Nickel In Alkaline Solution Research Articles

Compressive strain induced superior HER performance of nickel in alkaline solution.

The HER requires a highly efficient, cost-effective, and stable catalyst to adapt to the large-scale hydrogen industry. Nickel has been confirmed to be useful to drive the water splitting reaction, but the intrinsic performance remains unsatisfactory. In this work, nickel (EG-Ni) with compressive strain was prepared through a one-step electrochemical deposition strategy. It shows an outstanding enhancement for the HER, and it achieves a current density of 10 mA cm-2 at a low overpotential of 85.9 mV. A long-term durability test proves that the EG-Ni can tolerate a large current density of 100 mA cm-2, and the overpotential remains steady without dramatically increasing. Such a low overpotential and superior stability are attributed to the optimized adsorption energy on the catalyst surface, as evidenced by the downshifted position of the d-band center.

The Passivity of Pure Nickel in Alkaline Solution under Different Temperatures: Electrochemical Verification and First-Principles Calculation

Properties of a passive film formed on pure nickel in an anaerobic alkaline solution are investigated by a first-principles calculation and electrochemical experiments in this work, and both results show agreement with each other. The formation energy of nickel vacancies is lower than that of oxygen vacancies in the NiO film, which is consistent with the deduction of the point defect model in which nickel vacancies impart p-type semiconducting character to the passive film, as confirmed by Mott–Schottky analysis. The density of nickel vacancies (approximately 1021 cm−3) in the passive film increases with temperature but decreases with the film-formation potential. The thickness of the passive film increases linearly with the film-formation potential, as verified both by Auger electron spectroscopy and electrochemical impedance spectroscopy. The diffusion coefficient of the nickel vacancies increases from 10−18 to 10−16 cm2/s as the temperature rises from 298 to 348 K, respectively, in experiments using high-field equations and first-principles calculation.

Kinetics of the hydrogen evolution on nickel in alkaline solution: new insight from rotating disk electrode and impedance spectroscopy analysis

Nickel catalysts were characterized for the hydrogen evolution reaction (HER) using rotating disk electrode (RDE) and electrochemical impedance spectroscopy (EIS). The theoretical Levich slope was calculated on the basis of the HER mechanism in alkaline solution. Kinetic and thermodynamic parameters of the reaction were obtained for fresh polished nickel electrode (Nif), and for nickel after a quick chronoamperometric aging procedure (Nipc). Koutecky-Levich analysis indicated that the rate determining step on Nif is the one-electron Volmer reaction, while for Nipc decreases from one to 0.68 and exhibits a strong temperature dependence. A loss of catalytic activity, corresponding to an increase of 0.3V of the HER onset potential, was observed after aging. Furthermore, from the EIS-Tafel analysis we concluded that the H adsorption changes from a Langmuir type for Nif, to a Temkin type for Nipc.

Chloride induced pitting corrosion of nickel in alkaline solutions and its inhibition by organic amines

Cyclic voltammetry, potentiodynamic and potentiostatic anodic polarization techniques complemented by SEM investigation are used to study the initiation and inhibition of pitting corrosion of nickel in NaOH solutions. The presence of Cl − ions locally destroys the passive film formed on the nickel electrode at the pitting potentials, E p , which are more active the higher the concentration of the Cl − ions. E p varies with the logarithm of Cl − ions concentration according to sigmoidal S-shaped curves. The change in the integrated anodic charge amount, Δ q a , in the presence and absence of Cl − ions, is taken as a measure of pitting corrosion likelihood to take place. The logarithm of Δ q a changes linearly with the C C l − according to: log Δ q a = a 1 + b 1 log C C l − , where a 1 and b 1 are constants. Addition of monomethylamine, monoethylamine, and dimethylamine up to a certain threshold concentration, which depends on amine type, causes complete depression of the dissolution current peak and a marked shift of the critical pitting potential into the noble direction. Following this threshold concentration, the critical pitting potential, E p , changes with the inhibiting agent concentration according to the following equation: E p = α 1 + β 1 log C inh , where α 1 and β 1 are constants. Hydrazine enhances the active dissolution and pitting corrosion. The pitting potential is shifted into the active direction at all its concentrations. This behavior is attributed to the formation of hydrazine Ni-complexes. Urea behaves bifunctionally, inhibiting pitting corrosion of nickel when present in low concentrations, and enhancing the attack at higher concentrations.

