Nickel sponge catalyst

Metal Combustible Solid nickel sponge catalyst may ignite SPONTANEOUSLY in air. 

The behavior of carbon monoxide-hydrogen mixtures in the presence of metals of the platinum group lias been made the subject of special study by a number of investigators. Orloff82 was the first to observe that under certain conditions in the presence of a nickel-palladium catalyst, a reaction took place which resulted in the formation of ethylene. This is in contradiction to the observations of Breteau,88 who stated that in the presence of palladium sponge, carbon monoxide and hydrogen react in the cold to form methane and that at 400° C. this transformation becomes fairly rapid. Recently it has seemed desirable that the experiments of Orloff... 

Alcan 756 C.l. 77775 Carbonyl nickel powder CCRIS 427 EINECS 231-111-4 EL12 Fibrex Fibrex P HSDB 1096 Ni 0901-S Ni 270 Ni 4303T Nichel Nickel 200 Nickel 201 Nickel 205 Nickel 207 Nickel 270 Nickel catalyst Nickel compounds Nickel, elemental Nickel, elemental/metal Nickel particles Nickel sponge NP 2 Raney alloy Raney nickel RCH 55/5. Metallic element, used in electroplating, as a hydrogenation catalyst and in iron- and copper-based alloys. Metal mp = 1453° bp (calc) = 2732° d= 8.908. Atomergic Chemetals Inco, Europe Lancaster Synthesis Co. Sigma-Aldrich Fine Chem. 

Cavallito (66) reports that neither it nor 3-benzoxypyridine was hydrogenated in the presence of Willstatter s palladium sponge catalyst (67). Under low pressure conditions in ether or dioxane Raney nickel and platinum oxide were ineffective. However, other examples show that reduction takes place readily under a variety of conditions. Biel used Raney nickel at 125° and 50 atm (68), excellent yield of 6-propyl-3-hydroxypiperidine resulted from reduction of the pyridine in acetic acid with platinum oxide (69). Ruthenium in the conversion of 3-hydroxypyridine in aqueous solution gave very high yield of the corre-... 

Catalyst Sponge Nickel Cr-promoted Sponge Nickel Sponge Cobalt Cr-promoted Sponge Cobalt... 

CAS 7440-02-0 EINECS/ELINCS 231-111-4 Synonyms Cl 77775 Nickel catalysts Nickel dust Nickel particles Nickel sponge Raney alloy Raney nickel... 

The azido mesylate is suspended in absolute ethanol and 80% hydrazine hydrate (3 ml/g of azido mesylate). A small amount (tip of spatula) of Raney nickel (W-2 grade or commercial 50% sponge nickel catalyst from W. R. 

Some data fitting results are displayed in Figures 12.1 and 12.3. The general conclusion is that both models describe the behaviours of the main components, lactose and lactitol very well, both for sponge nickel and ruthenium catalysts. In this respect, no real model discrimination is possible. Both models also describe equally well the behaviour of lactobionic acid (D), including its concentration maximum when the reversible step is included (ks) (Figure 12.3). 

The most common and least expensive catalyst for producing primaiy amines from nitriles is sponge nickel. The generalized reaction, carried out in the presence of sponge nickel catalyst, is the following ... 

The reaction mass consists of two liquid phases and one solid phase no solvent is required. The major liquid phase is the crude amine product itself. The solid phase is promoted sponge nickel catalyst. Surrounding the catalyst is a second liquid phase consisting of concentrated caustic and water. Water and caustic are added continuously to make up for losses leaving in the crude product. The ratios of water, caustic, and catalyst in the reaction mass are controlled to produce high yields of product amine and very low catalyst usages. High catalyst concentrations are employed in the reaction mass to keep the concentration of unreacted nitriles very low the upper limit on the catalyst concentration is the point where the circulation rate is inhibited. 

Next, a series of runs was conducted to determine the effect of various alkali metal hydroxide additions along with the sponge nickel catalyst. The 50 wt. % sodium hydroxide and 50 wt. % potassium hydroxide caustic solution used in the initial test was replaced with an aqueous solution of the alkali metal hydroxide at the level indicated in Table 2. After the reaction number of cycles indicated in Table 2, a sample was removed for analysis. The conditions and results are shown in Table 2. The results reported in Table 2 show the level of 2° Amine in the product from the final cycle. The level of NPA in all of the mns was comparable to the level observed in the initial test. No significant levels of other impurities were detected. 

