Effect of Silica Source on the Structure of Pure Silica MCM-41 Mesoporous Molecular Sieves

Using tetraethyl orthosilicate (TEOS),silicasol and fumed-silica as silica sources,and cetyltriethylammonium bromide as templating agent,the mesoporous molecular sieves MCM-41 were synthesized by hydrothermal method in basic medium at 100 ℃ for 5 days.The synthesized samples were characterized by XRD and N_2 adsorption-desorption.Experimental results show that,compared with samples synthesized by tetraethyl orthosilicate,the samples synthesized with silicasol and fumed-silica have larger pore diameter (4 nm) and pore volume (1 cm~3/g) and higher specific surface area (1000 m~2/g).Thus,for preparing large pore mesoporous MCM-41,silicasol and fumed-silica may be the preferred silica sources.