Supported nickel-copper catalysts

Dahnon J A, Martin G A, Hydrogenolysis of C2H6, C3H8 and n-C4Hio over sUica-supported nickel-copper catalysts , J. Cataiysis, 1980 66 214—221 Tavares M T, Alstrup I, Bernard C A, Coking and decoking during methanation and methane decomposition on Ni-Cu supported catalysts , Materiais and Corrosion,... 

J.J. Prinsloo and P.C. Gravelle, Volumetric and calorimetric study of the adsorption of hydrogen, at 296 K, on supported nickel and nickel-copper catalysts containing preadsorbed carbon monoxide, J. Chem. Soc., Faraday Trans. I, 1980, 76, 512. 

Reduction. Acetaldehyde is readily reduced to ethanol (qv). Suitable catalysts for vapor-phase hydrogenation of acetaldehyde are supported nickel (42) and copper oxide (43). The kinetics of the hydrogenation of acetaldehyde over a commercial nickel catalyst have been studied (44). 

Early catalysts for acrolein synthesis were based on cuprous oxide and other heavy metal oxides deposited on inert siHca or alumina supports (39). Later, catalysts more selective for the oxidation of propylene to acrolein and acrolein to acryHc acid were prepared from bismuth, cobalt, kon, nickel, tin salts, and molybdic, molybdic phosphoric, and molybdic siHcic acids. Preferred second-stage catalysts generally are complex oxides containing molybdenum and vanadium. Other components, such as tungsten, copper, tellurium, and arsenic oxides, have been incorporated to increase low temperature activity and productivity (39,45,46). 

Catalysts used for preparing amines from alcohols iaclude cobalt promoted with tirconium, lanthanum, cerium, or uranium (52) the metals and oxides of nickel, cobalt, and/or copper (53,54,56,60,61) metal oxides of antimony, tin, and manganese on alumina support (55) copper, nickel, and a metal belonging to the platinum group 8—10 (57) copper formate (58) nickel promoted with chromium and/or iron on alumina support (53,59) and cobalt, copper, and either iron, 2iac, or zirconium (62). 

The predominant process for manufacture of aniline is the catalytic reduction of nitroben2ene [98-95-3] ixh. hydrogen. The reduction is carried out in the vapor phase (50—55) or Hquid phase (56—60). A fixed-bed reactor is commonly used for the vapor-phase process and the reactor is operated under pressure. A number of catalysts have been cited and include copper, copper on siHca, copper oxide, sulfides of nickel, molybdenum, tungsten, and palladium—vanadium on alumina or Htbium—aluminum spinels. Catalysts cited for the Hquid-phase processes include nickel, copper or cobalt supported on a suitable inert carrier, and palladium or platinum or their mixtures supported on carbon. 

Hydrogenation of Acetaldehyde. Acetaldehyde made from acetylene can be hydrogenated to ethanol with the aid of a supported nickel catalyst at 150°C (156). A large excess of hydrogen containing 0.3% of oxygen is recommended to reduce the formation of ethyl ether. Anhydrous ethanol has also been made by hydrogenating acetaldehyde over a copper-on-pumice catalyst (157). 

Other metal oxide catalysts studied for the SCR-NH3 reaction include iron, copper, chromium and manganese oxides supported on various oxides, introduced into zeolite cavities or added to pillared-type clays. Copper catalysts and copper-nickel catalysts, in particular, show some advantages when NO—N02 mixtures are present in the feed and S02 is absent [31b], such as in the case of nitric acid plant tail emissions. The mechanism of NO reduction over copper- and manganese-based catalysts is different from that over vanadia—titania based catalysts. Scheme 1.1 reports the proposed mechanism of SCR-NH3 over Cu-alumina catalysts [31b],... 

Five main types of CNFs, platelet (P-CNF), tubular (T-CNF), thick herringbone (thick FI-CNF), thin herringbone (thin H-CNF) and very thin herringbone (very thin FI-CNF) vere selectively prepared and examined as supports of anode catalysts for DMFCs. P-CNF was synthesized from carbon monoxide over a pure iron catalyst at 600 °C, whereas thick H-CNF was obtained from ethylene over a copper-nickel catalyst [Cu-Ni (2 8 w/w)]. An Fe-Ni alloy (6 4 w/w) was used for the selective synthesis of T-CNFs from carbon monoxide gas at 650 °C [15, 16]. 

Raney nickel, copper and platinum group metal catalysts have also been used as catalysts for transforming fructose into mannitol via catalytic hydrogenation (Scheme 14) 197-199,203,204 supported on carbon... 

One of the characteristic features of the metal-catalysed reaction of acetylene with hydrogen is that, in addition to ethylene and ethane, hydrocarbons containing more than two carbon atoms are frequently observed in appreciable yields. The hydropolymerisation of acetylene over nickel—pumice catalysts was investigated in some detail by Sheridan [169] who found that, between 200 and 250°C, extensive polymerisation to yield predominantly C4 - and C6 -polymers occurred, although small amounts of all polymers up to Cn, where n > 31, were also observed. It was also shown that the polymeric products were aliphatic hydrocarbons, although subsequent studies with nickel—alumina [176] revealed that, whilst the main products were aliphatic hydrocarbons, small amounts of cyclohexene, cyclohexane and aromatic hydrocarbons were also formed. The extent of polymerisation appears to be greater with the first row metals, iron, cobalt, nickel and copper, where up to 60% of the acetylene may polymerise, than with the second and third row noble Group VIII metals. With alumina-supported noble metals, the polymerisation prod-... 

Suitable catalysts for the process are supported nickel and copper oxide. 

Schwab et al. (46, 47) showed that nickel, copper and platinum supported on optically-active quartz behave as enantioselective catalysts for the dehydrogenation and oxidation of racemic sec-butyl alcohol. At low conversion, a measurable optical rotation of the reaction solution is observed, showing that one enantiomer has reacted... 

Supported nickel is invariably used as catalyst. Although other catalysts are equally or more effective, nickel has widespread acceptance from long use, ease of removal, and low cost. Unremoved traces of other metals such as copper might also reduce the oxidative stability of the product. 

Carbonyl groups. Breitner et al. found Engelhard Ru-C and Rh-C distinctly superior to Pl-C and Pd-C for the hydrogenation of ketones in neutral or basic medium. Hu.sek et til. iittcmpted reduction of tetramothy 1-1,3-cyclobutanedione with platinum, palladium, and rhodium catalysts but the results were very poor. With copper-chromium oxide and supported nickel culitlyilR yieldsol diols were moderate,... 

PREPARATION OF SYMMETRICAL AND MIXED SECONDARY ALKYLAMINES OVER RANEY NICKEL AND SUPPORTED COPPER CATALYSTS... 

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