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Kinetic and mechanism of the reaction between Cl and several mono-methyl branched alkanes

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Journal of Environmental Sciences 2024年第1期135卷 474-482页

作者： Yan Chen Weigang Wang Junling Li Li Zhou Bo Shi Cici Fan Ke Wang Hao Zhang Hong Li maofa ge State Key Laboratory for Structural Chemistry of Unstable and Stable Species Beijing National Laboratory for Molecular Sciences(BNLMS)CAS Research/Education Center for Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China National Engineering Research Center for Flue Gas Desulfurization Department of Environmental Science and EngineeringSichuan UniversityChengdu 610065China College of Chemistry and Materials Science Hebei Normal UniversityShijiazhuang 050024China

Branched alkanes are ubiquitous in the troposphere and play an important role in the chemical *** this work,the rate constants and products for the reaction of Cl atoms with 3-methylhexane and 2-methylheptane were measured at room temperature(298±0.2K)and atmospheric pressure using a conventional relative rate *** rate constants of 3-methylhexane and 2-methylheptane in units of cm~3/(mol·sec)are(3.09±0.31)×10^(-10)and(3.67±0.40)×10^(-10),***,the corresponding atmospheric lifetime of the studied branched alkanes with Cl was 6.92-89.90 hours and 5.82-75.69 hours,*** estimated atmospheric lifetimes indicated that the reaction with Cl atoms could be the most important atmospheric degradation pathway for 3-methylhexane *** gas-phase products of the reactions were identified and quantified,and particle-phase products were also *** atmosphere oxidation mechanism of Cl atoms with 3-methylhexane and 2-methylheptane is *** SOA yields of 3-methylhexane and 2-methylheptane from the reaction of Cl atoms were determined to be7.96%±0.89%and 13.35%±1.50%***,the results reveal that the primary loss process of branched alkanes is the reaction with Cl atoms,which impacts its degradation on a regional scale.

关键词： 3-Methylhexane 2-Methylheptane Chlorine atoms Kinetics Mechanism

Acid-catalyzed heterogeneous reaction of 3-methyl-2-buten-1-ol with hydrogen peroxide

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Journal of Environmental Sciences 2015年第5期27卷 89-97页

作者： Qifan Liu Weigang Wang maofa ge Beijing National Laboratory for Molecular Sciences (BNLMS) State Key Laboratory for Structural Chemistry of Unstable and Stable SpeciesInstitute of Chemistry Chinese Academy of Sciences

Acid-catalyzed heterogeneous oxidation with hydrogen peroxide（H2O2） has been suggested to be a potential pathway for secondary organic aerosol（SOA） formation from isoprene and its oxidation products. However, knowledge of the chemical mechanism and kinetics for this process is still incomplete. 3-Methyl-2-buten-1-ol（MBO321）, an aliphatic alcohol structurally similar to isoprene, is emitted by pine forests and widely used in the manufacturing industries. Herein the uptake of MBO321 into H2SO4-H2O2mixed solution was investigated using a flow-tube reactor coupled to a mass spectrometer. The reactive uptake coefficients（γ） were acquired for the first time and were found to increase rapidly with increasing acid concentration. Corresponding aqueous-phase reactions were performed to further study the mechanism of this acid-catalyzed reaction. MBO321 could convert to 2-methyl-3-buten-2-ol（MBO232） and yield isoprene in acidic media. Organic hydroperoxides（ROOHs） were found to be generated through the acid-catalyzed route,which could undergo a rearrangement reaction and result in the formation of acetone and acetaldehyde. Organosulfates, which have been proposed to be SOA tracer compounds in the atmosphere, were also produced during the oxidation process. These results suggest that the heterogeneous acid-catalyzed reaction of MBO321 with H2O2 may contribute to SOA mass under certain atmospheric conditions.

关键词： Gas-liquid interaction Uptake coefficients Organic hydroperoxide Organosulfate Secondary organic aerosol

Heterogeneous uptake of NO_2 on soils under variable temperature and relative humidity conditions

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Journal of Environmental Sciences 2012年第10期24卷 1759-1766页

作者： Lei Wang Weigang Wang maofa ge Beijing National Laboratory for Molecular Science (BNLMS) State Key Laboratory for Structural Chemistry of Unstable and Stable Species Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China. Beijing National Laboratory for Molecular Science (BNLMS) State Key Laboratory for Structural Chemistry of Unstable and Stable Species Peking University Beijing 100871 China

