Economic Synthesis Of Fe-Silicalite For Phenol Removal

Abstract

Fe-silicalite is a class of zeolite in which the Fe cation occupies sites with tetrahedral coordination, isomorphically replacing Si4+. It has been proposed that the activity of this material would be strongly related to the structural Fe and also to the iron species generated after the post-synthesis thermal treatment. This material shows catalytic activity and has also been used in the removal of organic compounds in contaminated waters. For this last application, the challenge is to obtain inexpensive materials that maintain high efficiency in the removal of contaminants and are easily regenerable for continuous reuse, thus ensuring sustainable and cost-effective water treatment.

In this context, the objective of this work was to obtain and characterize a low-cost Fe-silicalite for use in the removal of phenols in aqueous media. The material obtained was compared with a traditional Fe-silicalite, synthesized from an analytical grade silicon precursor.

The material was obtained through a hydrothermal process, using a prepolymerized industrial sodium silicate solution as a silicon source. A thermal treatment was then performed to remove the template agent. X-ray diffractograms confirmed that the synthesized material corresponds to an MFI structure. The Fe in the structure was corroborated by the presence of the band corresponding to the Fe-Si-O bonds in the FT-IR spectrum. HRTEM images showed prismatic habit crystals. The BET area showed a surface area of ​​356.41 m²/g.

This economically produced zeolite demonstrated a superior capacity for the removal of phenols in aqueous media. This shows a double benefit: it is a low-cost material and it could also be more effective for the removal of contaminating organic compounds.