Study of a Layered Au, Pt-YSZ Mixed-Potential Sensing Electrode by ESEM, XRD and GD-OES with Relation to Its Electrochemical Behaviour

摘要

Morphological and structural properties of layered Au, Pt-YSZ mixed-potential gas sensing electrodes (APE) prepared under different temperature treatments were studied by environmental scanning electron microscope (ESEM) and glow-discharge optical emission spectroscopy (GD-OES), and correlated with open-circuit potential (OCP) and cyclic voltammetry (CV) measurements under gas exposures at elevated temperatures. The OCP response of the APE sintered at 1050 ?°C is clearly higher than that of the APE sintered at 850 ?°C, and can be well correlated with a smaller oxygen reduction reaction (ORR) observed in the related CV diagrams. Moreover, a transition from the charge transfer reaction kinetics to the diffusional transport controlled mixed-potential formation was found between 550 ?°C and 650 ?°C.