Estudo comparativo por microscopia eletrônica de varredura da superfície de eletrodos de composição Ir0,3Ti(0,7-x)CexO2 antes e após serem submetidos às reações de oxigénio e cloro

Abstract

-

Ceramic oxide electrodes with nominal composition Ir0.3Ti(0.7-x)CexO2 (0≤x≤0.7) present a large variety of technological applications, especially in the electrochemical industry. They were prepared by thermal decomposition (450°C) of the precursors chlorides. A 2µm thick oxide layer was applied by brush on Ti supports (10x10x0.15mm). The morphological properties of these anodes are strongly influenced by the preparation process. In this work, the surface morphology of these electrodes has been determined by Scanning Electron Microscopy as a function of the composition, in fresh electrodes as well as after submission to high currents densities [~50mAcm-2), during oxygen and chlorine evolution reactions. It was observed that CeO2 provokes significant changes on the films morphology, increasing their surface area. This component provide a satisfactory mechanical stability to the electrodes, since after the oxygen and chlorine evolution reactions the films remained unaltered.