Manganese oxides, supported

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],... 

One result of this work is the conclusion that in chromia-alumina, and in other supported oxides, there must be local concentration of the supported oxide. This conclusion is reached because the Weiss constant shows definite indication of exchange interaction at concentrations of the paramagnetic ion too low to cover the surface of the support with even a monolayer. Another conclusion is that the support is sometimes able to modify the relative stabilities of oxidation states in the supported oxide. For instance, manganese oxide supported on gamma-alumina tends to be stabilized in the tripositive state, while on high-area titania it reverts to the tetrapositive state. 

The use of Pd-Co catalyst on a Hopcalite (a mixture of copper and manganese oxides) support increased DPC yield to 43.5% with exceptional selectivity (99.6%)... 

Fig. 14. Susceptibility isotherms for high-ignition manganese oxide supported on...

Magnetic moment (O) and chemical oxidation state for low-ignition manganese oxide supported on alumina. 

Einaga, H., Teraoka, Y., Ogata, A. (2013). Catalytic oxidation of benzene by ozone over manganese oxides supported on USY zeolite. Journal of Catalysis, 305, 227—237. 

Qi G, Yang R T (2003) Low-temperature selective catalytic reduction of NO withNHs over iron and manganese oxides supported on titania. Appl. Catal. B. 44 217-225. 

Li et al reported that the activity of a copper-manganese oxide supported catalyst... 

Wollner, A., Lange, F., Schmelz, H., et al. (1993). Characterization of mixed copper-manganese oxides supported on titania catalysts for selective oxidation of ammonia, Appl. Catal. A Gen., 94,181-203. 

The raw materials needed to supply about ten million new automobiles a year do not impose a difficult problem except in the case of the noble metals. Present technology indicates that each car may need up to ten pounds of pellets, two pounds of monoliths, or two pounds of metal alloys. The refractory oxide support materials are usually a mixture of silica, alumina, magnesia, lithium oxide, and zirconium oxide. Fifty thousand tons of such materials a year do not raise serious problems (47). The base metal oxides requirement per car may be 0.1 to 1 lb per car, or up to five thousand tons a year. The current U.S. annual consumption of copper, manganese, and chromium is above a million tons per year, and the consumption of nickel and tungsten above a hundred thousand tons per year. The only important metals used at the low rate of five thousand tons per year are cobalt, vanadium, and the rare earths. 

Fuel cell applications Manganese dioxide as a new cathode catalyst in microbial fuel cells [118] OMS-2 catalysts in proton exchange membrane fuel cell applications [119] An improved cathode for alkaline fuel cells [120] Nanostructured manganese oxide as a cathodic catalyst for enhanced oxygen reduction in a microbial fuel cell [121] Carbon-supported tetragonal MnOOH catalysts for oxygen reduction reaction in alkaline media [122]... 

Morales F., de Smit E., de Groot F.M.F., Visser T., and Weckhuysen B.M. 2007. Effects of manganese oxide promoter on the CO and H2 adsorption properties of titania-supported cobalt Fischer-Tropsch catalysts. J. Catal. 246 91-99. 

Bezemer, G. L., Radstake, P. B., Falke, U., Oosterbeek, H., Kuipers, H. P. C. E., van Dillen, A., and de Jong, K. P. 2006. Investigation of promoter effects of manganese oxide on carbon nanofiber-supported cobalt catalysts for Fischer-Tropsch synthesis. Journal of Catalysis 237 152-61. 

R. M. Torres Sanchez, A. Ueda, K. Tanaka and M. Hamta, Selective oxidation of CO in hydrogen over gold supported on manganese oxides, J. Catal. 168, 125—127 (1997). 

The high activity that supported gold catalysts have shown for CO oxidation at ambient temperature makes them ideal candidates for use as respiratory protectors. A copper manganese oxide, Hopcalite, has been used for many years to remove CO in toxic environments. Thus, supported gold catalysts may be chosen in the future. 

A similar oxidation-reduction mechanism in the carbon monoxide oxidation reaction on oxide catalysts has been proposed by Benton (71), Bray (72), Frazer (73), and Schwab (74). In this reaction also, Mooi and Selwood (57) found that a decrease in the percentage of iron oxide, manganese oxide or copper oxide on the alumina support first increased the rate, and then at lower percentages decreased the rate, of carbon monoxide oxidation, indicating that valence stabilization is again operative in these cases. 

In contrast with these observations, it has been found that manganese and iron oxide supported on magnesium oxide catalyze cracking reactions via a free-radical mechanism and ensure enhanced ethylene and ethane production.64... 

Manganese oxide finely divided, preparation, 78-79 supported, preparation, 79-80 Manifold fluorine, 228-230 glass, high vacuum, 100-102 for inert gas and vacuum, 9-10 rough vacuum, 119 Manometer designs, 129-131 reading(s), 132... 

CNTs were also demonstrated to be a perfect support for cheap transition metal oxides of poor electrical conductivity, such as amorphous manganese oxide (a-Mn02 H20) [5,96], The pseudocapacitance properties of hydrous oxides are attributed to the redox exchange of protons and/or cations with the electrolyte as in Equation 8.13 for a-Mn02 H20 [97] ... 

An example of a successful implementation of some of these ideas was the kinetic study of the selective catalytic reduction of NO over alumina-supported manganese oxide [39], Product analysis was performed by a mass spectrometer, six reactors were placed parallel in one oven, one of them served as the reference... 

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