Surface and catalytic properties of NiO-Fe2O3 solids supported on Al2O3

A series of NiO-Fe2O3 catalysts supported on gamma-Al2O3 was prepared. The effect of the NiO and Fe2O3 contents and the precalcination temperature on the surface and catalytic properties of the various solids has been investigated. The surface characteristics, viz. S-BET, V-p and (r) over bar, were determined using N-2 adsorption conducted at -196 degrees C. The catalytic activities of the various solids were studied using the oxidation of CO by O-2 at temperatures in the range between 150 degrees C and 400 degrees C. The prepared solids were preheated in air at various temperatures between 400 degrees C and 1000 degrees C. The results obtained revealed that the S-BET values of the different solids decrease progressively on increasing the precalcination temperature above 400 degrees C due to sintering. The specific surface areas were also found to decrease on increasing both the NiO and Fe2O3 contents. The catalytic activities, expressed as reaction rate constant (k) and reaction rate constant per unit area ((k) over bar), were found to decrease on increasing the precalcination temperature in the range 400-1000 degrees C. Furthermore, the amounts of NiO and Fe2O3 in the different solids modified their catalytic activities in different manners.