Effect of an Al2O3-based binder on the structure of extruded Fe-ZSM-5

• Published in: Catalysis today 2022-03, Vol.387, p.207-215
• Main Authors: Buttignol, Filippo, Garbujo, Alberto, Biasi, Pierdomenico, Rentsch, Daniel, Kröcher, Oliver, Ferri, Davide
• Format: Article
• Language: English
• Subjects: Binder; Extrudate; Framework Al; ZSM-5
• ISSN: 0920-5861; 1873-4308
• DOI: 10.1016/j.cattod.2021.09.020

The effect of an alumina-based binder on the structure of a commercial Fe-ZSM-5 catalyst has been investigated. Several ex-situ characterization techniques were used to show that the binder in the catalyst formulation allows obtaining a material that possesses improved features in terms of Fe species dispersion, framework Al content and acidity. UV–Vis and X-ray absorption spectroscopy showed that the extent of Fe agglomeration in the extruded catalyst was significantly lower compared to that in the catalyst without binder. 27Al and 29Si-MAS NMR spectroscopy demonstrated a remarkable difference in terms of framework Al migration. NH3-TPD experiments corroborated the NMR results suggesting a retention of Brønsted acidity in the extruded catalyst. We tentatively propose that by providing extra-framework Al species prior to the treatment at elevated temperature, the binder hinders the framework Al dislodgment and Fe agglomeration during calcination. [Display omitted] •The structure of Fe-ZSM-5 pristine, calcined and calcined after extrusion was compared.•XAS and UV–Vis data indicated a higher dispersion of Fe species in presence of the binder.•NMR spectroscopy and NH3-TPD revealed the binder controls migration of framework Al.•Extra-framework Al in the binder reduced agglomeration of Fe and framework Al.•The Al2O3 binder improves the structural properties of extruded Fe-ZSM-5.