Resumo

RODRIGUEZ, Pedro et al. Synthesis and characterization of mesoporous catalysts type MCM-41 and SBA-15 modified with 12-tungstophosphoric acid. Rev. Soc. Quím. Perú [online]. 2009, vol.75, n.4, pp.464-472. ISSN 1810-634X.

Mesoporous materials (MCM-41 and SBA-15) were hydrothermal synthesized at 373 K, using bromide, cetyl-trimethyl-ammonium (CTMABr) as a directing structural agent. The catalysts were prepared with different percentages of tungstophosphoric acid (10, 15, 20, 25, 30% w/w) in methanol under stirring. The solids were characterized by XRD, Nitrogen physisorption, SEM and EDX. The XRD results suggest that the synthesized samples are consistent with mesoporous structures. Nevertheless, the diffractograms of the samples with low percentages (<25%) of acid, show no diffraction peaks, however, at high percentage, there are diffraction lines that correspond to aggregates of tungstophosphoric acid. The surface area decreases with increasing the percentage of acid in sample, while the morphological analysis of impregnated samples show no appreciable change in the presence of acid. This suggests that acid particles are highly dispersed.

Palavras-chave : alkylation; MCM41; SBA15; superacid.

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