A study of metal (Ni, Pt, Au)/yttria-stabilized zirconia interface in hydrogen atmosphere at elevated temperature

The properties of selected metal (Pt, Ni, Au)/YSZ single crystal interfaces have been investigated by current-voltage measurements and impedance spect roscopy. A three-electrode cell consisting of a quasi-point-contact metal w orking electrode and Pt reference and counter electrodes were constructed a nd studied under various conditions. The impedance response consists of at least two processes, both belonging to interfacial properties: a high frequ ency process with peak frequency between 10(4) and 10(3) Hz, and a low freq uency process with peak frequency between 0.5 and 50 Hz. An increase in ove rall electrochemical reaction rate and in the interfacial capacitance under prolonged anodic polarization was observed. A mechanism based on the spill over of oxide or hydroxide ions on the metal surface is proposed. (C) 2001 The Electrochemical Society.