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Castro, E.B.; Gervasi, C.A.; Vilche, J. R.

doi:10.1023/a:1003488409147

Cited by 110 publications

(74 citation statements)

References 18 publications

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“…It would thus seem unlikely that the aforementioned relaxation process is associated with the double-layer capacitance, since it is difficult to understand why this would discharge much more rapidly in the case of Fe, than for Ni or Co. Consulting the literature, reveals that while Castro et al [6] Returning to Fig. 3, a comparison of the log|Z| vs. log freq.…”

Section: The Oer On Passive Oxide Covered Iron Electrodesmentioning

confidence: 97%

“…Likewise, impedance spectra presented by Kessler and co-workers [17] has been proposed [6,18] that the "additional" pseudo-capacitance arises from a nonhomogeneous charge distribution associated with the surface oxidation of Co(III) to Co(IV) species.…”

Section: Passive Oxide Covered Cobalt Electrodesmentioning

confidence: 99%

“…The technique has been applied extensively to the study of the anodic oxygen evolution reaction (OER) occurring on various different substrates. Amongst the anode materials for which impedance responses at overpotentials associated with significant OER current densities have been detailed are: oxidised polycrystalline Ni [2], Co [3] and Pt [4], cobalt oxides deposited on various substrates [5][6][7], Co and Ni mixed oxides [8,9] and alloys [10], perovskites (e.g. La 0.5 Ba 0.5 CoO 3 [11] or various ferrites [12]), IrO 2 and related materials [13][14][15][16] and various amorphous alloys [17,18].…”

Section: Introductionmentioning

confidence: 99%

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The significance of electrochemical impedance spectra recorded during active oxygen evolution for oxide covered Ni, Co and Fe electrodes in alkaline solution

Lyons

Brandon

2009

Journal of Electroanalytical Chemistry

181

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Please cite this article as: M.E.G. Lyons, M.P. Brandon, The significance of electrochemical impedance spectra recorded during active oxygen evolution for oxide covered Ni, Co and Fe electrodes in alkaline solution, Journal of Electroanalytical Chemistry (2009Chemistry ( ), doi: 10.1016Chemistry ( /j.jelechem.2009 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. ACCEPTED MANUSCRIPTTitle: The significance of electrochemical impedance spectra recorded during active oxygen evolution for oxide covered Ni, Co and Fe electrodes in alkaline solution. Abstract: Although the mechanism for the oxygen evolution reaction (OER) is likely to be similar for oxidised electrodes of the adjacent transition metals Ni, Co and Fe, the electrochemical impedance spectra, recorded for each of these anodes during oxygen evolution in 1.0 M NaOH, are significantly different in appearance. This impedance data is analysed using an approach similar to that of Cahan and Chen [1] in an earlier important article on this topic. A controversial proposal by these workers that OER "Tafel slopes" (measured by either ac or dc techniques) for many electrode systems are not in fact characteristic of the kinetics of the reaction, but instead of the potential dependent conductivity of the oxide, is dismissed on the basis of our data. In the case of Co however, it is found that the kinetics of the OER are masked by a dominant low frequency pseudo-capacitance, arising most likely from a nonhomogeneous surface charge distribution associated with the oxidation of Co(III) to Co(IV) oxy-hydroxide species. A consistent interpretation of the data is provided, which envisages that Fe exhibits the most general impedance response with the spectra for the other anodes taking the form of limiting cases. Consideration is also given to the most appropriate choice of equivalent circuit model (with a firm physical basis) to aid our understanding of the complex interface at which oxygen evolution proceeds.

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Section: The Oer On Passive Oxide Covered Iron Electrodesmentioning

confidence: 97%

Section: Passive Oxide Covered Cobalt Electrodesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The significance of electrochemical impedance spectra recorded during active oxygen evolution for oxide covered Ni, Co and Fe electrodes in alkaline solution

Lyons

Brandon

2009

Journal of Electroanalytical Chemistry

181

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“…According to the perturbation theory, this implies that the orbital energy of cobalt is similar to the one of oxygen [30]. Based on studies concerning the catalytic activity of, on the one side, cobalt macrocycles towards small adducts other than hydroxide and, on the other hand, the electrocatalytic activity of cobalt oxides towards the oxygen evolution [31], the following reaction mechanism is suggested (equatorial ligands are left out) [ O + e − Just before the onset of the oxygen evolution, the oxidation state of the cobalt ion is +III. In the first step, the hydroxide ion occupies the place of the axial ligand of the macrocycle followed by an internal electron shift leading to Co(II)(OH) ads , which is, because of the applied potential, directly oxidized to Co(III)(OH) ads in the third step.…”

