Abinitio molecular dynamics study of the Brnsted acid site in a gallium zeolite

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Ettore Fois, Aldo Gamba and Gloria Tabacchi


Abstract

We present the results of an abinitio molecular dynamics simulation on the structure and the dynamics of a gallium sodalite, H[GaSi11O24]. The average geometry of the system and the simulated vibrational spectrum are compared with the results obtained for the corresponding Al-substituted zeolite (H[AlSi11O24]). Our results suggest that the properties of the Brønsted acid site in the gallium sodalite are quite similar to those of a silanol. This finding represents a possible explanation of the minor activity shown experimentally by Ga-substituted zeolites in many catalytic processes.


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