Supported Nickel Oxide

M. Lo lacono, M. Schiavello, and A. Cimino, Structural, magnetic and optical properties of nickel oxide supported on tj- and y-aluminas, J. Phys. Chem. 75, 1044-1050 (1971). 

Copolymers may also be produced with a catalyst containing both chromium oxide and nickel oxide supported on silica-alumina. It is well-known that nickel oxide—silica—alumina by itself makes predominantly butenes from ethylene. In the mixed catalyst, butenes that are formed on nickel oxide copolymerize with ethylene on the chromium oxide to form ethylene-butene copolymers. The fact that infrared shows only ethyl branching in the polymer indicates that the initial product... 

The catalyst is nickel oxide supported by a refractory material, for example. NiO on calcium aluininatc as Raschig rings, or on alumina. 

The shape of the TPR curves for Ni/mordenite and Ni/USY (Figures 4 and 5) provides evidence that NiO is reducible only at high temperatures, a behavior which is not characteristic of nickel oxide supported on low surface area carriers [7]. The conclusion is that for zeolites the majority of nickel particles is located inside the crysMine structure of the supports. This is also supported by the results of coke deposition as studied by TGA. As seen in Tables 1 to 3, the total amount of coke found for each catalyst sample explains the deactivation curves in Figure 1 only if the stmctural aspect is considered. Nickel supported on USY contains 4.5 times more coke than nickel supported on ZSM5 and 2.6 times more... 

A number of techniques, including XRD [4,5], XPS [6], EXAFS [7] and TPR [5, 8-9], were applied to study the complex nature of nickel oxide-support interactions. 

Fig. 1. Reaction pathway in the oxidation of cyclohexane on nickel oxide supported catalysts.

Figure 1. Magnetic moment as a function of nickel oxide supported on O, alumina and magnesia.

Fio. 21. Susceptibility isotherms for nickel oxide supported on alumina. 

Fig. 24. Hydrogen equivalents, per gram atom of nickel, vs. nickel concentration, for reduction of nickel oxide supported on alumina.

Akers and Camp(1955) studied the reaction between steam and natural gas within the temperature range of 340-640°C at 1 atmosphere using 3mm diameter pellets of nickel produced by the reduction of nickel oxide supported on kieselguhr. There was little reaction at temperatures less than 600°C and they found first order dependence of the rate of disappearance of methane upon the partial pressure of methane at 640 C. They reported that there was no significant variation of catalyst activity with time. 

Eastgate and coworkers developed a Ni-catalyzed C-H functionalization procedure for the synthesis of pyridine core and applied in the synthesis of the potent JAK2 inhibitor BMS-911543 [7]. With nickel oxide supported on silica (PRICAT) as the catalyst, 74% of the key intermediate can be achieved (Scheme 2.4). 

The first promising catalyst was introduced by 1931 and contained a high proportion of nickel oxide supported on a mixture of thoria and kieselguhr. The convention widely used at the time was to describe composition as 100 parts nickel, 18 parts thoria, 100 parts kieselguhr. Catalysts made with cobalt rather than nickel were more effective but could not be considered eommercially at that time because cobalt was not available in suffieiently large quantities. The same problem had, of course, faced Haber and Boseh in the replaeement of osmium by iron oxide for the ammonia synthesis eatalyst. 

The catalysts contain more than 50% nickel oxide, supported on kieselguhr with some added alumina, and are prereduced and stabilized. This allows for rapid reduction in existing reactors. The process operates at the relatively low temperature of 80°C with hydrogen pressures in the range 20-40 atm. A liquid space velocity of about 2.5 h" is required and hydrogen addition depends on the aromatics content of the feed being treated. 

Nickel oxide supported on alumina and magnesia. Cracked gas streams containing hydrogen. 

Nickel oxide supported on y-alumina is also active and selective with typical pyrolysis gasolines. It can be reactivated very easily at intervals of two to nine months by heating in hydrogen or regenerated by conventional burning of deposits in air when necessary. Replacement is required after about two years. 

Secondary reforming catalyst contains about 7% nickel oxide, supported on temperature-resistant a-alumina or calcium aluminate, in the form of raschig rings. Additional catalyst used at the top of the bed as a heat guard is in the form of large solid cylinders of a-alumina containing 5% nickel oxide. 

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