Nickel oxide, hydrogenation catalyst

The first suitable activated-alumina catalyst contained 10% M0O3 activated by addition of 3% nickel oxide. This catalyst was superseded by a more active tungsten catalyst containing 70% activated alumina, 27% tungsten sulfide, and 3% nickel sulfide. This catalyst is used in commercial plants for the prehydrogenation of middle oils and also for the direct hydrogenation of shale oil and lignite tar (TTH process). 

The temperature required for the reduction of cobalt oxides to the metal appears to be somewhat higher than for the reduction of nickel oxide. The catalyst with a higher catalytic activity is obtained by reduction of cobalt hydroxide (or basic carbonate) than by reduction of the cobalt oxide obtained by calcination of cobalt nitrate, as compared in the decomposition of formic acid.91 Winans obtained good results by using a technical cobalt oxide activated by freshly calcined powdered calcium oxide in the hydrogenation of aniline at 280°C and an initial hydrogen pressure of 10 MPa (Section... 

Sabatier did not extend his work to liquid phase hydrogenation, possibly because the condensation of liquid on the catalyst surface interfered with the reactioa Nevertheless, by 1902 the liquid phase hydrogenation of fatty oils had been introduced on an industrial scale. Apart from nickel oxide the catalysts claimed in these patents included copper, platinum, and palladium, and were soon being supported on inert materials to increase activity. ... 

Adkins investigated the preparation of nickel and copper hydrogenation catalysts in 1931 and attempted to optimize a nickel oxide/kieselguhr catalyst preparation. A typical method of production was to add sodium carbonate solution to a sluny of kieselguhr with a nickel salt solution and precipitate basic nickel carbonate. The mixed solid was then filtered, washed, dried, calcined at 400°C, and pelletted with a lubricant such as graphite. 

Zelinsky, the Russian chemist, woiked with nickel oxide/alumina catalysts for a number of hydrogenation reactions and was probably one of the first to describe co-precipitation of nickel oxide and alumina in 1924. Since then many other nickel catalysts with alumina supports have been co-precipitated and used successfully in the production of synthesis gas, hydrogen, and town gas. 

The preparation of s-caprolactam via the Beckman rearrangement of cyclohexanone oxime was first described by Wallach in 1900. In the I.G. Faiben process, phenol was hydrogenated to cyclohexanol, at 140°-160°C and 15 bar, with a nickel oxide/silica catalyst. The cyclohexanol was del drogenated to cyclohexanone using a zinc/iron catalyst at 400°C, and the cyclohexanone oxime was formed by reaction with hydroxylamine monosidfonate. Conversion to cyclohexanone oxime was maximized at pH 7 by neutralizing the solution with ammonia. The organic layer of cmde oxime was crystallized and then isomerized to s-caprolactam with 20% oleum at 120°C. e-Caprolactam was purified and the ammonium sulfate recovered. 

The first process utilizes a bed of nickel catalyst which has been regenerated with hydrogen to reduce the nickel content to metallic form. The finely divided metal then reacts with impurities and retains them in the bed, probably as nickel oxide in the case of oxygen or as physisorbed compounds for other impurities. Periodically, the bed is regenerated at elevated temperature using hydrogen to restore the metallic content. The nickel process can be used and regenerated indefinitely. 

Na.tura.1 Ga.s Reforma.tion. In the United States, most hydrogen is presently produced by natural gas reformation or methane—steam reforming. In this process, methane mixed with steam is typically passed over a nickel oxide catalyst at an elevated temperature. The reforming reaction is... 

Nickel Arsenate. Nickel arsenate [7784-48-7] Ni2(As0 2 8H20, is a yellowish green powder, density 4.98 g/cm. It is highly iasoluble ia water but is soluble ia acids, and decomposes on heating to form As20 and nickel oxide. Nickel arsenate is formed by the reaction of a water solution of arsenic anhydride and nickel carbonate. Nickel arsenate is a selective hydrogenation catalyst for iaedible fats and oils (59). 

In the Sabatier reaction, methane and water are formed over a nickel— nickel oxide catalyst at 250°C. The methane is recovered and cracked to carbon and hydrogen, which is then recycled ... 

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 catalysts used in the process are essentially nickel metal dispersed on a support material consisting of various oxide mixtures such as alumina, silica, lime, magnesia, and compounds such as calcium aluminate cements. When the catalyst is made, the nickel is present as nickel oxide which is reduced in the plant converter with hydrogen, usually the 3 1 H2 N2 synthesis gas ... 

The reaction scheme is rather complex also in the case of the oxidation of o-xylene (41a, 87a), of the oxidative dehydrogenation of n-butenes over bismuth-molybdenum catalyst (87b), or of ethylbenzene on aluminum oxide catalysts (87c), in the hydrogenolysis of glucose (87d) over Ni-kieselguhr or of n-butane on a nickel on silica catalyst (87e), and in the hydrogenation of succinimide in isopropyl alcohol on Ni-Al2Oa catalyst (87f) or of acetophenone on Rh-Al203 catalyst (87g). Decomposition of n-and sec-butyl acetates on synthetic zeolites accompanied by the isomerization of the formed butenes has also been the subject of a kinetic study (87h). 

The nickel supported catalysts formed in this way have some specific features (144)- The catalysts containing about 3% of Ni are paramagnetic. When varying the nickel content from 0.1 to 20%, all the nickel the reduced catalyst (the exposed surface area of nickel was about 600 m2/g Ni) is oxidized by oxygen. The activity in benzene hydrogenation is very high and increases in proportional to the nickel content in the catalyst. 

Several other important commercial processes need to be mentioned. They are (not necessarily in the order of importance) the low pressure methanol process, using a copper-containing catalyst which was introduced in 1972 the production of acetic add from methanol over RhI catalysts, which has cornered the market the methanol-to-gasoline processes (MTG) over ZSM-5 zeolite, which opened a new route to gasoline from syngas and ammoxidation of propene over mixed-oxide catalysts. In 1962, catalytic steam reforming for the production of synthesis gas and/or hydrogen over nickel potassium alumina catalysts was commercialized. 

Morikawa et al. (42) suggest that nickel aluminate itself undergoes hydrogen reduction only to a superficial extent, and then produces extremely small nickel particles as the reduction product. In this circumstance, the nickel particle size distribution in a reduced nickel/alumina catalyst will obviously be much dependent on the preparative details that control the proportions nickel oxide and nickel aluminate and the size of the particles in which these substances exist before reduction. 

Carpenter-Evans A catalytic process for removing organic sulfur compounds from synthesis gas by hydrogenation to hydrogen sulfide, which is absorbed by iron oxide. The hydrogenation catalyst is nickel sub-sulfide, Ni3S2. Invented by E. V Evans and C. C. Carpenter in England around 1913 and operated in three commercial plants. 

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