Heterogeneous reactions of nitrogen dioxide （NO2） on soils collected from Dalian （S 1） and Changsha （S2） were investigated over the relative humidity （RH） range of 5%-80% and temperature range of 278-328 K using a horizontal coated-wall flow tube. The initial uptake coefficients of NO2 on S2 exhibited a decreasing trend from （10 ± 1.3） × 10-8 to （3.1 ± 0.5） x 10-8 with the relative humidity increasing from 5% to 80%. In the temperature effect studies, the initial uptake coefficients of S1 and S2 decreased from （10± 1.2） × 10-8 to （3.8 ± 0.5） × 10-8 and from （16± 2.2） × 10-8 to （3.8 ±0.4） × 10-8 when temperature increased from 278 to 288 K for S1 and from 278 to 308 K for S2, respectively. As the temperature continued to increase, the initial uptake coefficients of S1 and S2 returned to （7.9 ± 1.1）× 10-8 and （20 ± 3.1） × 10-8 at 313 and 328 K, respectively. This study shows that relative humidity could influence the uptake kinetics of NO2 on soil and temperature would impact the heterogeneous chemistry of NO2.

关键词： heterogeneous reactions soil particles uptake coefficients temperature dependence relative humidity effect

Uptake of isoprene, methacrylic acid and methyl methacrylate into aqueous solutions of sulfuric acid and hydrogen peroxide

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Journal of Environmental Sciences 2012年第11期24卷 1947-1953页

作者： Ze Liu maofa ge Weigang Wang Beijing National Laboratory for Molecular Science (BNLMS) State Key Laboratory for Structural Chemistry of Unstable and Stable Species Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China Beijing National Laboratory for Molecular Science (BNLMS) Peking University Beijing 100871 China

Multiphase acid-catalyzed oxidation by hydrogen peroxide has been suggested to be a potential route to secondary organic aerosol formation from isoprene and its gas-phase oxidation products, but the lack of kinetics data significantly limited the evaluation of this process in the atmosphere. Here we report the first measurement of the uptake of isoprene, methacrylic acid and methyl methacrylate into aqueous solutions of sulfuric acid and hydrogen peroxide. Isoprene cannot readily partition into the solution because of its high volatility and low solubility, which hinders its further liquid-phase oxidation. Both methacrylic acid and methyl methacrylate can enter the solutions and be oxidized by hydrogen peroxide, and steady-state uptake was observed with the acidity of solution above 30 wt.% and 70 wt.%, respectively. The steady-state uptake coefficient of methacrylic acid is much larger than that of methyl methacrylate for a solution with same acidity. These observations can be explained by the different reactivity of these two compounds caused by the different electron-withdrawing conjugation between carboxyl and ester groups. The atmospheric lifetimes were estimated based on the calculated steady-state uptake coefficients. These results demonstrate that the multiphase acid-catalyzed oxidation of methacrylic acid plays a role in secondary organic aerosol formation, but for isoprene and methyl methacrylate, this process is not important in the troposphere.

关键词： multiphase acid-catalyzed oxidation uptake steady-state uptake coefficient secondary organic aerosol

Environmental chamber study of the photochemical reaction of ethyl methyl sulfide and NO_x

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Journal of Environmental Sciences 2009年第2期21卷 137-141页

作者： WANG Kun DU Lin ge maofa State Key Laboratory for Structural Chemistry of Unstable and Stable Species Beijing National Laboratory for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China Graduate University of the Chinese Academy of Sciences Beijing 100039 China

A series of experiments were conducted in a self-made smog chamber at （300 ＋ 1） K and 1.01 × 10^5 Pa to simulate the photochemical reaction of ethyl methyl sulfide （EMS） and NOx. The results showed that the higher the initial concentration of EMS, the more ozone was generated in the simulative reactions. It was found that the light intensity plays a very important role in the evaluation of ozone formation potential for EMS. The parameters of d（Oa-NO） and IR （incremental reactivity） were used to quantify the potential of EMS on ozone formation. The obtained maximum IR values in this article for the five simulative reactions were 1.55 × 10^-2, 0.99 × 10^-2, 1.36 × 10^-2, 2.47 × 10^-2, and 1.65 × 10^-2, respectively. A comparison between the results we obtained here and the results we obtained previously for di-tert-butyl peroxide and acetylene showed that the potential reactivity of EMS on ozone formation was at a relatively low level.

