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Liu L, Zhang C, Xia Y, Zhang W, Wang Z, Tang X. Dimeric product formation in the self-reaction of small peroxy radicals using synchrotron radiation vacuum ultraviolet photoionization mass spectrometry. CHEMOSPHERE 2024; 363:142846. [PMID: 39025306 DOI: 10.1016/j.chemosphere.2024.142846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Revised: 07/11/2024] [Accepted: 07/12/2024] [Indexed: 07/20/2024]
Abstract
Peroxy radicals (RO2) are key reactive intermediates in atmospheric oxidation processes and yet their chemistry is not fully unraveled. Little is known about their structures and the structures of the dimeric products (ROOR) in the self-reaction of small RO2, which are among the most abundant RO2 in the atmosphere. The product branching ratios of ROOR and their atmospheric roles are still in controversy. Here, the self-reaction of propyl peroxy radicals (C3H7O2), a typical small RO2 radical in the atmosphere, has been studied using synchrotron radiation vacuum ultraviolet photoionization mass spectrometry. Both radical (C3H7O) and closed-shell molecular (C3H6O, C3H7OH, C3H7OOC3H7) products in the self-reaction are observed in photoionization mass spectra and their elusive isomers are definitely identified in mass-selected photoionization spectra. Three isomers of the C3H7OOC3H7 dimeric products, R1OOR1, R1OOR2, and R2OOR2 (R1 and R2 represent 1-C3H7 and 2-C3H7, respectively), as well as their complex structures have been determined for the first time. Kinetic experiments are performed and compared with chemical simulations to reveal the sources of specific products. The branching ratio of the C3H7OOC3H7 dimeric channel is measured at 10 ± 5%. This work demonstrates that the dimeric product formation in the self-reaction of small RO2 radicals is non-negligible and should provide valuable new insight into atmospheric modelling.
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Affiliation(s)
- Lingyu Liu
- Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031, Anhui, China; School of Environmental Science and Optoelectronic Technology, University of Science and Technology of China, Hefei, 230026, Anhui, China
| | - Cuihong Zhang
- Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031, Anhui, China
| | - Yu Xia
- Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031, Anhui, China; Science Island Branch, Graduate School, University of Science and Technology of China, Hefei, 230026, Anhui, China
| | - Weijun Zhang
- Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031, Anhui, China; School of Environmental Science and Optoelectronic Technology, University of Science and Technology of China, Hefei, 230026, Anhui, China.
| | - Zhandong Wang
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, 230029, Anhui, China
| | - Xiaofeng Tang
- Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031, Anhui, China.
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Pasik D, Frandsen BN, Meder M, Iyer S, Kurtén T, Myllys N. Gas-Phase Oxidation of Atmospherically Relevant Unsaturated Hydrocarbons by Acyl Peroxy Radicals. J Am Chem Soc 2024; 146:13427-13437. [PMID: 38712858 DOI: 10.1021/jacs.4c02523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
This study assesses the atmospheric impact of reactions between unsaturated hydrocarbons such as isoprene and monoterpenes and peroxy radicals containing various functional groups. We find that reactions between alkenes and acyl peroxy radicals have reaction rates high enough to be feasible in the atmosphere and lead to high molar mass accretion products. Moreover, the reaction between unsaturated hydrocarbons and acyl peroxy radicals leads to an alkyl radical, to which molecular oxygen rapidly adds. This finding is confirmed by both theoretical calculations and experiments. The formed perester peroxy radical may either undergo further H-shift reactions or react bimolecularly. The multifunctional oxygenated compounds formed through acyl peroxy radical + alkene reactions are potentially important contributors to particle formation and growth. Thus, acyl peroxy radical-initiated oxidation chemistry may need to be included in atmospheric models.
