Nickel Acetate Solution Research Articles

Formation of α,β-Type Hydroxides and Second-Stage Intermediate in Hydrothermal Decomposition of Nickel Acetate

During heating of nickel acetate solution at a constant rate of 4°C/min up to 350°C, α-type anion-exchangeable layered hydroxide Ni2(OH)3(OCOCH3)1.4H2O, containing the acetate anions in the interlayer spaces, first crystallized at 160°C. A second-stage intermediate phase losing the acetate guest in every second layer appeared at 180°C and subsequently transformed at 210°C to slightly disordered β-Ni(OH)2 phase with a small amount of acetate anions. β-Ni(OH)2 phases were gradually losing the acetate guest with increasing temperature, and perfectly ordered hexagonal-shaped β-Ni(OH)2 crystals with a mean diameter of 10 μm were obtained at 320°C. Above 340°C, dehydration of β-Ni(OH)2 to NiO occurred.

The kinetic model for carboreduction of zinc oxide

The carbothermal reduction of zinc oxide using highly concentrated solar radiation is a promising concept for the production of pure zinc and hydrogen. Solar energy is converted to chemical energy in the form of abundant fuel, easy to use and environmentally friendly. The present work is aimed to study kinetics of carboreduction of zinc oxide in laboratory reactor, developing the kinetic model and explore the possibility to accelerate the process (decrease in CO 2 concentration) by adding a catalyst to the solid ZnO and carbon mixture. A laboratory experimental set up for kinetic study of carbothermal reduction of zinc oxide is constructed and described in details. Experiments were carried out with mixtures of zinc oxide powder and 12-20 mesh activated carbon at temperatures of 1000-1300°C and C/ZnO wt, ratios =1:8. A kinetic model was proposed based on a mechanism of carboreduction that involves two chain gas-solid reactions with intermediate formation of CO and CO 2 . The rate constants and activation energy were determined from the experimental data. The validity of the model is discussed. The preliminary experiments were carried out on catalytic carboreduction of Zine Oxide. The sample for catalytic carboreduction was prepared by impregnation of the ZnO + C mixture with Nickel acetate solution. Two samples containing ZnO + C mixture and ZnO + C + 2%NiO were tested at 1000°C under the same conditions. It was found that adding Ni-catalyst to the mixture of Graphite and ZnO increases drastically the rate of carboreduction and conversion of Zinc Oxide.

Spray Pyrolysis in a Circulating Fluidized Bed.

In order to prepare fine metal-oxide particles and circulating fluidized particles coated with metal compounds, experimental investigations were carried out to study spray pyrolysis using the superior heat transfer characteristics of a circulating fluidized bed (CFB). Quartz sand particles of three different size ranges were used as circulating fluidized particles in the CFB loop, and a nickel-acetate solution was injected as droplets into the CFB riser.It was recognized that the size distribution of the prepared particles was considerably affected by the size of circulating fluidized particles. Increasing the circulating fluidized particle size was found to lead to larger nickel-oxide particles. It was shown that the concentration of the injected nickel-acetate solution had no influence on the geometric characteristics of the prepared nickel-oxide particles.

Kinetics and mechanism of pressure reduction of nickel(II) with hydrogen from aqueous acetate solutions containing bismuth(III)

An investigation was made of the kinetics and mechanism of pressure reduction with hydrogen of aqueous nickel(II) from its acetate solution containing 30 g/dm 3 of Ni(II) and 0.1–1.5 g/dm 3 of Bi(III). Powdered graphite and tungsten carbide were used as catalysts. It was found that the stability of aqueous Bi(III) in reduced solutions was strongly limited when tungsten carbide was used. Reduction of aqueous nickel(II) from acetate solutions containing Bi(III) was found to be governed by the adsorption of bismuth species on the surface of the powdered catalyst. Bismuth(III) created substantial lengthening of the induction period of reduction of aqueous nickel(II) with hydrogen and the total inhibition of the process was observed at Bi(III) concentrations exceeding 2g/dm 3. A three-stage mechanism for the reduction of Ni(II) with hydrogen from its acetate solution containing Bi(III) and graphite powder was established involving adsorption of Bi(III) on the graphite surface, reduction of Bi(III) to metallic bismuth, and reduction of nickel(II) to metallic nickel on bismuth-coated graphite grains. Introduction of Bi(III) into feed nickel acetate solutions resulted in high quality composite powders with a compact and uniform nickel coating.

