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Chemically controlling crystal structures in nanoscale is challenging, yet provides an effective way to improve catalytic performances. Pt-based nanoframes are a new class of nanomaterials that have great potential as high-performance catalysts. To date, these nanoframes are formed through acid etching in aqueous solutions, which demands long reaction time and often yields ill-defined surface structures. Herein we demonstrate a robust and unprecedented protocol for facile development of high-performance nanoframe catalysts using size and crystallographic facet-controlled PtNi4 tetrahexahedral nanocrystals prepared through a colloidal synthesis approach as precursors. This new protocol employs the Mond process to preferentially dealloy nickel component in the ⟨100⟩ direction through carbon monoxide etching of carbon-supported PtNi4 tetrahexahedral nanocrystals at an elevated temperature. The resultant Pt3Ni alloy tetrahexahedral nanoframes possess an open, stable, and high-indexed microstructure, containin...

The chapter describes a technique of analysing copper and nickel isotopes in ores and magmatic rocks of deposits. Average δ65Cu value strongly diverges in rich intrusions: Kharaelakh (−1.55‰), Talnakh (−0.7‰), and Norilsk-1 (+0.25‰). Perhaps this is due to the mixing of the crustal and mantle sources of matter in the formation of these massifs. The Kharaelakh intrusion by δ65Cu has a large share of crustal matter. In the remaining massifs, the average value of δ65Cu is almost the same (−0.8 to −0.3‰) and does not correlate with the isotope composition of sulphur. The average values of nickel 61Ni/60Ni isotope composition vary within narrow limits from −0.6 to 0‰ in all intrusions of the region and point to a single source of this metal. Data on copper and nickel isotopes in the products of mining and metallurgical companies in the world are given. Variations in the isotopic composition of copper are more associated with raw materials sources of companies, and the isotope composition of nickel, with different technological processes. A possible change in the isotopic composition of nickel during carbonylation (a mond process) is considered.

This article highlights the usefulness of nickel as a metal. Discussion is made about the global sources of this metal in context of its abundance and suitability of extraction. The processes of extraction from nickel ores are mentioned. Narrating its major physical properties, enumeration is made of different nickel alloys and their uses. Finally the novelty of nickel alloys as immune to chemically and mechanically aggressive service condition is discussed in consideration of austenitic stainless steels as benchmark.

The dissolution mechanism of nickel grown by the carbonyl process was investigated using laboratory Ni samples. These samples were purposely engineered to form an alternating lamellar structure of Ni layers grown under two limiting conditions. Three layers deposited from low nickel carbonyl gas concentrations (5%) at a decomposition temperature of 280 °C (LC/HT) were deposited between four layers formed from high nickel carbonyl gas concentrations (40%) at a decomposition temperature of 200 °C (HC/LT). These lamellar structures were used to simulate the two extremes found within an industrial decomposition chamber for nickel pellets grown using the Mond process. Cyclic voltammetry and fluctuations in the electrode potential were recorded during the 120 min constant current dissolution experiment. Complementary scanning electron microscopy (SEM) and white light interference microscopy (WLIM) measurements were used to monitor the changes in surface morphology, texture and roughness as a function of the dissolution time. The electrochemical measurements showed that the dissolution of the sample proceeded in the transpassive regime at overvoltages above 300 mV. Large oscillations were observed in the chronopotentiogram, which suggests that the passive layer breaks down and then regrows on the surface of the nickel samples. SEM and WLIM images revealed that pits with lacy coverings were formed during the initial stages of nickel dissolution. With increasing dissolution time, the LC/HT regions dissolved at a significantly faster rate than the HC/LT regions and the lacy covers were more readily removed causing the transition to an open pit dissolution mechanism. The formation of trenches at boundaries between the lamina was observed at longer dissolution times. The average depth and width of the trenches also increased as a function of dissolution time. The results from the laboratory-grown lamellar nickel samples in this study clearly show preferential dissolution at boundaries between the lamina and that the dissolution of the LC/HT regions proceeds faster than the dissolution of the HC/LT regions. Natural Sciences and Engineering Research Council (NSERC) of Canada and Vale Canada

The history of chemical vapour deposition (CVD) started in the 19th century with the production of lamp filaments and by the Mond process for the nickel production. In the 20th century Van Arkel deposited metals from the gas phase for application in lamp industry. TiC was the first hard coating deposited by CVD in the 1950s. Nearly 20 years later Krupp Widia introduced the first commercial TiC coating on hardmetal tools. Prof. Richard Kieffer started with TiN deposition by the CVD process in the 1970s at the “Technischer Hochschule Wien” and Prof. Benno Lux continued with Al2O3- and diamond coatings. In the following years CVD processes for TiN, Ti(C,N), ZrC, (Ti,Zr)C, TiB2, Al2O3, TaxC, CrxCy, diamond, BN and BCN were investigated at the University of Technology Vienna. The depositions of new crystalline solid solutions (mixed crystals), nano-crystalline materials and nano-crystalline mixtures of phases have been research topics so far.