Kinetics of the Hydrogen Electrode Reaction on Platinum in Alkaline Solutions at Elevated Temperatures

The kinetics of the hydrogen electrode reaction on a platinized nickel electrode in alkaline solutions over a wide temperature range from ambient up to 220oC have been investigated employing a controlled hydrodynamic cell. Due to the reversible nature of this reaction, the generalized Butler-Volmer equation was used in optimization upon the polarization data, so as to account for kinetic, thermodynamic, and mass transfer effects. The extracted model parameters are compared with those for other forms of platinum electrode, and platinized nickel shows excellent electrocatalytic activity as demonstrated by the exchange current density. The extracted apparent transfer coefficients for hydrogen evolution and hydrogen oxidation are temperature-dependent, while the apparent Tafel slope of the hydrogen evolution reaction is temperature-independent (approximately 120mV/dec), which is most probably due to two parallel reactions occurring at the interface with different rates and activation energies. An Arrhenius analysis yields an activation energy of 17.3 kJ/mole for the hydrogen electrode reaction on platinized nickel in alkaline solution.

In Situ STM Study of the Effect of Chloride on Passive Film on Nickel in Alkaline Solution

In situ electrochemical scanning tunneling microscopy (STM) measurements on the growth and structure of the passive film on in (, and ) aqueous solutions are reported. At the onset of the active-passive transition, the formation of the islands, assigned to the locally ordered coadsorption of hydroxide species and water molecules on the unreconstructed surface, is retarded or blocked by a competitive adsorption mechanism between and . A competitive mechanism, at step edges, of metal dissolution and nucleation of a 2D passive film is also observed. For , the nucleation of the passive film at the step edges is blocked at (standard hydrogen electrode). The rate of retraction of the step edges is not significantly enhanced by the chlorides, but the dissolution is sustained. Increasing the potential unblocks nucleation but leads to the formation of 3D nuclei. At , a crystalline passive film develops for . At higher chloride concentration, the crystallization is blocked, and clusters of nanograins are formed. Further growth of the grains by coalescence is blocked. Localized attacks of the substrate are developed by preferential dissolution at the boundaries between the grain clusters.

On the kinetics of the hydrogen evolution reaction on nickel in alkaline solution: Part II. Effect of temperature

The effect of temperature on the kinetics of the hydrogen evolution reaction (her) on nickel in 1.0 mol dm −3 NaOH solution was studied. In this article, four sets of experiments were done in a non-isothermal cell. In all experiments only the compartment of the Ni working electrode was thermostated at 278.5, 303.0, 313.0 and 323.0 K, while the reference electrode (Hg ∣ HgO) was held constantly at 298.0 K. It was found that the transfer coefficient, α decreased with temperature. Using the calculated chemical rate constants and the corresponding partial standard rate constants for the Volmer, Heyrovsky and Tafel steps in both directions and the corresponding Arrhenius relationship, the chemical enthalpies of activation and the corresponding pre-exponential factors were determined. It was demonstrated that the limiting current for the her at potentials more negative than −1.6 V occurs because the her takes place as an activationless process.

On the kinetics of the hydrogen evolution reaction on nickel in alkaline solution: Part I. The mechanism

The mechanism and kinetics of the hydrogen evolution reaction (her) were studied in 1.0 mol dm −3 NaOH at 393.0 K. It was found that a combination of classical steady-state voltammetry and impedance spectroscopy can help to elucidate dilemmas concerning the role of the Heyrovsky and Tafel steps in the mechanism of this reaction. Thus, within the potential region −0.95> E>−1.1 V (SHE) (curvilinear part of the polarization curve) the mechanism of the her is a consecutive combination of the Volmer step, followed dominantly by a rate controlling Tafel step, while the contribution of the parallel Heyrovsky step is negligible. At potentials E<(approximately −1.2 V) a Tafel line with a slope of −0.121 V dec −1 is obtained, with almost full coverage by H ads ( θ H→1). In this potential region the mechanism of the her is a consecutive combination of a Volmer step, followed by a Heyrovsky step, while the contribution of the Tafel step is negligible. The comparison of the calculated partial rate constants for these two steps shows that the rate of the her is controlled by the Heyrovsky step.

Passivating films on nickel in alkaline solutions II. Ni(II) anodic film growth: quantitative treatment and the influence of the OH− concentration

Through the development of a general quantitative model for the understanding of the growth of continuous passivating films on metals it was possible to describe in detail the voltammetric growth of the NiO film on nickel in NaOH solutions. The transfer coefficient and the exchange current density at the Ni ∣ NiO interface are about l.5 and 4–8 μA cm−2, respectively, and vary with the NaOH concentration in the solution. The overpotential through the film always increases with the potential. The charge density of the film (proportional to its thickness) versus potential presents a sigmoidal behaviour. The electrical field inside the film tends first to a plateau followed by a new increase after the peak current density. In parallel, the ionic specific resistance inside the film passes through a minimum (at the peak potential) during the growth. As a whole it decreases with the increase of the growth velocity and passes through a minimum with the increase of NaOH concentration. All these facts are explained and in agreement with the proposed model.

