1. Experimental study of surface contributions to molecule formation in a recombining N2/O2 plasma
- Author
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Jürgen Röpcke, Rah Richard Engeln, S Stefan Welzel, DC Daan Schram, G Göksel Yagci, Rab Rens Zijlmans, Onno Gabriel, van Jh Jean-Pierre Helden, Department of Applied Physics [Eindhoven], Eindhoven University of Technology [Eindhoven] (TU/e), Leibniz Institute for Plasma Science and Technology (INP), Leibniz Association, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH (HZB), The Physical and Theoretical Chemistry Laboratory, University of Oxford [Oxford], Plasma & Materials Processing, and Plasma-based gas conversion
- Subjects
010302 applied physics ,Tunable diode laser absorption spectroscopy ,Acoustics and Ultrasonics ,Absorption spectroscopy ,Chemistry ,82.33.Xj ,Analytical chemistry ,52.50.Nr ,CHEMKIN ,02 engineering and technology ,Partial pressure ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Chemical kinetics ,52.40.Hf ,13. Climate action ,0103 physical sciences ,Atom ,Molecule ,0210 nano-technology ,Spectroscopy ,52.70.Kz - Abstract
International audience; A low pressure recombining Ar plasma to which mixtures of N 2 and O 2 were added has been studied to explore the relevance of surface related processes for the total chemistry. The abundances of the stable molecules N 2, O 2, NO, N 2 O and NO 2 have been measured by means of a combination of infrared tunable diode laser absorption spectroscopy and mass spectrometry. A gas phase chemical kinetics model was developed in chemkin to investigate the contribution of homogeneous interactions to the conversion of the feedstock gases N 2 and O 2. At a partial pressure of N 2 plus O 2 less than 8 Pa, significant discrepancies between measured and calculated concentrations of N 2 O and NO 2 were observed, indicating that heterogeneous processes are dominating the chemistry in this pressure range. At a partial pressure of N 2 plus O 2 higher than 40 Pa and a relatively high fraction of admixed O 2 we observed a fair agreement between measured and calculated concentrations of NO molecules, indicating that homogeneous processes (notably Natom induced) are more dominant than heterogeneous processes.
- Published
- 2010
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