Deposition of CH3ReO3 onto the surface of dehydrated, amorphous silica-alumina generates a highly active, supported catalyst for the metathesis of olefins. However, silica-alumina with a high (10 wt %) Re loading is no more active than silica-alumina with low (1 wt %) loading, while CH3ReO3 on silica is completely inactive. Catalysts prepared by grafting CH3ReO3 on silica-alumina contain two ty...

The surface chemical activity of an alumina films grown on Mo(100) by oxidation of aluminum evaporated onto the surface and oxidized using water is examined using Auger, X-ray photoelectron and reflection/absorption infrared spectroscopies. The formation of alumina is confirmed using Auger and X-ray photoelectron spectroscopy from the positions and intensities of the aluminum features and using...

The control of particle size distribution of fabricated alumina nanoparticles from general alumina that has a large geometric standard deviation (GSD) is studied. A thermophoretic separator was used to control the GSD of the fabricated alumina nanoparticles. Unevaporated particles and primary particles were separated to yield a small GSD for fabricated alumina nanoparticles. The fabricated alum...

Alumina nanorods were prepared from chromium-containing alumina sludge, and the effects of doping elements, such as Cr, Fe, and Mg, were researched. The results show that the crystal transformation of alumina is restricted by the doped Cr and facilitated by the doped Fe and Mg, which is transformed from θ-Al2O3 to α-Al2O3 in the calcination process. Meanwhile, the crystal transformation of alum...

polycrystalline mfi zeolite membranes were prepared on α-alumina tubular support by hydrothermal treatments at 413 k. the synthesized zeolite membranes were characterized by xrd, sem and single gas permeation. the influence of hydrothermal treatment steps and the calcination time on the zeolite layer formation were investigated. mfi zeolite membrane prepared by four subsequent hydrothermal trea...

The heating of porous dielectrics, beef–air (b/a) and beef–oil (b/o), attached with ceramic, metallic or ceramic–metallic composite supports, has been studied analytically using microwaves. Three test porosities were considered, 0.3, 0.45 and 0.6. A preliminary understanding of enhanced heating and power absorption within the material was obtained from the average power vs slab depth plots. The...

We compared results for the liquid-chromatographic determination of free norepinephrine and epinephrine in urine after purifying the catechols by the following methods: (a) acid-washed alumina, (b) weak cation-exchange resin (WCX), (c) a combination of weak cation-exchange resin followed by alumina (WCX-alumina), and (d) commercially available phenylboronic acid adsorbent. We evaluated analytic...

Cell adhesion, migration, and proliferation are significantly affected by the surface topography of the substrates on which the cells are cultured. Alumina is one of the most popular implant materials used in orthopedics, but few data are available concerning the cellular responses of mesenchymal stem cells (MSCs) grown on nanoporous structures. MSCs were cultured on smooth alumina substrates a...

Catalysts based on zirconia and alumina-supported tungsten oxides (3–18 wt% W) with a small loading of platinum (0.3 Pt) were selected to study the influence W loading, support type, preparation methods hydroisomerization n-dodecane. The alumina- zirconia-supported catalysts show different catalytic properties that play an important role in n-dodecane conversion. Specific surface area acidity a...

The performances of alumina-supported cobalt catalysts strongly depend on Co/alumina interactions, that are poorly understood. In the present work, ?-alumina surfaces used as models polycrystalline support, to unravel their orientation dependent behavior by GI-EXAFS. CoII/?-alumina interactions in dried state investigated, with a resolution parallel versus perpendicular deposit formation. DFT c...