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: a) preparing a mixture starting from a tetraalkylorthosilicate, a C3-C6 alkyl alcohol or dialcohol, a tetraalkylammonium hydroxide having the formula R1(R2)3N-OH wherein R1 is a C3-C7 alkyl and R2 is a C1 or C3-C7 alkyl, optionally in the presence of one or more metal compounds, in which the molar ratios are within the following ranges: alcohol/SiO2 < or equal to 20; R1(R2)3N-OH/SiO2 = 0.05-0.4; H2O/SiO2 = 1-40; metal oxides/SiO2 = 0-0.02; b) subjecting this mixture to hydrolysis and subsequent gelation at a temperature of between 20 DEG C and a temperature close to the boiling point of the alcohol or mixture of alcohols present; c) subjecting the gel obtained to drying and calcination. The material thus obtained is characterized by a surface area of more than 500 m<2>/g, a pore volume of between 0.3 and 1.3 ml/g, an average pore diameter of less than 40 A and an X-ray diffraction spectrum (XRD) from powders which does not have a crystalline structure, but possibly a widespread "scattering" with angular values of not more than 2&thetas; = 5 DEG . Said material can be conveniently used as a heterogeneous catalyst, as an adsorbent or as a carrier for catalysts in industrial processes, in the fields of refining, petrochemistry, basic chemistry and fine chemistry.