The gas-phase formation mechanism of iodic acid as an atmospheric aerosol source

Autor(en)

Henning Finkenzeller, Siddharth Iyer, Xu Cheng He, Mario Simon, Theodore K. Koenig, Christopher F. Lee, Rashid Valiev, Victoria Hofbauer, Antonio Amorim, Rima Baalbaki, Andrea Baccarini, Lisa Beck, David M. Bell, Lucía Caudillo, Dexian Chen, Randall Chiu, Biwu Chu, Lubna Dada, Jonathan Duplissy, Martin Heinritzi, Deniz Kemppainen, Changhyuk Kim, Jordan Krechmer, Andreas Kürten, Alexandr Kvashnin, Houssni Lamkaddam, Chuan Ping Lee, Katrianne Lehtipalo, Zijun Li, Vladimir Makhmutov, Hanna E. Manninen, Guillaume Marie, Ruby Marten, Roy L. Mauldin, Bernhard Mentler, Tatjana Müller, Tuukka Petäjä, Maxim Philippov, Ananth Ranjithkumar, Birte Rörup, Jiali Shen, Dominik Stolzenburg, Christian Tauber, Yee Jun Tham, António Tomé, Miguel Vazquez-Pufleau, Andrea C. Wagner, Dongyu S. Wang, Mingyi Wang, Yonghong Wang, Stefan K. Weber, Wei Nie, Yusheng Wu, Mao Xiao, Qing Ye, Marcel Zauner-Wieczorek, Armin Hansel, Urs Baltensperger, Jérome Brioude, Joachim Curtius, Neil M. Donahue, Imad El Haddad, Richard C. Flagan, Markku Kulmala, Jasper Kirkby, Mikko Sipilä, Douglas R. Worsnop, Theo Kurten, Matti Rissanen, Rainer Volkamer

Abstrakt

Iodine is a reactive trace element in atmospheric chemistry that destroys ozone and nucleates particles. Iodine emissions have tripled since 1950 and are projected to keep increasing with rising O₃ surface concentrations. Although iodic acid (HIO₃) is widespread and forms particles more efficiently than sulfuric acid, its gas-phase formation mechanism remains unresolved. Here, in CLOUD atmospheric simulation chamber experiments that generate iodine radicals at atmospherically relevant rates, we show that iodooxy hypoiodite, IOIO, is efficiently converted into HIO₃ via reactions (R1) IOIO + O₃ → IOIO₄ and (R2) IOIO₄ + H₂O → HIO₃ + HOI + ⁽¹⁾O₂. The laboratory-derived reaction rate coefficients are corroborated by theory and shown to explain field observations of daytime HIO₃ in the remote lower free troposphere. The mechanism provides a missing link between iodine sources and particle formation. Because particulate iodate is readily reduced, recycling iodine back into the gas phase, our results suggest a catalytic role of iodine in aerosol formation. [Figure not available: see fulltext.]

Organisation(en)

Aerosolphysik und Umweltphysik

Externe Organisation(en)

University of Colorado, Boulder, University of Tampere, University of Helsinki, Johann Wolfgang Goethe-Universität Frankfurt am Main, Tsinghua University, Peking University, Carnegie Mellon University, Universidade de Lisboa, Paul Scherrer Institute, École polytechnique fédérale de Lausanne, Chinese Academy of Sciences (CAS), Pusan National University (PNU), California Institute of Technology (Caltech), Aerodyne Res Inc, Russian Academy of Sciences, Finnish Meteorological Institute, University of Eastern Finland, Moscow Institute of Physics and Technology, European Organization for Nuclear Research (CERN), Leopold-Franzens-Universität Innsbruck, University of Leeds, Sun Yat-sen University, Universidade da Beira Interior, Nanjing University, Université de La Réunion, Beijing University of Chemical Technology

Journal

Nature Chemistry

Band

15

Seiten

129-135

Anzahl der Seiten

7

ISSN

1755-4330

DOI

https://doi.org/10.1038/s41557-022-01067-z

Publikationsdatum

01-2023

Peer-reviewed

Ja

ÖFOS 2012

105208 Atmosphärenchemie, 103039 Aerosolphysik, 103037 Umweltphysik

ASJC Scopus Sachgebiete

Allgemeine Chemie, Allgemeine chemische Verfahrenstechnik

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/c8c7d507-c11c-4b0c-bd97-5fc3b66d569f