The effect of pretreatment on the attrition resistance of spray-dried alumina Original Research Article

Spray-dried alumina is useful as a support for metal catalysts used in fluidized bed and slurry phase reactors. Catalyst attrition resistance, which can be affected by catalyst preparation and pretreatment, is a key characteristic determining successful use of a particular catalyst. In this study, the effects of calcination temperature and pH of an impregnating solution on the attrition resistance of spray-dried Vista-B alumina have been investigated. BET, X-ray diffraction (XRD), scanning electron microscopy (SEM), and particle size distribution (PSD) were used to characterize the pretreated and attrited alumina. The results indicate that the attrition resistance of the boehmite/γ-Al2O3 passes through a maximum for a calcination temperature of around 300°C. The impregnation of γ-Al2O3 to incipient wetness using different pH-value solutions followed by drying does not itself cause much change in the PSD. However, this treatment changes significantly the attrition resistance of the γ-Al2O3 that decreases with increasing pH value of the impregnation solution. The possible causes of the changes in attrition resistance are discussed.