Modified vermiculites as effective catalysts for dehydration of methanol and ethanol

Two series of catalysts for the reactions of methanol and ethanol dehydration were obtained from vermiculite. The first series of the catalysts were obtained by treatment of raw clay with nitric acid solution. Such modification of vermiculite resulted in a significant increase of its specific surface area and also partial leaching of Al3+ and Fe3+ cations from clay layers. Acid treatment of vermiculite resulted in its activation in the processes of methanol and ethanol dehydration. The second series of the catalysts were obtained by intercalation of vermiculite with alumina pillars. Prior to the pillaring process, raw vermiculite was treated with nitric acid solution followed by complexation of Al3+ and Fe3+ cations, leached from clay layers, with oxalic acid or citric acid. Alumina pillared vermiculites, characterized by increased specific surface area, porosity and acidity, were found to be very active catalysts of alcohols dehydration. Catalytic performance of modified vermiculites was related mainly to the concentration and strength of acid sites present in the samples.