Abstract
The effects of Sm
2O
3 and Y
2O
3 doping of Fe
2O
3 on its surface and catalytic properties were investigated using nitrogen adsorption at −196
°C, oxidation of CO by O
2 at 225–275
°C and decomposition of H
2O
2 at 30–50
°C. Fe
2O
3 was prepared by thermal decomposition of ferric carbonate at 350
°C. The treated ferric oxide solid was prepared by wet impregnation method using finely powdered Fe
2(CO
3)
3 solid followed by doping with different amounts of samarium nitrate or yttrium nitrate. Pure and doped Fe
2O
3 solids were calcined at 350–650
°C. The extent of dopant added was varied between 1.0 and 6.0
mol%. The results obtained revealed that doping of Fe
2O
3 solids with different amounts of Sm
2O
3 and Y
2O
3 decreased the degree of crystallinity and particle size of Fe
2O
3 phase. This doping process led to a progressive increase in the specific surface area of the treated Fe
2O
3 solids to an extent proportional to the amount of Sm
2O
3 and Y
2O
3 added. The doping process led also to a progressive increase in the catalytic activities of the investigated solids towards CO oxidation by O
2 and H
2O
2 decomposition. Also, the doping process did not modify the mechanism of the catalytic reactions but increased the concentration of catalytically active sites involved in the catalyzed reactions.