Catalytic dehydration of 2 propanol over Al2O3-Ga2O3 and Pd/Al2O3-Ga2O3 catalysts

A series of mixed Al2O3-Ga2O3 oxides were prepared with different Ga2O3 content (labeled as AlGa-x; where x is the wt % of Ga2O3) by precipitation method. The oxides were then used as supports of palladium (2 wt %) catalysts (labeled as Pd/AlGa-x). Both series of samples, AlGa-x and Pd/AlGa-x were characterized by several techniques such as Raman spectroscopy, XPS, XRD, SEM, and HRTEM, and were tested in the 2-propanol dehydration reaction. The steady-state conversions displayed by the Pd/AlGa-x series was almost twice as that obtained for the AlGa-x series in all the range of tested temperatures. It was worth noting that the presence of palladium changed the yield observed for the AlGa-x series mainly at low temperatures. While at high temperatures the Lewis acidity provided by the well dispersed Pd nanoparticles increased the activity considerably and improved the propylene production. A balance between the dispersion of palladium and the surface acidity, both related to the Ga2O3 content was responsible for the observed catalytic behavior.