We report the results of a study (Arletti et al., 2017) performed by in situ synchrotron X-ray powder diffraction of the high pressure behavior of the natural zeolite amicite [K4Na4(Al8Si8O32)·10H2O], the GIS-type phase with ordered (Si,Al) and (Na,K) distribution. The experiments were carried out at the SNBL1 (BM01a) beamline at ESRF, up to 8.13(5) GPa in the penetrating pressure transmitting medium methanol:ethanol:water = 16:3:1 (m.e.w.), and up to 8.68(5) GPa in the non-penetrating medium silicone oil (s.o.). The crystal structure refinements of the patterns collected in m.e.w. were performed up to 4.71(5) GPa, while for the patterns collected in s.o. only the unit cell parameters were determined as a function of pressure. A number of microporous materials with GIS topology have been investigated under HP: i) the natural zeolite gismondine (Ori et al., 2008; Betti et al., 2007), the Ca member of this group; ii)the synthetic phase potassium gallo silicate K-GaSi-GIS (Lee et al., 2008); iii) the synthetic phase potassium alumino germanate K-AlGe-GIS (Jang et al., 2010). The framework deformation mechanism of amicite-similar to that reported for the other phases with GIS topology-is essentially driven by the distortion of the double crankshaft chains and the consequent changed shape of the 8-ring channels. The pressure-induced over-hydration, observed in amicite compressed in m.e.w., occurs without unit-cell volume expansion and is substantially reversible upon pressure release. The comparison of the high pressure behavior of amicite with that of the other GIS-type phases confirms that the compressibility of microporous materials is not simply related to their framework density and topology, but is also greatly affected by the type, amount, and location of the framework and extra-framework species.

High pressure behaviour of GIS-type zeolite amicite

Quartieri S.
2017-01-01

Abstract

We report the results of a study (Arletti et al., 2017) performed by in situ synchrotron X-ray powder diffraction of the high pressure behavior of the natural zeolite amicite [K4Na4(Al8Si8O32)·10H2O], the GIS-type phase with ordered (Si,Al) and (Na,K) distribution. The experiments were carried out at the SNBL1 (BM01a) beamline at ESRF, up to 8.13(5) GPa in the penetrating pressure transmitting medium methanol:ethanol:water = 16:3:1 (m.e.w.), and up to 8.68(5) GPa in the non-penetrating medium silicone oil (s.o.). The crystal structure refinements of the patterns collected in m.e.w. were performed up to 4.71(5) GPa, while for the patterns collected in s.o. only the unit cell parameters were determined as a function of pressure. A number of microporous materials with GIS topology have been investigated under HP: i) the natural zeolite gismondine (Ori et al., 2008; Betti et al., 2007), the Ca member of this group; ii)the synthetic phase potassium gallo silicate K-GaSi-GIS (Lee et al., 2008); iii) the synthetic phase potassium alumino germanate K-AlGe-GIS (Jang et al., 2010). The framework deformation mechanism of amicite-similar to that reported for the other phases with GIS topology-is essentially driven by the distortion of the double crankshaft chains and the consequent changed shape of the 8-ring channels. The pressure-induced over-hydration, observed in amicite compressed in m.e.w., occurs without unit-cell volume expansion and is substantially reversible upon pressure release. The comparison of the high pressure behavior of amicite with that of the other GIS-type phases confirms that the compressibility of microporous materials is not simply related to their framework density and topology, but is also greatly affected by the type, amount, and location of the framework and extra-framework species.
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11570/3119663
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact