Showing papers on "Nickel published in 1980"
TL;DR: In this paper, the effect of surface chemical composition on the kinetics of the catalytic methanation reaction over a single crystal Ni(100) catalyst was examined using a specially designed ultrahigh vacuum system.
472 citations
TL;DR: In this article, the effects of metal-support interactions on room-temperature H2 adsorption on alumina- and silica-supported Ni catalysts were investigated. But the results were limited to the case of Ni SiO 2 catalysts.
346 citations
TL;DR: In this paper, the authors investigated the properties of NiSiO2, NiAl2O3, and NiTiO2 catalysts representing wide ranges of dispersion and nickel concentration.
274 citations
TL;DR: In this paper, the reversible potentials for nickel hydroxide/oxyhydroxide couples were measured over a range of KOH concentrations from 0·01-10 M. The constant potential regions were derived from heterogeneous equilibria between pairs of coexisting phases both containing nickel in upper and lower states of oxidation.
Abstract: Reversible potentials (E
R) have been measured for nickel hydroxide/oxyhydroxide couples over a range of KOH concentrations from 0·01–10 M. It is shown that the couples derived from the parentα- andβ-Ni(OH)2 systems can be distinguished by the relative change in KOH level on oxidation and reduction. In the case of couples derived from theα-class of materials a dependence of 0·470 moles of KOH per 2e change is found compared with 0·102 moles of KOH per 2e change for theβ-class of materials. Couples derived from theα- andβ-Ni(OH)2 systems can be encountered in a series of ‘activated’ and ‘de-activated’ forms having a range of formal potentialsE
0
′
. ‘Activated’. and ‘de-activated’β-Ni(OH)2/β-NiOOH couples are found to lie in the range 0·443–0·470 V whilstα-Ni(OH)2/γ-NiOOH couples lie in the range 0·392–0·440 V w.r.t. Hg/HgO/KOH. It is demonstrated for ‘de-activated’,β-Ni(OH)2/β-NiOOH couples thatE
R is independent of the degree of oxidation of the nickel cation between states of charge of 25% and 70%. SimilarlyE
R is constant for states of charge between 12% and 60% for ‘activated’α-Ni(OH)2/γ-NiOOH couples. The constant potential regions are considered to be derived from heterogeneous equilibria between pairs of co-existing phases both containing nickel in upper and lower states of oxidation. Differences inE
0
′
between the ‘activated’ and ‘de-activated’ couples are considered to be related to the degree of order/disorder in the crystal lattice.
270 citations
TL;DR: The results from these four sites suggest that the pore water profiles of these metals are controlled by processes involving the major oxidants (O2, NO3−, Mn and Fe oxides) as discussed by the authors.
257 citations
216 citations
TL;DR: In this article, the oxidation states and compositions of the surfaces of CuAl2O4 and NiO promoted CuAl 2O4 were investigated by X-ray photoelectron spectroscopy (XPS).
212 citations
TL;DR: In this article, the adsorption and methanation of carbon dioxide on a nickel/silica catalyst were studied using temperature-programmed desorption, and temperatureprogrammed reaction.
193 citations
TL;DR: In this article, the attack of nickel, cobalt, iron, and alloys of these metals containing chromium and aluminum, by gases containing sulfur-oxygen, carbon-oxidegen, and nitrogen-oxyg has been studied at temperatures of 600 and 900°C.
Abstract: The attack of nickel, cobalt, iron, and alloys of these metals containing chromium and aluminum, by gases containing sulfur-oxygen, carbon-oxygen, and nitrogen-oxygen has been studied at temperatures of 600 and 900°C. The degradation of these metals and alloys was characterized by using standard analytical techniques with emphasis on optical metallography. Three types of accelerated degradation were identified for the attack of alloys by gases containing another oxidant in addition to oxygen. One type of degradation occurred because of the formation of reaction products composed of mixtures of phases involving both of the oxidants. Another type resulted from the reaction of second oxidant phases with oxygen. The third form of degradation involved the development of less protective phases due to thermodynamic instabilities. Thermodynamic stability diagrams are used to help account for the effects produced by different elements in the alloys.
190 citations
184 citations
Book•
01 Jan 1980
TL;DR: In this paper, a comprehensive review of current knowledge about the role and hazards of nickel in the environment is presented, which deals with the sources, distribution, behavior, and flow of Nickel in different ecosystems, as well as with the metabolism, biochemistry, and systemic toxicity of nickel.
