Study of obtaining dense ceramic membrane BaCeO3

ABSTRACT In recent years, ceramic powders based on oxides with structure of the perovskite have gained considerable attention due their technological applications in oxygen permeable membranes. The mixed oxide BaCeO3 is introduced as a broadly studied material in a large variety of uses, either as electrolyte materials for fuel cells, or as catalysts in catalysis reactions. Thus, this study had the goal to synthesize the BaCeO3 phase by coprecipitation method amid oxalate, verifying the effect of sintering with different binders in thermal stability and densification of the membrane. The co-precipitation technique in oxalate was effective to obtain the perovskite BaCeO3. The samples obtained during the syntheses were characterized by X-ray diffraction, and it was possible to notice the formation of the orthorhombic phase of perovskite BaCeO3. To stablish the average crystallite size it was used the equation of Scherrer and Williamson Hall, coming to a value close to 107 nm As the literature [1,2] and against the results defined as favorable conditions for formation of material with the smallest size of crystallite and greater purity of the phase formed the sample pH 13 and calcination temperature of 1000° C. By scanning electron microscopy (SEM) it could be seen the formation of homogeneous crystals. Finally, it was observed that the sintering in the presence of binders paraffin and polyvinyl alcohol at 1300ºC allowed the obtaining of dense pellets with good shrinkage levels, having ideal thermal stability for use as oxygen permeable membranes and as a fuel cell electrolyte.