The passivating films on nickel in alkaline solutions I. General aspects of the Ni (II) region

Abstract Passivating films at the Ni(II) potential region in alkaline solutions have been studied qualitatively by voltammetry. One anodic (a 1 ) and two cathodic (c 1 and c 2 ) peaks were observed. It is shown that the peak at the more negative potential (c 1 ) corresponds to the reduction of a film formed previously during the preparation of the electrode. Its appearance depends on the experimental conditions and it can be dissolved at sufficiently negative potentials. Peaks a 1 /c 2 correspond to the same film, which is attributed to NiO. As a consequence, the presence of the passivating film increases the hydrogen overpotential. The total cathodic charge densities have always been found to be smaller than the anodic one. In order to explain this behaviour, the existence of a disruption process which is discussed in the paper, is proposed.

Enhancement of catalytic activity of Raney nickel by cobalt addition

The effects of cobalt as a promoter of the catalytic activity of Raney nickel for various manufacturing esses have been studied. The variation of particle size distribution, specific surface area and residual aluminium content can also affect the catalytic properties of Raney nickel. The characteristics of the catalyst are considerably influenced by the relative nickel and aluminium contents. When the catalysts are prepared from 60 wt.% nickel and 40 wt.% aluminium, the electrode performance shows the highest current density of 450 mA/cm 2. With the addition of cobalt, the particle size is diminished from 13.92 to 11.70 μm and the decrease of the particle size contributes to a slight enlargement of the specific surface area. The mass activity of a hydrogen electrode manufactured with cobalt Raney nickel in alkaline solution is increased from 3.74 to 4.03 A/g when 120 mg/cm 2 of catalyst are loaded in the electrode.

Electrochemical oxidation of nickel in alkaline solutions: a voltammetric study and modelling

Abstract The reaction mechanisms of the oxidation of nickel in alkaline solutions has been studied by cyclic voltammetry and scanning electron micrography. It is shown that the formation of a layer of nickel hydroxide depends on the surface treatment of the nickel electrode. Even on a freshly polished electrode a hydroxide deposit was hardly obtained from an anodic polarization; cathodic prepolarization was required to obtain formation of nickel hydroxide. The quantity of nickel hydroxide electrochemically generated is related to the potential value and the duration of the cathodic treatment. The set of experimental data issued from this voltammetric study is used for comparison with the computed values obtained by digital simulation. The general multiple electrode reaction model used for these calculations is presented here. It involves the formation of nickel hydroxide according to a nucleation and growth mechanism, and redox reactions such as nickel hydroxide⇌nickel oxyhydroxide, hydrogen and oxygen evolution. A reasonable fit is obtained between experimental and computed responses by introducing the values of the thermodynamic and kinetic parameters found in the literature or calculated for this purpose.

Surface modification of Inconel-600 by growth of a hydrous oxide film

In this study, Inconel-600 (Ni–Cr–Fe alloy) was modified by repetitive potential cycling in 1M NaOH solution. This procedure induced the growth of a hydrous oxide film, following the same mechanism as previously reported for pure nickel in alkaline solution under similar experimental conditions. The electrode, modified by 30 repetitive potential cycles, exhibited about one order of magnitude lower current density in both the active and passive ranges of the anodic polarization curve. Selective dissolution of nickel and iron in acid solution was determined by rotating ring–disc electrode measurements. This process resulted in chromium enrichment as shown by use of X-ray electron spectroscopy. The proposed model for the enhanced stability of the modified electrode agrees with the percolation model of passivity of stainless steels and Fe–Cr alloys.

Spectroscopic ellipsometry study of nickel oxidation in alkaline solution

Spectroscopic ellipsometry and cyclic voltammetry were used to study the oxidation of nickel in alkaline solutions. Electrode surface films were formed by air exposure and by electrochemical oxidation at various potentials during the first voltammetric scan. Using a self-compensating ellipsometer and a previously developed data fitting program, it was possible to characterize the surface films formed in situ. We found that oxide layers formed during the polishing of nickel in air have a significant optical effect, and normal polishing conditions can produce NiO of 10 Å thickness. During the positive-going sweep at potentials between −0.9 V and −0.4 V ( vs Hg/HgO), a compact film of β-Ni(OH) 2 is formed. The surface layer that appears after the second anodic peak at +0.5 V contains a mixture of Ni(OH) 2 and NiOOH with an overlayer of β-NiOOH. This overlayer is completely reduced after the cathodic peak at +0.2 V is reached during the negative-going sweep, and the layer remaining at this potential consists of a mixture of Ni(OH) 2 and NiOOH. At very cathodic potentials (−0.9 V) NiOOH is still found on the electrode surface, and some electrode roughness appears. During a potentiostatic hold at this potential, NiOOH is reduced to Ni(OH) 2, and the Ni(OH) 2 is very slowly reduced to Ni with a decrease in electrode roughness.

