Nickel catalysts hydrogenation

Brown, H.C. Brown, C.A. The reaction of sodium borohydride with nickel acetate in ethanol solution—a highly selective nickel hydrogenation catalyst. J. Am. Chem. Soc. 1963, 85, 1005-1006. 

Fig. 1. Relative magnetization vs. absolute temperature for (1) coprecipitated nickel-silica containing 34% Ni, (2) Universal Oil Products Co. nickel hydrogenation catalyst containing 52% Ni, and (3) the same sintered for 6 hrs. at 650°. All reductions were in flowing hydrogen for 12 hrs. at 350°.

MA chain transfer, 244, 253 MA monomer, 239, 243-253, 259 Radical polymerization initiators, for polyester crosslinking, 487-491 Raman spectroscopy, MA spectrum, 8 Raney nickel hydrogenation catalyst, 42 7-Rays, polymerization initiation, 239-241,... 

Environmental limits on the aromatic content of gasoline and diesel fuel have led to a further application of supported nickel hydrogenation catalysts. Benzene can be completely removed from light Ce reformate or other similar streams by liquid phase hydrogenation, before blending into the refinery gasoline pool. 

Appreciable quantities are also obtained as a by-product in the manufacture of hydrogen from naphtha-gaseous hydrocarbons. In this process the gaseous hydrocarbon and superheated steam under a pressure of about 10 atmospheres and at a temperature of 1000 K are passed over a nickel-chromium catalyst. Carbon monoxide and hydrogen are produced ... 

The uncatalyzed addition of hydrogen to an alkene although exothermic is very slow The rate of hydrogenation increases dramatically however m the presence of cer tain finely divided metal catalysts Platinum is the hydrogenation catalyst most often used although palladium nickel and rhodium are also effective Metal catalyzed addi tion of hydrogen is normally rapid at room temperature and the alkane is produced m high yield usually as the only product... 

The French chemist Paul Sabatier received the 1912 Nobel Prize in chemistry for his discovery that finely di vided nickel is an effective hydrogenation catalyst... 

Disposal of spent hydrogenation catalyst requires a special chemical waste landfill because of its nickel content and the fact that oil-soaked catalysts tend to be pyrophoric. Compared to disposal costs, reprocessing to recover the nickel may become economically viable. 

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 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 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 ... 

Hydrogenation Catalysts. The key to catalytic hydrogenation is the catalyst, which promotes a reaction which otherwise would occur too slowly to be useful. Catalysts for the hydrogenation of nitro compounds and nitriles are generally based on one or more of the group VIII metals. The metals most commonly used are cobalt, nickel, palladium, platinum, rhodium, and mthenium, but others, including copper (16), iron (17), and tellurium... 

Steam Reforming Processes. In the steam reforming process, light hydrocarbon feedstocks (qv), such as natural gas, Hquefied petroleum gas, and naphtha, or in some cases heavier distillate oils are purified of sulfur compounds (see Sulfurremoval and recovery). These then react with steam in the presence of a nickel-containing catalyst to produce a mixture of hydrogen, methane, and carbon oxides. Essentially total decomposition of compounds containing more than one carbon atom per molecule is obtained (see Ammonia Hydrogen Petroleum). 

Isomerization of sorbitol, D-mannitol, L-iditol, and dulcitol occurs in aqueous solution in the presence of hydrogen under pressure and a nickel—kieselguhr catalyst at 130—190°C (160). In the case of the first three, a quasiequiUbrium composition is obtained regardless of starting material. Equilibrium concentrations are 41.4% sorbitol, 31.5% D-mannitol, 26.5% L-iditol, and 0.6% dulcitol. In the presence of the same catalyst, the isohexides estabUsh an equihbrium at 220—240°C and 15.2 MPa (150 atm) of hydrogen pressure, having the composition 57% isoidide, 36% isosorbide, and 7% isomannide (161). 

---