Selective metallization of alumina by laser

Nickel has been selectively deposited on an alumina substrate without any pretreatment from a flow of a nickel acetate solution using the focused beam of an excimer laser. Nickel spots as well as nickel lines were drawn and subsequently plated with an electroless Ni-B coating. Excellent adhesion of the metallized layers was achieved, since with laser irradiation, both etching and deposition took place simultaneously.

ChemInform Abstract: Surface Enrichment Phenomena in Sealed Anodic Alumina Films.

AbstractBoth surface and bulk chemical compositions of porous anodic alumina films sealed in nickel acetate solution have been investigated by means of Rutherford backscattering spectroscopy and secondary ion mass spectroscopy.

ChemInform Abstract: Parameters Influencing the Activity of Ni‐B Catalysts.

AbstractNi‐B catalysts have been prepared by reduction of either an ethanolic solution of nickel acetate or a solution of nickel hexanoate in cyclohexane using a NaBH4 ethanolic solution.

Bimetallic sulphide catalysts Ni-M-Sx/SiO2 prepared by unconventional method involving thiourea complexes

An unconventional method of preparation of hydrodesulphurization catalysts was tested. A series of M-Sx/SiO2 and Ni-M-Sx/SiO2 catalysts was prepared, where M was V, Cr, Mn, Mo, W or Nb, respectively. A mixture of a salt of the metal M, thiourea, glycerol, sulphur, isopropanol, and silica gel was thermally decomposed to obtain the M-Sx/SiO2 catalysts. Nickel was deposited from solution of nickel acetate in methanol. Activity of catalysts was tested in benzothiophene hydrodesulphurization and their surface composition was characterized by XPS. The activity of samples containing Ni-Mo and Ni-W was in the rank of classical Co-Mo/Al2O3 catalysts but other samples exhibited only low activity and no synergism. The increase in binding energy of Ni after mixing with second metal M was observed not only for Mo and W but also for V, Cr, and Mn. It is concluded that this shift is probably not the main cause of synergism as suggested in the literature.

Cobalt and Nickel Cations as Corrosion Inhibitors for Galvanized Steel

Gravimetric measurements on galvanized steel and cathodic polarization curves indicate that corrosion of zinc in 3% is inhibited by a low concentration of cobalt ions in solution or by simple predipping of the zinc in 0.05 or 0.1M solutions of . Corrosion inhibition is also obtained when zinc is predipped in a nickel acetate solution and nickel ions are present in the solution. The corrosion inhibition is attributed to the introduction of electron traps (cobalt or nickel atoms) in the oxide on the surface of zinc which lead to inhibition of the cathodic reaction, . When the concentration of elemental cobalt or nickel in or on the oxide becomes too great, the cathodic reaction, , is catalyzed and corrosion activation occurs.

Anodic deposition of NiOOH from nickel acetate solutions at constant potential

Download options Please wait... Article information DOI https://doi.org/10.1039/TF9666203217 Article type Paper Download Citation Trans. Faraday Soc., 1966,62, 3217-3228 BibTex EndNote MEDLINE ProCite ReferenceManager RefWorks RIS Permissions Request permissions Anodic deposition of NiOOH from nickel acetate solutions at constant potential G. W. D. Briggs and M. Fleischmann, Trans. Faraday Soc., 1966, 62, 3217 DOI: 10.1039/TF9666203217 To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page. If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given. If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page. Read more about how to correctly acknowledge RSC content. Search articles by author G. W. D. Briggs M. Fleischmann

The sealing of porous anodic oxide films on aluminium

The process of sealing the porous oxide films produced on aluminium by anodic oxidation in sulphuric acid by heating them in nickel acetate solution, in dichromate and chromate solutions, and in distilled water has been studied by a.c.-bridge measurements of the electrical impedance of the film during sealing, over a wide range of frequencies.The mechanism of sealing in dilute nickel acetate solution has been examined in detail. Changes in the complex impedance during sealing are best interpreted by supposing that the pores become filled mainly by inward movement of their sides, with a contribution also of some plugging at their outer ends.Chromate and especially dichromate solutions of the concentrations often employed in practice appear to give more rapid sealing than the commonly used nickel acetate solution, whereas plain water gives much slower sealing. The temperature dependence of the overall process is appreciable for nickel acetate sealing and small for dichromate sealing.An atomistic mechanism for the partial hydration of the original Al2O3 films to AlO(OH), involving lattice transport of OH− ions under a high field produced by H+ ions that have first ‘advanced’ by thermal diffusion, is proposed, and is extended to account for CrO42− uptake into the film in dichromate and chromate sealing.Practical implications of the work, including the use of the pore electrolytic resistance as determined by the a.c.-impedance method for the general assessment of rate and degree of sealing, are noted.