In situ IR study of the electrooxidation of hypophosphite on a polycrystalline nickel electrode

Electrooxidation of the hypophosphite ions on polycrystalline nickel in alkaline solutions has been investigated using cyclic voltammetry, chronoamperometry and in situ IR spectroscopy (SNIFTIRS). A spectroelectrochemical flow cell was used in order to keep the composition of the thin layer constant. The spectra were analysed as a function of the electrode potential during the anodic, cathodic scans and at open-circuit potential as a function of time. On the assumption that solvent bands are independent of applied potential, there is some evidence at open circuit for hypophosphite ions adsorbing to the nickel surface through the hydrogen atoms; this orientation persists until oxidation takes place. Phosphite ions were the only oxidation product to be detected.

In-situ potential difference Fourier transform infrared reflection absorption spectroscopic studies of the electrochemical oxidation of adsorbed carbon monoxide on nickel in alkaline solutions

The spectral properties of CO adsorbed on polycrystalline nickel electrodes in 0.1 M KOH have been examined using in situ potential difference Fourier transform infrared spectroscopy. The results obtained have shown that the voltammetric peak observed in the first linear scan in the positive direction for Ni(poly)/CO(ads) surfaces prepared by a special procedure is associated with the electrochemical oxidation of bridge-bond CO to generate solution-phase carbonate as the only detectable product. No changes in the stretching frequency of CO (ν CO ) could be found as a function of potential in a region negative to the onset of CO oxidation

ChemInform Abstract: Applications of Real‐Time FTIR Spectroscopy to the Elucidation of Complex Electroorganic Pathways: Electrooxidation of Ethylene Glycol on Gold, Platinum, and Nickel in Alkaline Solution.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Selective Hydrogenolysis of Bis(hydroxymethyl)aromatic Compounds

Selective hydrogenolysis of symmetric bis(hydroxymethyl)aromatic compounds has been performed over Raney nickel in alkaline solution for 24-36 h at 20°C. The yield of the corresponding monohydrogenolysis product was in the range of 75-96 %. The usefulness of the reaction was demonstrated by the synthesis of 4-(bromomethyl)benzoic acid.

Applications of real-time FTIR spectroscopy to the elucidation of complex electroorganic pathways: electrooxidation of ethylene glycol on gold, platinum, and nickel in alkaline solution

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTApplications of real-time FTIR spectroscopy to the elucidation of complex electroorganic pathways: electrooxidation of ethylene glycol on gold, platinum, and nickel in alkaline solutionSi Chung Chang, Yeunghaw Ho, and Michael J. WeaverCite this: J. Am. Chem. Soc. 1991, 113, 25, 9506–9513Publication Date (Print):December 1, 1991Publication History Published online1 May 2002Published inissue 1 December 1991https://doi.org/10.1021/ja00025a014RIGHTS & PERMISSIONSArticle Views903Altmetric-Citations89LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (962 KB) Get e-Alerts Get e-Alerts

高温濃厚苛性ソーダ溶液中におけるFe-Cr-Ni合金の腐食におよぼすNaClO&lt;SUB&gt;3&lt;/SUB&gt;およびNaClの影響

The corrosion behavior of iron-chromium-nickel alloys in 48%NaOH solutions containing NaClO3 and NaCl was investigated mainly by means of potentiodynamic polarization and measurement of the average penetration at temperatures between 140 and 200°C, and the following results were obtained. In 48%NaOH solutions containing NaClO3, anodic dissolution of iron-chromium-nickel alloys in the active state decreased with increasing the nickel and chromium content, and the NaClO3 content. However, the anodic dissolution as NiO22− ion at a low potential of Eh=−0.65 V was unchanged with and without NaClO3 in NaOH solutions. Then, the natural electrode potential of the alloys showed a noble potential with increase in the NaClO3 content. The immersion test showed that the alloys containing low chromium had a comparatively good corrosion resistance by addition of nickel in alkaline solutions containing NaClO3, but high chromium alloys having self-passivation ability decreased the corrosion resistance by addition of Ni in those solutions. The effect of NaClO3 on corrosion of the alloys is caused by its oxidation power. The corrosion behavior of iron-chromium-nickel alloys was invariable in 48%NaOH solutions when the NaCl content was less than 1%.