Catalytic conversion of isopropanol over NiO/MgO system doped with Li2O

The effects of Li2O-doping on the surface and catalytic properties of NiO/MgO system have been investigated. The extent of NiO loading was varied between 4.8 and 28.6 mol% and the dopant concentration was changed between 1 and 6 mol% Li2O. Pure and variously doped solids were subjected to heat treatment at 400-600degreesC. The techniques employed for characterization of different solids were IR, XRD, nitrogen adsorption at - 196degreesC and catalytic conversion of isopropanol at different reaction temperatures ranged between 200 and 400degreesC. The results revealed that Li2O doping increases more the reactivity of MgO support material to interact with atmospheric water vapor during the cooling of the doped solids from 400degreesC to room temperature. The S-BET of the investigated system was found to increase by increasing Li2O-doping conducted at 600degreesC and opposite trend was found in the case of the doped solids precalcined at 400degreesC. The catalytic activity in isopropanol conversion, which proceeds via dehydration yielding acetone increases as a function of extent of loading and decreases by increasing the precalcination temperature from 400 to 600degreesC and increasing the dopant content. The doping process did not modify the activation energy of the catalyzed reaction but rather changed the concentration of the catalytic active constituents without changing their energetic nature. (C) 2003 Elsevier B.V. All rights reserved.