Mw. Breiter et al., VOLTAMMETRIC STUDIES OF ELECTROCHEMICAL PROCESSES AT THE INTERFACE PTBICUVOX.10 BETWEEN 300-DEGREES-C AND 600-DEGREES-C/, Electrochimica acta, 43(3-4), 1998, pp. 325-334
Electrochemical processes occurring at the interface Pt/BICUVOX.10 wer
e investigated by cyclic voltammetry and potentiostatic current-potent
ial curves, taken under steady-state conditions, in different mixtures
of nitrogen and oxygen at temperatures between 300 and 600 degrees C.
Similar experiments were carried out for comparison at the Pt/YSZ int
erface. Point or paste electrodes were used. The equilibrium of the ox
ygen electrode is not established below 500 degrees C at both interfac
es any more. Reasons for this behavior are presented. It is concluded
on the basis of a comparison of the shape of voltammograms at differen
t interfaces that BICUVOX.10 is reduced and oxidised electrochemically
. Simultaneously a reoxidation of the solid elctrolyte by O-2 from the
gas phase occurs. At temperatures below 500 degrees C the reoxidation
is not fast enough to avoid a hysteresis at cathodic currents of the
voltammograms. At higher temperatures and larger partial pressures of
O-2 the hysteresis disappears. (C) 1997 Elsevier Science Ltd.