The effect of vanadium oxide as support and promoter on supported rhodium catalysts on the CO hydrogenation has been investigated at 0.15 and 4.0 MPa. Rh/V,O, reduced at 723 K has a good selectivity toward oxygenated products, especially C,-oxygenates, but has a low activity added as a promoter to catalysts consisting and stability. Vanadium oxide of rhodium supported on silica and alumina show...

In previous chapters, the synthesis of a highly hydrogen selective membrane formed by the deposition of a silica layer on top of a Vycor glass substrate was discussed. In this chapter, the preparation of a composite membrane using a porous alumina support is described. This membrane showed a high hydrogen permeance of the order of 10 mol m s Pa at 873 K with selectivity of hydrogen over CH4, CO...

This is a safety assessment of silica and the related cosmetic ingredients: alumina magnesium metasilicate, aluminum calcium sodium silicate, aluminum iron silicates, hydrated silica, and sodium potassium aluminum silicate. These ingredients are synthetic amorphous silicas and silicates; crystalline silica is not a cosmetic ingredient and is not used in cosmetics. These ingredients are used as ...

as benzimidazole ring is an important pharmacophore in modern drug discovery and benzimidazoles are very important intermediates in organic reactions, the preparation of benzimidazoles has gained considerable attention in recent years. here, a comparative study on the synthesis of benzimidazoles from aromatic, aliphatic and heterocyclic carboxylic acid, benzonitrile and o-phenylenediamine under...

Recently, there have been many materials used for denture base such as polymethyl methacrylate (PMMA) resin, modifi ed PMMA resin and nylon1,2). The material most often used to fabricate denture base and denture teeth was PMMA resin. PMMA is the most commonly used material due to its good mechanical and physical properties, compatibility with oral tissue, aesthetics, ease of repair and low cost...

DETERMINATION OF SILICA OXIDE iron ores usually are found in intimate association with sllica and phosphorus compounds. heir quantitative separation and purification sometimes present difficult problems to the chemist. Silicic acids may represent various degrees of dehydration. They are exceedingly weak, but combine with metallic oxides and form some of the most stable , oxides in nature, the s...

Understanding the interactions between metal complexes and oxide surfaces is crucial to the synthesis of supported metal catalysts. Recently developed in situ techniques have made it possible to closely characterize the solid/liquid interface. For the first time, the adsorption of platinum complexes on alumina and silica has been probed using a quartz crystal microbalance; we were able to obser...