Textural analysis of SBA-15 molecular sieve using ethanol as co-solvent

Abstract

The SBA-15 molecular sieve has been widely studied due to its unidirectional mesoporous structure, high average pore diameter and high thermal and hydrothermal stability. This study aimed to evaluate the effect of ethanol co-solvent in the texture of SBA-15 molecular sieve, performing the synthesis process in different proportions of co-solvent ethanol. The SBA-15 molecular sieve was synthesized by adopting the following molar composition of reaction mixture: 1TEOS: 0.017 P123: 5.7 HCl: 173 H2O: x EtOH. In which X took the values 10, 20, 30 and 40 due to the ethanol co-solvent ratio. Analyzing the X-ray diffractograms, it was possible to observe a greater structural organization for a higher molar proportion of co-solvent. The micrographs showed agglomerates of spherical particles which by increasing molar proportion of ethanol co-solvent became larger and more defined. By the BET method, it was observed that as the proportion of co-solvent increased the specific surface area also increase and a decrease in micropores occurred, pointing to the porous nature of the material. The walls of the material became thicker as it increased the proportion of co-solvent making it the most stable material.