The Al incorporation on SBA-15 type material and the effects of pH adjusting and presence of NaF were studied. The direct synthesis method was performed for comparison. The following parameters were evaluated: the Si/Al ratio, pH increase, and amount of NaF added. These parameters have a great influence on the synthesis of the mesoporous Al/SBA-15 type, but the pH the most influential parameter for the incorporation of Al into the SBA-15 structure. The formation of the SBA-15 structure was observed through the direct synthesis method. However, aluminum is not present in the material. The increase in pH contributed to the formation of a disorganized material. By EDX, it was observed that synthesis with a Si/Al = 5 ratio and pH approximately 4 provides materials containing aluminum. When the amount of aluminum during the synthesis is lower, a pH of approximately 8 is required to incorporate aluminum into the final material. The Al-NMR analysis showed that it was possible to insert aluminum in the structure of SBA-15, but with the presence of aluminum hexa and pentacoordinated. In the catalytic test of the dehydration reaction of ethanol, the samples with higher aluminum contents showed better catalytic performance due to its higher acidity.

FeCo nanoparticles coated with (Fe,Co)3O4 (magnetite doped with cobalt) were synthesized by the proteic sol-gel chemical route. The synthesized materials were characterized by Thermogravimetry (TG), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), vibrating-sample magnetometer (VSM) and Mössbauer spectroscopy (MS). The results show that the increase in temperature and the choice of the correct air/N2 flow directly influence on the final physical-chemical properties of the nanocomposite. The SEM and TEM images confirmed that a thin layer of oxide was formed on the alloy, indicating that it was obtained a self-assembled FeCo-(Fe,Co)3O4 nanocomposites. In addition, the VSM results show that a possible exchange-spring coupling in magnetic FeCo-(Fe,Co)3O4 nanoparticles occurred with high saturation magnetization from FeCo alloy and high coercivity from (Fe,Co)3O4. The rotary oven allows the uniform contact of the powder with the atmosphere of synthesis during the different oxidation-reduction steps, generating more homogeneous particles.

Mesoporous mixed copper-aluminum oxides and copper-silicon oxides were synthesized with polymeric precursors route in order to evaluate the effect of the support acidity on the catalytic stability due to the carbon deposit and the copper surface characteristics on the catalytic activity for the gas-phase conversion of glycerol to acetol. The samples were characterized by different techniques such as inductively coupled plasma (ICP), thermogravimetry and differential thermal analyses (TGA-DTA), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), N2 adsorption/desorption isotherms, temperature-programmed reduction with H2 (H2-TPR) and microcalorimetry of NH3 adsorption. The metallic copper surface was shown by XPS, which was observed an increase with the copper loading without marked changes between Si or Al support using the same copper content. The Cu-Al catalysts present acidic properties close to that of the pure alumina support while the Cu-Si solid is not acid, as expected. Reduced catalysts were evaluated in the reaction of glycerol conversion. The catalytic results showed a clear dependence of the glycerol conversion to acetol with the Cu metal surface and the initial catalytic properties did not depend on the support acidity, since the copper is the major active site. It was observed 95% of acetol selectivity and 80% of glycerol conversion for the best catalyst. However, the support acidity influenced the catalyst stability, since Cu-Al solid deactivated continuously by contrast to Cu-Si sample, which reached stability after 2 h of reaction. The higher acidity for the Al support leads to a greater carbon deposit compared to Si support, blocking the active sites and providing a rapid catalytic deactivation.

Polymeric precursor method and wet impregnation route were applied to synthesize copper and aluminium-based catalysts in order to obtain a material with interesting properties in catalytic reactions. The changes in the structural, morphological and textural properties due to the choice of preparation method were characterized by different techniques, such as XRD, N2 physisorption isotherms and SEM. The XRD results of the solids present the formation of γ-Al2O3 or CuO and β-Al(OH)3, depending on the preparation method. The average crystallite diameters of the alumina were estimated by the Scherrer's formula with a particle size of 5.2 nm. N2 physisorption isotherms analysis shows that the alumina is a mesoporous material with a high specific surface area. An excessive increase in surface area was observed after Cu2+ insertion by wet impregnation from β-Al(OH)3 support, which is explained by the redissolution and recrystallization of bayerite to γ-Al2O3 during the impregnation of Cu2+ and recalcination process, respectively. The SEM images confirmed this phenomenon. Catalytic tests explain that the combination of the two methods improves the activity, selectivity and the stability in the conversion of glycerol to acetol. The results indicate that the way of catalyst preparation affects its structural, textural and morphological properties and consequently the catalytic performance

Materials containing aluminum and iron oxide were synthesized through the preparation of hybrid spheres and tested in the dehydrogenation of ethylbenzene in the presence of CO2. The catalytic results suggest that the high initial ethylbenzene conversion is due to the contribution of basic sites. These results also point to a competitive process between CO2 adsorption and the oxidative dehydrogenation of ethylbenzene for the basic sites (lattice oxygen). In spite of the coke deposition is originating from ethylbenzene and CO2, the amount of carbonaceous deposits was smaller with the presence of CO2, if compared with the dehydrogenation in the absence of CO2.