In situ NMR measurements under hydrothermal conditions: study of the formation of polymeric Al hydrolysis species

In order to understand the formation mechanisms of oxide frameworks prepared by the hydrothermal method, in situ NMR experiments are performed. An attempt to describe the formation of Al hydrolysis species at 400K shows the necessity of high T NMR to observe polymers and aggregated polycations. Calibration of the intensity of a reference signal versus temperature allows to extract the fraction of Al observed by NMR together with the true proportions of Al species from RT to 400 K