Process for the preparation of a micro-meso porous material with a high surface area and controlled distribution of the porosity

摘要

The present invention relates to a process for the preparation of a micro-meso porous material which comprises:PPa) preparing a mixture starting from a tetraalkylorthosilicate, a C.sub.3 -C. sub.6 alkyl alcohol or dialcohol, a tetraalkylammonium hydroxide having the formula R.sub.1 (R.sub.2).sub.3 N--OH wherein R.sub.1 is a C.sub.3 -C. sub.7 alkyl and R.sub.2 is a C.sub.1 or C.sub.3 -C.sub.7 alkyl, optionally in the presence of one or more metal compounds, in which the molar ratios are within the following ranges:PP alcohol/SiO.sub.2 or equal to 20;PPR.sub.1 (R.sub.2). sub.3 N--OH/SiO.sub.2 =0.05-0. 4;PPH.sub.2 O/SiO.sub.2 =1- 40;PPmetal oxides/SiO.sub.2 =0-0.02; P Pb) subjecting this mixture to hydrolysis and subsequent gelation at a temperature of between 20° C. and a temperature close to the boiling point of the alcohol or mixture of alcohols present;P Pc) subjecting the gel obtained to drying and calcination.