The relation between surface acidity and MoO 3 :Al 2 O 3 ratio on the ternary mixed oxide catalysts for the conversion of propan-2-ol.

In this study, ternary mixed oxide catalysts containing Al 2 O 3 -MoO 3 -MgO and Al 2 O 3 -MoO 3 -WO 3 were prepared with a changing ratio of MoO 3 :Al 2 O 3 between 0.05 and 20.00. All catalysts showed 100% selectivity towards propene during the conversion of propan-2-ol at temperatures between 220 and 400 °C. The catalysts prepared from WO 3 possessed very strong acid sites, which cause higher catalytic activity than catalysts prepared from MgO. Besides, the ratio of MoO 3 :Al 2 O 3 was found to be directly proportional to the conversion yield for all catalysts. XRD results show that whole MgO reacted with Al 2 O 3 and MoO 3 to form amorphous MgMoO 4 and MgAl 2 O 4 phases during catalyst preparation. Furthermore, WO 3 reacted only with Al 2 O 3 to form Al 2 (WO 4 ) 3 and WO 3 phase was also detected in the final product. The higher surface acidity and catalytic activity of Al 2 O 3 -MoO 3 -WO 3 catalyst referred to this WO 3 phase within the structure.