SURFACE ELECTROCHEMISTRY OF OXIDES - THERMODYNAMIC AND MODEL APPROACHES

Surface phenomena on the oxide-with-metallic conductivity/electrolyte- solution interface are considered. In the simplest case they are gover ned both by the solution pH and the ratio of metal components in diffe rent valency states (oxide stoichiometry) in the solid phase. For such oxides, the electrocapillary curve can be transformed into the electr ocapillary surface in the space of three or more dimensions. Model app roaches must take this into account and explain the existence of the i nversed potential of zero free charge (pzfc) (at constant pH), the inv ariance of charge-pH curves for certain oxides, the peculiarity of Par sons-Zobel dependences, and the ''super-Nernstian'' behaviour of oxide s. Copyright (C) 1996 Published by Elsevier Science Ltd