Alumina oxidants

Silica Oxide to Alumina Oxide Ratio (SAR) is used to describe the framework composition of zeolite. 

Park PW, Ledford JS (1998) The influence of surface structure on the catalytic activity of cerium promoted copper oxide catalysts on alumina oxidation of carbon monoxide and methane. Catal Lett 50(1—2) 41 48... 

Electric breakdown of growing alumina films limits their maximum attainable thickness. It also causes degradation of thin film electronic devices with alumina films. Hence, it is a subject of intensive research and a large number of papers have been published and further reviewed. A good deal of controversy exists on various aspects of alumina oxide breakdown, and a variety of models have been proposed in attempts to fit experimental findings. 

Anodic alumina oxides find steadily growing application in various spheres of technology. Traditionally, they are most popular in civil industrial engineering for producing protective and decorative surface finish in panels and different objects. These applications are well reviewed in the literature.321 Anodic alumina is also widely used in the aircraft and aerospace industry for adhesive bonding of aluminum structures,322-324 composite materials, etc. 

KMn04 impregnated alumina oxidizes arenes to ketones within 10-30 min under solvent-free conditions using focused microwaves [111]. /i,/i-Disubstituted enamines have been successfully oxidized into carbonyl compounds with KMn04-Al203 in domestic (255 W, 82 °C) and in focused microwave ovens (330 W, 140 °C) under sol-vent-free conditions by Hamelin et al. [112]. The yields are better in the latter case. When the same reactions are conducted in an oil bath at 140 °C, no carbonyl compound formation is observed (Scheme 6.36). 

Oxone has been successfully used in aprotic solvents for oxidation reactions by dispersing it on an alumina surface. Thus, the oxidation of secondary aliphatic, alicyclic and benzylic alcohols using Oxone/wet alumina oxide in CH2CI2 or CH3CN afforded ketones in good to excellent yields (70-96%). Similarly, the conversion of cycloalkanones to lactones is also reported. 

Sugar, resin, essential oil—eolanine, 1-07 Citrate of potassa, phosphates of potassa, of lime and magnesia, silica, alumina, oxide of iron, ana manganese,. 1-50. 

Chromyl chloride adsorbed on silica-alumina oxidizes alcohols to aldehydes and ketones.430... 

Silica, alumina, silica-alumina. Oxidation of iodide ion in aqueous 72... 

During the last 20 years, the chromatographic use of aluminum oxide has steadily decreased even though alumina partially or totally overcomes the difficulty arising from the relatively low pH stability of silica [25,26]. Alumina oxide is stable over a broader pH range (2-12) than silica gel but generally has a lower specific surface area, typically 70 m2/g [27,28],... 

Aluminum oxide [BioRad Alumina (oxide), AG-7] is suspended in chloroform-methanol (1 1, v/v) and then transferred to a glass chromatography tube fitted with a Teflon stopcock. Solvent is allowed to flow through until... 

The surface properties of the aluminum oxide in aqueous solutions play an important role in the technology of dispersed system processing and utilization of wastes containing alumina oxides or hydroxides. The wide abundance and application of alumina oxide caused intensification of their investigations in colloid chemistry. Especially coagulation, flocculation, filtration and ion exchanging properties of the systems were examined. For all these processes, the electrical properties of the interface, that rule the accumulation and transportation of the charge, are very important. 

An exhaustive study has been carried out recently on the synthesis of BN nanotubes and nanowires by various CVD techniques.17 The methods examined include heating boric acid with activated carbon, multi-walled carbon nanotubes, catalytic iron particles or a mixture of activated carbon and iron particles, in the presence of ammonia. With activated carbon, BN nanowires are obtained as the primary product. However, with multi-walled carbon tubes, high yields of pure BN nanotubes are obtained as the major product. BN nanotubes with different structures were obtained on heating boric acid and iron particles in the presence of NH3. Aligned BN nanotubes are obtained when aligned multi-walled nanotubes are used as the templates (Fig. 40). Prior to this report, alignment of BN nanotubes was achieved by the synthesis of the BN nanotubule composites in the pores of the anodic alumina oxide, by the decomposition of 2,4,6-trichloroborazine at 750 °C.116 Attempts had been made earlier to align BN nanotubes by... 

Several of the early oxide studies have already been mentioned in the introduction. The copper-alumina oxidation catalyst, which finds applications for the synthesis of glyoxal from glycol and as the principal component of base-metal formulations for automobile exhaust emission control, has... 

A typical embodiment for the porous layer technology is described in several patents and patent applications, e.g., a US patent application in 2006. This patent application describes a method for the preparation of silicon dioxide dispersions wherein the surface of the silicon dioxide is modified by treatment with the reaction products of a compound of trivalent aluminum with amino-organo-silane. The invention relates to recording sheets for inkjet printing having such a dispersion incorporated in the porous inkreceiving layer. Another US patent describes the preparation of nanoporous alumina oxide or hydroxide which contains at least one element of the rare earth metal series with atomic numbers 57 to 71. 

Sodium metiq>eriodate, NaI04, is a two-electron chemoselective oxidant and when absorbed on alumina oxidizes alcohols to carbonyl compounds and sulfides to sulfoxides without overoxidation to sul-fones. 2 Alkenic double bonds in the substrate remain intact during this oxidation. Typically reactions are performed in 95% ethanol at room temperature for a few hours and with good (85-90%) yields. 

In 1966 Kemball returned to Scotland to take up the chair of chemistry at the University of Edinburgh. His choice of catalysts became more versatile. With D. A. Whan he studied molybdenum obtained by carbonyl decomposition on alumina. Oxides and zeolites featured strongly among the solids whose catalytic properties he investigated, notably with assistance from... 

To get more detail on the light transfer by the anodic alumina oxide film, the light intensity enhancement from a flat white light emitting diode panel was examined. The porous anodic alumina film was placed between LEDs and a detector at a variable LED film distance and the light intensity Laa was... 

Several new procedures for the selective oxidation of secondary alcohols in the presence of primary alcohols have appeared. Distannoxane-bromine, a neutral reagent, efficiently oxidizes secondary or benzylic alcohols to ketones in the presence of primary alochols.62 Trialkyltin alkoxides and bromine oxidize both primary and secondary alcohols.63 Woelm W-200, neutral, dehydrated alumina oxidizes secondary alcohols to ketones in the presence of primary alcohols with trichloroacetaldehyde as the hydride acceptor.6 The reverse reduction process had previously been reported. Oxidation of triphenylmethyl ethers of primary, secondary diols with triphenyl carbenium salts proceeds only at the secondary positions.65... 

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