Catalyst of nickel

Data have been obtained for the rate of the heterogeneous reaction with catalyst of nickel on silica at 191 C (Yates et al, JACS 86 2996,1964) ... 

This reaction is a reversible reaction and special conditions are employed to ensure that the reaction proceeds to the right (the forward reaction), producing hydrogen and carbon monoxide. The process is carried out at a temperature of 750 °C, at a pressure of 30 atmospheres with a catalyst of nickel. These conditions enable the maximum amount of hydrogen to be produced at an economic cost. 

Typical catalysts for the fixed-bed vapor-phase hydrogenation include nickel sulfide deposited on alumina. For example, First Chemical Corporation (since 2002 a subsidiary of DuPont) employs the Lonza process, with a fixed-bed catalyst of copper on pumice. First Chemical is the world s second largest merchant producer of aniline, at Pascagoula, Mississippi, and Baytown, Texas, and supplies North American Bayer Corporation with its aniline requirements for polyurethanes8. Similar processes are operated by Bayer, with a palladium catalyst on an alumina support, modified with vanadium and lead. A catalyst of nickel sulfide on ammonia has also been revealed. 

Nicomo-12 [Grace], TM for a hydrodesulfurization catalyst of nickel, cobalt, and molybdenum on alumina. 

The results of all the investigations on the thermal stability of methane show it to be rather refractory. Temperatures as high as 700° C. are necessary before decomposition becomes active and long times of contact are required even then before marked dissociation to hydrogen and carbon occurs. The dissociation is largely reversible at all temperatures and has been found to be chiefly a surface-catalyzed reaction. Catalysts of nickel and iron have been found to be particularly active. 

At 90° on a moderately active catalyst of nickel wire in the absence of ethylene the hydrogen-deuterium reaction is complete within 3 hrs. The presence of ethylene markedly retards the rate of this reaction as the following experiment showed 12 mm. of C2H4,9.6 mm. D2, and 10.1 mm. of H2 were contacted with the nickel wire for 4 hrs. At the end of this period, when 10% addition to the double bond took place, there were 6.1 mm. of D2,8.4 mm. H2, and 4.5 mm. HD. If equilibrium had been attained, the composition would be 4.0 mm. D2,6.0 mm. Hg, and 9.2 mm. HD, indicating that the ethylene had suppressed the equilibration of the hydrc en isotopes. 

Kim, H.D., Lee, J.H., Choi, W.S., 2011. Direct growth of carbon nanotubes with a catalyst of nickel nanoparticle-coated alumina powders. Journal of the Korean Physical Society, 58, 112-115. 

Each catalyst is designed to be best suited to one type of feed or one type of treating goal. When hydrotreating is done for sulfur removal, the process is called hydrodesulfurization, and the catalyst generally is cobalt and molybdenum oxides on alumina. A catalyst of nickel-molybdenum compounds on alumina can be used for denitrogenation and cracked-stock saturation. 

Insoluble in water, soluble in organic solvents b.p. — 15°C. Prepared by treating 1,4-dibromo-butane with metallic sodium. Reduced to n-butane by hydrogen at 200" C in presence of nickel catalysts. 

CH3CH1CH2CH2OCH2CH2OH. Colourless liquid with a pleasant odour b.p. 17rC. Manufactured by heating ethylene oxide with 1-butanol in the presence of nickel sulphate as a catalyst. Used as a solvent in brushing lacquers. 

Raney nickel A special form of nickel prepared by treating an Al-Ni alloy with NaOH solution. The nickel is left in a spongy mass which is pyrophoric when dry. This form of nickel is a most powerful catalyst, especially for hydrogenations. 

In the practical applications of Raney nickel it is more convenient to measure the catalyst than to weigh it. The product, prepared as above, contains about 0-6 g. of the catalyst per millilitre of settled material a level teaspoonful is about 3 g. of nickel. 

Nickel catalysts although less expensive than rhodium and platinum are also less active Hydrogenation of arenes m the presence of nickel requires high temperatures (100-200°C) and pressures (100 atm)... 

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. 

Reppe s work also resulted in the high pressure route which was estabUshed by BASF at Ludwigshafen in 1956. In this process, acetylene, carbon monoxide, water, and a nickel catalyst react at about 200°C and 13.9 MPa (2016 psi) to give acryUc acid. Safety problems caused by handling of acetylene are alleviated by the use of tetrahydrofuran as an inert solvent. In this process, the catalyst is a mixture of nickel bromide with a cupric bromide promotor. The hquid reactor effluent is degassed and extracted. The acryUc acid is obtained by distillation of the extract and subsequendy esterified to the desked acryhc ester. The BASF process gives acryhc acid, whereas the Rohm and Haas process provides the esters dkecdy. 

Tetrahydronaphthalene is produced by the catalytic treatment of naphthalene with hydrogen. Various processes have been used, eg, vapor-phase reactions at 101.3 kPa (1 atm) as well as higher pressure Hquid-phase hydrogenation where the conditions are dependent upon the particular catalyst used. Nickel or modified nickel catalysts generally are used commercially however, they are sensitive to sulfur, and only naphthalene that has very low sulfur levels can be used. Thus many naphthalene producers purify their product to remove the thionaphthene, which is the principal sulfur compound present. Sodium treatment and catalytic hydrodesulfuri2ation processes have been used for the removal of sulfur from naphthalene the latter treatment is preferred because of the ha2ardous nature of sodium treatment. 

Nickel also is an important iadustrial catalyst. The most extensive use of nickel as a catalyst is ia the food iadustry ia connection with the hydrogenation or dehydrogenation of organic compounds to produce edible fats and oils (see Fats and FATTY oils). 

Uses. Nickel nitrate is an intermediate in the manufacture of nickel catalysts, especially those that are sensitive to sulfur and therefore preclude the use of the less expensive nickel sulfate. Nickel nitrate also is an intermediate in loading active mass in nickel—alkaline batteries of the sintered plate type (see Batteries, SECONDARY cells). Typically, hot nickel nitrate symp is impregnated in the porous sintered nickel positive plates. Subsequendy, the plates are soaked in potassium hydroxide solution, whereupon nickel hydroxide [12054-48-7] precipitates within the pores of the plate. 

Nickel sulfide, NiS, can be prepared by the fusion of nickel powder with molten sulfur or by precipitation usiag hydrogen sulfide treatment of a buffered solution of a nickel(II) salt. The behavior of nickel sulfides ia the pure state and ia mixtures with other sulfides is of iaterest ia the recovery of nickel from ores, ia the high temperature sulfide corrosion of nickel alloys, and ia the behavior of nickel-containing catalysts. 

Nickel plays a role in the Reppe polymeriza tion of acetylene where nickel salts act as catalysts to form cyclooctatetraene (62) the reduction of nickel haUdes by sodium cyclopentadienide to form nickelocene [1271 -28-9] (63) the synthesis of cyclododecatrienenickel [39330-67-1] (64) and formation from elemental nickel powder and other reagents of nickel(0) complexes that serve as catalysts for oligomerization and hydrocyanation reactions (65). 

The approximate worldwide aimual usage of nickel chemicals at 10 t, other than for steel and nickel refining, in 1994 was, for plating salts, 12—15 catalysts, 10—12 specialty ceramics, 3—4 specialty chemicals, 2—3 and other specialties, 1—2. 

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