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Affiliation(s)
- Dominika Pasik
- Department of Chemistry, University of Helsinki, Helsinki 00014, Finland
- Institute for Atmospheric and Earth System Research, University of Helsinki, Helsinki 00014, Finland
| | - Benjamin N Frandsen
- Department of Chemistry, University of Helsinki, Helsinki 00014, Finland
- Aerosol Physics Laboratory, Tampere University, Tampere 33014, Finland
| | - Melissa Meder
- Institute for Atmospheric and Earth System Research, University of Helsinki, Helsinki 00014, Finland
| | - Siddharth Iyer
- Aerosol Physics Laboratory, Tampere University, Tampere 33014, Finland
| | - Theo Kurtén
- Department of Chemistry, University of Helsinki, Helsinki 00014, Finland
- Institute for Atmospheric and Earth System Research, University of Helsinki, Helsinki 00014, Finland
| | - Nanna Myllys
- Department of Chemistry, University of Helsinki, Helsinki 00014, Finland
- Institute for Atmospheric and Earth System Research, University of Helsinki, Helsinki 00014, Finland
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Zhang R, Zhang Z, Chen X, Jiang J, Hua L, Jia X, Bao R, Wang F. Pyrogenic Carbon Degradation by Galvanic Coupling with Sprayed Seawater Microdroplets. J Am Chem Soc 2024; 146:8528-8535. [PMID: 38497738 DOI: 10.1021/jacs.4c00290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Surface waves are known for their mechanical role in coastal processes that influence the weather and climate. However, their chemical impact, particularly on the transformation of pyrogenic carbon, is poorly understood. Pyrogenic carbon is generally assumed to show negligible postformational alteration of its stable carbon isotope composition. Here we present an electrochemical interaction of pyrogenic carbon with the sprayed seawater microdroplets resulting from wave breaking, driven by the galvanic coupling between the microdroplet water-carbon interfaces and the microdroplet water-vapor interfaces. This enables refractory pyrogenic carbon to rapidly degrade via the oxygenation and mineralization reaction, which makes it ∼2.6‰ enriched in 13C, far exceeding the generally assumed postformation alteration values (<0.5‰) of pyrogenic carbon. The unique chemical dynamics of seawater microdroplets provide new insights into the discrepancy in carbon isotope signatures between riverine and marine black carbon, emphasizing the potential of coastal oceans for carbon sequestration in the global carbon cycle.
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Affiliation(s)
- Ruolan Zhang
- Henan Institute of Advanced Technology, Zhengzhou University, Zhengzhou 450000, P. R. China
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China
| | - Zhenyuan Zhang
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Xuke Chen
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Jichun Jiang
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China
| | - Lei Hua
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China
| | - Xiuquan Jia
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China
| | - Rui Bao
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Lab of Marine Chemistry Theory and Technology, Ocean University of China, Qingdao 266100, P. R. China
| | - Feng Wang
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
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Nozière B, Durif O, Dubus E, Kylington S, Emmer Å, Fache F, Piel F, Wisthaler A. The reaction of organic peroxy radicals with unsaturated compounds controlled by a non-epoxide pathway under atmospheric conditions. Phys Chem Chem Phys 2023; 25:7772-7782. [PMID: 36857663 PMCID: PMC10015623 DOI: 10.1039/d2cp05166d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Today, the reactions of gas-phase organic peroxy radicals (RO2) with unsaturated Volatile Organic Compounds (VOC) are expected to be negligible at room temperature and ignored in atmospheric chemistry. This assumption is based on combustion studies (T ≥ 360 K), which were the only experimental data available for these reactions until recently. These studies also reported epoxide formation as the only reaction channel. In this work, the products of the reactions of 1-pentylperoxy (C5H11O2) and methylperoxy (CH3O2) with 2,3-dimethyl-2-butene ("2,3DM2B") and isoprene were investigated at T = 300 ± 5 K with Proton Transfer Reaction Time-of-Flight Mass Spectrometry (PTR-ToF-MS) and Gas Chromatography/Electron Impact Mass Spectrometry. Unlike what was expected, the experiments showed no measurable formation of epoxide. However, RO2 + alkene was found to produce compounds retaining the alkene structure, such as 3-hydroxy-3-methyl-2-butanone (C5H10O2) with 2,3DM2B and 2-hydroxy-2-methyl-3-butenal (C5H8O2) and methyl vinyl ketone with isoprene, suggesting that these reactions proceed through another reaction pathway under atmospheric conditions. We propose that, instead of forming an epoxide, the alkyl radical produced by the addtion of RO2 onto the alkene reacts with oxygen, producing a peroxy radical. The corresponding mechanisms are consistent with the products observed in the experiments. This alternative pathway implies that, under atmospheric conditions, RO2 + alkene reactions are kinetically limited by the initial addition step and not by the epoxide formation proposed until now for combustion systems. Extrapolating the combustion data to room temperature thus underestimates the rate coefficients, which is consistent with those recently reported for these reactions at room temperature. While slow for many classes of RO2, these reactions could be non-negligible at room temperature for some functionalized RO2. They might thus need to be considered in laboratory studies using large alkene concentrations and in biogenically-dominated regions of the atmosphere.
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Affiliation(s)
- Barbara Nozière
- KTH, Royal Institute of Technology, Department of Chemistry, 114 28 Stockholm, Sweden.
| | - Olivier Durif
- KTH, Royal Institute of Technology, Department of Chemistry, 114 28 Stockholm, Sweden.
| | - Eloé Dubus
- KTH, Royal Institute of Technology, Department of Chemistry, 114 28 Stockholm, Sweden.
| | - Stephanie Kylington
- KTH, Royal Institute of Technology, Department of Chemistry, 114 28 Stockholm, Sweden.
| | - Åsa Emmer
- KTH, Royal Institute of Technology, Department of Chemistry, 114 28 Stockholm, Sweden.