Abstract: Provides the first comprehensive review of current knowledge about the role and hazards of nickel in the environment. Systematically deals with the sources, distribution, behavior, and flow of nickel in different ecosystems, as well as with the metabolism, biochemistry, and systemic toxicity of nickel in plants, human beings, and other organisms. Investigates the carcinogenic and dermatological effects of nickel and interactions of nickel with essential minerals.
TL;DR: In this paper, a controlled atmosphere electron microscopy has been used to follow the growth of filamentous carbon on NiFe surfaces from the catalyzed decomposition of acetylene.
TL;DR: In this paper, the kinetics of corrosion were measured by accelerated oxidation tests on Co 30Cr and Ni 30Cr as a function of temperature from 600°-900°C, in the environment and deposit composition.
Abstract: The kinetics of corrosion were measured by accelerated oxidation tests on Co‐30Cr and Ni‐30Cr as a function of temperature from 600°–900°C, in the environment and deposit composition. The alloys were rapidly attacked at temperatures between 650° and 750°C when a liquid sulfate phase was obtained from an initially pure solid deposit. The rapid rate of attack resulted from sulfation of the transient surface nickel or cobalt oxides and the dissolution of these transition metal sulfates into to yield a liquid phase. This retarded the formation of a protective scale. The exposure conditions under which liquids could form from mixtures were calculated from thermodynamic considerations.
TL;DR: In this paper, the authors employ detailed electronic structure calculations to investigate a model of grain boundary embrittlement, and show that adding sulphur to a cluster of nickel atoms causes strong bonds to be formed between the sulphur atom and the nickel atoms nearest to it, while simultaneously weakening bonds between these nickel atoms and their neighbouring nickel atoms in the cluster.
Abstract: This paper reports the first study employing detailed electronic structure calculations to investigate a model of grain boundary embrittlement. The results show that adding sulphur to a cluster of nickel atoms causes strong bonds to be formed between the sulphur atom and the nickel atoms nearest to it, while simultaneously weakening bonds between these nickel atoms and their neighbouring nickel atoms in the cluster. As a consequence one can suggest that sulphur forms very strong bonds within the plane of the boundary but weakens metal–metal bonds perpendicular to this plane. Although, for the present, the results can be considered only as suggesting one possible embrittling mechanism, they do demonstrate the insight which such calculations can provide into this very central question of grain boundary embrittlement.
TL;DR: Two compounds with properties of Factor F-430 were purified from Methanobacterium bryantii by column chromatography and analysis of these compounds revealed the presence of nickel and the absence of other metals commonly associated with molecules of biological origin.
TL;DR: In this paper, a new principle is described for the synthesis of multimetal π-complexes with hitherto unknown structural features, which can be obtained from metallocenes, alkali metals, and unsaturated compounds.
Abstract: In this progress report a new principle is described for the synthesis of multimetal π-complexes with hitherto unknown structural features. The nickel(0)-olefin complexes 1,5,9-cyclododecatrienenickel(0) and bis(1,5-cyclooctadiene)nickel(0) react unexpectedly with main-group metals, in particular alkali metals, their hydrides, and organometallic compounds, to give nickelligand species with a surplus charge. These species endeavor to transfer the excess charge onto π-ligands such as olefins or dinitrogen. Multimetal complexes with electron rich transition metal π-ligand units can, in addition, be prepared from metallocenes, alkali metals, and unsaturated compounds. The syntheses, structures, and reactions of this new class of substances will be summarized.
TL;DR: In this article, it was shown that the alloy elements nickel, molybdenum and chromium are accumulated in the metal phase underneath the oxide and that the enrichment of chromium seems to be dependent on the moly bdenum content of the alloy.
TL;DR: In this paper, the authors measured the rates of C2H6, C3H8, and n-C4H10 hydrogenolysis on homogeneous, SiO2-supported NiCu alloys for which surface and bulk compositions were shown to be very similar.
TL;DR: In this paper, X-ray and neutron diffraction experiments performed on Mg2Ni(H,D)x (0 ⊽ x ⩽ 3.9) confirmed the existence of a structural phase transformation at about 235 °C.
Abstract: X-ray and neutron diffraction experiments performed on Mg2Ni(H,D)x (0 ⩽ x ⩽ 3.9) confirmed the existence of a structural phase transformation at about 235 °C. The high temperature phase (a = 6.49 A, space group Fm3m) has an antifluorite-type metal structure in which the deuterium atoms surround the nickel atoms octahedrally in a disordered manner (D−Ni =1.47 A, D−Mg = 2.30 A). Refined atomic parameters of Mg2Ni as well as absorption and desorption isotherms for the deutende and hydride phases are reported.
