THE EFFECT OF THE NATURE OF INCLUDED METAL CATIONS ONTHE STRUCTURE AND THE ADSORPTION AND ACIDIC CHARACTERISTICS OF VFI ALUMINOPHOSPHATES

For a series of metal aluminophosphate zeolites with the VFI structure it was established that the cations of alkaline-earth and transition metals are mostly included isomorphously at the octahedral positions of the framework with substantial deformation of the structure. The strength of the Brönsted acid centers decreases greatly in the series of substituent cations Mg >> Ca > Sr ≥Ba and increases in the series Cu ≤ Ni≤ Mn