Department of Chemistry

 

Date of this Version

2017

Citation

NATURE COMMUNICATIONS | 8: 700 | DOI: 10.1038/s41467-017-00823-x.

Comments

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License.

Abstract

Oxidation of bromide in aqueous environments initiates the formation of molecular halogen compounds, which is important for the global tropospheric ozone budget. In the aqueous bulk, oxidation of bromide by ozone involves a [Br•OOO] complex as intermediate. Here we report liquid jet X-ray photoelectron spectroscopy measurements that provide direct experimental evidence for the ozonide and establish its propensity for the solution-vapor interface. Theoretical calculations support these findings, showing that water stabilizes the ozonide and lowers the energy of the transition state at neutral pH. Kinetic experiments confirm the dominance of the heterogeneous oxidation route established by this precursor at low, atmospherically relevant ozone concentrations. Taken together, our results provide a strong case of different reaction kinetics and mechanisms of reactions occurring at the aqueous phase-vapor interface compared with the bulk aqueous phase.

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