Hydrothermal synthesis of pure AlPO4-5 without fluoride medium: synthesis, characterization and application as a support

Hydrothermal synthesis of pure AlPO₄-5 crystals using various reaction gels is reported. The influence of synthesis conditions on the purity of the AlPO₄-5 has been studied by changing Al sources and factors affecting the pH of the starting gel. It was observed that the additive acid to adjust the gel pH value has strongly influenced both the crystallinity and purity of the resulting AlPO₄-5 crystals. The crystals were characterized by XRD, FT-IR, TGA, BET, SEM and TPD techniques. The resulting microporous AlPO₄-5 was used as an efficient support for a functional polymer to produce an efficient heterogeneous basic nanocomposite catalyst. The catalytic activity of this novel nanocomposite was tested for Knoevenagel reaction under solvent-free conditions at room temperature. The catalyst showed a considerable degree of reusability besides very good activity.