TL;DR: In this paper, a sputter-cleaned TiO2(110) surface shows a (1 × 1) low energy electron diffraction pattern after annealing at 400°C for 15 min and a ( 1 × 2) pattern after a (615°C) extension at 615°c.
TL;DR: In this article, a field ion microscope study of single atom self-diffusion on Ni(311, (331), (110), (111) and (100) planes is presented.
TL;DR: In this paper, trace-metal analyses of water samples obtained during a cruise with the Soviet R.V. "Akademik Kurchatov" in the Indian Ocean are presented.
TL;DR: In this article, the oxidation and reduction behavior of a series of FeSiO2, NiSiO 2, and 4Fe:NiNiO2 catalysts, each with total metals loading of 5 wt%, has been investigated using Mossbauer effect spectroscopy, X-ray diffraction and temperature-programmed reduction.
TL;DR: The influence of the amino acids, cysteine, and tryptophan on the corrosion behavior of Ti-Ni and Ti-6A1-4V was studied and produced no significant effects.
Abstract: Anodic polarization measurements made in Hanks' physiological solution at 37 degrees C and a pH of 7.4 show titanium materials to be the most passive of the following metals: titanium, Ti-6A1-4V, Ti-Ni (memory alloy), MP35N (Co-Ni-Cr-Mo), Co-Cr-Mo, 316L stainless steel, and nickel. The influence of the amino acids, cysteine, and tryptophan on the corrosion behavior of Ti-Ni and Ti-6A1-4V was studied. Cysteine caused a lower breakdown potential for Ti-Ni, but it did not affect the breakdown of Ti-6A1-4V, although an increase in current density for Ti-6A1-4V was observed. Tryptophan produced no significant effects.
TL;DR: In this article, the chemical classification of independent iron meteorites is discussed, which include 57 meteorites based on structural observations and concentrations of Ni, Ga, Ge, and Ir. Instrumental neutron activation analysis indicates that five previously studied irons with very high Ge/Ga ratios are compositionally closely related and can be gathered together as group IIF.
TL;DR: The effect of nickel plating on the hydriding and dehydriding characteristics of magnesium were studied in this paper, where the authors found that the nickel in an electroless plated form (nominal composition, 0 −10 wt% Ni) had little effect on the initial activation, the maximum achievable capacity and the absorption kinetics.
Abstract: The effect of nickel plating on the hydriding and dehydriding characteristics of magnesium were studied It was found that the nickel in an electroless plated form (nominal composition, 0–10 wt% Ni) had little effect on the initial activation, the maximum achievable capacity and the absorption kinetics The effect on desorption kinetics, however, was profound Nickel plating improved the kinetics to the range required for automotive applications, but the rate decayed rapidly with cycling because of sintering of the nickel on the magnesium surface This decay suggests that an important parameter influencing the desorption rate is the amount of surface nickel in contact with magnesium
Further work with these systems may lead to an Mg/Ni system with a minimum nickel content and desorption rates approaching those of Mg2Ni
TL;DR: In this article, the authors investigated the oxidation properties of Ni•2 and 6 w/o Al alloys in 1 atm oxygen at temperatures in the range 1273°-1573°K.
Abstract: Oxidation properties of Ni‐2 and 6 w/o Al alloys were investigated in 1 atm oxygen at temperatures in the range 1273°–1573°K. Ni‐2 w/o Al oxidized parabolically, one order of magnitude more rapid than pure nickel, to a duplex scale by metal diffusion consisting of outer and inner layers of Al‐doped and , respectively, and an internal zone of rodlike precipitates by oxygen diffusion through the Al‐depleted alloy. Oxidation kinetics of Ni‐6 w/o Al alloy were irreproducible due to early‐stage formation of an imperfect scale containing nodules. Impingement of favorably oriented rodlike precipitates growing beneath the nodules accompanied with lateral diffusion of aluminum to react with oxygen at the precipitation front eventually led to transition from internal oxidation to development of a multilayered scale.
TL;DR: It is shown with Methanobacterium thermoautotrophicum that factor F,,, becomes labelled when the organism is grown in the presence of F-[4-14C]ALA, which is the amount predicted for a tetrapyrrole compound.
TL;DR: In this paper, a parameter Δ q was proposed to characterize the electronic properties of the catalysts of the nickel catalysts based on the X-ray photoelectron spectroscopic results.