Ni/C catalyst

The vinylalane was then transferred via cannula to the Ni/C catalyst at room temperature. 

Low activity and selectivity toward carbonylation products, methyl acetate, and acetic acid are obtained in methanol carbonylation on Ni/C at normal pressure (Table 11). However, by using Sn-Ni/C catalysts a higher activity is reached (34). The promoting effect of Sn on Ni/C for carbonylation is clearly observed in Table 11. For example, with the addition of 1 wt% Sn to Ni/C, the Sn-Ni/C catalysts produces a 24% increase in methanol conversion (34). The increase is in proportion to the Sn loading within the experimental range. This result can be interpreted as Sn being capable of increasing the number of active sites for carbonylation. This interpretation was supported by the CO chemisorption data. An increase in CO adsorption indicated by these data to occur as Sn is added to Ni/C. 

Neyerlin, K.C., Singh, A., and Chu, D. (2008) Kinetic characterization of a Pt-Ni/C catalyst with a phosphoric acid doped PBI membrane in a proton exchange membrane fuel cell. J. Power Sources, 176, 112-117. 

Nakamura A, Takahashi H, Takeguchi T, Yamanaka T, Wang Q, Uchimoto Y, Ueda W (2010) Effect of reduction temperature of Fe-Co-Ni/C catalyst on the solid alkalme fuel cell performance. Electrochem Soc Trans 33 1817-1821... 

Pd-cataly2ed reactions of butadiene are different from those catalyzed by other transition metal complexes. Unlike Ni(0) catalysts, neither the well known cyclodimerization nor cyclotrimerization to form COD or CDT[1,2] takes place with Pd(0) catalysts. Pd(0) complexes catalyze two important reactions of conjugated dienes[3,4]. The first type is linear dimerization. The most characteristic and useful reaction of butadiene catalyzed by Pd(0) is dimerization with incorporation of nucleophiles. The bis-rr-allylpalladium complex 3 is believed to be an intermediate of 1,3,7-octatriene (7j and telomers 5 and 6[5,6]. The complex 3 is the resonance form of 2,5-divinylpalladacyclopentane (1) and pallada-3,7-cyclononadiene (2) formed by the oxidative cyclization of butadiene. The second reaction characteristic of Pd is the co-cyclization of butadiene with C = 0 bonds of aldehydes[7-9] and CO jlO] and C = N bonds of Schiff bases[ll] and isocyanate[12] to form the six-membered heterocyclic compounds 9 with two vinyl groups. The cyclization is explained by the insertion of these unsaturated bonds into the complex 1 to generate 8 and its reductive elimination to give 9. 

MPa (300—400 psig), using a Ni-based catalyst. Temperatures up to 1000°C and pressures up to 3.79 MPa (550 psia) are used in an autothermal-type reformer, or secondary reformer, when the hydrogen is used for ammonia, or in some cases methanol, production. 

In the final step the dinitrile is formed from the anti-Markovrukov addition of hydrogen cyanide [74-90-8] at atmospheric pressure and 30—150°C in the hquid phase with a Ni(0) catalyst. The principal by-product, 2-methylglutaronitrile/4j5 j5 4-ti2-, when hydrogenated using a process similar to that for the conversion of ADN to hexamethylenediamine, produces 2-meth5i-l,5-pentanediamine or 2-methylpentamethylenediamine [15520-10-2] (MPMD), which is also used in the manufacture of polyamides as a comonomer. 

Trickle bed reaction of diol (12) using amine solvents (41) has been found effective for producing PDCHA, and heavy hydrocarbon codistiUation may be used to enhance diamine purification from contaminant monoamines (42). Continuous flow amination of the cycloaUphatic diol in a Hquid ammonia mixed feed gives >90% yields of cycloaUphatic diamine over reduced Co /Ni/Cu catalyst on phosphoric acid-treated alumina at 220°C with to yield a system pressure of 30 MPa (4350 psi) (43). 

Remaining trace quantities of CO (which would poison the iron catalyst during ammonia synthesis) are converted back to CH4 by passing the damp gas from the scmbbers over a Ni methanation catalyst at 325° CO -t- 3H2, CRt -t- H2O. This reaction is the reverse of that occurring in the primary steam reformer. The synthesis gas now emerging has the approximate composition H2 74.3%, N2 24.7%, CH4 0.8%, Ar 0.3%, CO 1 -2ppm. It is compressed in three stages from 25 atm to 200 atm and then passed over a promoted iron catalyst at 380-450°C ... 

The first step is the liquid phase addition of acetic acid to butadiene. The acetoxylation reaction occurs at approximately 80°C and 27 atmospheres over a Pd-Te catalyst system. The reaction favors the 1,4-addition product (l,4-diacetoxy-2-butene). Hydrogenation of diacetoxybutene at 80°C and 60 atmospheres over a Ni/Zn catalyst yields 1,4-diacetoxybu-tane. The latter compound is hydrolyzed to 1,4-butanediol and acetic acid ... 

Dealkylation also can be effected by steam. The reaction occurs at 600-800°C over Y, La, Ce, Pr, Nd, Sm, or Th compounds, Ni-Cr203 catalysts, and Ni-Al203 catalysts at temperatures between 320-630°C. Yields of about 90% are obtained. This process has the advantage of producing, rather than using, hydrogen. 

Fig. 6. Dependence of relative molar concentrations Wj/nA0 of reaction components on reciprocal space velocity W/F (hr kg mole-1) in the consecutive demethylation of m-xylene. Temperature 330°C, catalyst Ni-AljOs (55% wt. AljOs), initial molar ratio of reactants 0 = 5. The curves were calculated (1—xylene, 2—toluene, 3—benzene) the points are experimental values.

Catalytic hydrogenation seldom breaks unactivated C—C bonds (i.e., R—R + H2 RH + R H), but methyl and ethyl groups have been cleaved from substituted adamantanes by hydrogenation with a Ni-Al203 catalyst at about 250°C. Certain C—C bonds have been cleaved by alkali metals. ... 

Fig. 3 showed the catalyst stability of Ni-Mg/HY, Ni-Mn/HY, and Ni/HY catalysts in the methme reforming with carbon dioxide at 700°C. Nickel and promoter contents were fixed at 13 wt.% and 5 wt.%, respectively. Initial activities over M/HY and metal-promoted Ni/HY catalysts were almost the same. It is noticeable that the addition of Mn and Mg to the Ni/HY catalyst remarkably stabilized the catalyst praformance and retarded the catalyst deactivation. Especially, the Ni-Mg/HY catalyst showed methane and carbon dioxide conversions more thrm ca. 85% and 80%, respectively, without significant deactivation even after the 72 h catalytic reaction. 

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