The nickel and cobalt salts of the aliphatic acids studied decompose by primary cleavage into metal oxide and anhydride. The anhydrides then suffer extensive pyrolysis and the ultimate products include metal, metal oxide, carbide and a mixture of vapours (acids, ketones, carbon dioxide, carbon monoxide and hydrogen). The decomposition of nickel acetate in particular provides a good method of preparing nickel carbide Ni3C. The oxide formed from the slow air decomposition of nickel acetate is possibly a useful oxide catalyst. A new modification of cobaltous oxide is formed in good yield from the acetate.

Nickel oxide was prepared by the decomposition of nickel hydroxide and then the nickel oxide was reduced to form the nickel catalyst. The properties of the nickel oxide and the reduced nickel were studied in relation to the enantio-differentiating ability (e.d.a.) of a tartaric acid-NaBr-modified reduced nickel catalyst. The modified nickel catalyst prepared from nickel oxide with less non-stoichiometric oxygen produced a high e.d.a. for the hydrogenation of methyl acetoacetate. The high crystallinity of the nickel oxide and the resultant nickel would be required to attain a high e.d.a.

The decomposition of methanol to carbon monoxide and hydrogen can be catalyzed at 250°C over nickel supported on silica. The activity of the catalyst prepared by a sol–gel method increases with an increase in the content of nickel up to 40 wt.% while that for the sample prepared by an impregnation technique almost reaches a plateau at the nickel content of 10 wt.%. The activity does not relate simply to the nickel surface area of the sample, but it depends on the amounts of carbon monoxide and hydrogen strongly adsorbed on the catalyst. Small nickel particles are disadvantageous in the reaction.

Roasted calcine of a sulphidic nickel-iron ore and nickeliferous laterite ore were reduced in a horizontal tube furnace and in a laboratory scale fluidised bed reactor. Hydrogen, carbon monoxide and their mixtures were used as reducing gases. The possibility for selective reduction of nickel oxide to metallic nickel with minor formation of metallic iron was studied by adding a controlled amount of CO2 or H2O in the reducing gas. The results showed prominent enrichment of nickel in the final product as compared with the starting material. However, pure nickel could not be produced by “selective” reduction, i.e. the product was ferronickel, the grade of which depended on the feed material and the experimental conditions. A two step process for pyrometallurgical nickel-ferronickel production is proposed. In the first step a part of nickel is selectively reduced at minimum reduction potential and at a low temperature to avoid iron reduction and dissolution into the nickel. After separation of the nickel metal...

About 25% of nickel sulfide converter matte is refined to high-purity nickel (99.99% Ni) by (i) oxidizing the matte to impure nickel oxide; (ii) reducing the oxide product to impure nickel alloy; (iii) selectively producing nickel carbonyl gas, Ni(CO) 4 , from the alloy; and, (iv) decomposing the carbonyl gas to high-purity nickel, 99.99% nickel. The carbonylation is done continuously at ambient pressure or batch wise at about 70 bar. The products of the process are high-purity nickel pellets and powders. The pellets are mostly used for making high-nickel and iron-base alloys. The powders are used for powder metallurgy, batteries, fuel cells, and many other applications.

Under nitrogen atmosphere an unsaturated carbon-carbon double bond was hydrogenated to give a saturated one with nickel catalyst system(NiBr2/Zn/H2O/EtOH). It was found that hydrogen gas was generated from water and zinc powder by using metallic nickel catalyst, which was prepared from anhydrous nickel bromide and zinc powder. Metallic nickel was an active species for the reaction and zinc powder was a reagent to produce hydrogen. A probable pathway was presented.

Nickel hydride with a diphosphinite-based ligand catalyzes the highly efficient reduction of CO(2) with catecholborane, and the hydrolysis of the resulting methoxyboryl species produces CH(3)OH in good yield. The mechanism involves a nickel formate, formaldehyde, and a nickel methoxide as different reduced stages for CO(2). The reaction may also be catalyzed by an air-stable nickel formate.