Skeletal nickel consists of highly-dispersed nickel with a large surface area [68, 91-96], the structure often being likened to a sponge [51,74], The activity of the catalyst is proportional to the surface area and hence the degree of nickel crystallite dispersion [26,76,91], The nickel crystallites are about 1-20 nm in size [24,92,94-96], and decrease in size with decreasing temperature... 

Deactivation of Sponge Nickel and Ru/C Catalysts in Lactose and Xylose... 

Catalyst deactivation during consecutive lactose and xylose hydrogenation batches over Mo promoted sponge nickel (Activated Metals) and Ru(5%)/C (Johnson Matthey) catalysts were studied. Deactivation over sponge nickel occurred faster than on Ru/C in both cases. Product selectivities were high (between 97 and 100%) over both catalysts. However, related to the amount of active metal on the catalyst, ruthenium had a substantially higher catalytic activity compared to nickel. 

Catalyst deactivation often plays a central role in manufacturing of various alimentary products. Sugar alcohols, such as xylitol, sorbitol and lactitol, are industrially most commonly prepared by catalytic hydrogenation of corresponding sugar aldehydes over sponge nickel and ruthenium on carbon catalysts (5-10). However, catalyst deactivation may be severe under non-optimized process conditions. 

Figure 1. A. Consecutive xylose hydrogenation batches over 2.5 wt-% sponge nickel and 1.5 wt-% Ru/C catalyst. B. Catalyst deactivation during consecutive lactose hydrogenation batches over 5 wt-% sponge nickel and 2 wt-% Ru/C catalyst.

Figure 2. A. Consecutive xylose hydrogenation batches over sponge nickel catalyst (XA=xylonic acid). B. Influence of lactobionic acid (LBA) on lactose hydrogenation rate.

A solution of 5.0 g (14.3 mmoles) 5-amino-N-methoxy-l-p-D-ribofuranosylimidazole-4-carboxamidine 3, 5 -cyclic phosphate in 200 ml H2 preheated to 60°C and containing approximately 5.0 g moist sponge nickel catalyst, was shaken with 2-3 atm. H2 at 60°C for 2 h. The filtered solution was evaporated to dryness to give 3.75 g of 5-amino-l-p-D-ribofuranosylimidazole-4-carboxamidine 3, 5 -cyclic phosphate (82%), (recrystallization from water). 

Following the development of sponge-metal nickel catalysts by alkali leaching of Ni-Al alloys by Raney, other alloy systems were considered. These include iron [4], cobalt [5], copper [6], platinum [7], ruthenium [8], and palladium [9]. Small amounts of a third metal such as chromium [10], molybdenum [11], or zinc [12] have been added to the binary alloy to promote catalyst activity. The two most common skeletal metal catalysts currently in use are nickel and copper in unpromoted or promoted forms. Skeletal copper is less active and more selective than skeletal nickel in hydrogenation reactions. It also finds use in the selective hydrolysis of nitriles [13]. This chapter is therefore mainly concerned with the preparation, properties and applications of promoted and unpromoted skeletal nickel and skeletal copper catalysts which are produced by the selective leaching of aluminum from binary or ternary alloys. 

In the majority of cases, the last step in the preparation of catalytically active metals is a reduction. The precursor is very frequently an oxide. An oxychloride is the real precursor of active platinum and some noble metals if chlorometal complexes (e.g. chloroplatinic acid) are used. It may be advantageous to use still other precursors and to reduce them directly without any intermediary transformation to oxide. On the other hand, nearly all catalytic metals are used as supported catalysts. The only notable exception is iron for ammonia synthesis, which is a very special case and then the huge body of industrial experience renders scientific analysis of little relevance. The other important metals are Raney nickel, platinum sponge or platinum black, and similar catalysts, but they are obtained by processes other than reduction. This shows the importance of understanding the mechanisms involved in activation by reduction. 

Nickel metal occurs as a lustrous, white, hard, ferromagnetic, metallic solid. Nickel is commonly used as a catalyst for hydrogenation reactions for food chemicals. Depending on the use, Nickel catalysts fall into two general categories Sponge Nickel Catalyst and Supported Nickel Catalyst. 

---