Medium-pore (diameter ~ 6A) zeolites such as ZSM-5 and silicalite impregnated with Group VIII metals provide selective catalytic pathways for the conversion of synthesis gas to gasoline or olefins. Mössbauer and magnetic studies on these catalysts containing iron or iron plus cobalt are reported. The zeolites were impregnated with metal nitrate solutions, reduced, and carbided to yield showed F...

Disperse fine equiaxed α-Al2O3 nanoparticles with narrow size distribution are important materials in nanotechnology and nanomaterials, but syntheses of disperse fine equiaxed α-Al2O3 nanoparticles usually result in fine γ-Al2O3 nanoparticles or large α-Al2O3 nanoparticles larger than 15 nm. α-Al2O3 has a higher surface energy than γ-Al2O3 and becomes thermodynamically not stable with respect t...

Low temperature fabrication of Al2O3-polyimide composite substrates was carried out by an aerosol deposition process using a mixture of Al2O3 and polyimide starting powders. The microstructures and dielectric properties of the composite thick films in relation to their Al2O3 contents were characterized by X-ray diffraction analysis. As a result, the crystallite size of α-Al2O3 calculated from S...

Five monolithic catalysts with low noble metal content were prepared by immerge method (Pt/gamma-Al2O3, Pt/La-Al2O3, Pt/YSZ-Al2O3, Pt+Pd/La-Al2O3 and Pd/La-Al2O3) and their activity measurements were carried out in a conventional fixed-bed flow reactor. The results show that La-Al2O3 can promote activity of the prepared catalysts and can decrease the complete conversion temperature of cooking f...

Ordered mesoporous SBA-15 analogs with different Si/Al ratios were successfully prepared in a two-step process from self-assembly of ZSM-5 nanoseeds at high temperature in mildly acidic media (473 K, pH 3.5). The obtained products were characterized as SAXS, XRD, N₂ sorption, FTIR, TEM, NH₃-TPD, AAS and ICP. The results show that the initial Si/Al molar ratio of ZSM-5 precursors strongly affect...

Visualizing proton-transfer processes at the nanoscale is essential for understanding the reactivity of zeolite-based catalyst materials. In this work, the Brønsted-acid-catalyzed oligomerization of styrene derivatives was used for the first time as a single molecule probe reaction to study the reactivity of individual zeolite H-ZSM-5 crystals in different zeolite framework, reactant and solven...

One-dimensional medium-pore zeolites are promising catalysts for propylene production from naphtha cracking due to their high selectivity. However, fast deactivation pore mouth blockage is preventing these being widely used in commercial applications. In this study, we molecular dynamics simulations investigate the diffusion of three one-dimensional aluminosilicate frameworks (ZSM-23, ZSM-22, Z...

The characterization and catalytic performance of Zn/ZSM-5 Zn-B/ZSM-5 catalysts in the n-hexane aromatization was reported. Catalysts were prepared by post-synthesis ion exchange thoroughly characterized means XRD, Py-FTIR, N2 adsorption, 27Al 11B MAS NMR spectroscopy electron microscopy techniques. incorporation zinc reduces Brønsted acid site density increases Lewis acidic sites final ZSM-5 b...