Synthesis of Zeolite-Like Inorganic Compounds

Abstract

Zeolite and aluminophosphate synthesis is already highly developed to produce materials with desired properties such as catalytic activity, good adsorption or ion exchange behavior, optical transparency or satisfactory guest incorporation. Although microporous lattices of zeolite systems are powerful tools for shape and size selective catalysis or the organization of small organic molecules, sometimes even simple features like phase purity can be a big problem that has to be overcome. In addition, zeolite systems have a number of limitations that are not favorable for many applications. Framework constituents are predominantly boron, aluminum, gallium, silicon and phosphorus as T-atoms, bridged by oxygen. Thus, these materials are group III to V element oxides of the second and third period, and it can easily be seen that the resulting materials will be insulators. Another disadvantage of zeotype materials is certainly that transition metal uptake in the framework is in most cases limited to a few percent, and overloading will often lead to a collapse of the framework. Looking at many catalytic applications this is a limiting factor and there might also arise problems for possible optical applications.