Preparation and Characterization of Porous Silica Obtained by Hydrochloric Acid Selective Leaching Metakaolinite
Porous silica was prepared by selective leaching of metakaolinite with 20 mass% HCl solution. The metakaolinite was derived from the 1:1 layered structure clay mineral kaolinite by firing at 600°C for 24 h. The characteristics of porous silica were studied. The content of Al2O3 in metakaolinite was sharply changed from 45% to less than 2% after 2 h leaching. The maximum specific surface area of the leached sample was about 350 m2/g. The average pore size is about 2 nm. The total pore volume is 0.3 ml/g. The layer structure of kaolinite and metakaolinite is responsible for forming micropores.
Wei Pan and Jianghong Gong
L. J. Wang and X. L. Xie, "Preparation and Characterization of Porous Silica Obtained by Hydrochloric Acid Selective Leaching Metakaolinite", Key Engineering Materials, Vols. 368-372, pp. 342-344, 2008