Effect of y-irradiation on catalytic conversion of ethanol and isopropanol over pure and Na2O doped Mn2O3 /Al2O3

The catalytic conversion of ethanol and isopropanol had been carried out over pure and Na 2 O doped Mn 2 O 3 / A1 2 O 3 solids subjected to different doses of γ-radiation. The reaction temperature was varied between 200 to 350 °C, the extent of loading of manganese oxide was fixed at 9 mol% Mn 2 O 3 and the amounts of sodium oxide were 1.5 and 6 mol% Na 2 O. The radiation doses were 0.4, 0.8 and 1.6 MGy. The results obtained revealed that irradiation brought a progressive decrease in the catalytic activity of pure and doped solids towards dehydration of the investigated alcohols. The percentage conversion of ethanol measured at 300 °C over the 6 mol% Na 2 O treated sample was found to decrease from 99 to 35% upon exposure to 1.6 MGy. This dose effected a decrease in the total conversion of ethanol measured at 300 °C from 40 to 12% over the pure catalyst. A dose of 1.6 MGy effected a decrease in the total conversion of the isopropanol measured at 300 °C over pure catalyst from 57 to 30%, and from 92 to 4% for the doped catalyst sample. The significant decrease in the catalytic activity of the investigated solids due to γ-irradiation was discussed in terms of the progressive removal of surface OH groups of the treated solids.