Copper oxide reduction with

I lope for Ihe emergence of bery llium beyond the laboratory curiosity status resulted from publication of the work of the French scientist Lebeau in 1899. His paper described the electrolysis of fused sodium fluoberyllate to produce small hexagonal crystals of beryllium. Lebeati also reported the direct reduction of a beryllium oxide-copper oxide mixture with carbon to... 

Williamson WB, Lunsford JH (1976) Nitric oxide reduction with ammonia over copper(II) Y zeolites. J Phys Chem 80 (24) 2664-2671... 

Because of the excellent catalytic performance of the ceria-based C03O4 and CuO catalysts, a combination of the two systems was investigated by preparing, through co-precipitation, mixed Cu-Co-Ce-O oxides with different compositions. The mixed oxides had a larger surface area with respect to the Co-Ce-O and Cu-Ce-O composite oxides. Moreover, the addition of cobalt to the Cu-Ce-O catalyst enhanced thermal stability because the particle size was unchanged on calcination at 850 °C. According to the H2-TPR patterns, the peaks due to cobalt oxide reduction and those for copper oxide reduction were reciprocally affected and shifted towards lower temperatures. The interaction between cobalt and... 

Note. Both tetramethylene glycol (1 4-butanediol) and hexamethylene glycol (1 6 hexaiiediol) may be prepared more conveniently by copper-chromium oxide reduction (Section VI,6) or, for small quantities, by reduction with lithium aluminium hydride (see Section VI,10). 

Impurities can be removed by formation of a gaseous compound, as in the fire-refining of copper (qv). Sulfur is removed from the molten metal by oxidation with air and evolution of sulfur dioxide. Oxygen is then removed by reduction with C, CO, in the form of natural gas, reformed... 

The fixed-bed catalyst is a siUca-based extmdate containing precipitated iron oxide promoted with potassium and copper. The catalyst is activated by hydrogen reduction of most of the iron cataly2ed by small amounts of copper. As the catalyst is used, additional reduction occurs and Hagg carbide [12127 5-6] Fe C2, is formed. 

Fire refining, the final smelting operation, removes further impurities and adjusts the oxygen level ia the copper by air oxidation followed by reduction with hydrocarbons, ammonia, or reformed gas (CO + H2). 

Aldehydes are formed by the reduction of the ester of the corresponding acid to the alcohol, and then oxidising the alcohol with heated copper as catalyst. It is well known that when primary alcohols in the gaseous state are passed over finely-divided copper dust, obtained by reduction of copper oxide, at 250° to 400°, they yield hydrogen, and aldehydes or ketones respectively. 

Oxidation-reduction potential Because of the interest in bacterial corrosion under anaerobic conditions, the oxidation-reduction situation in the soil was suggested as an indication of expected corrosion rates. The work of Starkey and Wight , McVey , and others led to the development and testing of the so-called redox probe. The probe with platinum electrodes and copper sulphate reference cells has been described as difficult to clean. Hence, results are difficult to reproduce. At the present time this procedure does not seem adapted to use in field tests. Of more importance is the fact that the data obtained by the redox method simply indicate anaerobic situations in the soil. Such data would be effective in predicting anaerobic corrosion by sulphate-reducing bacteria, but would fail to give any information regarding other types of corrosion. 

As a third oxidation-reduction example, suppose a strip of metallic zinc is placed in a solution of copper nitrate, Cu(N03)j. The strip becomes coated with reddish metallic copper and the bluish color of the solution disappears. The presence of zinc ion, Zn+2, among the products can be shown when the Cu+2 color is gone. Then if hydrogen sulfide gas is passed into the mixture, white zinc sulfide, ZnS, can be seen. The reaction between metallic zinc and the aqueous copper nitrate is... 

Sometimes the metal may be transformed into a different oxidation state thus copper(II) may be reduced in acid solution by hydroxylamine or ascorbic acid. After rendering ammoniacal, nickel or cobalt can be titrated using, for example, murexide as indicator without interference from the copper, which is now present as Cu(I). Iron(III) can often be similarly masked by reduction with ascorbic acid. 

The relatively high cost and lack of domestic supply of noble metals has spurred considerable efforts toward the development of nonnoble metal catalysts for automobile exhaust control. A very large number of base metal oxides and mixtures of oxides have been considered, especially the transition metals, such as copper, chromium, nickel, manganese, cobalt vanadium, and iron. Particularly prominent are the copper chromites, which are mixtures of the oxides of copper and chromium, with various promoters added. These materials are active in the oxidation of CO and hydrocarbons, as well as in the reduction of NO in the presence of CO (55-59). Rare earth oxides, such as lanthanum cobaltate and lanthanum lead manganite with Perovskite structure, have been investigated for CO oxidation, but have not been tested and shown to be sufficiently active under realistic and demanding conditions (60-63). Hopcalities are out-... 

Copper (Cu) is deposited in boilers either by direct exchange with iron or by the hydrogen reduction of copper oxide during the corrosion of steel. 

According to these conclusions, it is possible to propose a catalytic cycle (Fig. 20) involving no radical species, but a copper(I) complex with the classical oxidative addition, nucleophilic substitution and reductive elimination resulting lastly in the arylated nucleophile. 

In a review of the course and mechanism of the catalytic decomposition of ammonium perchlorate, the considerable effects of metal oxides in reducing the explosion temperature of the salt are described [1], Solymosi s previous work had shown reductions from 440° to about 270° by dichromium trioxide, to 260° by 10 mol% of cadmium oxide and to 200°C by 0.2% of zinc oxide. The effect of various concentrations of copper chromite , copper oxide, iron oxide and potassium permanganate on the catalysed combustion of the propellant salt was studied [2], Similar studies on the effects of compounds of 11 metals and potassium dichromate in particular, have been reported [3], Presence of calcium carbonate or calcium oxide has a stabilising effect on the salt, either alone or in admixture with polystyrene [4],... 

The reduction of a solution of a trialkylphosphine copper(I) iodide complex (CuIPR ) with preformed lithium naphthalide (LiNp) in THF or DME under argon was found to give a more reactive copper species, which will undergo oxidative addition with a variety of organic substrates at room... 

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