Journal of Physical Chemistry B, Vol.104, No.45, 10473-10481, 2000
NMR characterization of mesostructured aluminophosphates
The atomic structure of ordered mesostructured aluminophosphates with dodecyl phosphate as the structure-directing template was investigated by multinuclear solid-state NMR. Two different types of materials were studied: one with the template headgroup as the only phosphate source and one where additionally phosphoric acid was used in the synthesis. All P-31 and Al-27 NMR resonances can be subdivided into three groups depending on the sample composition. Furthermore, 2D heteronuclear correlation NMR measurements allow a conclusive and unambiguous identification of the phosphate headgroup resonances of the template molecules and the determination of water and/or hydroxyl units. Most notably, there is an obvious correlation between the door values of the samples as measured by powder X-ray diffraction and the appearance of the various groups of Al-27 and P-31 resonances.