Proton-ceramic fuel cells (PCFCs) are promising devices for electrochemical energy conversion purposes due to their combination of high energy efficiency, environmental friendliness, and high durability. In the present work, the polarization characteristics of promising electrodes for PCFCs based on BaFex Ce0.7−x Zr0.2 Y0.1 O3−δ (BCZYFx) are comprehensively studied. Along with the individual BCZYFx electrodes, we investigated a method for improving their electrochemical activity by introducing nanoparticles of PrOx electrocatalysts into the porous structure of the electrode mate-rial. According to the experimental data, electroactivation allowed for the polarization resistances of the electrodes at 700° C to be reduced from 1.16, 0.27, 0.62 Ω° cm2 to 0.09, 0.13, 0.43 Ω° cm2 for x = 0.5, 0.6, and 0.7, respectively. For a PCFC cell with an air electrode of BCZYF0.6 composition activated using PrOx nanoparticles, it was possible to achieve a maximum specific power of 300 mW cm−2 at 750° C, which is competitive for a single cell with Co-free cathodes. The results obtained provide insight into the processes occurring in the studied electrodes after electroactivation. It is shown how the improvement of electrochemical characteristics of the electrode can be realized by a simple infiltration method in combination with a subsequent thermal treatment. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.