Preparation and Characterization of Different Phases of Aluminum Trifluoride

Abstract

Several phases (α, ε 2, and γ) of aluminum fluoride were prepared from precursors such as NH 4 AlF 4, (NH 4 ) 3 AlF 6, and β-AlF 3 ·3H 2 O using various synthetic strategies. The precursors and the aluminum fluoride phases obtained were characterized by X-ray diffraction (XRD), X-ray fluorescence, scanning electron microscopy (SEM), and infrared spectra (FT-IR). The structural evolution of the precursors to the different phases of aluminum fluoride during thermal treatment was studied by dynamic XRD experiments, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). α- and γ-AlF 3 phases were obtained with high BET surface areas (>120 and 30 m 2 /g, respectively). These aluminum fluorides with high BET areas are of potential interest as supports or catalysts in hydrodechlorination and fluorination reactions.