Mesoporous Silica-Pillared H+-Kenyaite with Highly Ordered Gallery Structure

Abstract

Mesoporous silica-pillared H+-kenyaite (SPK) derivatives with highly ordered gallery structure and thermal resistance were prepared by the hydrolysis of TEOS (tetraethylorthosilicate) in interlayer space, using DDA (dodecylamine) as catalyst and template. DDA-TEOS/H+-kenyaite intercalation compounds were obtained by the dispersion of H+-kenyaite in DDA-TEOS solution. DDA-TEOS/H+-kenyaites were hydrolyzed rapidly in pure water, forming siloxane pillared H+-kenyaites. Calcination of siloxane pillared H+-kenyaites for 5 h at 600 degrees C in air resulted in mesoporous SPK derivatives. These exhibited refractions corresponding to a basal spacing of 5.0-5.5 nm, a uniform pore size of 2.5-3.0 nm and large surface areas between 707 and 877 m(2)/g. TEM images confirmed that SPK had uniform interlayer spaces of 2.0-3.0 nm in agreement with the gallery height and pore size data. The structure and physical properties of SPK remained stable after heating for 5 h at 800 degrees C in air. This is attributed to the stable structure of kenyaite composed of 4-fold SiO4 tetrahedral sheets, and the formation of firm silica pillars.