Catalytic conversion of ethanol over Co3O4/MgO system treated with γ-irradiation

The catalytic conversion of ethanol over Co3O4/MgO system was conducted at temperatures that ranged between 250 and 400 degreesC using microcatalytic pulse method, with the extent of cobalt oxide varied between 4.76 and 16.70 mol%. The prepared catalyst samples precalcined at 500 degreesC were subjected to different doses of gamma-irradiation that ranged between 0.2 and 1.6 MGy. The results obtained revealed that gamma-irradiation resulted in progressive increase in specific surface area to an extent proportional to the absorbed dose of gamma-irradiation. This treatment resulted in a progressive decrease in the degree of crystallinity and particle size of Co3O4 phase. The employed MgO supported material precalcined at 500 degreesC exhibited no detectable catalytic activity in ethanol conversion at temperatures reaching 400 degreesC. On the other hand, all Co3O4/MgO samples exhibited convenient catalytic activity and acting as dehydration catalysts. The catalytic activity of the catalysts investigated increased by increasing the extent of cobalt oxide present and also by increasing the dose of gamma-irradiation. These results were discussed in terms of an effective increase in the concentration of the catalytically active constituent taking part in the dehydration reaction via decreasing the particle size of cobalt oxide phase. (C) 2002 Elsevier Science B.V. All rights reserved.