| | - Fabienne Fache
- Université Lyon 1 and CNRS, UMR 5246, ICBMS, 69626 Villeurbanne, France
| | - Felix Piel
- University of Oslo, Department of Chemistry, 0315 Oslo, Norway
| | - Armin Wisthaler
- University of Oslo, Department of Chemistry, 0315 Oslo, Norway
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Shi X, Tang R, Dong Z, Liu H, Xu F, Zhang Q, Zong W, Cheng J. A neglected pathway for the accretion products formation in the atmosphere. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 848:157494. [PMID: 35914590 DOI: 10.1016/j.scitotenv.2022.157494] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/09/2022] [Accepted: 07/15/2022] [Indexed: 06/15/2023]
Abstract
Highly oxygenated organic molecules (HOM) formed by the autoxidation of α-pinene initiated by OH radicals play an important role in new particle formation. It is believed that the accretion products, ROOR´, formed by the self- and cross-reaction of peroxy radicals (RO2 + R'O2 reactions), have extremely low volatility and are more likely to participate in nucleation. However, the mechanism of ROOR´ formation has not been fully demonstrated by experiment or theoretical calculation. Herein, we propose a novel mechanism of RO2 reacting with α-pinene (RO2 + α-pinene reactions) that have much lower potential barriers and larger rate constants than the reaction of RO2 with R'O2, which explains the ROOR´ formation found in the mass spectrometry experiments. The ROOR´ resulting from the reaction of RO2 with α-pinene can produce HOM dimers and trimers with a higher oxygen-to‑carbon (O/C) ratio through a autoxidation chain. We also demonstrated that the presence of NOx and HO2 radical will reduce the RO2 concentration, but cannot completely inhibit the formation of HOM monomers and ROOR´. Even if one or both of RO2 radicals are acyl peroxy radicals (RC(O)O2), the potential barriers of the reactions between RC(O)O2 and α-pinene (RC(O)O2 + α-pinene reactions) are lower than that of RO2 reacting with RC(O)O2 (RO2 + RC(O)O2 reactions) or RC(O)O2 self-reactions (RC(O)O2 + RC(O)O2 reactions). The current work revealed, for the first time, a mechanism of RO2/RC(O)O2 reacting with α-pinene in the atmosphere, which provides new insight into the atmospheric chemistry of accretion products as SOA precursors.
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Affiliation(s)
- Xiangli Shi
- College of Geography and Environment, Shandong Normal University, Jinan 250014, PR China
| | - Ruoyu Tang
- College of Geography and Environment, Shandong Normal University, Jinan 250014, PR China
| | - Zuokang Dong
- College of Geography and Environment, Shandong Normal University, Jinan 250014, PR China
| | - Houfeng Liu
- College of Geography and Environment, Shandong Normal University, Jinan 250014, PR China
| | - Fei Xu
- Environment Research Institute, Shandong University, Qingdao 266237, PR China
| | - Qingzhu Zhang
- Environment Research Institute, Shandong University, Qingdao 266237, PR China
| | - Wansong Zong
- College of Geography and Environment, Shandong Normal University, Jinan 250014, PR China.
| | - Jiemin Cheng
- College of Geography and Environment, Shandong Normal University, Jinan 250014, PR China
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Goldman MJ, Green WH, Kroll JH. Chemistry of Simple Organic Peroxy Radicals under Atmospheric through Combustion Conditions: Role of Temperature, Pressure, and NO x Level. J Phys Chem A 2021; 125:10303-10314. [PMID: 34843244 DOI: 10.1021/acs.jpca.1c07203] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Organic peroxy radicals (RO2) are key intermediates in the oxidation of organic compounds in both combustion systems and the atmosphere. While many studies have focused on reactions of RO2 in specific applications, spanning a relatively limited range of reaction conditions, the generalized behavior of RO2 radicals across the full range of reaction conditions (temperatures, pressures, and NO levels) has, to our knowledge, never been explored. In this work, two simple model systems, n-propyl peroxy radical and γ-isobutanol peroxy radical, are used to evaluate RO2 fate using pressure-dependent kinetics. The fate of these radicals was modeled based on literature data over 250-1250 K, 0.01-100 bar, and 1 ppt to 100 ppm of NO, which spans the typical range of atmospheric and combustion conditions. Covering this entire range provides a broad overview of the reactivity of these species under both atmospheric and combustion conditions, as well as under conditions intermediate to the two. A particular focus is on the importance of reactions that were traditionally considered to occur in only one of the two sets of conditions: RO2 unimolecular isomerization reactions (long known to occur in combustion systems but only recently appreciated in atmospheric systems) and RO2 bimolecular reactions of RO2 with NO (thought to occur mainly in atmospheric systems and rarely considered in combustion chemistry).
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Affiliation(s)
- Mark Jacob Goldman
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - William H Green
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Jesse H Kroll
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.,Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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