Effect of Al2O3and MoO3Doping of Co3O4Solid on its Surface and Catalytic Properties

Abstract

Pure and doped Co3O4 samples were prepared by thermal decomposition at 500–1000°C of pure basic cobalt carbonate and of the basic carbonate treated with aluminium nitrate and ammonium molybdate. The amounts of dopants added were varied within the range 0.75–6 mol% Al2O3, and 0.025–6 mol% MoO3. The influence of this treatment on the specific surface areas and catalytic activities of the Co3O4 solids was investigated using nitrogen adsorption at −196°C and studies of the decomposition of H2O2 at 30–50°C.The results obtained revealed that doping of cobaltic oxide solids with either Al2O3 or MoO3, followed by calcination at 500°C and 700°C, resulted in a progressive increase in the BET surface areas. This increase was, however, more pronounced in the case of MoO3 doping. Calcination of the doped solids at 900°C led to an increase in the BET surface areas of the Al2O3-treated solids and to a small decrease in the specific surface areas of the MoO3-doped samples.Calcination of the variously doped solids at 500–...