Measurement report: Rapid oxidation of phenolic compounds by O 3 and HO : effects of air-water interface and mineral dust in tropospheric chemical processes

Huo, Yanru; Li, Mingxue; Wang, Xueyu; Sun, Jianfei; Zhou, Yuxin; Ma, Yuhui; He, Maoxia

Environmental media affect the atmospheric oxidation processes of phenolic compounds (PhCs) released from biomass burning in the troposphere. Phenol (Ph), 4-hydroxybenzaldehyde (4-HBA), and vanillin (VL) are chosen as model compounds to investigate their reaction mechanism and kinetics at the air-water (A-W) interface, on TiO 2 clusters, in the gas phase, and in bulk water using a combination of molecular dynamics simulation and quantum chemical calculations. Of them, Ph was the most reactive one. The occurrence percentages of Ph, 4-HBA, and VL staying at the A-W interface are ~72 %, ~68 %, and ~73 %, respectively. As the size of (TiO 2) n clusters increases, the adsorption capacity decreases until n > 4, and beyond this, the capacity remains stable. A-W interface and TiO 2 clusters facilitate Ph and VL reactions initiated by the O 3 and HO , respectively. However, oxidation reactions of 4-HBA are little affected by environmental media because of its electron-withdrawing group. The O 3- and HO•-initiated reaction rate constant ( k) values follow the order of Ph A-W > VL TiO2 > VL A-W > 4-HBA A-W > 4-HBA TiO2 > Ph TiO2 and VL TiO2 > Ph A-W > VL A-W > 4-HBA TiO2 > Ph TiO2 > 4-HBA A-W, respectively. Some byproducts are more harmful than their parent compounds, so should be given special attention. This work provides key evidence for the rapid oxidation observed in the O 3/HO + PhCs experiments at the A-W interface. More importantly, differences in oxidation of PhCs by different environmental media due to the impact of substituent groups were also identified.

Zitieren

Zitierform:

Huo, Yanru / Li, Mingxue / Wang, Xueyu / et al: Measurement report: Rapid oxidation of phenolic compounds by O3 and HO•: effects of air-water interface and mineral dust in tropospheric chemical processes. 2024. Copernicus Publications.

Zugriffsstatistik

Gesamt:
Volltextzugriffe:
Metadatenansicht:
12 Monate:
Volltextzugriffe:
Metadatenansicht:

Grafik öffnen

Rechte

Rechteinhaber: Yanru Huo et al.

Nutzung und Vervielfältigung:

Export