Effect of added metal chelating organosilane on mesoporous titanosilicate formation properties

Abstract

We describe the effects of adding the organosilane n-(trimethoxysilylpropyl)ethylenediaminetriacetic acid (EDATAS) during hydrothermal synthesis on the formation properties of titanium containing SBA-15 mesoporous silica. X-ray photoelectron spectroscopy revealed that the Si/Ti atomic ratio decreased significantly with the addition of the organosilane compared to the non-funtionalized silicates, showing that the EDATAS silicates contained more surface titanium. X-ray powder diffraction and nitrogen gas adsorption analysis revealed that the functionalized titanosilicates were ordered mesoporous materials with narrow pore size distributions with a BJH pore size of 92–96 Å. Solid state CP/MAS NMR experiments demonstrated that addition of EDATAS during hydrothermal synthesis produced a mesoporous silica with 6-coordinated Ti(IV) coordination. Using the same synthesis without the EDATAS, mesoporous silicas with 4-coordinated Ti(IV) were produced.