Cobalt-copper-manganese catalyst

An oxidation catalyst containing cobalt, copper, manganese and silver species. It adsorbs nitroalkanes strongly, which may then ignite. Respirator cartridges containing it should not be used in high concentrations of nitroalkanes. 

NICKEL, COBALT, COPPER, MANGANESE AND GOLD CATALYSTS... 

Oxidation. Acetaldehyde is readily oxidised with oxygen or air to acetic acid, acetic anhydride, and peracetic acid (see Acetic acid and derivatives). The principal product depends on the reaction conditions. Acetic acid [64-19-7] may be produced commercially by the Hquid-phase oxidation of acetaldehyde at 65°C using cobalt or manganese acetate dissolved in acetic acid as a catalyst (34). Liquid-phase oxidation in the presence of mixed acetates of copper and cobalt yields acetic anhydride [108-24-7] (35). Peroxyacetic acid or a perester is beheved to be the precursor in both syntheses. There are two commercial processes for the production of peracetic acid [79-21 -0]. Low temperature oxidation of acetaldehyde in the presence of metal salts, ultraviolet irradiation, or osone yields acetaldehyde monoperacetate, which can be decomposed to peracetic acid and acetaldehyde (36). Peracetic acid can also be formed directiy by Hquid-phase oxidation at 5—50°C with a cobalt salt catalyst (37) (see Peroxides and peroxy compounds). Nitric acid oxidation of acetaldehyde yields glyoxal [107-22-2] (38,39). Oxidations of /)-xylene to terephthaHc acid [100-21-0] and of ethanol to acetic acid are activated by acetaldehyde (40,41). 

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). 

Most commercial sorbic acid is produced by a modification of this route. Catalysts composed of metals (2inc, cadmium, nickel, copper, manganese, and cobalt), metal oxides, or carboxylate salts of bivalent transition metals (2inc isovalerate) produce a condensation adduct with ketene and crotonaldehyde (22—24), which has been identified as (5). 

Metal-Catalyzed Oxidation. Trace quantities of transition metal ions catalyze the decomposition of hydroperoxides to radical species and greatiy accelerate the rate of oxidation. Most effective are those metal ions that undergo one-electron transfer reactions, eg, copper, iron, cobalt, and manganese ions (9). The metal catalyst is an active hydroperoxide decomposer in both its higher and its lower oxidation states. In the overall reaction, two molecules of hydroperoxide decompose to peroxy and alkoxy radicals (eq. 5). 

Two classes of metals have been examined for potential use as catalytic materials for automobile exhaust control. These consist of some of the transitional base metal series, for instance, cobalt, copper, chromium, nickel, manganese, and vanadium and the precious metal series consisting of platinum [7440-06-4], Pt palladium [7440-05-3], Pd rhodium [7440-16-6], Rh iridium, [7439-88-5], Ir and mthenium [7440-18-8], Ru. Specific catalyst activities are shown in Table 3. 

Traces as low as parts per million of certain transition metals, notably copper, manganese, cobalt and iron, which may have been introduced as catalysts, are able to propagate oxidation. Metal deactivators serve to reduce these effects. 

Copper, manganese and cobalt are oxidation catalysts and must be avoided, in particular for inserts. 

Good behaviour up to 60°C except chlorinated solvents, certain oxidants, aromatic hydrocarbons Copper, manganese and cobalt are oxidation catalysts and must be avoided in particular for inserts Possible for special grades... 

Although the decomposition of ozone to dioxygen is a thermodynamically favoured process,126 it is thermally stable up to 523 K and catalysts are needed to decompose it at ambient temperature in ventilation systems, in the presence of water vapour and at high space velocity. A limited number of catalysts have been evaluated and active components are mainly metals such as platinum, palladium and rhodium, and metal oxides including those of manganese, cobalt, copper, iron, nickel and silver. Supports that have been used include 7-alumina, silica, zirconia, titania and activated carbon.125,170... 

The activity of NiO has been studied by Wagner and Hauffe (47) and others (22,49,50). Catalytic activity of this oxide is enhanced considerably by the addition of manganese dioxide. For the simple oxides, the activity decreases in the following series Mn02 > C02O3 > NiO > CuO (48). The catalysts containing nickel oxide are promoted by the addition of oxides of iron, copper, aluminum, and chromium. Iron, nickel, and cobalt chromites, as catalysts for the oxidation of CO, were investigated by Lory (30). 

Redox-active metals are the initiators of perhaps greatest importance for lipid oxidation in oils, foods, and biological systems because they are ubiquitous and active in many forms, and trace quantities (electron transfers appear to be active catalysts these include cobalt, iron, copper, manganese, magnesium, and... 

Hutchings, G.J., Copperthwaite, R.G., Gottschalk, F.M., Hunter, R., Mellor, J., Orchard, S.W., and Sangiorgio, T. A comparative evaluation of cobalt chromium oxide, cobalt manganese oxide, and copper manganese oxide as catalysts for the water-gas shift reaction. Journal of Catalysis, 1992, 137, 408. 

In the atmospheric pressure synthesis of hydrocarbons from hydrogen and carbon monoxide. Elvins32 showed experimentally that reduced un-suoported catalysts of cobalt, copper, or manganese prepared by ignition of the nitrates gave much greater conversions than the reduced precipitated oxides. 

Since methanol is a direct reaction product of hydrogen and carbon monoxide, it is theoretically possible by using an excess of carbon monoxide in the original water gas mixture to form first methanol and then acetic acid or ester in one operation. With this end in view, catalysts composed of metals or their compounds, i.e. of nickel, chromium, cobalt, copper, cadmium, or manganese, have been patented.1"4 Catalysts similar to those proposed for the carbon monoxide-methanol reaction and comprising the oxides of copper, tin, lead, the acetate of copper, or tire methylates of aluminum or tin, or mixtures have been claimed for the same reaction at pressures of 150 to 200 atmospheres and at about 300° C.1 4e... 

Catalysts formed by igniting asbestos threads that have been impregnated with nitrates of iron, nickel, cobalt, chromium, copper, manganese, cerium, or silver will also ignite ether-air mixtures with formation of acetaldehyde.188... 

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