Electrochemical Properties of Electrode Materials Based on Pr5Mo3O16+δ

The electrochemical activity of electrode materials based on Pr5Mo3O16 + delta (P\MO), 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/H-2) conditions. The polarization resistance (R-eta) at 1073 K is found to be 8.8 and 4.8 ohm cm(2) in air and in the reductive atmosphere, respectively. With the aim of enhancing the electrochemical activity of P\MO in the oxygen reduction reaction, the electrochemical properties of P\MO-xGDC and P\MO-xPr(6)O(11) composite electrodes are studied in air. The P\MO-xPr(6)O(11) composites are shown to be the best choice from the viewpoint of attaining the high electrochemical efficiency. When going from single-phase P\MO to the PMO-xPr(6)O(11) composite, a considerable decrease in R-eta is observed (by an order of magnitude for x = 50 wt % Pr6O11, i.e., to 0.6 ohm cm(2) 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.