In the Mond process, impure nickel is converted to nickel carbonyl by exposure to carbon monoxide at about 70 °C which is, in turn, decomposed back to nickel at about 200 °C. The decomposition reaction can be made to happen on the surface of a sensor where the rate of nickel deposition is used to calculate the concentration of nickel carbonyl in the gas sample. A novel heated sensor based on an SC cut quartz thickness shear mode acoustic resonator operating at 18 MHz with one electrode acting as a thin film heating element has been demonstrated to be capable of quantitatively detecting nickel carbonyl at 6 parts per billion in a timely manner.

The century-old Mond process for carbonyl extraction of metals from ore shows great promise as an efficient low energy scheme for producing high-purity Fe, Ni, Cr, Mn, and Co from lunar or asteroidal feedstocks. Scenarios for winning oxygen from the lunar regolith can be enhanced by carbonyl processing of the metallic alloy by-products of such operations. The native metal content of asteroidal regoliths is even more suitable to carbonyl processing. High-purity, corrosion resistant Fe and Ni can be extracted from asteroidial feedstocks along with a Co-rich residue containing 0.5 percent platinum-group metals. The resulting gaseous metal carbonyl can produce a variety of end products using efficient vapor forming techniques.

The kinetics of the reaction of steam and of hydrogen with carbon deposited on nickel foil and on supported nickel catalysts are reported for the temperature range 820–1020 K. The rate of reaction with steam has been shown to be controlled by the diffusion of carbon through nickel. Gasification of carbon by hydrogen is governed by the rate of the surface reaction.

The methanation activity of unsupported and alumina supported nickel and nickel borides, prepared by sodium borohydride reduction, was determined during in situ exposure to 10 ppm H 2 S at 525 K and 1.3 atm as a function of time. Using a recently developed deactivation model, deactivation rate constants and estimates of catalyst life were determined. The results indicate that nickel boride and Raney nickel catalysts are significantly more sulfur resistant, i.e. deactivate much more slowly in the presence of H 2 S, compared to unsupported nickel and nickel alumina catalysts. The superior sulfur resistance of the boron and aluminium promoted catalysts is explained by (i) their intrinsically low deactivation rate constants and (ii) their large capacity for sulfur adsorption.

The oxalate rather than the nitrate was chosen because of the difficulties in heating the latter and removing the large amounts of nitrogen oxides that would be formed. Many industrial processes, such as the Hogana.s process (magnetite and carbon) and the Pyron process (millscale and hydrogen), involve the decomposition of oxides to produce iron powders. Other techniques involve the chloride, as in the Peace River process,! to produce iron. The ammonium sulphates have been used to produce nickel powders as in the Sherrit-Gordon process.2 The last two processes involve heating the compound in a stream of hydrogen. The Sol-Gel process3 makes use of the hydroxide gels which are reduced in hydrogen; this method is able to produce submicrometre sized powders. More elaborate reduction processes are used by the Domsa process for making iron powders by the reduction of millscale (Fe304) in methane. Other methods using hydrides as reducing agents4 have been used to produce vanadium and chromium powders. Arias5 describes a method used to produce chromium and nickel from their oxides by reduction with magnesium, sodium, or lithium vapour. It is possible to use the carbony16 to produce nickel powders by heating alone, as in the Mond process, and in theory this process could be used to produce iron powders. In many of the processes mentioned it is sometimes difficult to control the final particle size of the powder and, in some iron powder production processes, a crushing/grinding/milling stage has to be introduced. The oxalate has not been used in an industrial metal powder production process so far; however, the present work was part of a larger research programme 7 investigating the kinetics of reduction processes involving metallic salts. The results on the fine iron powders produced from that research by this route are presented here because of

On the basis of studying the isotope exchange of oxygen and the position of the Fermi level in the system MiO−LixNi1−xO, an explanation is proposed for the compensation effect in the reaction of CO oxidation on nickel oxide and its solid solutions.

Previous studies from our laboratory have emphasized the prevalence of cancer of the lung among industrial workers exposed to nickel carbonyl, Ni(CO).,.' ' -' 42 Nickel carbonyl is a volatile, highly toxic compound which is formed whenever reactive nickel comes into contact with carbon monoxide. Nickel carbonyl is an intermediate product in the Mond process for refining nickel ore. Owing to its catalytic properties, nickel carbonyl also finds application in a wide variety of industrial operations.

