The relation between surface acidity and MoO₃:Al₂O₃ ratio on the ternary mixed oxide catalysts for the conversion of propan-2-ol

Authors: HANI ZEIDAN, EBRU ERÜNAL, MUSTAFA ESEN MARTI

Abstract: In this study, ternary mixed oxide catalysts containing Al₂O₃-MoO₃-MgO and Al₂O₃-MoO₃-WO₃ were prepared with a changing ratio of MoO₃:Al₂O₃ 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 WO₃ possessed very strong acid sites, which cause higher catalytic activity than catalysts prepared from MgO. Besides, the ratio of MoO₃:Al₂O₃ was found to be directly proportional to the conversion yield for all catalysts. XRD results show that whole MgO reacted with Al₂O₃ and MoO₃ to form amorphous MgMoO₄ and MgAl₂O₄ phases during catalyst preparation. Furthermore, WO₃ reacted only with Al₂O₃ to form Al₂(WO₄)₃ and WO₃ phase was also detected in the final product. The higher surface acidity and catalytic activity of Al₂O₃-MoO₃-WO₃ catalyst referred to this WO₃ phase within the structure.

Keywords: Catalyst, mixed oxides, propene, surface acidity, ternary system

Full Text: PDF