽  
First Time

Abstract. The kinetics of the gas phase reactions of hydroxyl radicals with two unsaturated ketoethers (UKEs) at (298±3) K and 1 atm of synthetic air have been studied for the first time using the relative-rate technique in an environmental reaction chamber by in situ Fourier-transform infrared spectroscopy (FTIR). The rate coefficients obtained using propene and isobutene as reference compounds were (in units of 10−10 cm3 molecule−1 s−1) as follows: kTMBO (OH + (E)-4-methoxy-3-buten-2-one)  =  (1.41±0.11) and kMMPO (OH + (1E)-1-methoxy-2-methyl-1-penten-3-one)  =  (3.34±0.43). In addition, quantification of the main oxidation products in the presence of NOx has been performed, and degradation mechanisms for these reactions were developed. Methyl formate, methyl glyoxal, peroxyacetyl nitrate (PAN) and peroxypropionyl nitrate (PPN) were identified as main reaction products and quantified for both reactions. The results of the present study provide new insights regarding the contribution of these multifunctional volatile organic compounds (VOCs) in the generation of secondary organic aerosols (SOAs) and long-lived nitrogen containing compounds in the atmosphere. Atmospheric lifetimes and implications are discussed in light of the obtained results.

scholarly journals Atmospheric fate of two relevant unsaturated ketoethers: kinetics, products and mechanisms for the reaction of hydroxyl radicals with (<i>E</i>)-4-methoxy-3-buten-2-one and 1-(<i>E</i>)-1-methoxy-2-methyl-1-penten-3-one

2020 ◽  
Author(s):  
Rodrigo Gastón Gibilisco ◽  
Ian Barnes ◽  
Iustinian Gabriel Bejan ◽  
Peter Wiesen
Keyword(s):  
Gas Phase ◽  
Hydroxyl Radicals ◽  
Relative Rate ◽  
Reaction Chamber ◽  
Oxidation Products ◽  
Rate Coefficients ◽  
Gas Phase Reactions ◽  
Ozone Formation Potential ◽  
Nitrogen Containing Compounds ◽  
First Time

Abstract. The kinetics of the gas-phase reactions of hydroxyl radicals with two unsaturated methoxy-ketones at (298 ± 3) K and 1 atm of synthetic air have been studied for the first time using the relative rate technique in an environmental reaction chamber by in situ FTIR spectrometry. The rate coefficients obtained using propene and isobutene as reference compounds were (in units of 10–10 cm3 molecule−1 s−1) as follows: k1(OH + (E)-4-methoxy-3-buten-2-one) = (1.42 ± 0.12), and k2(OH + 1-(E)-1-methoxy-2-methyl-1-penten-3-one) = (3.34 ± 0.43). In addition, quantification of the main oxidation products has been performed and degradation mechanisms for these reactions were developed. The formation products and kinetic data confirm that the reactions proceed mainly via an addition of the OH radical to the double bond. Gas phase products, identified and quantified from these reactions, are carbonyls like methyl formate, methyl glyoxal and 2,3-pentanedione and long-lived nitrogen containing compounds such as PAN and PPN. Atmospheric lifetimes and the ozone formation potential have been estimated and possible atmospheric implications assessed.

scholarly journals Atmospheric sink of methyl chlorodifluoroacetate and ethyl chlorodifluoroacetate: temperature dependent rate coefficients, product distribution of their reactions with Cl atoms and CF2ClC(O)OH formation

RSC Advances ◽  
2016 ◽  
Vol 6 (57) ◽  
pp. 51834-51844
Author(s):  
María B. Blanco ◽  
Ian Barnes ◽  
Peter Wiesen ◽  
Mariano A. Teruel
Keyword(s):  
Relative Rate ◽  
Product Distribution ◽  
Rate Coefficients ◽  
Gas Phase Reactions ◽  
Temperature Dependent ◽  
Dependent Rate ◽  
P Rate ◽  
Distribution Studies ◽  
First Time ◽  
Cl Atoms

