Multiphase Chemistry Group

The Multiphase Chemistry group performs laboratory studies related to the chemistry, photochemistry and kinetics of atmospheric multiphase processes involving organic, halogen, nitrogen oxide and odd oxygen species on substrates relevant for aerosol particles, cirrus ice, ocean surface, soil surfaces, snow and sea ice. Understanding these processes is relevant for the assessment of the human impact on atmospheric composition, climate, human and ecosystem health.
We use a combination of in-situ spectroscopy, flow tube and chamber techniques to cover scales from molecular level world of interfaces to the microstructure in aerosol particles and to the mesosopic medium of snow.
We educate young scientists in laboratory atmospheric chemistry within the frame of the Institute of Atmospheric and Climate Sciences (IAC) at ETH Zürich (Department of Environmental Systems Sciences, D-USYS).

overview ReCLEAN

ReCLEAN - Reactive nitrogen at the CLimate, Energy, Agriculture, water, and health Nexus

ETH Domain Joint Initiative: Reactive nitrogen at the CLimate, Energy, Agriculture, water, and health Nexus (ReCLEAN)

Aerosol Multiphase Photochemistry

Multiphase Photochemistry

The interplay between reactive oxygen species and the multiphase chemistry of nitrogen, halogen and secondary organic species in aerosol particles. Reactive oxygen species are at the origin of redox processes within the aqueous phase of aerosol particles containing secondary organic and inorganic species. The consequences are halogen and nitrogen oxides recycling, formation and loss of organics, which are all implicated in atmospheric oxidation capacity as well as the burden and health impact of aerosol particles. 

AcidBaseIce

Interfacial Ice Chemistry

Interfacial Ice Chemistry: Photolysis and Acid-Base Equilibria in the QLL and Brine. Dissociation and photochemistry of nitric acid and nitrous acid at frozen and liquid air-water interfaces have since long attracted scientific interest, most notably due to the pivotal role that this surface chemistry plays in modifying the nitrogen oxide budget and thus the oxidative capacity of the atmosphere.

Confinement

Chemistry of confined water

The hydrogen bonding network of interfacial nano-confinements in clay. Clays are composed of crystalline aluminosilicate layers that may be held together by hydrogen bonds of embedded water. This project investigates the local chemical environment of ions in the interlayer space of clay and the structure of the hydrogen-bonding network at subfreezing temperatures.

teaser for STXM

Scanning Transmission Microscopy for Environmental and Energy Research

We develop Scanning Transmission X-ray Microspectroscopy for environmental and energy research at the Swiss Light Source.

Napp

X-ray excited photoelectron spectroscopy for environmental science

We investigate multiphase chemistry of atmospheric relevance at the air-water and air-solid interfaces using X-ray excited electron spectroscopy  at the SIM & Phoenix & ISS endstations at the Swiss Light Source (SLS) and the ALS at the Lawrence Berkeley National Laboratory.

Evolution of a research project

FAIR data visualization

IVDAV : Instant and versatile data visualization during the current dark period of the life cycle of FAIR research. This project develops changes to current data treatment exploring and prototyping processes to foster teamwork, effective communication, and improved data visualization to the benefit of the entire atmospheric chemistry research community. 

A complete publication list is available at the institutional repository (DORA PSI).

