STSM by Jan Zabka, J. Heyrovsky Institute of Physical Chemistry of the ASCR, v. v. i., Prague (CZ), with Christian Alcaraz, Laboratoire de Chimie Physique, Orsay (FR)
On October 7th, 2014 (7 days)
From CZECH REPUBLIC to FRANCE
State-selected reactivity of CO2+ with CH4 of relevance for the modelling of plasma systems and the Earth atmosphere.
The purpose of the STSM was to perform a study the reactivity of CO2+ ions, generated in the electronic ground state with a known amount of vibrational excitation, with CH4. These reactions are of relevance for the modelling of plasma based dry reforming of methane and the chemistry of the Earth atmosphere.
The experiments was performed with the CERISES apparatus, (Collisions Et Réactions d’Ions Sélectionnés par Electrons de Seuil) an associated experiment to synchrotron SOLEIL. Vibrational state selection of CO2+ was performed via the Threshold Photoelectron Photoion Coincidence (TPEPICO) method using the cell ion source of CERISES and the DESIRS beamline. The photon energies were in the range from about 13.7 to 17.3 eV to produce the parent ion by photoionization.
Fig.1.: CERISES: Experimental setup
For the reactive systems described above, were obtaining an absolute cross sections (and hence branching ratios) and product velocity distributions for the various reaction pathways as a function of the vibrational excitation of CO2+ and at selected values of the collision energy within the 0.1 – 10 eV range.
From the dependences on the collision energy were get some insights onto the reaction dynamics, e.g. reaction mechanism or presence of energy barriers. The obtained cross sections and branching ratios will be useful to improve the predictability of chemical models for plasma based reforming of hydrocarbons and atmospheric chemistry.
Fig.2.: Exp. results: a) States of CO2+
Fig.2.: Exp. results: c) Collision energy dependences