SÍNTESE E CARACTERIZAÇÃO DE MATERIAIS DO TIPO MCM–41 SULFATADA

Resumo

The use of heterogeneous catalysts is highlighted because of the possibility of reducing environmental impacts and increasing process efficiency. Mesoporous heterogeneous catalysts, such as Mobil Composition of Matter-41 (MCM-41), has been studied by many researchers in the application in reactions involving macromolecules. The main advantages of using this mesoporous molecular sieve are: high surface area, high pore diameter and pore volume and good thermal stability. MCM-41 is catalytically inactive material or may present very weak acid sites, these mesoporous materials, in turn may have their surface modified by incorporating an active phase. Among which stand out the addition of heteroatoms to generate acid sites and the sulfate ion which gives the material the characteristic of superacid. Thus, the aim of this study was to evaluate the synthesis and characterization of MCM-41 support and ZrO2-MCM-41 and SO42--ZrO2-MCM-41 catalysts. The catalysts were synthesized by incorporation physical mixture method with a concentration of 5% in mass ratio of ZrO2 and then characterized by XRD, SEM and EDX. The results suggest that the behavior characteristic of mesoporous materials of the MCM-41 was reached after synthesis and the materials are essentially constituted by silica. Alternatively, it was observed the presence of zirconia and sulfur based compounds after analysis of catalysts. In relation to morphology, it was found that the materials exhibit heterogeneous forms with the presence of agglomerates.