SILICA-TITANIA COGEL FROM TWO-STEP HYDROLYSIS

摘要

A silica-titania cogel is produced in a two-step process wherein in the first step an alkyl polysilicate and/or a tetraalkyl silicate is partially hydrolyzed in an alkaline organic solvent using insufficient water to complete hydrolysis and thereafter a tetraalkyl titanate and an excess of water are added to complete the hydrolysis. The resulting product is as good or better than silica-titania cogels made by expensive prior art techniques and offers the advantage of not requiring washing step to remove alkali metal ions and thus also does not require an azeotrope drying step to remove water.