Some Physicochemical, Surface and Catalytic Properties of the MoO/AlO System

• Main Author: Nabil H. Amin
• Format: Article
• Language: English
• Published: Hindawi - SAGE Publishing 2000-06-01
• Series: Adsorption Science & Technology
• Online Access: https://doi.org/10.1260/0263617001493521

The effects of MoO 3 doping on the solid–solid interactions, surface and catalytic properties of Al 2 O 3 solid were investigated using DTA, TG and XRD methods, N 2 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 0.5MoO 3 :Al 2 O 3 . 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 Al 2 O 3 support material when precalcined at 500°C exhibited the highest catalytic activity and selectivity towards isopropanol conversion (100% selective towards propylene formation). Moreover, loading MoO 3 on Al 2 O 3 , 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 Al 2 O 3 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.