Organic Peroxides in Aerosol: Key Reactive Intermediates for Multiphase Processes in the Atmosphere

Chemical Reviews, Год журнала: 2023, Номер 123(4), С. 1635 - 1679

Опубликована: Янв. 11, 2023

Organic peroxides (POs) are organic molecules with one or more peroxide (−O–O−) functional groups. POs commonly regarded as chemically labile termination products from gas-phase radical chemistry and therefore serve temporary reservoirs for oxidative radicals (HOx ROx) in the atmosphere. Owing to their ubiquity, active gas-particle partitioning behavior, reactivity, key reactive intermediates atmospheric multiphase processes determining life cycle (formation, growth, aging), climate, health impacts of aerosol. However, there remain substantial gaps origin, molecular diversity, fate due complex nature dynamic behavior. Here, we summarize current understanding on POs, a focus identification quantification, state-of-the-art analytical developments, molecular-level formation mechanisms, chemical transformation pathways, well environmental impacts. We find that interactions SO2 transition metal ions generally fast PO pathways liquid water, lifetimes estimated be minutes hours, while hydrolysis is particularly important α-substituted hydroperoxides. Meanwhile, photolysis thermolysis likely minor sinks POs. These distinctly different fates, such reaction OH radicals, which highlights need understand By summarizing advances remaining challenges investigation propose future research priorities regarding fate,

Язык: Английский

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Insufficient Condensable Organic Vapors Lead to Slow Growth of New Particles in an Urban Environment

Environmental Science & Technology, Год журнала: 2022, Номер 56(14), С. 9936 - 9946

Опубликована: Июнь 24, 2022

Atmospheric new particle formation significantly affects global climate and air quality after newly formed particles grow above ∼50 nm. In polluted urban atmospheres with 1-3 orders of magnitude higher rates than those in clean atmospheres, growth are comparable or even lower for reasons that were previously unclear. Here, we address the slow Beijing advanced measurements size-resolved molecular composition nanoparticles using thermal desorption chemical ionization mass spectrometer gas precursors nitrate CI-APi-ToF. A model combining condensational particle-phase acid-base chemistry was developed to explore mechanisms. The 8-40 nm during events is dominated by organics (∼80%) sulfate (∼13%), remainder from base compounds, nitrate, chloride. With increase sizes, fraction decreases, while slow-desorbed organics, organic acids, increases. simulated consistent measured results most cases, they both indicate vapors H2SO4 major pathway reactions play a minor role. comparison high concentrations gaseous sulfuric acid amines cause rates, concentration condensable comparably under NOx levels, relatively high-volatility nitrogen-containing oxidation products higher. insufficient lead growth, which further causes low survival environments. Thus, some extent, counteract impact on

Язык: Английский

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Road Traffic Emissions Lead to Much Enhanced New Particle Formation through Increased Growth Rates

Environmental Science & Technology, Год журнала: 2024, Номер 58(24), С. 10664 - 10674

Опубликована: Июнь 8, 2024

New particle formation (NPF) is a major source of atmospheric aerosol particles, including cloud condensation nuclei (CCN), by number globally. Previous research has highlighted that NPF less frequent but more intense at roadsides compared to urban background. Here, we closely examine both background and roadside sites in Central Europe. We show the concentration oxygenated organic molecules (OOMs) greater roadside, OOMs along with sulfuric acid onto new particles sufficient explain growth sites. identify hitherto unreported traffic-related OOM contributing 29% 16% total background, respectively. Critically, this undiscovered an essential component NPF. Without their contribution rates subsequent enhancements survival, >50 nm produced would be reduced factor 21 site. Reductions hydrocarbon emissions from road traffic may thereby reduce numbers CCN counts.

Язык: Английский

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The effect of COVID-19 restrictions on atmospheric new particle formation in Beijing

Atmospheric chemistry and physics, Год журнала: 2022, Номер 22(18), С. 12207 - 12220

Опубликована: Сен. 19, 2022

Abstract. During the COVID-19 lockdown, dramatic reduction of anthropogenic emissions provided a unique opportunity to investigate effects reduced activity and primary on atmospheric chemical processes consequent formation secondary pollutants. Here, we utilize comprehensive observations examine response new particle (NPF) changes in cocktail. We find that main clustering process was unaffected by drastically traffic emissions, rate 1.5 nm particles remained unaltered. However, survival probability enhanced due an increased growth (GR) during lockdown period, explaining NPF earlier studies. For GR at 1.5–3 nm, sulfuric acid (SA) contributor high temperatures, whilst there were unaccounted contributing vapors low temperatures. 3–7 7–15 oxygenated organic molecules (OOMs) played major role. Surprisingly, OOM composition volatility insensitive large change NOx concentration; instead associated rates concentration period mostly caused oxidative capacity. Overall, our findings suggest limited role NPF.

