Abstract
The effects of MoO3 doping on the solid–solid interactions, surface and catalytic properties of Al2O3 solid were investigated using DTA, TG and XRD methods, N2 adsorption at −196°C and the catalytic conversion of isopropanol at 150–400°C using a flow technique under atmospheric pressure. The nominal composition of the mixed solid was 0.5MoO3:Al2O3. Pure and Mo oxide-treated solids were subjected to thermal treatment at 500–1000°C prior to surface and catalytic measurements.
The results showed that the Al2O3 support material when precalcined at 500°C exhibited the highest catalytic activity and selectivity towards isopropanol conversion (100% selective towards propylene formation). Moreover, loading MoO3 on Al2O3, followed by precalcination at 500°C, resulted in the formation of an active catalyst towards dehydration and dehydrogenation, especially for the reaction carried out below 200°C. Further increase in the precalcination temperature of Al2O3 from 500°C to 900°C resulted in a dramatic decrease in its dehydration activity due to the decrease in its surface area and surface acidity. The solids precalcined at 1000°C showed a maximum dehydrogenation activity for the catalytic reaction when the latter was carried out at 400°C.