Cobalt powders catalyst

Cobalt salts are used as activators for catalysts, fuel cells (qv), and batteries. Thermal decomposition of cobalt oxalate is used in the production of cobalt powder. Cobalt compounds have been used as selective absorbers for oxygen, in electrostatographic toners, as fluoridating agents, and in molecular sieves. Cobalt ethyUiexanoate and cobalt naphthenate are used as accelerators with methyl ethyl ketone peroxide for the room temperature cure of polyester resins. 

Cobalt has been used as a Fischer-Tropsch catalyst in a variety of forms(80). Thus it was not surprising to see that both active forms of cobalt powders were moderate Fischer-Tropsch catalysts. Reacting synthesis... 

Table V shows the salient features of several Fischer-Tropsch processes. Two of these—the powdered catalyst-oil slurry and the granular catalyst-hot gas recycle—have not been developed to a satisfactory level of operability. They are included to indicate the progress that has been made in process development. Such progress has been quite marked in increase of space-time yield (kilograms of C3+ per cubic meter of reaction space per hour) and concomitant simplification of reactor design. The increase in specific yield (grams of C3+ per cubic meter of inert-free synthesis gas) has been less striking, as only one operable process—the granular catalyst-internally cooled (by oil circulation) process—has exceeded the best specific yield of the Ruhrchemie cobalt catalyst, end-gas recycle process. The importance of a high specific yield when coal is used as raw material for synthesis-gas production is shown by the estimate that 60 to 70% of the total cost of the product is the cost of purified synthesis gas.

DFG MAK DFG TRK 0.5 mg/m calculated as cobalt in that portion of dust that can possibly be inhaled in the production of cobalt powder and catalysts hard metal (mngsten carbide) and magnet production (processing of powder, machine pressing, and mechanical processing of unsintered articles) other cobalt alloys and compounds 0.1 mg/m calculated as cobalt in that portion of dust that can possibly be... 

Use Pigment in paints and ceramics, preparation of cobalt salts, catalyst, porcelain enamels, coloring glass, feed additive, cobalt metal powder. 

Figure 3 Catalytic oxidation of toluene, testing conditions 0.5g immobilised fluorous cobalt (powder C), 0.2 mmol NaBr, 14.1 mmol toluene, 500 pi H2O, trace methane as internal standard, 10 bar O2 and 150 bar CO2 were blended at 120°C performance of the fresh catalyst (a) a repeated test of recovered catalysts (b) performance of a recovered catalyst from b with addition of O.lmmol cobalt acetate (c).

Commercially, mther cobalt powder or soluble cobalt salts of fatty acids or naphthenates are used, depending upon the process. Usually a quantity of catalyst equivalent to about 0.5-5 mole per cent of cobalt is used. 

Finally, significant amounts of single shell carbon nanotubes were obtained by adding metal catalysts such as Co, Fe, or Ni [15] [34] to the plasma arc process. The addition of metal catalysts seems to facilitate a controlled process by a VLS phase transformation. For example, the addition of cobalt was achieved with a modified positive carbon rod (electrode) into which a hole had been drilled that was filled with cobalt powder [34]. 

Cobalt has been used as a Fischer-Tropsch catalyst in a variety of forms [8]. Thus it was not surprising to see that both active forms of cobalt powders were moderate Fischer-Tropsch catalysts. Reacting synthesis gas with 2 in batch reactor conditions at elevated pressure and temperatures generated methane as the primary product. The life spans of the catalyst and to a lesser extent the products were affected by whether a support was used or how the cobalt was deposited on the support. Catalytic activity was not especially high and amounted to 4-7 mol of methane/mol of cobalt. 

Tian and co-workers reported the hydrothermal synthesis of n-butanol from ethanol [186]. This process used commercially available cobalt powder as a catalyst combined with NaHCOa (0.01 mol) as a base under hydrothermal conditions using 0.15 mol of ethanol and water (11.24 mL) at 200 °C for 3 days to give n-butanol with 69 % selectivity. 

UCI in USA introduced 73-03-2 spherical catalyst containing cobalt. The catalyst is prepared via powder sintering method. The process technology and devices was complex, and it was hard to produce catalysts with small particles. The particles of the catalysts are so large that the advantages of small particles which have high activities are completely lost. 

