Preparation and Characterization of Al-Zr Mixed Oxide Catalysts

xAl-yZr mixed oxide catalysts with different molar ratios of Al/(Al+Zr) were prepared by a co-precipitation method and its catalytic performance was compared in the iso-propanol dehydration as a model reaction. The catalysts were charac- terized by X-ray diffraction (XRD), differential thermal analysis (DTA), N2 adsorprion-desorption, NH3 temperature programmed desorption (NH3-TPD), and iso-propanol TPD analyses. The addition of Al into ZrO2 promoted the formation of relatively small particles with large surface areas and retarded the transformation of teragonal phase to monoclnic phase. NH3-TPD results revealed that the relative acidity of the catalysts increased along with the increase of Al molar ratio. The catalytic activity for the dehydration of iso-propanol to propylene was also increased with the same tendency. The catalytic activity could be correlated with high surface area, acidity and easy desorption of iso-propanol.