ABSTRACT
The nature of alumina depends considerably on the precursor from which it is obtained by calcination, the calcination conditions and the amount of impurities as well as the pretreatment conditions before its use as a catalyst. The reactivity of commercially available aluminas with different structures and varying impurity contents are compared with a Model alumina prepared in the laboratory. The relative importance of the effect of structure and impurity content is analyzed. In the alcohol dehydration reactions, propene and dipropylether were the major reaction products along with water and traces of propionaldehyde or acetone. The measurements were carried out over a temperature range of 423 to 673 K. Among the transitional aluminas, impurities like Na have a greater effect on reactivity than differences in structure. Based on the flow reactor data, it is not possible to speculate whether the differences in reactivity are caused by changes in the number of reactive sites or by differences in specific activity.
