Synthesis of mesoporous silica-pillared clay by intragallery ammonia-catalyzed hydrolysis of tetraethoxysilane using quaternary ammonium surfactants as gallery templates

Mesoporous silica-pillared montmorillonite (MMT) materials were synthesized by intragallery ammonia-catalyzed hydrolysis tetraethoxysilane (TEOS). The reaction involved hydrolysis and condensation of tetraethoxysilane in the presence of intragallery surfactants templates. Powder X-ray diffraction (XRD), N2 adsorption–desorption isotherms, scanning electron microscopy (SEM) and Fourier transform infra-red (FT-IR) spectra were employed to characterize the mesoporous silica-pillared montmorillonite. These novel materials exhibited reflections corresponding to a basal spacing of 4.76–5.62 nm, a uniform pore size of 3.75–4.51 nm and large surface areas of 597.2–712.4 m2/g. And the porous structure and physical properties of silica-pillared montmorillonite derivatives remained stable after heating for 5 h at 700 °C in air. Our results indicate that surfactants play a decisive role in pore formation, because they act as micelle-like template during the hydrolysis of TEOS. These mesoporous silica-pillared montmorillonite materials exhibit excellent catalytic activity and selectivity for coker gas oil cracking reaction in comparison to normal MCM-41 and Al-MCM-41.

Schematic for preparation of mesoporous silica-pillared clay.Figure optionsDownload as PowerPoint slide