Section: Interaction Between Hydroxide and Metal Ion Phthalocyanines mentioning

confidence: 99%

Comparison between the electrocatalytic properties of different metal ion phthalocyanines and porphyrins towards the oxidation of hydroxide

Wael

Adriaens

2008

Talanta

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This work reports on the electrocatalytic oxidation of hydroxide using different central metal ion phthalocyanines and porphyrins immobilized on gold electrodes. The apparent electrocatalytic activity of cobalt phthalocyanine or porphyrin modified electrodes was found to be the greatest among the present series of metal ion macrocycles investigated. Copper and unmetallated phthalocyanine or porphyrin modified electrodes show no electrocatalytic behaviour towards hydroxide, such as bare gold. A possible mechanism for the enhanced reactivity of cobalt ion macrocycles towards the oxygen evolution is given. It is also stated that the electrocatalytic activity towards an adsorbate involves several aspects, such as the coordination state of the central metal ion, the nature of the ligand, the stability of the complexes, the number of d electrons, the energy of orbitals and the strength of the bonding between the central metal ion and the axial ligand.

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“…[13][14][15][16][17][18] Consequently, a significant body of research exists on the application of non-noble transition metal oxides as OER anodes. Among the most promising materials are various intermetallic alloys, [19][20][21] electrodeposited nickel, [22][23][24][25] cobalt [26][27][28] and manganese oxides, 29 spinels including nickelites, [30][31][32][33] cobaltites [34][35][36] and ferrites, 37,38 perovskites, [39][40][41][42] and hematite photoanodes. 43 An important practical and fundamental factor which should also be noted when considering OER anode materials is that, even in the case of the parent metal, the anodic OER always occurs at an oxidised surface.…”

Section: Introductionmentioning

confidence: 99%

Redox and electrochemical water splitting catalytic properties of hydrated metal oxide modified electrodes

Doyle

Godwin

Brandon

et al. 2013

Phys. Chem. Chem. Phys.

511

565

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This paper presents a review of the redox and electrocatalytic properties of transition metal oxide electrodes, paying particular attention to the oxygen evolution reaction. Metal oxide materials may be prepared using a variety of methods, resulting in a diverse range of redox and electrocatalytic properties. Here we describe the most common synthetic routes and the important factors relevant to their preparation. The redox and electrocatalytic properties of the resulting oxide layers are ascribed to the presence of extended networks of hydrated surface bound oxymetal complexes termed surfaquo groups. This interpretation presents a possible unifying concept in water oxidation catalysis -bridging the fields of heterogeneous electrocatalysis and homogeneous molecular catalysis. In contextOver the past 50 years considerable research efforts have been devoted to the realisation of efficient, economical and renewable energy sources. Metal oxide materials have played a large part in this drive with demonstrated applications at both the research and commercial level. Their use in areas such as batteries, fuel cells and water electrolysis has resulted in the development of materials with a diverse range of structural and chemical properties. In all cases, understanding the fundamental electrochemistry of the material can be invaluable for rational design and optimisation. This review focuses on the redox, charge transport and electrocatalytic properties of transition metal oxide electrodes as they pertain to the electrolytic splitting of water. Particular emphasis is placed on the nature of the active surface which is interpreted in terms of hydrated interlinked oxymetal complexes termed surfaquo groups. In this way, the review seeks to bridge the gap between heterogeneous electrocatalysis and homogeneous molecular catalysis for water oxidation, areas of considerable modern interest and activity.

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Cited by 110 publications

References 18 publications

The significance of electrochemical impedance spectra recorded during active oxygen evolution for oxide covered Ni, Co and Fe electrodes in alkaline solution

The significance of electrochemical impedance spectra recorded during active oxygen evolution for oxide covered Ni, Co and Fe electrodes in alkaline solution

Comparison between the electrocatalytic properties of different metal ion phthalocyanines and porphyrins towards the oxidation of hydroxide

Redox and electrochemical water splitting catalytic properties of hydrated metal oxide modified electrodes

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