Control of textural properties of ordered mesoporous materials

Two different types of ordered mesoporous materials have been synthesized. On one hand, SBA-15 silicas with different textural properties were prepared using tetraethyl orthosilicate (TEOS) as silica source and a triblock copolymer (P123) as template. Their textural properties were controlled by using different TEOS/P123 mass ratios. On the other hand, mesoporous carbons were synthesised by incipient wetness impregnation of the differently prepared SBA-15 silicas with a mixture of furan resin and acetone. X-ray diffraction (XRD), transmission electron microscopy (TEM), temperature programmed oxidation (TPO) and N2-physisorption were used to characterize the structure and textural properties of such materials. All samples had a high specific surface area and a large pore volume. Silica materials had a hexagonally ordered porous structure, the structure of carbon materials being the inverse replica of the silicas used as templates. The results show that the specific surface area and the pore volume, just like the degree of structural ordering, increased with decreasing the TEOS/P123 mass ratio. However, the size of the mesopores was found to be independent of this ratio. It is shown that the textural and structural properties of SBA-15 silicas can be tailored by the mass ratio of their precursors, thus allowing the preparation of different carbon materials with controlled properties.