Preparation of mesoporous silica-pillared H+-titanosilicates

Abstract

H+-titanosilicate (H4Ti2Si8O22 center dot 4H(2)O), formed by proton ion exchange of layered titanosilicate JDF-L1 (Na4Ti2Si8O22 center dot 4H(2)O) produced intercalation compounds in DDA (dodecylamine)-TEOS (tetraethylorthosilicate) solution. H+-titanosilicate/DDA/TEOS intercalation compounds rapidly hydrolyzed in pure water to form siloxane-pillared H+-titanosilicates. Calcination of siloxane-pillared H+-titanosilicates for 5 h at 500 degrees C in air resulted in the formation of mesoporous silica-pillared H+-titanosilicate (SPT) derivatives. SPT derivatives exhibited refractions corresponding to a basal spacing of 4.16-4.32 nm, a uniform pore size of 2.8-3.4 nm, and a large surface area of 535-618 m(2)/g. The structures and physical properties of SPT derivatives remained stable after heating for 5 h at 700 degrees C in air. These results indicate that DDA molecules have a decisive role in pore formation within SPT derivatives, because they act as a base catalyst and as a template, like surfactant micelles. during the hydrolysis of TEOS. (C) 2008 Elsevier Inc. All rights reserved.