Studies on porosity control and stabilization of mesoporous silicas and aluminas

Mesoporous silicas and aluminas have had an extensive development during the last decades for their chemical, structural and textural properties that have allowed them to be used as supports for catalysts in large scale processes among other applications as adsorption, separation, etc. However, these materials have a relatively low thermal and hydrothermal stability, in particular when the material has a poor condensation, i.e. when the polymerization degree of the matrix is limited. Therefore, the challenge is to develop synthesis methods for porosity control and condensation improvement to stabilize these materials.
The present thesis investigates synthetic routes to develop mesoporous silicas and aluminas in order to improve the stability of such materials. This work aims towards achieving
(a) a facile and quicker synthesis protocol for mesoporous silicas by means of a combined Fenton detemplation with drying in a low-surface-tension solvent to produce a material with a well-preserved structure,
(b) synthesis of mesostructured aluminas with high thermal and hydrothermal stability by means of a systematic study on the influence of several parameters, e.g. aluminium source, solvent,
(c) to obtain stable a -alumina and transitional alumina from the previous approach with a high surface area and excellent textural properties without the addition of any structural promoter.