We report a new one-pot synthesis procedure for hierarchical zeolites with intracrystalline macropores and metal particles encapsulated within the zeolitic walls. The allows to prepare macroporous of MFI topology different heteroatoms (silicalite-1, ZSM-5 TS-1) noble particles, such as gold, platinum palladium. hierarchically structured contain large diameters around 400 nm, which are well dist...

Zeolites with the faujasite structure (FAU) are extensively used as catalysts and in gas separation. A detailed knowledge of their structure, particularly the positions of extra−framework cations in the case of gas adsorption, is therefore central to understanding their performance. Typically zeolites X (Si/Al ~.1.1−1.5) and Y (Si/Al ~5−11) are used. A common assertion of structural determinati...

The chemistry of radicals adsorbed on zeolites is remarkable in that the products of radical-radical reactions, which are nonselective in solution, can be made selective and can be controlled by supramolecular effects and magnetic isotope effects. The photolysis of ketones adsorbed on zeolites can be manipulated so that either primary or secondary radicals produced by photolysis can be directed...

We have investigated various silica zeolites using density functional theory with periodic supercells, plane waves, and pseudopotentials. These zeolitic phases include silica sodalite, chabazite, mordenite, silica LTA, and silicalite. Atom-level geometries, elastic properties, and cohesive energies are presented. Although the zeolites exhibit a wide range of Si-O-Si angles and densities, the co...

guishing high and low Si/Al ratio zeolites and may be important in studies of zeolites that are chemically or physically altered. ence Foundation under Grant CHE 8204417 is gratefully acknowledged. We thank Professor T. L. Barr, Professor J. Vedrine, Dr. C. D. Wagner, Dr. J. M. Stencel, and Dr. T. D. Debies for helpful discussions and for their comments and suggestions concerning this manuscrip...

Various metal-β zeolites have been synthesized under similar ion-exchange conditions. During the exchange process, the nature and acid strength of the used cations modified the composition and textural properties as well as the Brönsted and Lewis acidity of the final materials. Zeolites exchanged with divalent cations showed a clear decrease of their surface Brönsted acidity and an increase of ...

1. Introduction Measuring diffusion in zeolites is a long-lasting challenge. For more than 70 years many efforts have been made to determine the diffusion coefficient of host molecules in the porous framework of zeolites [1]. Actually the different techniques, which were applied, observed different processes and provided dissenting diffusion coefficients. Precisely, there are methods observing ...

The poor hydrothermal stability of germanosilicate zeolites greatly retards their industrial application. Herein, we present a direct synthesis of Ge-containing IWR zeolites with outstanding hydrothermal stability. A simple quaternary ammonium cation, diethyldimethylammonium, was used as the structure-directing agent for the first time. The structure and chemical composition of the framework wa...