Study on preparation of S2O82- /Fe2O3–SiO2 solid acid and its catalytic activity

Abstract

The precursors of Fe₂O₃-SiO₂ mixed oxides prepared through co-precipitation method were modified by microwave hydrothermal treatment for the first time. S₂O₈^2-/Fe₂O₃-SiO₂ solid acids were formed after being impregnated by (NH₄)₂S₂O₈ solution and calcined at high temperature. The samples were characterized by XRD, TEM, N₂ adsorption/desorption methods. It was found that the presence of SiO₂ obviously retarded the formation and growth of Fe₂O₃ crystals. Catalyst with appropriate specific surface area and narrow pore size distribution was obtained. The catalytic activities of the solid acids were evaluated by esterification of acetic acid and butanol and the results were compared with those catalysts prepared at normal conditions. The results showed that catalytic activity was extensively improved by microwave hydrothermal treatment.