Collection of Czechoslovak Chemical Communications - digital archive 

Abstract

In contrast to a number of investigations concerning preparation of layers and coatings of palladium(II) oxides this communication describes a reproducible electrolytic preparation from activation baths containing Pd(II) ions of coatings with hydrated palladium oxides, in particular on platinum supports. The voltammetric curves of coatings formed in such a way are reproducible over the whole pH range and exhibit an irreversible cathodic-anodic couple of peaks. For the voltammetric curve on an active layer deposited on a platinum support from a solution of Pd(NO₃)₂ at pH 7.03 E^k_p is + 0.02 V and E^a_p +0.33 V (vs SCE). The observed character of the pH dependences for the peak potentials and current densities with a similar, mostly linear, behaviour has been also observed with layers deposited on glassy carbon or nickel. The deposited layers containing hydrated palladium oxides exhibit oxidative activity as follows from voltammograms in slightly acidic to neutral and strongly alkaline region. These curves point to the ability to oxidize not only ethanol but also toluene used as a with difficulty oxidizable model substrate.