Nickel-manganese oxide catalysts

Kolbel et al. (K16) examined the conversion of carbon monoxide and hydrogen to methane catalyzed by a nickel-magnesium oxide catalyst suspended in a paraffinic hydrocarbon, as well as the oxidation of carbon monoxide catalyzed by a manganese-cupric oxide catalyst suspended in a silicone oil. The results are interpreted in terms of the theoretical model referred to in Section IV,B, in which gas-liquid mass transfer and chemical reaction are assumed to be rate-determining process steps. Conversion data for technical and pilot-scale reactors are also presented. 

Morales MR, Barbero BP, Cadus LE (2007) Combustion of volatile organic compounds on manganese iron or nickel mixed oxide catalysts. Appl Catal B Environ 74 1... 

The relatively high cost and lack of domestic supply of noble metals has spurred considerable efforts toward the development of nonnoble metal catalysts for automobile exhaust control. A very large number of base metal oxides and mixtures of oxides have been considered, especially the transition metals, such as copper, chromium, nickel, manganese, cobalt vanadium, and iron. Particularly prominent are the copper chromites, which are mixtures of the oxides of copper and chromium, with various promoters added. These materials are active in the oxidation of CO and hydrocarbons, as well as in the reduction of NO in the presence of CO (55-59). Rare earth oxides, such as lanthanum cobaltate and lanthanum lead manganite with Perovskite structure, have been investigated for CO oxidation, but have not been tested and shown to be sufficiently active under realistic and demanding conditions (60-63). Hopcalities are out-... 

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],... 

Shortly after the introduction of the bismuth molybdate catalysts, SOHIO developed and commercialized an even more selective catalyst, the uranium antimonate system (4). At about the same time, Distillers Company, Ltd. developed an oxidation catalyst which was a combination of tin and antimony oxides (5). These earlier catalyst systems have essentially been replaced on a commercial scale by multicomponent catalysts which were introduced in 1970 by SOHIO. As their name implies, these catalysts contain a number of elements, the most commonly reported being nickel, cobalt, iron, bismuth, molybdenum, potassium, manganese, and silica (6-8). 

Model Ni/MnOx catalysts were prepared by 150-X nickel deposition onto an oxidized manganese disk under ultra-high vacuum. The surface composition of the catalyst wa-s followed as a function of time at 500 K in ultra-high vacuum. Rapid diffusion of reduced manganese oxide onto the nickel surface was observed. This oxide migration phenomenon was observed for a wide range of metal/... 

The oxides of certain metals of the first, sixth, seventh, and eighth groups of the periodic system, such as copper, chromium, manganese, nickel, cobalt, etc., when deposited on non-vitreous alumina catalyze dehydrogenation reactions. These materials are also active oxidation catalysts and most of the catalysts used today for oxidation reactions occur in these periodic groupings. Hence, the actions of these materials may lead to difficulties in the separation of products because of side reactions which may be set up. ... 

In order to overcome certain difficulties such as the dissipation of heat and the use of inflammable mixtures, certain liquid phase processes have been proposed for the oxidation of aromatic hydrocarbons and compounds. In such a process 100 the aromatic hydrocarbons or their halogenated derivatives are treated with air or gas containing free molecular oxygen in the liquid phase at temperatures above ISO0 C. and under pressure in the presence of a substantial quantity of liquid water. A small quantity of such oxidation catalysts as oxides or hydroxides of copper, nickel, cobalt, iron or oxides of manganese, cerium, osmium, uranium, vanadium, chromium and zinc is used. The formation of benzaldehyde from toluene is claimed for the process. 

The mechanical strength of the fluidized catalyst is a significant process issue that must be solved. To address this operational problem, a two-step approach was taken to (1) identify and develop economical and attrition resistant support materials that could withstand high-temperature fluidization, and (2) prepare reforming catalysts from the best supports. The catalysts, containing nickel oxide (NiO), manganese oxide (MgO) and/or potassium oxide (K2O), were then evaluated for attrition resistance and activity in a fluid bed system. 

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