Porous Properties of γ-Alumina/Potassium Aluminosilicate Gel Composites Prepared by Selective Leaching and Precipitation Method

Composites of mesoporous γ-alumina and potassium aluminosilicate (KAS) gel were prepared by selective leaching of calcined kaolinite using KOH solution followed by neutralization of the solution at pH 5.5 with nitric acid. The porous properties of the composites were characterized by N2 gas adsorption and their microtextures were observed by electron microscope. The resultant composites have specific surface areas of about 290 m2/g, pore sizes of about 1.85 nm in radius and pore volumes of about 0.5 ml/g. The porous properties of the composites are compared with those of γ-alumina and KAS gel.