  • Chen S, Abouhaidar R, Artiglia L, Yang H, Boucly A, Iezzi L, et al.
    Influence of surfactants with differently charged headgroups on the surface propensity of bromide
    Journal of Physical Chemistry A. 2025; 129(13): 3085-3097. https://doi.org/10.1021/acs.jpca.4c07539
    DORA PSI
  • Mishra A, Kilchhofer K, Iezzi L, Pöschl U, Alpert PA, Ammann M, et al.
    Photochemical degradation of iron citrate in anoxic viscous films enhanced by redox cascades
    ACS Earth and Space Chemistry. 2025. https://doi.org/10.1021/acsearthspacechem.4c00364
    DORA PSI
  • Richter C, Gholami S, Manoharan Y, Buttersack T, Longetti L, Artiglia L, et al.
    Uptake of ammonia by ice surfaces at atmospheric temperatures
    Faraday Discussions. 2025. https://doi.org/10.1039/d4fd00169a
    DORA PSI
  • Vattioni S, Peter T, Weber R, Dykema JA, Luo B, Stenke A, et al.
    Injecting solid particles into the stratosphere could mitigate global warming but currently entails great uncertainties
    Communications Earth & Environment. 2025; 6(1): 132 (10 pp.). https://doi.org/10.1038/s43247-025-02038-1
    DORA PSI
  • Alpert PA, Corral Arroyo P, Ammann M
    Microanalytical studies of multiphase reactions and particle aging
    In: Conny JM, Buseck PR, eds. Microanalysis of Atmospheric Particles Microanalysis of atmospheric particles: techniques and applications. Geophysical monograph series. Hoboken: Wiley; 2024:201-222. https://doi.org/10.1002/9781119554318.ch10
    DORA PSI
  • Ammann M, Alpert PA, Artiglia L, Bao F, Bartels-Rausch T, Ospina JFF, et al.
    Multiphase chemistry in the atmosphere
    Chimia. 2024; 78(11): 754-761. https://doi.org/10.2533/chimia.2024.754
    DORA PSI
  • Buttersack T, Gladich I, Gholami S, Richter C, Dupuy R, Nicolas C, et al.
    Direct observation of the complex S(IV) equilibria at the liquid-vapor interface
    Nature Communications. 2024; 15(1): 8987 (8 pp.). https://doi.org/10.1038/s41467-024-53186-5
    DORA PSI
  • De Angelis D, Longetti L, Bonano G, Cresi JSP, Foglia L, Pancaldi M, et al.
    A sub-100 nm thickness flat jet for extreme ultraviolet to soft X-ray absorption spectroscopy
    Journal of Synchrotron Radiation. 2024; 31(Part 3): 605-612. https://doi.org/10.1107/S1600577524001875
    DORA PSI
  • Decker ZCJ, Alpert PA, Ammann M, Anet JG, Bauer M, Cui T, et al.
    Emission and formation of aircraft engine oil ultrafine particles
    ACS ES&T Air. 2024; 1(12): 1662-1672. https://doi.org/10.1021/acsestair.4c00184
    DORA PSI
  • Fauré N, Chen J, Artiglia L, Ammann M, Bartels-Rausch T, Kanji ZA, et al.
    Formation of sodium chloride on the surface of sulfate-rich gobi desert salt in response to water adsorption
    ACS ES&T Air. 2024; 1(11): 1373-1382. https://doi.org/10.1021/acsestair.4c00092
    DORA PSI
  • Garner NM, Top J, Mahrt F, El Haddad I, Ammann M, Bell DM
    Iron-containing seed particles enhance α-pinene secondary organic aerosol mass concentration and dimer formation
    Environmental Science and Technology. 2024; 58(38): 16984-16993. https://doi.org/10.1021/acs.est.4c07626
    DORA PSI
  • Knopf DA, Ammann M, Berkemeier T, Pöschl U, Shiraiwa M
    Desorption lifetimes and activation energies influencing gas-surface interactions and multiphase chemical kinetics
    Atmospheric Chemistry and Physics. 2024; 24(6): 3445-3528. https://doi.org/10.5194/acp-24-3445-2024
    DORA PSI
  • Kuhn J, Stutz J, Bartels-Rausch T, Thomas JL, Cesler-Maloney M, Simpson WR, et al.
    The interplay between snow and polluted air masses in cold urban environments
    Faraday Discussions. 2024. https://doi.org/10.1039/d4fd00176a
    DORA PSI
  • Nikkho S, Bai B, Mahrt F, Zaks J, Peng L, Kiland KJ, et al.
    Secondary organic aerosol from biomass burning phenolic compounds and nitrate radicals can be highly viscous over a wide relative humidity range
    Environmental Science and Technology. 2024; 58(49): 21702-21715. https://doi.org/10.1021/acs.est.4c06235
    DORA PSI
  • Reza M, Iezzi L, Finkenzeller H, Roose A, Ammann M, Volkamer R
    Iodine activation from iodate reduction in aqueous films via photocatalyzed and dark reactions
    ACS Earth and Space Chemistry. 2024; 8(12): 2495-2508. https://doi.org/10.1021/acsearthspacechem.4c00224
    DORA PSI
  • Sellegri K, Simó R, Wang B, Alpert PA, Altieri K, Burrows S, et al.
    Influence of open ocean biogeochemistry on aerosol and clouds: recent findings and perspectives
    Elementa: Science of the Anthropocene. 2024; 12(1): 00058 (35 pp.). https://doi.org/10.1525/elementa.2023.00058
    DORA PSI
  • Testa B, Durdina L, Alpert PA, Mahrt F, Dreimol CH, Edebeli J, et al.
