Al₂O₃/Fe₂O₃ Mesoporous Composite Prepared with Activated Carbon Template in Supercritical Carbon Dioxide

Abstract

A Al2O3/Fe2O3 mesoporous composite has been prepared with a nanoscale casting process using activated carbon as template in supercritical carbon dioxide (SC CO2). The composite precursor of iron(III) acetylacetonate (Fe(acac)3) and aluminum acetylacetonate (Al(acac)3) and acetone were dissolved in supercritical CO2 and then coated on activated carbon in the desired supercritical conditions. After removal of activated carbon template by calcination in air at 600 °C, a Al2O3/Fe2O3 mesoporous composite was obtained. Temperature, pressure, and composite precursor ratio effects were studied. X-ray diffraction pattern proved that the product was composed of α-Al2O3 and γ-Fe2O3. Dendritic nanocrystals were observed from TEM graphs. SEM results show that the porous structure of activated carbon template was well replicated by composite product. The product pore structure information was calculated from the nitrogen sorption isotherms.