The results of a potentiodynamic anodic polarization study of palladium-based binary alloys such as Pd-Cu, Pd-Ag, Pd-Ni and Pd-Co indicate composition dependent polarization behavior in selected chloride media. In general, palladium appears to shift the potential region of active corrosion to noble values and to introduce active-passive polarization behavior. The results are explained by the electron donor acceptor theory of passivity based on chemisorption properties associated with transition metals such as Pd. However, chloride ions appear to cause significant destabilization of passivity by widening the potential region of active corrosion. Destabilization of passivation is more pronounced on Pd-Ni and Pd-Co systems indicating preferential adsorption of chloride ions on these electrode surfaces.
ASJC Scopus subject areas
- Metals and Alloys
- Industrial and Manufacturing Engineering