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.