Nickel-uranium oxide catalysts

Table 13.6 Activity of nickel-uranium oxide catalysts for steam reforming of naphtha [72],...

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). 

Nicklin, with others, filed several early patents describing the use of uranium oxides as steam reforming catalysts [69], U3O8 was used along with nickel oxide as the basis of a steam reforming catalyst, and it was modified with potassium species (potassium hydroxide, potassium oxide and/or potassium carbonate), all supported on either alumina or a mix of alumina and magnesium oxide. The uranium and nickel catalysts proved to be extremely efficient for steam reforming. 

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. 

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). 

Molybdenum In its pure form, without additions, it is the most efficient catalyst of all the easily obtainable and reducible substances, and it is less easily poisoned than iron. It catalyzes in another way than iron, insofar as it forms analytically easily detectable amounts of metal nitrides (about 9% nitrogen content) during its catalytic action, whereas iron does not form, under synthesis conditions, analytically detectable quantities of a nitride. In this respect, molybdenum resembles tungsten, manganese and uranium which all form nitrides during their operation, as ammonia catalysts. Molybdenum is clearly promoted by nickel, cobalt and iron, but not by oxides such as alumina. Alkali metals can act favorably on molybdenum, but oxides of the alkali metals are harmful. Efficiency, as pure molybdenum, 1.5%, promoted up to 4% ammonia. 

Lead hydroxide is used in making porous glass in electrical-insulating paper in electrolytes in sealed nickel-cadmium batteries in recovery of uranium from seawater and as a catalyst for oxidation of cyclododecanol. 

Results of experiments varying the ratio of uranium to nickel showed that the ratios giving the largest surface area and catalyst volume were in the range 0.45-0.76 (U Ni). These two characteristics were the most important for activity for these reactions. The catalysts were in a reduced state, which could explain the addition of the reduction-oxidation step in the previous patent A further reason for using catalysts in the 0.45-0.74 U Ni range was that the catalyst demonstrated greatest resistance to coke deposition at a raho of 0.71 1. 

Uranium can also be obtained as uranium(lV) oxide from the alkaline solutions by reduction with hydrogen at 140 to 150°C under pressures of 6 to 10 bar in the presence of a nickel catalyst ... 

Tn review completely the numerous examples of promoted catalysts, most of which are mentioned in the patent literature, would be entirely out of place here. It is, however, interesting to note that the term was used and the effect noticed early in the industrialization of the water gas reaction.- Additions of the oxide of chromium, thorium, uranium, beryllium, and antimony to the nickel, iron, or cobalt catalysts was found to increase greatly the activity of these materials toward this reaction.24... 

Suitable catalysts for oxidation (22) are oxides of cobalt, cerium, vanadium, and uranium. Catalysts for ester formation are oxides of lead, molybdenum, silicon, uranium, and cerium. The best flavors are produced by the use of oxides of lead, copper, nickel, molybdenum, cobalt, titanium, and silicon. 

SPERSUL or SPERSUL THIOVIT (7704-34-9) Combustible solid (flash point 405°F/207°C). Finely divided dry material forms explosive mixture with air. The vapor reacts violently with lithium carbide. Reaets violently with many substances, including strong oxidizers, aluminum powders, boron, bromine pentafluoride, bromine trifluoride, calcium hypochlorite, carbides, cesium, chlorates, chlorine dioxide, chlorine trifluoride, chromic acid, chromyl chloride, dichlorine oxide, diethylzinc, fluorine, halogen compounds, hexalithium disilicide, lampblack, lead chlorite, lead dioxide, lithium, powdered nickel, nickel catalysts, red phosphorus, phosphorus trioxide, potassium, potassium chlorite, potassium iodate, potassium peroxoferrate, rubidium acetylide, ruthenium tetraoxide, sodium, sodium chlorite, sodium peroxide, tin, uranium, zinc, zinc(II) nitrate, hexahydrate. Forms heat-, friction-, impact-, and shock-sensitive explosive or pyrophoric mixtures with ammonia, ammonium... 

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