Elastic behavior of MFI-type zeolites: 3 – Compressibility of silicalite and mutinaite

Nanostructured zeolite with brain-coral morphology and tailored acidity: a self-organized hierarchical porous material with MFI topology

Nano-zeolite with brain-coral morphology formed by self-organization of ultra-small nanospheres, exhibits micro/meso porosity with high surface area, distributed acid sites, and reduced diffusion resistance making it a promising solid acid catalyst.

Periodic modeling of zeolite Ti-LTA

We have proposed a combination of density functional theory calculations and interatomic potential-based simulations to study the structural, electronic, and mechanical properties of pure-silica zeolite Linde Type A (LTA), as well as two titanium-doped compositions. The energetics of the titanium distribution within the zeolite framework suggest that the inclusion of a second titanium atom with configurations Ti-(Si)₀-Ti, Ti-(Si)₁-Ti, and Ti-(Si)₂-Ti is more energetically favorable than the mono-substitution. Infra-red spectra have been simulated for the pure-silica LTA, the single titanium substitution, and the configurations Ti-(Si)₀-Ti and Ti-(Si)₂-Ti, comparing against experimental benchmarks where available. The energetics of the direct dissociation of water on these Lewis acid sites indicate that this process is only favored when two titanium atoms form a two-membered ring (2MR) sharing two hydroxy groups, Ti-(OH)₂-Ti, which suggests that the presence of water may tune the distribution of titanium atoms within the framework of zeolite LTA. The electronic analysis indicates charge transfer from H₂O to the Lewis acid site and hybridization of their electronic states.

Pressure-induced penetration of guest molecules in high-silica zeolites: the case of mordenite

A synthetic high-silica mordenite (HS-MOR) has been compressed in both non-penetrating (silicone oil, s.o.) and penetrating [methanol : ethanol : water (16 : 3 : 1) (m.e.w.), water : ethanol (3 : 1) (w.e.), and ethylene glycol (e.gl.)] pressure transmitting media (PTM).

High-pressure-induced structural changes, amorphization and molecule penetration in MFI microporous materials: a review

This is a comparative study on the high-pressure behavior of microporous materials with an MFI framework type (i.e.natural mutinaite, ZSM-5 and the all-silica phase silicalite-1), based onin-situexperiments in which penetrating and non-penetrating pressure-transmitting media were used. Different pressure-induced phenomena and deformation mechanisms (e.g.pressure-induced over-hydration, pressure-induced amorphization) are discussed. The influence of framework and extra-framework composition and of the presence of silanol defects on the response to the high pressure of MFI-type zeolites is discussed.