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 modifications. 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.

Kratak revijalni prikaz poroznih alumofosfata i njihovih modifikacija koje sadrže jone prelaznih metala. Za ove materijale je karakteristična strukturna i hemijska raznolikost, kao i različite dimenzije pora koje su uređene u kristalografskom smislu i čija veličina se može podešavati promenom uslova sinteze. Prečnik pora, kaveza i kanala je u opsegu od 0,4 do 1,5 nm što alumofosfate čini primenljivim u oblasti nano-katalize. Ugrađivanjem jona prelaznih metala sa redoks svojstvima u rešetki alumofosfata nastaju aktivni centri čime alumofosfati postaju primenljivi i kao selektivni bi-funkcionalni katalizatori. Da bi se stekao uvid u položaj i koordinacionu geometriju jona prelaznih metala, moraju se koristiti različite instrumentalne tehnike.