Emissions of O− Radical Anions and Electrons from Silver on a Solid Electrolyte

The emissions of O− radical anions and electrons from a silver electrode on a solid electrolyte, yttria-stabilized zirconia (YSZ) or a quartz glass, have been observed using a quadrupole mass spectrometer. A simple experimental apparatus was designed to incorporate a gap between a silver electrode on a YSZ anode and a platinum space electrode. By applying a DC voltage across the gap, O− radical anions and electrons were observed. The results of Arrhenius plots with respect to O− show that the value of activation energy Ed for O− dissociation from a silver electrode on YSZ is approximately 91.5–142.3 kJ/mol with respect to different electric fields. These values are considerably lower than the bonding energy between silver and oxygen atoms (4.2 eV). It is suggested that the change in the activation energy of O− desorption with an electric field is due to the change of surface coverage of O− on silver and O− is correlated with backspillover oxygen.