After investigating the action of gold in causing the union of carbon monoxide and oxygen at temperatures between 275° and 325° C., as already described in Part I of this series,* we turned our attention to nickel, copper and their oxides, as examples of surfaces which certainly are not chemically indifferent to the reacting gases. For, as is well known, freshly reduced nickel forms a carbonyl with carbon monoxide at quite moderate temperatures (30° to 80° C.), and copper (as we have found) is by no means indifferent to the gas at somewhat higher temperatures. Again, whilst copper very readily combines with oxygen at moderate temperatures, nickel is more resistent to oxidation, but, like iron, will burn if sufficiently heated in oxygen. Nickel, therefore, has a greater affinity for carbon monoxide, but a less affinity for oxygen, than has copper ; also, their oxides are all readily reducible by carbon monoxide at moderate temperatures. Altogether, the properties of these two metals and their oxides are such as would seem to be highly conducive to “catalytic” activity towards mixtures of carbon monoxide and oxygen, if, in any circumstances, such activity is essentially chemical. Hence our choice of them for a detailed experimental study, the results of which are summarized in this paper. The apparatus and experimental method employed were in all essential respects the same as those already detailed in Part I hereof, namely, the “circulation method” as introduced by Bone and Wheeler, with the inclusion of a suitable arrangement for continuously removing the reaction product (CO 2 ) from the system by means of a solution of purified barium hydroxide. Also, the plan of recording the experiments in their chronological sequence will again be adopted, using the same symbols as before.

Iron- and nickel-copper catalysts have been prepared by catalytic decomposition of iron or nickel carbonyl within a previously produced copper catalyst. In order to prevent transport limitations during iron (nickel) carbonyl decomposition the reaction is carried out in a fluidized-bed reactor with small particles (0.2 −0.4 mm in diameter) of the pure copper catalyst. This method leads to exclusive alloy formation between iron (or nickel) and copper as assessed by means of infrared spectra of adsorbed carbon monoxide. As the iron (nickel) is completely taken up in the copper particles, the interaction of iron (nickel) ions with the support is prevented. As a result the reduction of iron (nickel) is markedly facilitated if compared to the reduction of pure iron (ncikel) catalysts. Furthermore, with these bimetallic catalysts carbon deposition in the Fischer-Tropsch reaction is markedly suppressed, which leads to a better activity maintenance of the alloy catalysts in the F.T. reaction as compared to the monometallic iron (nickel) catalysts.

The experiments recorded in this paper were designed to investigate the effects of the inhalation of nickel carbonyl by rats and rabbits, and to study in detail the distribution of nickel in the body, the development of pathological lesions, and the in fluence of the therapeutic agent 2-3 dimercapto propanol (BAL) on these changes. The study was made because occasional cases of accidental poison ing in man by mixtures of nickel carbonyl and carbon monoxide occur in the production of nickel by the Mond process, which entails the formation and subsequent decomposition by heat of gaseous nickel carbonyl. When the process was first developed in this country, accidental exposure to nickel carbonyl led to some fatalities and from time to time fatal accidents have been reported in other countries. No fatal accidents have occurred in Great Britain during the past 40 years, but accidental exposure due to leaks and other technical faults in the factory sometimes leads to severe and protracted illness in workmen. The toxic material, nickel carbonyl, is a clear volatile liquid, boiling at 43 ?C. Its vapour rapidly decomposes in the presence of moisture to give metallic nickel and carbon monoxide ; in the presence of carbon dioxide the nickel is deposited as the suboxide. Some of the earlier writers con sidered that the toxic action of nickel carbonyl was due to the carbon monoxide that it liberated, but this view was effectively refuted by Armit (1907, 1908) who has made the only significant con tribution to the experimental study of nickel carbonyl poisoning. Armit pointed out that nickel carbonyl had a higher toxicity than could be accounted for by its carbon monoxide moiety, and that a dose of nickel carbonyl sufficient to kill a rabbit would liberate so little carbon monoxide that only 5% of the animal's haemoglobin could be converted to carboxy-haemoglobin. In addition to the considerable pathological changes in the lung

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Publisher Summary The presence of sulfur, combined or elementary, has a great influence on the course of a reaction carried out over nickel catalysts. A reaction which either proceeds at a greater rate or more selectively over nickel catalysts in the presence of sulfur is said to be ‘‘promoted” and a reaction which is retarded or which proceeds less selectively is said to be “poisoned.” It is convenient to speak of these sulfurized nickel catalysts collectively as nickel sulfide catalysts. In some systems in which nickel sulfide catalysts are used, the nickel is initially introduced into the catalytic reactor either in the form of the metal or of the oxide. The equilibrium between nickel and sulfur-containing reactants is established in a short time, so that the resulting nickel sulfide corresponds to the solid phase which is in equilibrium with the reacting components at the temperature and partial pressures prevailing. On the other hand, nickel sulfide catalysts may be prepared prior to their use in the reactor by procedures that lead to catalysts with predetermined properties, such as chemical composition, crystal structure, electronic structure, and specific surface.

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