关键词： smog chamber photochemical reaction ethyl methyl sulfide incremental reactivity

Knudsen cell and smog chamber study of the heterogeneous uptake of sulfur dioxide on Chinese mineral dust

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Journal of Environmental Sciences 2014年第12期26卷 2423-2433页

作者： Li Zhou Weigang Wang Yanbo Gai maofa ge Beijing National Laboratory for Molecular Science (BNLMS) State Key Laboratory for Structural Chemistry of Unstable and Stable SpeciesInstitute of Chemistry Chinese Academy of Sciences Beijing National Laboratory for Molecular Science (BNLMS) State Key Laboratory for Structural Chemistry of Unstable and Stable SpeciesPeking University

The heterogeneous uptake processes of sulfur dioxide on two types of Chinese mineral dust（Inner Mongolia desert dust and Xinjiang sierozem） were investigated using both Knudsen cell and smog chamber system. The temperature dependence of the uptake coefficients was studied over a range from 253 to 313 K using the Knudsen cell reactor, the initial uptake coefficients decreased with the increasing of temperature for these two mineral dust samples, whereas the steady state uptake coefficients of the Xinjiang sierozem increased with the temperature increasing, and these temperature dependence functions were obtained for the first time. In the smog chamber experiments at room temperature, the steady state uptake coefficients of SO2 decreased evidently with the increasing of sulfur dioxide initial concentration from 1.72 × 1012 to 6.15 × 1012mol/cm3. Humid air had effect on the steady state uptake coefficients of SO2 onto Inner Mongolia desert *** about the understanding of the uptake processes onto mineral dust samples and the environmental implication were also discussed.

关键词： Mineral dust Sulfur dioxide Uptake coefficient Temperature dependence

Heterogeneous uptake of gaseous hydrogen peroxide on mineral dust

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Journal of Environmental Sciences 2016年第2期28卷 44-50页

作者： Li Zhou Weigang Wang maofa ge Shengrui Tong Beijing National Laboratory for Molecular Science(BNLMS) State Key Laboratory for Structural Chemistry of Unstable and Stable SpeciesInstitute of ChemistryChinese Academy of Sciences

The heterogeneous uptake processes of hydrogen peroxide on Arizona test dust and two types of authentic Chinese mineral dusts, i.e., Inner Mongolia desert dust and Xinjiang calciferous dust, were investigated using a Knudsen cell reactor coupled with a quadrupole mass spectrometer. The uptake coefficients were measured as a function of the initial concentration of H_2O_2 from 2.6 × 10^（11） to 1.2 × 10^（12）molecules/cm^3, and the temperature dependence of the uptake coefficients was investigated over a range from 253 to 313 K. The concentration of H_2O_2 showed little effect on the uptake coefficients of these heterogeneous processes. As a function of temperature, the initial uptake coefficients decrease with increasing temperature, whereas the steady state uptake coefficients of Arizona test dust and Inner Mongolia desert dust increase with increasing temperature. Implications for the understanding of the uptake processes onto mineral dust samples were also discussed.

关键词： Hydrogen peroxide Mineral dust Heterogeneous uptake Uptake coefficients

Temperature dependent kinetics of the gas-phase reaction of OH radicals with EMS

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Chinese Science Bulletin 2011年第4期56卷 391-396页

作者： WANG Kun ge maofa WANG WeiGang Beijing National Laboratory for Molecular Sciences (BNLMS) State Key Laboratory for Structural Chemistry of Unstable and Stable Species Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China Graduate School of Chinese Academy of Sciences Beijing 100049 China

Using an improved smog chamber system,the temperature dependence of OH radical reaction with EMS was investigated over the temperature range of 297-346 K at 1.01×105 Pa pressure of air. The Arrhenius expression of th... 详细信息

关键词：环境管理体系温度相关气相反应 OH自由基动力学 Arrhenius 自由基反应温度范围

Extinction efficiencies of mixed aerosols measured by aerosol cavity ring down spectrometry

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Chinese Science Bulletin 2012年第20期57卷 2567-2573页

作者： WANG Lei WANG WeiGang ge maofa State Key Laboratory for Structural Chemistry of Unstable and Stable Species Beijing National Laboratory for Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China Beijing National Laboratory for Molecular Science State Key Laboratory for Structural Chemistry of Unstable and Stable SpeciesPeking UniversityBeijing 100871China

A cavity ring down spectroscopy instrument was introduced and designed for measuring extinction efficiencies of pure and mixing aerosols in this *** averaging 500 individual waveforms,the minimal detectable aerosol extinction coefficient of 8.4 × 10-7 m-1 was *** the test results using the NaCl particles,we concluded that this system could measure the extinction efficiencies of an aerosol with an uncertainty less than 3% under laboratory controlled experimental *** refractive indices of different aerosols were retrieved through comparing the measured extinction efficiencies of each aerosol type with which predicted by Mie *** composed of ammonium sulphate and succinic acid with different weight ratios were used to create a model of mixed aerosols using these two materials,whose extinction efficiencies and complex refractive indices were *** refractive indices of the mixed aerosols were also calculated by various optical mixing *** found that all the molar refraction/absorption mixing rule,the volume ratio linear rule,and Maxwell-Garnett rule did provide comparable results,of which the volume ratio linear rule gave a slightly worse fit than the others.

关键词：大气气溶胶混合使用光效率测量下降法混合规则线性规则折射率