Effect of preparation on the surface and electrocatalytic properties of RuO2 + IrO2 mixed oxide electrodes

Angelinetta, C.; Atanasoska, Lj.; Minevski, Zoran; Atanasoski, Radoslav

doi:10.1016/0254-0584(89)90039-4

Cited by 92 publications

(38 citation statements)

References 22 publications

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“…In the literature for ruthenium oxide and iridium] ruthenium oxide Tafel slopes at room temperature and with an electrolyte of 1M HC104 of 40-55mVdec -l, depending strongly upon the preparation conditions, have been reported [28][29][30]. Upon correction of the present data for temperature the resulting value of 57mVdec -1 (Ru-oxide) and of 48 mVdec -~ (Ir/Ru-oxide) falls within this range of results.…”

Section: Oxygen Evolution Reactionsupporting

confidence: 76%

Bifunctional electrodes for an integrated water-electrolysis and hydrogen-oxygen fuel cell with a solid polymer electrolyte

Ahn

Holze

1992

J Appl Electrochem

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An alternative concept of an integrated water electrolysis/hydrogen-hydrogen fuel cell using metal electrocatalysts and a solid polymer electrolyte is described. Instead of operating both electrodes as hydrogen and oxygen electrodes respectively the electrodes are used as oxidation and reduction electrodes in both modes of operation. A more suitable selection of electrocatalysts and an improved cell design are possible; both can increase the efficiency of the cell co/Isiderably. New results on the electrocatalytic activity of various noble-metal containing catalysts with respect to both oxygen evolution and hydrogen oxidation in a proton exchange membrane-cell at 80 ~ are reported. Kinetic data derived from Tafel plots of the oxygen evolution polarization curves agree closely with those of experiments with aqueous sulphuric acid electrodes. This agreement allows the determination of kinetic parameters for electrocatalysts difficult to prepare in solid smooth electrodes but easy to be made into porous deposits. Polarization curves of the hydrogen oxidation reaction clearly indicate a relative activity rating of the studied catalysts. In cycling tests the lifetime stability of the new bifunctional oxidation electrode was determined. Polarization data obtained under these conditions agree with those obtained in earlier experiments where electrodes were exposed to only one type of oxidation reaction. During a test of 10 cycles (30 min of electrolyser and 30 min of fuel cell mode each) no changes in the electrode potential were observed. With the conventional cell design employing a hydrogen and an oxygen electrode both catalyzed with platinum and a current density of 100 mA cm-2 a storage efficiency of 50% was calculated; with the alternative concept of oxidation and reduction electrodes and selected oxidation catalysts this was improved to 57%. With further improvements these efficiencies seem possible even at current densities of 500 mAcm -2.

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Section: Oxygen Evolution Reactionsupporting

confidence: 76%

Bifunctional electrodes for an integrated water-electrolysis and hydrogen-oxygen fuel cell with a solid polymer electrolyte

Ahn

Holze

1992

J Appl Electrochem

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“…One apparent limitation of the electrochemical oxide mechanism is that is does not give Tafel slopes of 30 and 60 mV -the typical values observed for RuO 2 and IrO 2 anodes [6][7][8][9][10][11]17]. In fact several authors appear to rule out the electrochemical oxide mechanism on the basis that the experimental Tafel slopes do not match those predicted from the mechanism, and then develop new mechanisms, to overcome this apparent limitation [6,10,13,17].…”

Section: Resultsmentioning

confidence: 94%

“…An equivalent experimentally measurable quantity which can be used in place of the classical Tafel slope is the transfer coefficient as defined by α = RT F d ln i dE [4,5]. For OER electrocatalysts such as RuO 2 or IrO 2 , the Tafel slope is normally between 30 and 60 mV, but can exhibit Tafel slopes of up to 120 mV at high overpotentials [6][7][8][9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Avoid the quasi-equilibrium assumption when evaluating the electrocatalytic oxygen evolution reaction mechanism by Tafel slope analysis

Marshall

Vaisson-Béthune

2015

Electrochemistry Communications

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Tafel slope analysis is a powerful tool in comparing experimental data to a proposed reaction mechanism. Typically, in order to simplify the analysis, the non-rate-determining steps in the reaction mechanism are assumed to be in quasi-equilibrium. Here, Tafel analysis of the oxygen evolution reaction following the electrochemical oxide mechanism is performed using a full kinetic model. It is shown that this model (which uses the steady-state assumption) predicts a larger number of Tafel slopes than if the quasi-equilibrium assumption is used, and provides predicts the surface coverages which underpin these Tafel slopes. Importantly, this model predicts Tafel slopes of 30, 40, 60 and 120 mV, all of which are experimentally found on IrO 2 and RuO 2 anodes. Models using the quasi-equilibrium assumption fail to predict some Tafel regions, as these can occur when a non-rate-determining step is not at quasi-equilibrium.

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“…It was reported that oxide anodes prepared from organic solvent systems display better performance [15,16]. It was also shown that coatings prepared by heating the precursor films at a low temperature display a low stability due to incomplete thermal decomposition resulting in the dissolution of the coating during electrolysis [17,18].…”

Section: Introductionmentioning

confidence: 99%

Investigation of RuO2/Ta2O5 thin film evolution by thermogravimetry combined with mass spectrometry

et al. 2005

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Effect of preparation on the surface and electrocatalytic properties of RuO2 + IrO2 mixed oxide electrodes

Cited by 92 publications

References 22 publications

Bifunctional electrodes for an integrated water-electrolysis and hydrogen-oxygen fuel cell with a solid polymer electrolyte

Bifunctional electrodes for an integrated water-electrolysis and hydrogen-oxygen fuel cell with a solid polymer electrolyte

Avoid the quasi-equilibrium assumption when evaluating the electrocatalytic oxygen evolution reaction mechanism by Tafel slope analysis

Investigation of RuO2/Ta2O5 thin film evolution by thermogravimetry combined with mass spectrometry

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