The effect of preparation method on the catalytic activity of amorphous aluminas in ethanol dehydration

The known heterogeneous catalytic dehydration of ethanol on amorphous alumi nium oxide samples was adopted as a measure of catalytic activity and selec tivity. The aluminium oxide samples were prepared by hydrolysis of aluminiu m chloride using propylamine, as proton acceptor, in pure and mixed aqueous ethanolic and acetonic media, freeze dried and activated. The catalytic ac tivity and selectivity of the samples was measured in the temperature range 623-698 K for various flow rates of ethanol. The apparent activation energ ies were calculated (53-78 kJ mol(-1)) and depended on the solvent used in the preparation of the aluminas. The effect of solvent medium on the activi ty and selectivity was discussed. (C) 2001 Society of Chemical Industry.