A Combined Experimental and Theoretical Evaluation of the Structure of Hydrated Microporous Aluminophosphate AlPO 4 -18 - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Journal of Physical Chemistry B Année : 2005

A Combined Experimental and Theoretical Evaluation of the Structure of Hydrated Microporous Aluminophosphate AlPO 4 -18

Résumé

Water adsorption in the microporous aluminophosphate AlPO4-18 is studied by a combination of solid-state NMR, X-ray diffraction, and d. functional theory calcns. The change of the framework structure upon hydration is moderate, and NMR gives local information on the environment of Al and P atoms. The structural distribution of water mols. in the channels has been explored by a combination of first-principle mol. dynamics simulations and of static geometry optimizations. Two starting points have been considered for the calcns. If the structure of the dehydrated aluminophosphate is used, the simulation result is not satisfactory with an incomplete hydration and no agreement with NMR results. Starting from a partial refinement of the aluminophosphate framework for the hydrated system, a structure with six tetrahedral and six octahedral Al atoms in the unit cell is obtained, involving twelve water mols. coordinated to Al atoms and twelve others in the channels, and in good agreement with exptl. data.

Domaines

Chimie Catalyse

Dates et versions

hal-01906937 , version 1 (27-10-2018)

Identifiants

Citer

G. Poulet, A. Tuel, P. Sautet. A Combined Experimental and Theoretical Evaluation of the Structure of Hydrated Microporous Aluminophosphate AlPO 4 -18. Journal of Physical Chemistry B, 2005, 109 (48), pp.22939 - 22946. ⟨10.1021/jp050670x⟩. ⟨hal-01906937⟩
41 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More