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Automated, High-resolution Mobile Collection System for the Nitrogen Isotopic Analysis of NOx
Published on: December 20, 2016
Isotope evidence for ozone formation on surfaces
Christof Janssen1, Béla Tuzson
1Laboratoire de Physique Moléculaire pour l'Atmosphère et l'Astrophysique, Université Pierre et Marie Curie, case 76, 4 place Jussieu, 75252 Paris Cedex 05, France. janssen@lpmaa.jussieu.fr
The Journal of Physical Chemistry. A
|May 8, 2010
Summary
Ozone formation via electric discharge shows temperature-dependent isotope effects. Wall reactions contribute significantly to ozone production, influencing its isotopic composition.
Area of Science:
- Atmospheric Chemistry
- Isotope Geochemistry
- Plasma Physics
Background:
- Gas-phase ozone formation exhibits unusual isotope effects crucial for geochemistry and climate research.
- Limited understanding exists regarding similar nonstandard mass-dependent fractionations in other recombination reactions.
Purpose of the Study:
- To investigate the pressure and temperature dependence of isotopic composition in ozone formed by electric discharge in molecular oxygen.
- To assess the role of wall-assisted ozone formation in oxygen plasma chemistry and its potential implications for extraterrestrial environments.
Main Methods:
- Ozone was generated via electric discharge in molecular oxygen.
- Isotopic composition of ozone was analyzed under varying pressures and temperatures.
- Ozone formation on Pyrex reactor walls was quantified using the atom recombination coefficient.
Main Results:
- Low-pressure isotope signatures exhibited standard mass-dependent depletion, strongly influenced by temperature.
- Wall-assisted ozone formation was confirmed with a recombination coefficient of (0.4 ± 0.1)% at room temperature.
- Wall recombination coefficient values were slightly higher at lower temperatures.
Conclusions:
- Wall-assisted ozone formation is a significant, previously underestimated, component of oxygen plasma chemistry.
- This surface reaction mechanism could explain ozone presence on icy satellites.
- Surface recombination reactions are unlikely to produce the anomalous isotope effects observed in gas-phase ozone formation.
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