Silicalite-1 core/Al-ZSM-5 shell zeolite crystals were prepared in various sizes for use as catalysts methane dehydroaromatization (MDA), and the growth kinetics corresponding physicochemical properties of this core–shell investigated. Al-ZSM-5 was grown on silicalite-1 seeds at Si/Al ratios. Core–shell all size variations exhibited similar deactivation trends MDA reaction, with minor changes a...

Quantitative agreement with experimental data for adsorption of argon, krypton, and methane in high-silica zeolites is achieved with a molecular model, which (1) assumes pairwise additivity of intermolecular forces; (2) ignores partially concealed silicon atoms and lumps their dispersion energy with the oxygen atoms; (3) neglects energy induced by the weak electric field inside silicalite; (4) ...

Catalytic biomass conversion is often hindered by coking. Carbon compounds cover active surface and plug pores, causing catalyst deactivation. Material design at the nanoscale allows tailoring of the catalytic activity and stability. Here, we report a simple synthesis of nanosized ZSM-5 materials by using a silicalite-1 seeding suspension. ZSM-5 crystals were grown from a deionized silica sourc...

Zeolite-supported metal catalysts are widely employed in a number of chemical processes, and the stability catalytically active species is one most critical factors determining reaction performance. A good example Pd/zeolite catalyst, which provides high activity for methane oxidation but deactivates rapidly under conditions due to palladium nanoparticle sintering. Although coating metals with ...

A unidirectional ensemble of hemicyanine molecules was prepared by inserting the molecules into the vertical channels of a uniformly oriented zeolite (silicalite-1) film grown on a glass substrate. Fluorescence from this sample excited with light polarized along the vertical channel was 50 times larger than that excited with light polarized orthogonal to the vertical channel direction. These ve...

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...