Open-framework aluminophosphates: Synthesis, characterization and transition metal modifications

Abstract

This review is a brief summary of open-framework aluminophosphates and their transition metal-substituted modifictions. The materials exhibit structural and compositional diversity, as well as a wide range of pore openings, which are crystallographically ordered and can be tuned by an appropriate choice of synthesis conditions. The diameters of the apertures, cages and channels fall in the range of 0.4 to about 1.5 nm, which recommends aluminophosphates for a novel area of application - nanocatalysis. Isomorphous substitution of the framework elements by transition metal ions which possess redox ability creates active sites inside the aluminophosphate lattice and opens routes towards shape selective bi-functional catalysis. In order to obtain an insight into the location of the transition metal ions, different characterization techniques have to be used.