Mechanism of the Hydrazine Hydrate Electrooxidation Reaction on Metallic Ni Electrodes in Alkaline Media as Revealed by Electrochemical Methods, Online DEMS and Ex situ XPS
Résumé
Metallic Ni surface was examined as a catalyst for the hydrazine hydrate oxidation reaction (HHOR) by cyclic voltammetry, chronoamperometry, and on-line differential electrochemical massspectrometry (DEMS). It was found that N2 is a sole gaseous product formed during the HHOR on Ni and 4 electrons are transferred in the process, which corresponds to a complete oxidation of the hydrazine molecule. The mechanism of the HHOR on the Ni surface involves OH -and adsorbed OHads intermediate, the latter improving the rate of the HHOR. Ni catalysts were found to be poisoned during the HHOR, the extent of poisoning depending on the number of surface sites, hydrazine concentration, and the α-Ni(OH)2 coverage. Ex situ X-ray photoelectron spectroscopy (XPS) measurements were performed to characterize the species poisoning Ni surface.
Domaines
Chimie| Origine | Fichiers produits par l'(les) auteur(s) |
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