Electrochemical Properties of Electrode Materials Based on Pr5Mo3O16 + δ

The electrochemical activity of electrode materials based on Pr5Mo3O16 + δ (РМО), and applied on the surface of Ce0.9Gd0.1O1.95 (GDC) solid electrolyte is studied in the temperature range from 873 to 1173 K under oxidative (air) and reductive (Ar/H2) conditions. The polarization resistance (Rη) at 1073 K is found to be 8.8 and 4.8 Ω cm2 in air and in the reductive atmosphere, respectively. With the aim of enhancing the electrochemical activity of РМО in the oxygen reduction reaction, the electrochemical properties of PМО–xGDC and PМО–xPr6O11 composite electrodes are studied in air. The PМО–xPr6O11 composites are shown to be the best choice from the viewpoint of attaining the high electrochemical efficiency. When going from single-phase РМО to the PMO–xPr6O11 composite, a considerable decrease in Rη is observed (by an order of magnitude for х = 50 wt % Pr6O11, i.e., to 0.6 Ω cm2 at 1073 K in air). The data obtained here show that PMO can serve as the basis in elaborating the electrode material for symmetrical solid-oxide fuel cells.