Oxidation of aluminum

Aluminum Oxide. Emery [57407-26-8] is a natural oxide of aluminum with various impurities. One of these impurities, iron oxide, also acts as an abrasive. Pure aluminum oxide is made from bauxite [1318-16-7] and has partially replaced emery. 

Daumengrofes Labor aus Aluminium-Folie, Blick durch die Wirtschafi, June 1997 Heterogeneous gas-phase micro reactor micro-fabrication of this device anodic oxidation of aluminum to porous catalyst support vision of complete small laboratory numbering-up development of new silicon device [225]. 

Formation of mesoporous aluminum oxide by anodic oxidation of aluminum in acid electrolytes... 

Campbell T, Kalia RK, Nakano A, Vashishta P, Ogata S, Rodgers S (1999) Dynamics of oxidation of aluminum nanoclusters using variable charge molecular-dynamics simulations on parallel computers. Phys Rev Lett 82(24) 4866 t869... 

Numerous publications have been devoted to the investigation of the morphology of porous oxides of aluminum. Pores of virtually... 

There is a complex relationship among the oxide, hydroxide, and hydrous oxide of aluminum. Conversion between several phases is possible as a result of the reactions... 

Direct measurement of the change in interfacial potential difference at the oxide-electrolyte interface with change in pH of solution can be measured with semiconductor or semiconductor-oxide electrodes. These measurements have shown d V g/d log a + approaching 59 mV for TiC (36, 37). These values are inconsistent with the highly sub-Nernstian values predicted from the models with small values of K. (Similar studies 138.391 have been performed with other oxides of geochemical interest. Oxides of aluminum have yielded a value of d t)>q/A log aH+ greater than 50 mV, while some oxides of silicon have yielded lower values.)... 

Yamada, M., K. Fugii, H. Ham and K. Itabashi. 1988. Preparation and catalytic properties of special alumina membrane formed by anodic oxidation of aluminum. Proc. 9th Inti. Cong. Catal. 1945-1951. 

The mechanism of developing corrosion protective properties in an inorganic coating principally consists of forming insoluble oxides on the netal surface. Additionally, oxides must have certain corrosion inhibition (redox) properties which can protect the nnetal substrate from corrosive species like Cl and 804 . In the case of chromate conversion coating, OCC, the oxides of aluminum and chromium have been responsible for their corrosion inhibitive properties which were derived from their soluble and insoluble portions of the... 

Oblath, S.B., and J. L. Gole. 1980. On the continuum emissions observed upon oxidation of aluminum and its compounds. Gombustion Flame 37 293-312. 

Alumina nanotubes have been prepared by the anodic oxidation of aluminum [41] the resulting tubes have one-dimensional channels with uniform diameters of 5nm and lengths of 50-100 nm. An alumina membrane with a highly ordered nanohole array in 50-100 nm diameter has also been synthesized by long-period anodization thus these local alumina nanotubes have been tried as a template for metal nanowire formation. 

The AI-H2O reaction increases the temperature and the number of moles of gas in the bubble by the production of H2 molecules. The pressure in the bubble is thereby increased. As a result, the bubble energy and shock wave energy are increased. It must be understood that the oxidation of aluminum powder is not like that of gaseous reactants. Reaction occurs at the surface of each aluminum particle and leads to the formahon of an aluminum oxide layer that coats the particle. The oxidized layer prevents the oxidation of the interior particle. The combustion efficiency of aluminum parhcles increases with decreasing particle size.l =l The shock wave energy and bubble energy are increased by the use of nano-sized aluminum powders. 

The common oxide of aluminum provides a second example, but this time, begin with the weight percent and deduce the atomic ratio. Careful laboratory analysis of aluminum oxide determines it to be approximately 53% aluminum and 47% oxygen by weight, as shown in the second column in Table 2-3. 

In this special field, earlier work had been done in other laboratories, such as by the Schering Company, Berlin (36), and by Ipatieff (37) in connection with his work on the hydrogenation of camphor and of other organic compounds. At both places, the favorable effect of alkali oxides and earth alkali oxides on nickel, cobalt and copper has been investigated. Similarly, Paal and his coworkers (38) have used a palladium-aluminum hydroxide catalyst in 1913 for the hydrogenation of double bonds. Bedford and Erdman (39) had reported that the catalytic action of nickel oxide is enhanced by the oxides of aluminum, zirconium, titanium, calcium, lanthanum, and magnesium. 

Reforming Both thermal and catalytic processes are utilized to convert naphtha fractions into high-octane aromatic compounds. Thermal reforming is utilized to convert heavy naphthas into gasoline-quality aromatics. Catalytic reforming is utilized to convert straight-run naphtha fractions into aromatics. Catalysts utilized include oxides of aluminum, chromium, cobalt, and molybdenum as well as platinum-based catalysts. 

In this case the hydrazine is the sole source of the working gas, which is expanded by the heat released by the oxidation of aluminum, whereas in the unmetallized system a significant part of the hydrogen from hydrazine decomposition furnishes energy by oxidation as well as part of the working gas in the form of water. 

What do the oxidation of zinc and the oxidation of aluminum have in common ... 

The oxidation of iron to rust is a problem structural engineers need to be concerned about, but the oxidation of aluminum to aluminum oxide is not. Why ... 

Aluminum—air battery. A second potential application of this available energy is based on electrochemical oxidation of aluminum in air to produce electricity. In an aluminum—air battery, for example, thin coils of aluminum strip may be used as the fuel. No elech ic battery recharging would be required since the aluminum is consumed to generate the electricity directly. This fuel would not give off fumes or pollute and could be stored in solid form indefinitely. If this concept materializes into commercial viability, it will provide the energy needed for electric vehicles. 

LATERITE. The suh-aerial decay of rocks in tropica) regions, ha mg a distinctly moist or rainy climate, results in the development of a residual, reddish, and usually sticky soil frequently containing concretions. The principal products of laicri/alion are the hydrated oxides of aluminum and iron cither in the crystalline ur amorphous form. If the concentration of iron oxide is sufficiently high the laicrite may be valuable as an iron ore. If. on the other hand, the concentration of alumina is high the laleritc may he valuable as an ore ol that metal. 

Aluminum, chromium, titanium, and several other metals can be colored by an electrochemical process called anodizing. Unlike electroplating, in which a metal ion in the electrolyte is reduced and the metal is coated onto the surface of the cathode, anodizing oxidizes a metal anode to yield a metal oxide coat. In the oxidation of aluminum, for instance, the electrode reactions are... 

Oxidation can be viewed as the chemisorption of oxygen. For example, nickel and silicon are oxidized at ambient conditions. The resulting oxide layer is thermodynamically more stable and passivates the pure material below it. Another important example is the oxidation of aluminum which provides the metal with a very hard roughly 100 nm thick aluminum oxide (AI2O3) layer. To stabilize the aluminum surface even more and to passivate it against reactive chemicals the thickness of the oxide layer can be increased electrochemically. This procedure is called the eloxal process (efectrolytical oxidation of a/uminum). 

A convenient method to produce porous surfaces is the anodic oxidation of aluminum plates. Such microstructured aluminum platelets have been coated by wet impregnation with Pt-, V- and Zr-precursors [35], and tested under catalytic methane combustion conditions. The conversion rate of oxygen followed directly the platinum content in the catalysts. These data were well reproducible even after five different runs. 

In the case of catalytic methane combustion, aluminum was chosen as an appropriate material for the catalyst wafers since anodic oxidation of aluminum can be used to obtain porous surfaces. Such micro structured aluminum platelets were coated by wet impregnation with Pt, V and Zr precursors [50],... 

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