Estudo de réplicas de materiais mesoporosos obtidos a partir de hard template, usando como molde de estrutura CMK-3

Abstract

Obtaining new materials with defined porosities and high specific areas gives rise to new possibilities both in science and in industry. Among the ways to obtain new materials with porosity are the Hard-template and Soft-template synthesis routes. In the Hard-template synthesis route, a template with a defined structure is used to obtain the desired structure from it, among the materials used as the mold of structures there is the SBA-15 that is formed based on silicon and the CMK-3. This is a carbon-based material that has rods interconnected by micro rods that generate a mesoporous structure. Therefore, the objective of this work is to use CMK-3 as a template for structures to obtain new mesoporous materials, which are organized in a hexagonal way. Initially, a study was carried out varying the amount of silicon source to assess the optimal amount for obtaining mesopore materials. Then, the same study was carried out, varying the amount of aluminum in the insertion of the studied replicas. The materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), N2 adsorption and desorption at 77 K. Mesoporous silicas of the SBA-15 type were successfully synthesized, having specific areas greater than 600 m2/g and uniform pores. CMK-3 carbon replicas were also synthesized using SBA-15 as a structural mold, and the materials obtained showed excellent textural and structural properties. The replicas obtained showed areas greater than 700 m2/g and a total pore volume of 1.02 cm3/g. From the SEM images, it was possible to observe materials with characteristic morphologies for materials of the SBA-15 type, which shows that the procedure used in the synthesis was efficient to replicate structures using materials of the CMK-3 type as a template.