Abstract
The insertion of H2O in the siliceous zeolites TON (Theta-one) and MFI (Mobil Five) was studied at pressures up to 0.9 GPa by synchrotron X-ray diffraction, infrared spectroscopy, and Monte Carlo m...
Highlights
The penetration of H2O in porous materials is of great importance for chemistry, materials and Earth science
4 The goal of the present study is to investigate the mechanism of pore filling of TON and MFI by H2O at high pressure from a structural point of view using a combination of in situ X-ray powder diffraction and Monte Carlo modelling and from a vibrational point of view by infrared spectroscopy
The relative intensities of the diffraction lines were strongly modified with respect to those observed at ambient pressure, clearly indicating the insertion of H2O
Summary
The penetration of H2O in porous materials is of great importance for chemistry, materials and Earth science. Particular interest has been directed towards microporous zeolite-type materials with typical diameters between 3-8Å, for which it has been shown that high pressure can lead to a superhydrated state[1,2,3,4,5,6,7,8,9,10] This effect strongly modifies the phase stability and the elastic properties of these materials. One of the most studied siliceous zeolites for such applications, both from an experimental and computational point of view, is silicalite-1 with a MFI structure[19] This material is characterized by a three dimensional pore system consisting of 5.1×5.5Å diameter straight channels along the [010] direction and intersecting 5.3×5.6Å sinusoidal channels in the ac plane. Porosimetric studies revealed that, once H2O is intruded in silicalite-1 a reversible-penetration of molecules occurs close to 100 MPa11, 18 with some hysteresis
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
