Catalytic Conversion of Ethanol over γ-Irradiated CuO/MgO

Abstract

Copper oxide supported on MgO was prepared by the wet impreg- nation method using basic magnesium carbonate and copper nitrate. Thus, a known weight of basic magnesium carbonate was treated with a known amount of copper nitrate dissolved in the least amount of distilled water necessary to make a paste. The paste was dried and then precalcined for 5 h at 400o C, 500o C or 600o C, respectively. The solids obtained were exposed to different doses of -rays rang- ing between 0.2 MGy and 1.6 MGy. Catalytic conversion of ethanol was carried out at 250-400o C over various irradiated solids employing a micropulse tech- nique. Other techniques used were nitrogen adsorption measurements at -196oC, IR spectroscopy and XRD measurements. The results obtained revealed that all the catalysts investigated were selective towards dehydration, their activities decreasing slightly on increasing the precalcination temperature over the range 400 -600oC. -Irradiation brought about a progressive decrease in their catalytic activities with a dose of 0.8 MGy being sufficient to effect a decrease of more than 90% in the initial value. The irradiated catalysts regained virtually all their initial activity upon increasing the -ray dose to 1.6 MGy. These results were discussed in terms of the progressive removal of OH groups from the solid surface by exposure to -irradiation in the range 0.2 -0.8 MGy. The attainment of the initial catalytic activity upon exposure to a dose of 1.6 MGy was attributed to the creation of surface OH groups due to the interaction between the catalyst samples and water liberated during the early stages of the dehydration reaction.