Rate coefficients as a function of temperature and product distribution studies have been performed for the first time for the gas-phase reactions of chlorine atoms with methyl chlorodifluoracetate (k1) and ethyl chlorodifluoroacetate (k2) using the relative rate technique.

scholarly journals Atmospheric Chemistry of 2-Methoxypropene and 2-Ethoxypropene: Kinetics and Mechanism Study of Reactions with Ozone

Atmosphere ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 401 ◽  
Author(s):  
Chen Lv ◽  
Lin Du ◽  
Narcisse Tsona ◽  
Xiaotong Jiang ◽  
Wenxing Wang
Keyword(s):  
Atmospheric Chemistry ◽  
Atmospheric Pressure ◽  
Methyl Acetate ◽  
Relative Rate ◽  
Reaction Chamber ◽  
Alkoxy Group ◽  
Rate Coefficients ◽  
Reaction Products ◽  
Mechanism Study ◽  
Vinyl Ethers

Rate coefficients at ambient temperature and atmospheric pressure for the reaction of ozone with 2-methoxypropene (2-MPE) and 2-ethoxypropene (2-EPE) were determined in an evacuable 100 L Teflon reaction chamber using absolute and relative rate methods. The product experiments were carried out using a 50 L Teflon reaction chamber in conjunction with FTIR as the detection technique. The rate coefficients (k in units of cm3 molecule−1 s−1) obtained are 1.18 ± 0.13 × 10−17 and 1.89 ± 0.23 × 10−17 for reactions with 2-MPE and 2-EPE, respectively. The effects of the alkoxy group on the gas-phase reactivity of alkyl vinyl ethers toward ozone are compared and discussed. The major ozonolysis products are methyl acetate, formaldehyde and CO2 for 2-MPE, and ethyl acetate, formaldehyde and CO2 for 2-EPE. Possible mechanisms for the two vinyl ethers are proposed based on the observed reaction products. Additionally, atmospheric lifetimes of 32 h and 21 h for 2-MPE and 2-EPE were estimated based on the measured rate constants and the ambient tropospheric concentration of ozone, respectively. The obtained values of the lifetimes indicate that the reaction with ozone is an important loss process for these vinyl ethers in the atmosphere, especially in polluted areas.

scholarly journals NO<sub>3</sub> chemistry of wildfire emissions: a kinetic study of the gas-phase reactions of furans with the NO<sub>3</sub> radical

2021 ◽  
Author(s):  
Mike J. Newland ◽  
Yangang Ren ◽  
Max R. McGillen ◽  
Lisa Michelat ◽  
Véronique Daële ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Reaction Rate ◽  
Relative Rate ◽  
Rate Coefficients ◽  
Nitrate Radical ◽  
Gas Phase Reactions ◽  
Removal Process ◽  
Order Of Magnitude ◽  
First Time ◽  
Substituted Furans

Abstract. Furans are emitted to the atmosphere during biomass burning from the pyrolysis of cellulose. They are one of the major contributing VOC classes to OH and NO3 reactivity in biomass burning plumes. The major removal process of furans from the atmosphere at night is reaction with the nitrate radical, NO3. Here we report a series of relative rate experiments in the 7300 L indoor simulation chamber at CNRS-ICARE, Orléans, using a number of different reference compounds to determine NO3 reaction rate coefficients for four furans, two furanones, and pyrrole. In the case of the two furanones, this is the first time that NO3 rate coefficients have been reported. The recommended values (cm3 molecule−1 s−1) are: furan (1.50 ± 0.23) × 10−12, 2-methylfuran (2.37 ± 0.55) × 10−11, 2,5-dimethylfuran (1.10 ± 0.33) × 10−10, furan-2-aldehyde (9.28 ± 2.3) × 10−14, 5-methyl-2(3H)-furanone (3.00 ± 0.45) × 10−12, 2(5H)-furanone < 1.410−16, and pyrrole (7.35 ± 2.06) × 10−11. The furan-2-aldehyde + NO3 reaction rate is found to be an order of magnitude lower than previously reported. We also recommend a faster rate for the α-terpinene+NO3 reaction ((2.70 ± 0.81) × 10−10 cm3 s−1). These experiments show that for furan, alkyl substituted furans, 5-methyl-2(3H)-furanone, and pyrrole, reaction with NO3 will be the dominant removal process at night, and may also contribute during the day. For 2(5H)-furanone, reaction with NO3 is not an important atmospheric sink.

