Copper alumina

The hydrogenation of but-2-yne in the gas phase has been investigated using alumina-supported Group VIII metals, other than palladium, and over copper—alumina [200,201], With the exception of copper, which was 100% stereoselective for c/s-but-2-ene formation, the distribution of the initial reaction products, as shown in Table 20, are more complex than was observed with palladium. 

Alkylphenanthridines (and 6-aryl) have been obtained by passing a mixture of 2-nitrobiphenyl and the appropriate alcohol over a copper-alumina catalyst at 320-360°.59... 

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... 

Calcium Carbonate, Calcium Silicate, Powdered Aluminium, Copper Alumina, Flint Powder, Carborundum, Silica, Molybdenum Disulphide Chopped Glass Mica, Silica, Powdered or flaked Glass Metallic Filler or Alumina Colloidal Silica, Bentonite Clay Improved Thermal Conductivity Improved Machinability Improved Abrasion Resistance Improved Impact Strength Improved Electrical Conductivity Improved Thixotropic Response... 

In such situation, when copper is deposited on these supports one may expect the presence of at least three kinds of copper entities differing in their interactions with the underlying support and which may be designated as copper-alumina, copper-2D-Ce and copper-3D-Ce. The chemical behaviour of the first and the last of these entities can be assumed in principle to be close to that of copper supported on the pure supports. For the calcined samples, in the case of the CuA catalyst two different Cu entities have been identified on the EPR spectra differing in their dispersion degree, with a fraction of Cu remaining undetected. On CuC, the observable species is clearly different from those... 

An extensive literature exists on the characterization and structure—activity correlation of industrial copper-alumina oxychlorination catalysts [95-120]. At least two different major copper species have been identified. At low concentrations of copper (below ca 5 %), a well-dispersed copper species in intimate interaction with the alumina surface is formed. This species has a very low oxychlorination activity. At higher concentrations, a second species, probably formed by the de-position/precipitation of the copper chloro complexes, is observed. The latter gives rise to the active sites during the oxychlorination reaction. On the basis of an FTIR study of the oxychlorination reaction Finocchio et al. [42] postulated the formation of surface copper chloride-ethylene r-complex intermediates (which lead eventually to EDC) and weakly adsorbed HCl during oxychlorination. Formate species associated with copper and probable precursors for formation of the oxides of carbon by combustion were also identified. 

Single-bed catalysts had been used to produce sulfur from dry sulfur dioxide gases. Ryason 1,2) used either Cu, Pd, Ag, Co, or Ni supported on alumina. Khalafalla and Haas (3) optimized the composition of iron-alumina catalysts to produce sulfur from dry gases containing sulfur dioxide and carbon monoxide. Querido and Short (4) demonstrated the feasibility of reducing sulfur dioxide by carbon monoxide on a copper-alumina catalyst at concentrations and temperatures typical of power plant stack gases. 

Recently Okay and Short (5) reported that the sulfur dioxide reduction activity of the single-bed copper-alumina catalyst was reduced when water was added to an inlet gas containing 0.2% sulfur dioxide. Neither hydrogen nor hydrogen sulfide was detected in their experiments although thermodynamic calculations indicate that these gases could form at detectable concentrations. 

The disparity between these results and those reported by Okay and Short (5) on a copper-alumina catalyst can best be explained in the... 

A few measurements of catalytic activity have been made on the reduced copper-alumina system. Comparison of catalysts containing varying proportions of copper was made as usual by mechanically mixing all samples, except the lowest in copper, with 7-alumina so that all samples contained 3.2 per cent copper. The catalytic measurements were not extended below that concentration. The reaction chosen was the dehydrogenation of isopropyl alcohol. 

Relative Catalytic Activity of Copper-Alumina Catalyeis Acetone High-boiling Catalyst % %... 

Additive type Calcium carbonate calcium silicate powdered aluminum or copper Alumina flint powder carborundum silica molybdenum disulphide Chopped glass Mica silica powdered or flaked glass Metallic fillers or alumina Colloidal silica Bentonite clay... 

The catalytic carbon monoxide clean-up worked with a two-stage water-gas shift in tubular reactors cooled by steam generation. The kinetics for a rhenium-alumina catalyst for high temperature water-gas shift and for a copper/alumina catalyst for low temperature shift had been extracted from the literature. 

ZeinEddine, W., Matteazzi, P., CeUs, J.P., 2013. Mechanical and tribological behaviour of nanostructured copper—alumina cermets obtained by pulsed electric current sintering. Wear 297, 762-773. 

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