The feed used for all experiments was straight-run gas oil obtained from a heavy crude oil, whose properties are presented in Table 7.3. The commercial catalyst used for the experiments was a presulfided cobalt-molybdenum supported on y-alumina. The reactor was loaded with 99.43 g (100 mL) of powdered catalyst previously crushed and sieved, the properties of which are also given in Table 7.3. The bench-scale reactor is operated in downflow and isothermal mode provided with independent temperature control of a three-zone electric furnace. The internal diameter of the reactor is 2.54cm, and at the center, a thermowell of external diameter of 0.635 cm was placed. Catalytic length was of 25.2 cm (Figure 7.14). 

Heterogeneous vapor-phase fluorination of a chlorocarbon or chlorohydrocarbon with HP over a supported metal catalyst is an alternative to the hquid phase process. Salts of chromium, nickel, cobalt or iron on an A1P. support are considered viable catalysts in pellet or fluidized powder form. This process can be used to manufacture CPC-11 and CPC-12, but is hampered by the formation of over-fluorinated by-products with Httle to no commercial value. The most effective appHcation for vapor-phase fluorination is where all the halogens are to be replaced by fluorine, as in manufacture of 3,3,3-trifluoropropene [677-21 ] (14) for use in polyfluorosiHcones. 

Chiral salen chromium and cobalt complexes have been shown by Jacobsen et al. to catalyze an enantioselective cycloaddition reaction of carbonyl compounds with dienes [22]. The cycloaddition reaction of different aldehydes 1 containing aromatic, aliphatic, and conjugated substituents with Danishefsky s diene 2a catalyzed by the chiral salen-chromium(III) complexes 14a,b proceeds in up to 98% yield and with moderate to high ee (Scheme 4.14). It was found that the presence of oven-dried powdered 4 A molecular sieves led to increased yield and enantioselectivity. The lowest ee (62% ee, catalyst 14b) was obtained for hexanal and the highest (93% ee, catalyst 14a) was obtained for cyclohexyl aldehyde. The mechanism of the cycloaddition reaction was investigated in terms of a traditional cycloaddition, or formation of the cycloaddition product via a Mukaiyama aldol-reaction path. In the presence of the chiral salen-chromium(III) catalyst system NMR spectroscopy of the crude reaction mixture of the reaction of benzaldehyde with Danishefsky s diene revealed the exclusive presence of the cycloaddition-pathway product. The Mukaiyama aldol condensation product was prepared independently and subjected to the conditions of the chiral salen-chromium(III)-catalyzed reactions. No detectable cycloaddition product could be observed. These results point towards a [2-i-4]-cydoaddition mechanism. 

Catalysts - A commercial Raney nickel (RNi-C) and a laboratory Raney nickel (RNi-L) were used in this study. RNi-C was supplied in an aqueous suspension (pH < 10.5, A1 < 7 wt %, particle size 0.012-0.128 mm). Prior to the activity test, RNi-C catalyst (2 g wet, 1.4 g dry, aqueous suspension) was washed three times with ethanol (20 ml) and twice with cyclohexane (CH) (20 mL) in order to remove water from the catalyst. RCN was then exchanged for the cyclohexane and the catalyst sample was introduced into the reactor as a suspension in the substrate. RNi-L catalyst was prepared from a 50 % Ni-50 % A1 alloy (0.045-0.1 mm in size) by treatment with NaOH which dissolved most of the Al. This catalyst was stored in passivated and dried form. Prior to the activity test, the catalyst (0.3 g) was treated in H2 at 250 °C for 2 h and then introduced to the reactor under CH. Raney cobalt (RCo), a commercial product, was treated likewise. Alumina supported Ru, Rh, Pd and Pt catalysts (powder) containing 5 wt. % of metal were purchased from Engelhard in reduced form. Prior to the activity test, catalyst (1.5 g) was treated in H2 at 250 °C for 2 h and then introduced to the reactor under solvent. 10 % Ni and 10 % Co/y-Al203 (200 m2/g) catalysts were prepared by incipient wetness impregnation using nitrate precursors. After drying the samples were calcined and reduced at 500 °C for 2 h and were then introduced to the reactor under CH. 

Nickel citrate, molecular formula, 6 638t Nickel-coated powder products, 77 123 Nickel-cobalt plating, 9 821 Nickel compounds, 77 106-132 in agricultural chemicals, 77 125 analytical methods for, 77 117-119 as catalysts, 77 121-123 chronic toxicity of, 77 120 economic aspects of, 77 118t in electroplating, 77 123 environmental concerns related to, 77 121... 

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