Preparation and Applications of the Expandable Graphite Catalyst with Hierarchically Porous Structure in the Aldol Condensation

Abstract

The expandable graphite catalyst with hierarchically porous structure was prepared by chemical oxidation. The catalyst samples were characterized by X-ray diffraction, scanning electron microscope, N2 adsorption-desorption, X-ray photoelectron spectroscopy, UV spectroscopy. The results indicated that the expandable graphite is hierarchically porous structure catalyst. The concentrated sulphuric acid and the acetic acid had been inserted into the hierarchically pores. As the volume of the expandable graphite expanded, the amount of mixed acid in the hierarchically pores increased,as well as the acid catalytic centre increased. It can be concluded that the catalytic activity increase. The aldol condensation showed the expandable graphite with hierarchically porous structure has excellent catalytic activity and reusability. The reaction conditions were moderate and pollutions had not been found.