The dehydration of the large pore aluminophosphate AlPO4-54•xH2O was studied in situ as a function of vacuum pressure at room temperature by infrared spectroscopy and x-ray diffraction. On polycrystalline samples, under primary vacuum, the adsorbed water is removed very rapidly. The structural water in the AlO6 octahedra is then removed slowly with the quantity of the fully dehydrated form gradually increasing from 43 to 65% of the total material. This results in a two-phase mixture of fully dehydrated and a distinct partially dehydrated AlPO4-54•1/2H2O phase containing structural water. These phases have almost identical a cell parameters and very close c parameters. Secondary vacuum increases the amount of fully dehydrated material to more than 76%. Prolonged heating under vacuum increases the amount of fully dehydrated material to 90%. On single crystal samples, removal of adsorbed water is slower and results in a reduction in crystal quality, however prolonged exposure to primary vacuum yielded fully dehydrated material without the need for heating. The monoclinic structure of anhydrous AlPO4-54, space group Cm, with a doubled unit cell was confirmed using single crystal synchrotron x-ray diffraction data.

An in-situ x-ray diffraction and infrared spectroscopic study of the dehydration of AlPO4-54 / Fabbiani, M.; Polisi, M.; Fraisse, B.; Arletti, R.; Santoro, M.; Alabarse, F.; Haines, J.. - In: SOLID STATE SCIENCES. - ISSN 1293-2558. - 108:(2020), pp. 106378-106394. [10.1016/j.solidstatesciences.2020.106378]

An in-situ x-ray diffraction and infrared spectroscopic study of the dehydration of AlPO4-54

Polisi M.;Arletti R.;
2020

Abstract

The dehydration of the large pore aluminophosphate AlPO4-54•xH2O was studied in situ as a function of vacuum pressure at room temperature by infrared spectroscopy and x-ray diffraction. On polycrystalline samples, under primary vacuum, the adsorbed water is removed very rapidly. The structural water in the AlO6 octahedra is then removed slowly with the quantity of the fully dehydrated form gradually increasing from 43 to 65% of the total material. This results in a two-phase mixture of fully dehydrated and a distinct partially dehydrated AlPO4-54•1/2H2O phase containing structural water. These phases have almost identical a cell parameters and very close c parameters. Secondary vacuum increases the amount of fully dehydrated material to more than 76%. Prolonged heating under vacuum increases the amount of fully dehydrated material to 90%. On single crystal samples, removal of adsorbed water is slower and results in a reduction in crystal quality, however prolonged exposure to primary vacuum yielded fully dehydrated material without the need for heating. The monoclinic structure of anhydrous AlPO4-54, space group Cm, with a doubled unit cell was confirmed using single crystal synchrotron x-ray diffraction data.
2020
108
106378
106394
An in-situ x-ray diffraction and infrared spectroscopic study of the dehydration of AlPO4-54 / Fabbiani, M.; Polisi, M.; Fraisse, B.; Arletti, R.; Santoro, M.; Alabarse, F.; Haines, J.. - In: SOLID STATE SCIENCES. - ISSN 1293-2558. - 108:(2020), pp. 106378-106394. [10.1016/j.solidstatesciences.2020.106378]
Fabbiani, M.; Polisi, M.; Fraisse, B.; Arletti, R.; Santoro, M.; Alabarse, F.; Haines, J.
File in questo prodotto:
File Dimensione Formato  
Fabbiani_SolidStateSciences_revised2.docx

Accesso riservato

Tipologia: Versione dell'autore revisionata e accettata per la pubblicazione
Dimensione 5.44 MB
Formato Microsoft Word XML
5.44 MB Microsoft Word XML   Visualizza/Apri   Richiedi una copia
Pubblicazioni consigliate

Licenza Creative Commons
I metadati presenti in IRIS UNIMORE sono rilasciati con licenza Creative Commons CC0 1.0 Universal, mentre i file delle pubblicazioni sono rilasciati con licenza Attribuzione 4.0 Internazionale (CC BY 4.0), salvo diversa indicazione.
In caso di violazione di copyright, contattare Supporto Iris

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11380/1208644
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 4
  • ???jsp.display-item.citation.isi??? 3
social impact