Язык: Английский

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Particle number size distribution and new particle formation in Xiamen, the coastal city of Southeast China in wintertime

The Science of The Total Environment, Год журнала: 2022, Номер 826, С. 154208 - 154208

Опубликована: Фев. 28, 2022

Язык: Английский

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Iodine oxoacids and their roles in sub-3 nm particle growth in polluted urban environments

Atmospheric chemistry and physics, Год журнала: 2024, Номер 24(3), С. 1873 - 1893

Опубликована: Фев. 12, 2024

Abstract. New particle formation contributes significantly to the number concentration of ultrafine particles (UFPs, d ≤ 100 nm) and has a great impact on human health global climate. Iodine oxoacids (HIOx, including iodic acid, HIO3, iodous HIO2) have been observed in pristine regions proved dominate new (NPF) at some sites. However, knowledge HIOx polluted urban areas is rather limited. Here, we conducted long-term measurements gaseous iodine sulfuric acid Beijing from January 2019 October 2021 also Nanjing March February 2020 investigated contribution UFP both environments. HIO3 highest summer, up 2.85 × 106 2.78 cm−3 Nanjing, respectively, lowest winter by 96 % 75 %, respectively. exhibits more prominent variation than H2SO4 shows clear diurnal pattern sites with daily maximum around noontime, similar atmospheric temperature, solar radiation, ozone (O3) levels. HIO2 same seasonal trend as but overall about an order magnitude lower concentration. Back trajectory analysis suggests that sources for inland species could be mix marine terrestrial origins, having peak emission warm seasons. While growth marginal our results demonstrate enhances survival probability sub-3 nm 40 (median) occasionally NPF events, suggesting are significant contributor UFPs areas. As per-molecule basis, propose sum used estimate inorganic origin atmospheres amount HIOx.

Язык: Английский

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Measurement of atmospheric nanoparticles: Bridging the gap between gas-phase molecules and larger particles

Journal of Environmental Sciences, Год журнала: 2022, Номер 123, С. 183 - 202

Опубликована: Март 11, 2022

Язык: Английский

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Molecular Characterization of Oxygenated Organic Molecules and Their Dominating Roles in Particle Growth in Hong Kong

Environmental Science & Technology, Год журнала: 2023, Номер 57(20), С. 7764 - 7776

Опубликована: Май 8, 2023

Oxygenated organic molecules (OOMs) are critical intermediates linking volatile compound oxidation and secondary aerosol (SOA) formation. Yet, the understanding of OOM components, formation mechanism, impacts still limited, especially for urbanized regions with a cocktail anthropogenic emissions. Herein, ambient measurements OOMs were conducted at regional background site in South China 2018. The molecular characteristics revealed dominant nitrogen-containing products, influences different factors on composition state elucidated. Positive matrix factorization analysis resolved complex species to featured fingerprint from pathways. A new method was developed identify key functional groups OOMs, which successfully classified majority into carbonyls (8%), hydroperoxides (7%), nitrates (17%), peroxyl (10%), dinitrates (13%), aromatic ring-retaining (6%), terpenes (7%). volatility estimation improved based their identified used simulate growth process contributed by condensation those low-volatile OOMs. results demonstrate predominant role contributing sub-100 nm particle SOA highlight importance products multistep oxidation.

Язык: Английский

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Variations in source contributions of particle number concentration under long-term emission control in winter of urban Beijing

Environmental Pollution, Год журнала: 2022, Номер 304, С. 119072 - 119072

Опубликована: Март 14, 2022

Язык: Английский

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Fostering a Holistic Understanding of the Full Volatility Spectrum of Organic Compounds from Benzene Series Precursors through Mechanistic Modeling

Environmental Science & Technology, Год журнала: 2024, Номер 58(19), С. 8380 - 8392

Опубликована: Май 1, 2024

A comprehensive understanding of the full volatility spectrum organic oxidation products from benzene series precursors is important to quantify air quality and climate effects secondary aerosol (SOA) new particle formation (NPF). However, current models fail capture due absence reaction pathways. Here, we develop a novel unified model framework, integrated two-dimensional basis set (I2D-VBS), simulate by simultaneously representing first-generational oxidation, multigenerational aging, autoxidation, dimerization, nitrate formation, etc. The successfully reproduces O/C distributions oxygenated molecules (OOMs) as well concentrations SOA over wide-ranging experimental conditions. In typical urban environments, autoxidation are two main pathways for OOMs with similar contributions, but contributes more low-volatility products. NOx can reduce about two-thirds SOA, most extremely compared clean conditions, suppressing dimerization autoxidation. I2D-VBS facilitates holistic product which helps fill large gap in predictions NPF, growth, formation.

Язык: Английский

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