Nickel-alumina catalyst preparation

The formation of trace amounts of 2,2 -bipyridine following reaction between pyridine and ammonia in the presence of a variety of catalysts led Wibaut and Willink to develop a method for the preparation of 2,2 -bipyridine from pyridine under the influence of a nickel-alumina catalyst. Using a pyridine-to-catalyst ratio of 10 1, temperatures between 320° and 325°C, and pressures between 42 and 44 atm, 2,2 -bipyridine was formed in yields of 0.30-0.67 gm per gram of catalyst. This method w as later applied to -picoline, to quino-line, - and to some of its derivatives, ... 

With nickel/alumina catalysts (cf. 4 ) preparation by coprecipitation or by the decomposition of a high dispersion of nickel hydroxide on fresh alumina hydrogel, yields nickel aluminate exclusively. On the other hand, when, as in impregnation, larger particles of nickel compound are deposited, the calcination product is a mixture of nickel oxide and nickel aluminate. The proportion of nickel oxide increases when occlusion of the impregnation solution leads to a very nonuniform distribution (49). 

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. 

Bipyridine has been prepared by the action of ferric chloride, iodine, or a nickel-alumina catalyst on pyridine at temperatures ranging from 300° to 400°. It has also been obtained from the reaction of 2-bromopyridine and copper. The present procedure is a modification of a previously published, general method. The W7-J nickel catalyst was developed from the description of the W7 Raney nickel catalyst of Billica and Adkins. ... 

Lippens, B. C., Fransen, P., van Ommen, J. G., Wijingaarden, R., Bosch, H., and Ross, J. R. H. 1985. The preparation and properties of lanthanum-promoted nickel-alumina catalysts structure of the precipitates. Solid State Ionics 16 275-82. 

The temperature profiles for each catalyst at two different space velocities are plotted in Figure 1. The catalysts with lower nickel content had reasonable activity, but the activity obviously decreased with nickel content. At 25,000/hr space velocity, the 30% nickel-on-alumina catalyst used 50% of the bed to obtain the maximum temperature whereas with 50% nickel the reaction used only 30% or the bed. The method used to prepare the C150-3-02 catalyst resulted in a non-reduceable nickel silicate... 

The reactions are carried out at about 900 to 1,000°C and catalyzed by nickel, nickel-alumina, or rhodium-alimina catalysts. In the laboratory, hydrogen may be prepared by the reaction of zinc or iron with dilute hydrochloric or sulfuric acid ... 

In the nickel- and cobalt-catalysed reactions [166,207] it was observed that the butene distribution depended upon the temperature of reduction of the catalyst. For both powders and alumina-supported catalysts prepared by reduction of the oxides, reduction at temperatures below ca. 330° C gave catalysts which exhibited so-called Type A behaviour where but-2-ene was the major product and the frans-but-2-ene/cis-but-2-ene ratio was around unity. Reduction above 360° C (Ni) or 440° C (Co) yielded catalysts which gave frans-but-2-ene as the major product (Type B behaviour). It is of interest to note that the yield of cis-but-2-ene was not significantly dependent upon the catalyst reduction temperature with either metal. 

Hydrogenation tests made on the 600°-1000°F heavy gas oil from in situ crude shale oil showed that a nickel-molybdenum-on-ahimina catalyst was superior to either cobalt-molybdenum-on-alumina or nickel-tungsten-on-alumina catalysts for removing nitrpgen from shale oil fractions. This nickel-molybdenum-on-alumina catalyst was used in the preparation of the synthetic crude oil. A high yield of premium refinery feedstock whose properties compared favorably with those of a syncrude described by the NPC was attained by hydrogenating the naphtha, light... 

Catalyst Preparation. The catalysts were prepared by impregnation of -alumina extrudates ( SA=253 m /g ). Each impregnation was followed by drying overnight at 120°C and calcination at the indicated temperatures during one hour. Molybdenum was brought on the support as an ammonium molybdate solution cobalt and nickel as nitrate solutions. Each component was impregnated separately. 

Acetylene hydrogenation. Selective hydrogenation of acetylene to ethylene is performed at 200°C over sulfided nickel catalysts or carbon-monoxide-poisoned palladium on alumina catalyst. Without the correct amount of poisoning, ethane would be the product. Continuous feed of sulfur or carbon monoxide must occur or too much hydrogen is chemisorbed on the catalyst surface. Complex control systems analyze the amount of acetylene in an ethylene cracker effluent and automatically adjust the poisoning level to prepare the catalyst surface for removing various quantities of acetylene with maximum selectivity. 

L.M. Knijff, P.H. Bolt, R. van Yperen, A.J. van Dillen, J.W. Geus, Production of nickel-on-alumina catalysts from preshaped bodies K.P. de Jong, Deposition-precipitation onto preshaped carrier bodies — possibilities and limitations P.J. van den Brink, A. Scholten, A. van Wageningen, M.D.A. Lamers, A.J. van Dillen, J.W. Geus, The use of chelating agents for the preparation of iron oxide catalysts for the selective oxidation of hydrogen sulfide, all in Preparation of Catalysts V, Elsevier, Amsterdam, 1991. 

Molina, R., M. A. Centeno, and G. Poncelet, a-Alumina-Supported Nickel Catalysts Prepared with Nickel Acetylacetonate. 1. Adsorption in the Liquid Phase , J. Phys. Chem. B. 1999,103, 6036-46. 

Theories and principles of the characterization techniques are not described here. For consistenc), all the catatysts described in this review are referred to with the same nomenclature, although a different nomenclature is sometimes used in the cited publications. Each catalyst component (element) separated by the symbol indicates the sequence of its introduction into the catalyst formulation from right to left. Those separated by the symbol 7 between right and left belong to the support material and the elements on the support, respectively. For example, NiMo-P/Al refers to a catalyst prepared such that the phosphorus-containing precursor is loaded on the alumina support first, followed by nickel and molybdenum, which are introduced simultaneously. CoMo/Al — P refers to a catalyst in which cobalt and molybdenum are introduced simultaneously onto an alumina support doped with phosphorus-containing species. Each element may represent its oxide or sulfide forms. In all cases, A1 refers to the alumina-based support or to its hydroxide precursor. 

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