An EQCM investigation of charging RuO2 thin films prepared by the polymeric precursor method

Santos, Mauro C.; Terezo, Ailton José; Fernandes, V. C.; Pereira, Ernesto C.; Bulhões, L.O.S.

doi:10.1007/s10008-004-0512-2

Cited by 36 publications

(26 citation statements)

References 22 publications

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“…In accordance with [5], it also has been shown in [14] that cathodic reduction of surface compounds layer formed anodically at E > 1.2 V is hindered, and the initial mass of Ru electrode is regained only after 30 s of polarizing the electrode at 0 V. Attempts of the authors of [14] to relate coulometric and microgravimetric data within the context of Equation 1 have resulted in electrochemical reaction equations with fractional stoichiometric coefficients. Whereas in the case of RuO 2 electrode formed by means of sol-gel procedure Santos et al [6] have found that within E range between 0.4 V and 1.4 V mass of the electrode decreases during the anodic process and increases during the cathodic one, i.e., microgravimetric behavior of RuO 2 is quite opposite to that of active Ru electrode [14].…”

Section: Introductionmentioning

confidence: 95%

“…Microgravimetric behavior of Ru and RuO 2 electrodes has been studied recently in the solutions of 0.5 M H 2 SO 4 and 0.1 M HClO 4 by the authors of Refs. [6,14], respectively. Vukovic et al [14] have found that in the case of active Ru surface, the anodic process within 0 V < E < 0.8 V is accompanied by increase in mass, whereas the cathodic one by mass decrease, as it should be expected in the case when the layer of slightly soluble oxygen compounds forms on the electrode surface.…”

Section: Introductionmentioning

confidence: 97%

“…Many studies have been performed with RuO 2 electrodes prepared either electrochemically [2,3], thermally [4,5], by means of sol-gel procedure [6,7] or with RuO 2 single crystal electrodes [8,9]. The RuO 2 electrode should be treated, in fact, like ruthenium electrode in its passive state, with the passivity being determined by hardly reducible layer of anhydrous RuO 2 present on the electrode surface.…”

Section: Introductionmentioning

confidence: 99%

“…Thus within the zone of passivity, i.e., between 0 V and 1.4 V RuO 2 layer should be electrochemically stable. In literature, however, the electrochemical pseudocapacity of RuO 2 [6,11] or RuO x · nH 2 O [2,7] electrodes is usually attributed to the reversible redox transitions between Ru(III)/Ru(IV) [5] or Ru(II)/Ru(III), Ru(III)/ Ru(IV) and Ru(IV)/Ru(VI) [3] oxidation states. Pseudocapacity effects should be determined by surface faradaic processes, which, in our view, take place on the active ruthenium surface, i.e., in the E range preceding the formation of passivating RuO 2 layer.…”

Section: Introductionmentioning

confidence: 99%

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EQCM Study of Ru and RuO₂ Surface Electrochemistry

Juodkazytė¹,

Vilkauskaitė²,

Stalnionis³

et al. 2007

Electroanalysis

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The present study represents comparative analysis of voltammetric and microgravimetric behavior of active ruthenium (Ru), electrochemically passivated ruthenium (Ru/RuO 2 ) and thermally formed RuO 2 electrodes in the solutions of 0.5 M H 2 SO 4 and 0.1 M KOH. It has been found that cycling the potential of active Ru electrode within E ranges 0 V -0.8 V and 0 V -1.2 V in 0.5 M H 2 SO 4 and 0.1 M KOH solutions, respectively, leads to continuous electrode mass increase, while mass changes observed in alkaline medium are considerably smaller than those in acidic one. Microgravimetric response of active Ru electrode in 0.5 M H 2 SO 4 within 0.2 V -0.8 V has revealed reversible character of anodic and cathodic processes. The experimentally found anodic mass gain and cathodic mass loss within 0.2 -0.8 V make 2.2 -2.7 g F À1 , instead of 17 g F À1, which is the theoretically predicted value for Ru(OH) 3 formation according to equationIn the case of Ru/RuO 2 electrode relatively small changes in mass have been found to accompany the anodic and cathodic processes within E range between 0.4 V and 1.2 V in the solution of 0.5 M H 2 SO 4 . Meanwhile cycling the potential of thermally formed RuO 2 electrode under the same conditions has lead to continuous decrease in electrode mass, which has been attributed to irreversible dehydration of RuO 2 layer. On the basis of microgravimetric and voltammetric study as well as the coulometric analysis of the results conclusions are presented regarding the nature of surface processes taking place on Ru and RuO 2 electrodes.

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Section: Introductionmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

EQCM Study of Ru and RuO₂ Surface Electrochemistry

Juodkazytė¹,

Vilkauskaitė²,

Stalnionis³

et al. 2007

Electroanalysis

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“…[19][20][21] Dobholfer et al 30 proposed that RuO 2 electrodes present redox transitions between Ru 2+ to Ru 6+ in the potential range between 0.4 and 1.4 V (vs. RHE) in acidic medium, 30 which was confirmed using EQCN method. 31,32 The peak at 0.75 V could be associated with the redox transition of Ru 3+ to Ru…”

Section: Electrochemical Characterizationmentioning

confidence: 99%

Ethanol electrooxidation using Ti/(RuO2)(x) Pt(1-x) electrodes prepared by the polymeric precursor method

