We have investigated the nature and extent of nanoscale disorder in prototypical host–guest zeolites, made silicalite-1 (host) organic structure-directing agent (OSDA, guest). The four different selected OSDA-silicalite-1 differ in: mineralizing used (F– vs OH–), synthesis method (hydrothermal solvent-free), OSDA (tetrapropylammonium (TPA) tripropylethylammonium TPEA). comparison between TPA TP...

Zeolites are the catalytic materials that widly applied in processing of conventional and renewable fuels chemicals. The present study provides a comprehensive analysis factors controlling acidic medium synthesis high silica silicalite-1 zeolite. effect various sources (TEOS, fumed colloidal silica) alkali metal cations (Na K) on formation is studied. efficiency different types seeds (micron-si...

Defect free MFI type silicalite-1 membranes have been fabricated inside tubular TiO2 ceramic supports to be used for the separation of greenhouse gases. In this work, single gas permeance experiments have been conducted. The results of which in conjunction with adsorption isotherms for each gas investigated have been used to calculate the effective diffusivities of N2, CH4, and CO2. The permean...

Molecular dynamics simulations of the diffusion of trans-2-butene in zeolite type MEL at 623 K have revealed an initial increase of the self-diffusivity with increasing loading, in contrast to simulation data collected for the other butene isomers. This is usually the signature of repulsive guest-guest interactions. At higher loadings, however, the concentration dependence was shown to decrease...

The main results obtained by using IR, Raman and W-Vis techniques concerning the structure of the Ti(IV) center in Ti-silicalite is briefly reviewed and discussed with recent XAFS results. The Ti(1V) is in tetrahedral coordination in vacuo and expands its coordination sphere upon interaction with adsorbates. Present EXAFS results indicate, for the dehydrated sample, a fust shell coordination nu...