Interplay of quantum mechanical calculations and experimental data on hyperfine coupling constants of ethyl radical in zeolites at several temperatures was engaged to study the geometries and binding energies and to predict the temperature dependence of hyperfine splitting of a series of alkyl radicals in zeolites for the first time. The main focus is on the hyperfine interaction of alkyl radic...

Tailoring the Ti coordination states in titanosilicate zeolites to simultaneously improve feedstock conversion and maximize target product selectivity remains a challenge pursuit of high-performance catalysts for selective oxidation reactions. Herein, we provide facile strategy synthesize hierarchical anatase-free TS-1 (MFI-type) with tetrahedrally coordinated (TiO4) octahedrally species (TiO6)...

Zeolites A, X and HS were synthesized from natural Iranian Kaolinite by alkaline fusion,,followed by refluxing the mixture. The transformation of zeolites X to HS and Y to P were studied at different time intervals by X-ray diffraction and Scanning Electron Microscopy (SEM). It was revealed that in solution, zeolites HS and P are more stable than zeolites X and Y respectively

Zeolites are widely applied as solid acid catalysts in various technological processes. In this work we have computationally investigated how catalytic reactivity scales with acidity for a range of zeolites with different topologies and chemical compositions. We found that straightforward correlations are limited to zeolites with the same topology. The adsorption energies of bases such as carbo...

O NE OF THE methods currently being investigated for the regenerable removal of carbon dioxide from space vehicle atmospheres involves its adsorption on synthetic zeolites. These materials, known commercially as "molecular sieves" (Linde Company) or "microtraps" (Davison Chemical Company) are crystalline alumino silicates of alkali and alkaline earth metals. Synthetic zeolites being crystalline...

The pyrolysis of lignocellulosic biomass is a promising technology for obtaining renewable chemicals and fuels to replace fossil-based products. However, due the complexity lignin, cellulose hemicellulose molecules, large variety compounds are often formed, making commercial implementation difficult. use catalyst during reactions has been recognized as one major improvements in pyrolysis, allow...

ZnO modified ZSM-5 and Y zeolites are synthesized by performing atomic layer deposition (ALD) of ZnO to HZSM-5 and HY using diethyl zinc and water as the precursors. The surface area and pore volume of ZSM-5 and Y zeolites are progressively reduced with the increasing number of ZnO ALD cycles. XRD and SEM characterization methods show that highly dispersed ZnO species are deposited on the inter...

Synthetic zeolites are used widely throughout the petroleum refining and chemical process industries as selective adsorbents, catalysts and ion exchangers. The research described in this thesis focuses on the characterization and environmental applications of faujasite zeolites, including nanocrystalline Y zeolites that have particle sizes less than