Surface evolution of the Sn–Ce–O powders in various atmospheres

Tin and cerium based oxide ceramics, due to their peculiar properties, are good candidates for using as sensors, solid electrolytes in fuel cells, and catalysts. In the present work, Sn–Ce–O powders with the composition of interest for catalysis applications were obtained by solid state reactions and by thermal decomposition of the different tin and cerium precursors. The structural characterization of the resulted samples was performed by X-ray diffraction. Morphological characteristics were evaluated from X-ray microstructural parameters and BET surface areas measurements. Surface evolution of the studied powders was investigated by electrical measurements in various atmospheres in the 25–400 °C temperature range. The samples studied behave as a n-type semiconductor. The catalytic activity for CO oxidation was measured in gas flow between 25 and 400 °C. The conversion degree depends on the preparation method of the samples. Magnetic susceptibility measurements at room temperature of the samples before and after catalytic test indicated a paramagnetic behavior. Higher values of magnetic susceptibility of the samples after catalytic test compared to initial ones could indicate the influence of CeO2 on the catalytic activity.