Theoretical study of the adsorption of Methyl Iodide on model sea-salt surfaces

Oceans, through algae and phytoplankton activities, are the main source of iodine, including monohalogenated organic compounds as CH₃I [1].  There is missing knowledge about interactions between iodinated compounds and aerosols in the troposphere. In this context, this work investigates the adsorption of gaseous iodomethane (CH₃I) on model sea-salt aerosols at various humidities. The water coverage tends to stabilize CH₃I at the salt surface. The lifetime of CH₃I in the atmosphere (in gas phase or adsorbed on aerosols) may be altered by its reaction with gas phase radicals. The reaction of CH₃I with OH is thus investigated both in gas phase and in presence of water by means of quantum mechanical calculations.

 

References:

[1] Saiz-Lopez et al, Chem. Rev. 2012, 112, 1773–1804.

 

Acknowledgments:

I-SITE ULNE OVERSEE project (contract ANR-16-IDEX-004)

The CaPPA project (Chemical and Physical Properties of the Atmosphere) is funded by the French National Research Agency (ANR) through the PIA (Programme d’Investissement d’Avenir) under contract « ANR-11-LABX-0005-01 » and by the Regional Council « Hauts-de-France » and the « European Funds for Regional Economic Development » (FEDER)