Freitas¹,

Marchesi²,

Forim³

et al. 2011

J. Braz. Chem. Soc.

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Este trabalho descreve um estudo detalhado da oxidação eletroquímica de etanol sobre eletrodos de Ti/(RuO 2 ) (x) Pt (1-x) com várias composições, preparados pelo método de precursores poliméricos. Os resultados obtidos usando voltametria cíclica e cronoamperometria mostraram que a melhor composição dos eletrodos de Ti/(RuO 2 ) (x) Pt (1-x) para os processos de oxidação do CO e do etanol é Ti/(RuO 2 ) (0.5) Pt (0.5) . Nessa composição, a oxidação do CO e do etanol ocorreram em 380 mV e 220 mV mais negativos do que em Ti/Pt, respectivamente. Por outro lado, observou-se um aumento de 2.5 vezes na densidade de corrente para a oxidação do etanol sob potencial constante. Análises de HPLC in situ mostraram que os eletrodos de Ti/(RuO 2 ) (0.5) Pt (0.5) produziram baixas quantidades de ácido acético comparadas com aquelas quantidades geradas pelos eletrodos de Ti/ Pt ou Pt policristalina. Além disso, um produto que não é comum a partir da oxidação do etanol foi observado em eletrodos com maior teor de RuO 2 : o acetato de etila. Finalmente, os dados de impedância mostraram que os eletrodos com a composição Ti/(RuO 2 ) (0.5) Pt (0.5) apresentaram menores resistências de transferência de carga, entre as composições investigadas.This work describes a detailed study of the ethanol electrooxidation on Ti/(RuO 2 ) (x) Pt (1-x) electrodes using several compositions prepared by the polymeric precursor method. The results obtained using cyclic voltammetry and chronoamperometry showed that the best composition of Ti/(RuO 2 ) (x) Pt (1-x) electrodes for CO and ethanol oxidation processes is Ti/(RuO 2 ) 0.50 Pt 0.50 . On this electrode composition the onset of CO and the ethanol oxidation occurred at 380 mV and 220 mV more negative than on Ti/Pt, respectively. Besides, there was an increase of 2.5-fold in the current density for ethanol electrooxidation under constant potential polarization. The Ti/(RuO 2 ) 0.50 Pt 0.50 electrodes produced lower amount of acetic acid compared to Ti/Pt and polycrystalline Pt electrodes using in situ HPLC spectrometric analysis. Also, a non common product from ethanol oxidation could be observed on higher RuO 2 loads: ethyl acetate. Finally, the impedance data showed that Ti/(RuO 2 ) 0.50 Pt 0.50 electrode composition had the smallest charge transfer resistance for ethanol oxidation among those compositions investigated.Keywords: ethanol electrooxidation, polymeric precursor method, CO electrooxidation, eletrocatalysis, in situ HPLC IntroductionFuel cells are widely recognized as very attractive devices to obtain directly electric energy from the combustion of a chemical product. In the last decades, much attention has been devoted to the study of the electrooxidation of small organic molecules, due to their possible utilization as fuels in direct organic fuel cell (DOFCs) devices.1,2 Ethanol has emerged as important choice due to its low toxicity and volatility together with a higher energy density than methanol (8.01 kWh kg −1 versus 6.09 kWh kg −1). 3 Other important considerations for choos...

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Recent Progress in Ruthenium Oxide‐Based Composites for Supercapacitor Applications

Majumdar¹,

Maiyalagan

Jiang³

2019

ChemElectroChem

253

147

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Electrochemical energy storage has emerged as one of the principal topics of present‐day research to deal with the high energy demands of modern society. Accordingly, besides fuel cells and battery technologies, interesting and challenging results have been observed in the recent past, during the materialization of “supercapacitors” or “ultracapacitors”, which have provoked a sharp increase in research inclination to revisit this aspect of renewable and sustainable energy storage. Supercapacitor performances are largely dependent on electrode materials, the nature of the electrolyte used, and the range of voltage windows employed. Carbon‐based electrode materials have tunable properties such as electrical conductivity, extensive surface area, and faster electron transfer kinetics with low fabrication costs. But their specific capacitances are found to be too low for commercialization. Ruthenium dioxide (RuO2), owing to its high theoretical specific capacitance value (1400–2000 F g−1), has been extensively recognized as a favorable material for supercapacitor devices, but high production cost and agglomeration effects stand as high barriers preventing marketable usage. Consequently, RuO2‐based nanocomposites have been widely studied to optimize the material cost, with simultaneous improvement in the electrochemical performances. This Review describes comprehensively the recent progress in terms of the fabrication and design, electrochemical performance, and achievements of RuO2 and its nanocomposites as electrode materials for supercapacitors, which will be beneficial for further research designing high‐performance supercapacitor devices.

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An EQCM investigation of charging RuO2 thin films prepared by the polymeric precursor method

Cited by 36 publications

References 22 publications

EQCM Study of Ru and RuO₂ Surface Electrochemistry

EQCM Study of Ru and RuO₂ Surface Electrochemistry

Ethanol electrooxidation using Ti/(RuO2)(x) Pt(1-x) electrodes prepared by the polymeric precursor method

Recent Progress in Ruthenium Oxide‐Based Composites for Supercapacitor Applications

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An EQCM investigation of charging RuO2 thin films prepared by the polymeric precursor method

Cited by 36 publications

References 22 publications

EQCM Study of Ru and RuO2 Surface Electrochemistry

EQCM Study of Ru and RuO2 Surface Electrochemistry

Ethanol electrooxidation using Ti/(RuO2)(x) Pt(1-x) electrodes prepared by the polymeric precursor method

Recent Progress in Ruthenium Oxide‐Based Composites for Supercapacitor Applications

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Product

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EQCM Study of Ru and RuO₂ Surface Electrochemistry

EQCM Study of Ru and RuO₂ Surface Electrochemistry