Preparation and Characterization of Platinum–Ceramic Composite Powders and Thin Films

Pt–ceramaic (TiO₂, ZrO₂, and ZrO₂–5 mol% Y₂O₃ (PSZ)) composite powders were prepared by liquid-phase reaction. These composite powders show highly functional properties such as the following. The sintered films of these powders are good metallic conductors. The resistivity of the Pt–PSZ film at room temperature is about 1.5 × 10⁻⁵Ω·cm, which is almost comparable to that of pure platinum (1.05 × 10⁻⁵Ω·cm). This film shows excellent cathodic oxygen reduction. The overpotential for the oxygen reduction at 750°C is less than 20 mV even at a high current density of 0.1 A/cm². The Pt–TiO₂ composite powders have highly catalytic activity for the reduction of NO gas.