    Soot aerosols from commercial aviation engines are poor ice-nucleating particles at cirrus cloud temperatures
    Atmospheric Chemistry and Physics. 2024; 24(7): 4537-4567. https://doi.org/10.5194/acp-24-4537-2024
    DORA PSI
  • Alpert PA, Bernard F, Connolly P, Crabeck O, George C, Kaiser J, et al.
    Application of simulation chambers to investigate interfacial processes
    In: Doussin J-F, Fuchs H, Kiendler-Scharr A, Seakins P, Wenger J, eds. A practical guide to atmospheric simulation chambers. Cham: Springer Nature; 2023:293-330. https://doi.org/10.1007/978-3-031-22277-1_8
    DORA PSI
  • Bartels-Rausch T, Ammann M
    It is time to introduce the next generation of chemists to FAIR and open science
    Chimia. 2023; 77(10): 694-696. https://doi.org/10.2533/chimia.2023.694
    DORA PSI
  • Bartels-Rausch T, Gabathuler JP, Yang H, Manoharan Y, Artiglia L, Ammann M
    Removing gas-phase features in near ambient pressure partial Auger-Meitner electron yield oxygen K-edge NEXAFS spectra
    Journal of Electron Spectroscopy and Related Phenomena. 2023; 264: 147320 (7 pp.). https://doi.org/10.1016/j.elspec.2023.147320
    DORA PSI
  • Chen J, Jiang H, Chen X, Wang J, Huang D, Lian C, et al.
    A novel mechanism for NO2-to-HONO conversion on soot: synergistic effect of elemental carbon and organic carbon
    Environmental Science and Technology Letters. 2023; 10(10): 878-884. https://doi.org/10.1021/acs.estlett.3c00624
    DORA PSI
  • Fauré N, Chen J, Artiglia L, Ammann M, Bartels-Rausch T, Li J, et al.
    Unexpected behavior of chloride and sulfate ions upon surface solvation of Martian salt analogue
    ACS Earth and Space Chemistry. 2023; 7(2): 350-359. https://doi.org/10.1021/acsearthspacechem.2c00204
    DORA PSI
  • Hong AC, Ulrich T, Thomson ES, Trachsel J, Riche F, Murphy JG, et al.
    Uptake of hydrogen peroxide from the gas phase to grain boundaries: a source in snow and ice
    Environmental Science and Technology. 2023; 57(31): 11626-11633. https://doi.org/10.1021/acs.est.3c01457
    DORA PSI
  • Jeong D, McNamara SM, Chen Q, Mirrielees J, Edebeli J, Kulju KD, et al.
    Quantifying the contributions of aerosol- and snow-produced ClNO2 through observations and 1D modeling
    ACS Earth and Space Chemistry. 2023; 7(12): 2548-2561. https://doi.org/10.1021/acsearthspacechem.3c00237
    DORA PSI
  • Kiland KJ, Mahrt F, Peng L, Nikkho S, Zaks J, Crescenzo GV, et al.
    Viscosity, glass formation, and mixing times within secondary organic aerosol from biomass burning phenolics
    ACS Earth and Space Chemistry. 2023; 7(7): 1388-1400. https://doi.org/10.1021/acsearthspacechem.3c00039
    DORA PSI
  • Knopf DA, Alpert PA
    Atmospheric ice nucleation
    Nature Reviews Physics. 2023; 5: 203-217. https://doi.org/10.1038/s42254-023-00570-7
    DORA PSI
  • Kong X, Gladich I, Fauré N, Thomson ES, Chen J, Artiglia L, et al.
    Adsorbed water promotes chemically active environments on the surface of sodium chloride
    Journal of Physical Chemistry Letters. 2023; 14(26): 6151-6156. https://doi.org/10.1021/acs.jpclett.3c00980
    DORA PSI
  • Kärcher B, Marcolli C, Mahrt F
    The role of mineral dust aerosol particles in aviation soot-cirrus interactions
    Journal of Geophysical Research: Atmospheres. 2023; 128(3): e2022JD037881 (15 pp.). https://doi.org/10.1029/2022JD037881
    DORA PSI
  • Mahrt F, Rosch C, Gao K, Dreimol CH, Zawadowicz MA, Kanji ZA
    Physicochemical properties of charcoal aerosols derived from biomass pyrolysis affect their ice-nucleating abilities at cirrus and mixed-phase cloud conditions
    Atmospheric Chemistry and Physics. 2023; 23(2): 1285-1308. https://doi.org/10.5194/acp-23-1285-2023
    DORA PSI
  • Mallet MD, Humphries RS, Fiddes SL, Alexander SP, Altieri K, Angot H, et al.
    Untangling the influence of Antarctic and Southern Ocean life on clouds
    Elementa: Science of the Anthropocene. 2023; 11(1): 00130 (18 pp.). https://doi.org/10.1525/elementa.2022.00130
    DORA PSI
  • Vattioni S, Luo B, Feinberg A, Stenke A, Vockenhuber C, Weber R, et al.
    Chemical impact of stratospheric alumina particle injection for solar radiation modification and related uncertainties
    Geophysical Research Letters. 2023; 50(24): e2023GL105889 (10 pp.). https://doi.org/10.1029/2023GL105889
    DORA PSI
  • Yao Y, Alpert PA, Zuend A, Wang B
    Does liquid-liquid phase separation impact ice nucleation in mixed polyethylene glycol and ammonium sulfate droplets?
    Physical Chemistry Chemical Physics. 2023; 25(1): 80-95. https://doi.org/10.1039/d2cp04407b
    DORA PSI