Several phases (α, ε2, and γ) of aluminum fluoride were prepared from precursors such as NH4AlF4, (NH4)3AlF6, and β-AlF3·3H2O 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-AlF3 phases were obtained with high BET surface areas (>120 and 30 m2/g, respectively). These aluminum fluorides with high BET areas are of potential interest as supports or catalysts in hydrodechlorination and fluorination reactions.

Three series of layered double hydroxides (LDH) with a hydrotalcite-like structure and composition corresponding to [Mg 4 Al 2 (OH) 12 (CO 3 )]·3H 2 O have been prepared from a common batch by applying three different aging procedures, namely, stirring at room temperature, hydrothermal treatment, and microwave-hydrothermal treatment. It has been found that the tested properties of the samples (mainly related to their crystallinity) are considerably improved by using the microwave-hydrothermal treatment. Shorter times are also evinced than in the other two aging treatments; however, if the microwave-hydrothermal treatment is too far extended, incipient destruction of the particles is observed.

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