SBA-15 materials: calcination temperature influence on textural properties and total silanol ratio

SBA-15 ordered mesoporous materials were synthesized using the method reported by Zhao et al. (Science 279:548-552, 1998a). This study seeks to determine the calcination temperature influence on texture and chemical properties of SBA-15 materials. In the present work, materials calcined at 523, 623, 723, 823 and 923 K were studied. The hexagonal structure of these solids was characterized by powder X-ray diffraction (XRD) and transmission electron microscopy. Textural properties were assessed by nitrogen adsorption. The chemical species in materials were determined by nuclear magnetic resonance and fourier transform infrared pyridine (pyridine-FTIR). The results obtained indicate that calcination at 623 K is enough to promote both, the total silanol ratio and superficial specific area. Afterward, materials calcined at 623 and 823 K were functionalized with APTES molecules via "grafting" method. Next, materials texture was characterized by nitrogen adsorption. Finally, their CO2 adsorption capacity was also evaluated. Material calcined at 623 K and amine-functionalized showed the higher CO2 adsorption capacity.