The saturation of negative charges of zeolites by specific cations to modify their physicochemical and catalytic properties has broadened the applications of zeolites. The adsorption behavior of H+ to Li+, Na+, K+, Rb+ and Cs+-saturated Linde-type A, Na-P1, mordenite, X type and Y type zeolites was evaluated at different pH-pM, where pH-pM is equal to log {(M+)/(H+)} and M+ represents either Li...

In this study, beta nanozeolite, ultra-stable Y zeolite (USY) and amorphous silica-alumina (ASA) were synthesized. These compounds were used as the support of hydrocracking catalyst. Ni-Mo/beta zeolite-ASA and Ni-Mo/USY zeolite-ASA catalysts were prepared by the impregnation method. The samples were characterized with X-Ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM)...

Time-resolved near-IR phosphorescence spectroscopy was employed to determine the lifetime of singlet oxygen in Y-zeolites and porous silica and it was found to depend strongly on the alumina content of the zeolite.

Ru(III)-exchanged FAU-Y zeolite was used as an efficient reusable heterogeneous catalyst for preparation of oxindoles from condensation reaction of indoles with isatins under very mild reaction conditions.

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...

Poly(p-phenylene) (PPP) was chemically synthesized via oxidative polymerization using benzene and doped with FeCl(3). The electrical conductivity response of the doped PPP (dPPP) towards CO, H(2) and NH(3) is investigated. dPPP shows no electrical conductivity response towards the first two gases (CO and H(2)), but it shows a definite negative response towards NH(3). The electrical conductivity...

1. Introduction 1. Introduction Information on mass transport in polycrystalline zeolite membranes is necessary for a theoretical estimation of the membrane performances. Zeolite membranes are usually prepared as thin layer of an assembly of small zeolite crystals including many intercrystalline regions. Thus, the intercrystal region would influence their individual diffusion properties, which ...

Article type: Original article Objective(s): In this research, zeolite X and zeolite Y were used as vehicle to prepare intestine targeted oral delivery systems of indomethacin and ibuprofen. Materials and Methods: A soaking procedure was implemented to encapsulate indomethacin or ibuprofen within synthetic zeolites. Gravimetric methods and IR spectra of prepared formulations were used to assess...

Cu-exchanged Y zeolite was investigated in order to determine the location of the copper cations relative to the zeolite framework and to determine which Cu cations are active for the oxidative carbonylation of methanol to dimethyl carbonate (DMC). Cu-Y zeolite was prepared by vapor-phase exchange of H-Y with CuCl. The oxidation state, local coordination, and bond distances of Al and Cu were de...