In addition, the usage of the CeSSZ electrolyte with the
higher level of ionic conductivity in comparison to YSZ also leads to
increased electrochemical activity. After impregnation of the Nicermet
electrodes by cerium oxide their polarization resistance
reduced approximately by 2 orders of magnitude at 900 C (at
700 C approximately by 3 orders of magnitude) and was about
0.03 (0.06) for Ni-CeSSZ and 0.3 (1.33) Ohm cm2 for Ni-YSZ at 900
(700) C, respectively. The impregnation of Pt-YSZ cathode by
praseodymium oxide also resulted in decreasing the polarization
resistance approximately by 1 order of magnitude at all temperatures
studied. It should be noted that after impregnation the
cathode polarization resistance remained high in comparison with
high-activity cathodes [22]. The activation energies of the specific
polarization resistance are listed in Table 2. After impregnation the
activation energy of the Ni-CeSSZ and Pt-YSZ electrodes decreased
from 110 and 132 to 41 and 110 kJ mol1, respectively. It can be
suggested that the reaction mechanism changes. At the same time,
the activation energy of the Ni-YSZ electrode has not changed and
was about 70 kJ mol1. Authors of [23,24] also noted the decrease of
the activation energy of the electrode polarization resistance after
impregnation, nevertheless, in Ref. [22] almost has no change in
activation energy after impregnation was reported.