La integration (at various nominal contents) in SBA-15 prepared under acidic medium was intended from corresponding direct nitrate addition during mesoporous silica formation. Materials were impregnated with Pt (1.5 w%) and studied through several textural (N2 physisorption), structural (XRD, TG-DTG) and surface (FTIR, STEM-HAADF, SEM-EDS, NH3 and CO2 TPD) instrumental techniques. Pt-impregnated solids were tested in phenol hydrodeoxygenation (HDO, T=250 °C, 3.2 MPa, batch reactor, n-decane as solvent). Catalytic activity (in pseudo first order kinetic constant, kHDO basis) was related to Pt dispersion which was, however, not determined by nominal rare earth content. Determining actual composition of modified SBA-15 materials is crucial in reaching sound conclusions regarding their physicochemical properties, especially when La modifier is directly added during mesoporous matrices formation where efficient interaction among constituents could be difficult to get. Otherwise, results from some characterization techniques (N2 physisorption and FTIR, for instance) could be misleading and even contradictory. Indeed, extant modifier precursors when under SBA-15 synthesis conditions could affect the properties of prepared materials even though they were absent in obtained| formulations. Performing a simple compositional analysis could eliminate uncertainties regarding the role of various modifiers on characteristics of final catalysts. However, several groups have failed in doing so.

Strategies followed to improve SBA-15 surface (essentially inert) included modifications by adding acidic or basic (or both) species during or after silica synthesis. Amphoteric properties are especially important as some reactions (alcohols dehydrations, for instance) require of both type of sites to efficiently take place. In this work, single Zr (nominal 3, 5 and 10 wt%, as ZrOCl2•8H2O) direct addition during SBA-15 synthesis was used to impart amphoteric characteristics (as determined by NH3 and CO2 TPD) to mesostructured SiO2 matrices. Additional materials characterization included textural (N2 physisorption) and structural (XRD, FTIR and UV-vis spectroscopies, and HRTEM as well) studies. Actual solids composition was also determined (EDS). Degree of Zr incorporation to mesoporous silica was enhanced with nominal content in binary formulations, although not necessarily integrated in SBA-15 walls forming Zr-O-Si linkages. It seemed that single ZrO2 domains (framework and extra-framework) could provide suitable amphoteric properties by significantly increasing number and strength of both acid and basic sites (especially formulation containing nominal 5 wt% Zr), as to those over mesostructured silica matrices. Also, potentially deleterious strong acid sites were avoided. The binary oxides present great potential to be applied in reactions requiring vicinal acid-basic pairs (alcohols dehydration, for instance).