Copper oxide hydrogenation catalyst

Copper chromite has been made by the ignition of basic copper chromate at a red heat and by the thermal decomposition of copper ammonium chromate. The procedure given here is a modification of the latter method in which barium ammonium chromate is also incorporated. Copper-chromium oxide hydrogenation catalysts have also been prepared by grinding or heating together copper oxide and chromium oxides, by the decomposition of copper ammonium chromium carbonates... 

Not only esters, but also free acids can be hydrogenated catalytically. For instance, 1-dodecanol is obtained in 94% yield in 90 min from dodecanoic acid by using copper oxide as catalyst at 250 atm pressure of hydrogen and 300°.528... 

Nitrogen and hydrogen can be determined simultaneously by burning in dry carbon dioxide in the presence of a copper-copper oxide-silver catalyst, when water and nitrogen are liberated and subsequently determined . 

When Adkins tried to modify the Lazier recipe and make a copper chromite hydrogenation catalyst, he found that an active black cupric oxide was produced instead of the red oxide claimed by Lazier. Adkins and Folkers subsequently suggested modifications to the recipe, including the addition of barium, magnesium, or calcium oxides to stabilize the black oxide form, which was more active. Atypical recipe and catalyst composition is shown in Table 3.11. 

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). 

Because the synthesis reactions are exothermic with a net decrease in molar volume, equiUbrium conversions of the carbon oxides to methanol by reactions 1 and 2 are favored by high pressure and low temperature, as shown for the indicated reformed natural gas composition in Figure 1. The mechanism of methanol synthesis on the copper—zinc—alumina catalyst was elucidated as recentiy as 1990 (7). For a pure H2—CO mixture, carbon monoxide is adsorbed on the copper surface where it is hydrogenated to methanol. When CO2 is added to the reacting mixture, the copper surface becomes partially covered by adsorbed oxygen by the reaction C02 CO + O (ads). This results in a change in mechanism where CO reacts with the adsorbed oxygen to form CO2, which becomes the primary source of carbon for methanol. 

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. Gas-phase catalytic hydrogenation of succinic anhydride yields y-butyrolactone [96-48-0] (GBL), tetrahydrofiiran [109-99-9] (THF), 1,4-butanediol (BDO), or a mixture of these products, depending on the experimental conditions. Catalysts mentioned in the Hterature include copper chromites with various additives (72), copper—zinc oxides with promoters (73—75), and mthenium (76). The same products are obtained by hquid-phase hydrogenation catalysts used include Pd with various modifiers on various carriers (77—80), Ru on C (81) or Ru complexes (82,83), Rh on C (79), Cu—Co—Mn oxides (84), Co—Ni—Re oxides (85), Cu—Ti oxides (86), Ca—Mo—Ni on diatomaceous earth (87), and Mo—Ba—Re oxides (88). Chemical reduction of succinic anhydride to GBL or THF can be performed with 2-propanol in the presence of Zr02 catalyst (89,90). 

Salts of neodecanoic acid have been used in the preparation of supported catalysts, such as silver neodecanoate for the preparation of ethylene oxide catalysts (119), and the nickel soap in the preparation of a hydrogenation catalyst (120). Metal neodecanoates, such as magnesium, lead, calcium, and zinc, are used to improve the adherence of plasticized poly(vinyl butyral) sheet to safety glass in car windshields (121). Platinum complexes using neodecanoic acid have been studied for antitumor activity (122). Neodecanoic acid and its esters are used in cosmetics as emoUients, emulsifiers, and solubilizers (77,123,124). Zinc or copper salts of neoacids are used as preservatives for wood (125). 

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. 

For more selective hydrogenations, supported 5—10 wt % palladium on activated carbon is preferred for reductions in which ring hydrogenation is not wanted. Mild conditions, a neutral solvent, and a stoichiometric amount of hydrogen are used to avoid ring hydrogenation. There are also appHcations for 35—40 wt % cobalt on kieselguhr, copper chromite (nonpromoted or promoted with barium), 5—10 wt % platinum on activated carbon, platinum (IV) oxide (Adams catalyst), and rhenium heptasulfide. Alcohol yields can sometimes be increased by the use of nonpolar (nonacidic) solvents and small amounts of bases, such as tertiary amines, which act as catalyst inhibitors. 

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. 

Hydrogenation of Fatty Acid Methyl Esters The hydrogenolysis of fatty acid methyl esters into the corresponding fatty alcohols and methanol is performed at 200-300°C and a H2 pressure of 200-300 bar with the aid of copper oxide/chromium oxide catalysts (Adkins catalysts). Three different procedures are applied [39 a-c] ... 

In addition to a-additions to isocyanides, copper oxide-cyclohexyl isocyanide mixtures are catalysts for other reactions including olefin dimerization and oligomerization 121, 125, 126). They also catalyze pyrroline and oxazoline formation from isocyanides with a protonic a-hydrogen (e.g., PhCH2NC or EtOCOCHjNC) and olefins or ketones 130), and the formation of cyclopropanes from olefins and substituted chloromethanes 131). The same catalyst systems also catalyze Michael addition reactions 119a). 

Aqueous cyanide effluent containing a little methanol in a 2 m3 open tank was being treated to destroy cyanide by oxidation to cyanate with hydrogen peroxide in the presence of copper sulfate as catalyst. The tank was located in a booth with doors. Addition of copper sulfate (1 g/1) was followed by the peroxide solution (27 1 of 35 wt%), and after the addition was complete an explosion blew off the doors of the booth. This was attributed to formation of a methanol vapour-oxygen mixture above the liquid surface, followed by spontaneous ignition. It seems remotely possible that unstable methyl hydroperoxide may have been involved in the ignition process. 

Airco A modification of the Deacon process for oxidizing hydrogen chloride to chlorine. The copper catalyst is modified with lanthanides and used in a reversing flow reactor without the need for external heat. Developed by the Air Reduction Company from the late 1930s. U.S. Patents 2,204,172 2,312,952 2,271,056 2,447,834. 

Shell Deacon An improved version of the Deacon process for oxidizing hydrogen chloride to chlorine, using a catalyst containing the mixed chlorides of copper, potassium, and rare earths. Formerly operated in The Netherlands and still in operation in India. 

In the third step, the mesityl oxide is hydrogenated (hydrogen added) to MIBK by heating it to the vapor stage at 300—400°F and passing it over a copper or nickel catalyst at 50-150 psi in the presence of hydrogen. 

The adipic acid process we have developed involves butadiene oxidative carbonylation in the presence of methanol, a l, l-dimethoxycyclohexane dehydration agent, and a palladium(ll)/ copper(ll) redox catalyst system (Equation 1.). The reaction sequence includes an oxycarbonylation, hydrogenation and hydrolysis step(17-19). The net result is utilization of butadiene, the elements of synthesis gas, l, -dimethoxycyclohexane and air to give adipic acid, cyclohexanone and methanol. 

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