EFFECTS OF HYDROGEN AT HIGH-TEMPERATURE ON ZNAL2O4 AND SN-ZNAL2O4

ZnAl2O4 and Sn-ZnAl2O4 were synthesized by coprecipitation, sol-gel an d impregnation methods. These materials were calcined and treated in H -2 at 1073 K. Thermal analysis (DTA and TG), nitrogen physisorption (B ET method), X-ray diffraction (XRD) and scanning electron microscopy ( SEM) were used as characterization techniques. H-2 treatment promoted AlxZny crystallization in the coprecipitated and impregnated samples. When tin was added to zinc aluminate, the tin acted as a protective sh ell against high-temperature reduction, independently of the preparati on technique.