CHARACTERISATION OF MIXED OXIDE CATALYSTS USED IN OXIDATION REDUCTION REACTIONS

Abstract

The study of decomposition of hydrogen peroxide on oxide catalysts has been given a relatively great attention. These oxide catalysts are mainly transition metal oxides, whihle possess high activity in this raaction . Mixed oxides are also active, and in some cases more active than either component of the mixture. The higher activity or the better selectivity of mixed oxides is generally explained on the basis of various types of interactions between the two component oxides. The present work is under taken and a characterization of the mixed transition metal oxides with correlation between the catalytic and solid state properties of Mn-oxide, Co-oxide, Ni-oxide, Mn-Ni, Mn-Co and Co-Ni mixed oxides is attempted. Pure and mixed oxide catalysts were prepared by pyrolysis of the corresponding carbonate. The pure and mixed salts were heated at 250, 500, 750 and I000°C for 4 h. X-ray diffraction patters are obtained and revealed that Mn CO3 and Ni CO3 Ni (OH). 4HO showed poorly crystalline oxide. the inc_rease of temperature of calcination increased the probability for the formation and / or increase of the degree of crystallinity of oxide .