Effects of preparative process for Fe₂O₃/γ-Al₂O₃ catalyst on surface properties and dehydration of ethanol

Iron is introduced at different synthetic stage of γ-Al₂O₃ by precipitation. Three kinds of Fe₂O₃/γ-Al₂O₃ are prepared: one prepared by an in-situ synthesis, another prepared by the impregnation modification of γ-AlOOH, and the last one prepared by the impregnation modification of γ-Al₂O₃, respectively. The specific surface area, pore volume and pore diameter can be changed appreciably, the distribution of surface acid amount and forms of Fe₂O₃ species on catalyst surface can be changed as well when different processes used. The one prepared by the impregnation modification of γ-Al₂O₃ has the largest medium acid amount and acid density, with the form of easily reduced Fe₂O₃ loaded on the surface of γ-Al₂O₃ support, which shows the best catalytic performance on the dehydration of ethanol to ethylene.