Preparation of Pt-YSZ nanocomposites by MOCVD and their electrochemical properties

Pt-YSZ nanocomposites were prepared on amorphous quartz substrates by using a horizontal hot-wall MOCVD apparatus. Pt-, Y- and Zr-acetylacetonates were used as the precursors for the composite synthesis. The precursors were mixed and evaporated together (220 °C) to achieve the codeposition. Oxygen was employed as a carrier and reactive gas with a flow rate of 130 cm ³/min. The deposition temperature (T_dep) was fixed at 600 °C and the total pressure (P_tot) was controlled at 1.0 Torr. TEM observations revealed that the composites are constituited by singlephase particles of about 25 nm in size, with an excellent component distribution. The intrinsic properties of these composites such as catalytic activity, electric conductivity and thermal stability make them attractive for electrodes of zirconia-based solid electrolyte devices. The Pt-YSZ nanocomposites were deposited on YSZ pellets to investigate their electrochemical properties. The electrochemical measurements were carried out in a potentiostat/galvanostat with an impedance/gain-phase analyzer interface in the temperature range of 300-800 °C in air. MOCVD Pt-YSZ nanocomposites showed superior electrochemical properties than Pt-C and conventional Pt paste electrodes.