Aluminium introduction on the STF zeolite synthesized with the organic structure-directing agent 123TE4MI

Abstract

In this research work we studied the structure-director effect of the organic compound 1,2,3-triethyl-4-methylimidazolium in the synthesis of zeolitic aluminosilicates following the fluoride route. One-phase STF products were obtained, having a morphology similar to thin long sticks. We also studied the influence of the Si/Al gel ratio variations. The aluminium incorporation was proven by solid-state nuclear magnetic resonance, a bulk technique, and a comparison with a surface technique, such as X-ray photoelectron spectroscopy, was performed. The results of the first technique showed the presence of various aluminium coordination in different proportions, reporting for the first time the resonances between 10–30 ppm in the aluminium spectrum for this zeolitic topology. Meanwhile, by the second technique, the octahedral and tetrahedral aluminium were the only observed at the surface. The results showed in this article intent to help controlling the introduction of aluminium for future applications, such as catalysis.