Direct observation of the complex S(IV) equilibria at the liquid-vapor interface
The multi-phase oxidation of S(IV) plays a crucial role in the atmosphere, leading to the formation of haze and severe pollution episodes. We here contribute to its understanding on a molecular level by reporting experimentally determined pK<sub>a</sub> values of the various S(IV) tautomers and reaction barriers for SO<sub>2</sub> formation pathways. Complementary state-of-the-art molecular-dynamics simulations reveal a depletion of bisulfite at low pH at the liquid-vapor interface, resulting in a different tautomer ratio at the interface compared to the bulk. On a molecular-scale level, we explain this with the formation of a stable contact ion pair between sulfonate and hydronium ions, and with the higher energetic barrier for the dehydration of sulfonic acid at the liquid-vapor interface. Our findings highlight the contrasting physicochemical behavior of interfacial versus bulk environments, where the pH dependence of the tautomer ratio reported here has a significant impact on both SO<sub>2</sub> uptake kinetics and reactions involving NO<sub>x</sub> and H<sub>2</sub>O<sub>2</sub> at aqueous aerosol interfaces.
Authors
- Lucia Iezzi
- Tillmann Buttersack (ORCID: https://orcid.org/0000-0002-4547-2656)
- Shirin Gholami (ORCID: https://orcid.org/0000-0002-0647-1490)
- Anthony Boucly (ORCID: https://orcid.org/0000-0003-1436-3462)
- Annette Trunschke (ORCID: https://orcid.org/0000-0003-2869-0181)
- Luca Artiglia (ORCID: https://orcid.org/0000-0003-4683-6447)
- Rémi Dupuy (ORCID: https://orcid.org/0000-0002-8372-2142)
- Evelyne A. Parmentier
- Markus Ammann (ORCID: https://orcid.org/0000-0001-5922-9000)
- Clemens Richter (ORCID: https://orcid.org/0000-0003-1807-1643)
- Antoine Roose (ORCID: https://orcid.org/0000-0001-5431-0184)
- Ivan Gladich (ORCID: https://orcid.org/0000-0003-0929-3439)
- Hendrik Bluhm (ORCID: https://orcid.org/0000-0001-9381-3155)
- Ruth Signorell (ORCID: https://orcid.org/0000-0003-1111-9261)
- Daniel Delgado (ORCID: https://orcid.org/0000-0002-2976-3322)
- Christophe Nicolas (ORCID: https://orcid.org/0000-0002-1396-0444)
- Florian Trinter (ORCID: https://orcid.org/0000-0002-0891-9180)
- Bernd Winter (ORCID: https://orcid.org/0000-0002-5597-8888)
- Pablo Corral Arroyo
Institutions
- Centre National de la Recherche Scientifique (FR)
- Institut Mines-Télécom (FR)
- Fritz Haber Institute of the Max Planck Society (DE)
- Synchrotron soleil (FR)
- Paul Scherrer Institute (CH)
- ETH Zurich (CH)
- Sorbonne Université (FR)
- Laboratoire de Chimie Physique - Matière et Rayonnement (FR)
- Hamad bin Khalifa University (QA)
Publication Details
- Journal
- Nature Communications
- Published
- 2024-10-18
- DOI
- https://doi.org/10.1038/s41467-024-53186-5
- Citations
- 15
- Primary Topic
- Atmospheric chemistry and aerosols
- Type
- article
- Field-Weighted Citation Impact
- 5.64
Funders
- National Science Foundation
- Alexander von Humboldt-Stiftung
- Qatar Foundation
- Hamad Bin Khalifa University
- European Commission
- Deutsche Forschungsgemeinschaft
- Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung
- Bundesministerium für Bildung und Forschung
- Max-Planck-Gesellschaft
- Deutsches Elektronen-Synchrotron