Thermal analysis of large pore microporous zincophosphates

Samples of tridimensional microporous zinc phosphates with fully connected framework with faujasite (FAU) and chiral zincophosphate (CZP) structures have been prepared and characterized by thermal analyses comprising TGA, TGA–MS and in situ thermal XRD. They have been also characterized by ICP and 13C MAS NMR. Analyses of the ZnPO–FAU demonstrate that the tetramethylammonium (TMA+) cations are incorporated preferentially in the β-cages and that this material is stable up to 673 K. The crystallinity of the sample only decreases when the TMA+ cations located in the β-cages are eliminated (above ∼723 K). In the case on ZnPO–CZP the thermal removal of the water more strongly held by the structure produces a marked decrease of crystallinity at ∼523 K