scholarly journals Kinetic study of the gas-phase reaction of atomic chlorine with a series of aldehydes

2005 ◽  
Vol 5 (12) ◽  
pp. 3433-3440 ◽  
Author(s):  
D. Rodríguez ◽  
A. Rodríguez ◽  
A. Notario ◽  
A. Aranda ◽  
Y. Díaz-de-Mera ◽  
...  
Keyword(s):  
Relative Rate ◽  
Weighted Average ◽  
Rate Coefficients ◽  
Phase Reaction ◽  
Additional Information ◽  
Relative Rate Constants ◽  
Relative Measurements ◽  
First Time ◽  
Structure Versus ◽  
Atomic Chlorine

Abstract. The reactions of Cl atoms with a series of unsaturated aldehydes have been investigated for the first time using a relative method. In order to obtain additional information for a qualitative structure versus reactivity discussion, we have also determined the rate coefficients for the reactions of atomic chlorine with their respective saturated aldehydes. These relative measurements were performed at room temperature and atmospheric pressure of air and N2, by using ethane, propene and 1-butene as reference compounds. The weighted average relative rate constants obtained, kCl±2σ (in units of cm3 molecule−1 s−1) were: trans-2-pentenal (1.31±0.19)×10−10; trans-2-hexenal (1.92±0.22)×10−10; trans-2-heptenal (2.40±0.29)×10−10; n-pentanal (2.56±0.27)×10−10; n-hexanal (2.88±0.37)×10−10; n-heptanal (3.00±0.34)×10−10. Finally, results and atmospheric implications are discussed and compared with the reactivity with OH and NO3 radicals.

Rate Coefficients for the Gas-Phase Reactions of Hydroxyl Radicals with a Series of Methoxylated Aromatic Compounds

2015 ◽  
Vol 119 (24) ◽  
pp. 6179-6187 ◽  
Author(s):  
Amélie Lauraguais ◽  
Iustinian Bejan ◽  
Ian Barnes ◽  
Peter Wiesen ◽  
Cécile Coeur
Keyword(s):  
Gas Phase ◽  
Hydroxyl Radicals ◽  
Aromatic Compounds ◽  
Rate Coefficients ◽  
Gas Phase Reactions ◽  
Methoxylated Aromatic

scholarly journals Fe-modified activated carbon obtained from biomass as a catalyst for α-pinene autoxidation

2021 ◽  
Vol 23 (2) ◽  
pp. 73-80
Author(s):  
Adrianna Kamińska ◽  
Nikola Maciejewska ◽  
Piotr Miądlicki ◽  
Karolina Kiełbasa ◽  
Joanna Sreńscek-Nazzal ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Orange Peel ◽  
Raw Material ◽  
Main Reaction ◽  
Reaction Products ◽  
Modified Activated Carbon ◽  
X Ray ◽  
Alpha Pinene ◽  
Instrumental Methods ◽  
First Time

Abstract The presented work describes the autoxidation of alpha-pinene for the first time using a catalyst based on activated carbon from biomass with introduced Fe. The raw material for the preparation of the carbon material was waste orange peel, which was activated with a KOH solution. The following instrumental methods characterized the obtained catalyst (Fe/O_AC):N2 adsorption at 77 K, XRD, UV, SEM, TEM, X-ray microanalysis, and catalytic studies. It was shown that the Fe/O_AC catalyst was very active in the autoxidation of alpha-pinene. The main reaction products were: alpha-pinene oxide, verbenone, verbenol, and campholenic aldehyde.

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