Electrocatalytic properties of ternary oxide mixtures of composition Ru0.3Ti(0.7−x)CexO2: oxygen evolution from acidic solution

Faria, Luiz A. De; Boodts, Julien Françoise Coleta; Trasatti, S.

doi:10.1007/bf00243745

Cited by 133 publications

(101 citation statements)

References 8 publications

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“…17,[24][25][26] These investigations also show that for this kind of electrode material the main contribution to the total resistance of the system comes from the solution resistance between the working electrode and the Luggin capillary.…”

Section: Tafel Linesmentioning

confidence: 72%

Chlorine evolution reaction at Ti/(RuO2+Co3O4) electrodes

Silva¹,

Boodts²,

Faria³

2003

J. Braz. Chem. Soc.

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A investigação do mecanismo eletródico e das propriedades eletrocatalíticas da reação de desprendimento de cloro, RDCl, foi executada em eletrodos mistos de óxido do tipo rutila e espinélio de composição nominal Ti/[RuO 2 (x)+Co 3 O 4 (1-x)]. Os eletrodos foram preparados por decomposição térmica (T calc. = 470 o C; t calc. = 1h), com x variando entre 0 e 1 mudado em intervalos de 0,1. O estudo cinético foi executado registrando-se curvas corrente-potencial e pela determinação da ordem de reação com respeito aos íons H + e Cl -. Um valor constante do coeficiente de Tafel de 33 mV foi obtido para concentrações de RuO 2 entre 0-80% mol, aumentando para 40 mV para concentrações superiores de RuO 2 . Os dados experimentais apoiam o mecanismo de Erenburg e cols. para a RDCl. Um único mecanismo explica os resultados experimentais assumindo que o efeito "edge" influencie os valores do coeficiente de transferência eletrônica. A análise da atividade eletrocatalítica mostra que misturas de óxidos aumentam a atividade eletrocatalítica aparente.A systematic investigation of the mechanistic and electrocatalytic properties of the chlorine evolution reaction, ClER, on mixed rutile/spinel oxides of nominal composition Ti/ [RuO 2 (x)+Co 3 O 4 (1-x)] was done. Electrodes were prepared using the thermal decomposition procedure (T calc. = 470 o C; t calc. = 1h), with x varied between 0 and 1, changed in 0.1 steps. Kinetics were studied recording quasi-stationary current-potential curves and reaction order determined with respect to H + and Cl -. A constant Tafel slope of about 33 mV was found for the 0 -80 mol% RuO 2 concentration interval, increasing to 40 mV for higher RuO 2 contents. Experimental data support the mechanism originally proposed by Erenburg et al. for the ClER. The edge effect exerts an influence on the electronic transfer coefficient values. Analysis of the electrocatalytic activity reveals an increase in the apparent electrocatalytic activity for the mixed oxides.Keywords: cobalt, ruthenium, chlorine evolution, electrocatalytic activity IntroductionInvestigations of the chlorine evolution reaction, ClER, reveal this reaction is an "easy" one (low overpotential) characterised by a close to theoretical Tafel coefficient (30-40 mV). [1][2][3][4] Normally the ClER does not show a significant dependence on the nature of the electrode material. 1 However, the electrode kinetics can present a dependence on such parameters as the electrode morphology (e.g. roughness, porosity) and the electrolyte pH. 5 The ClER is thermodynamically unfavoured (E o = 1.36V(vs. RHE)) compared to the oxygen evolution reaction, OER, (E o = 1.23V(vs. RHE)). However, chlorine can be produced from aqueous solutions with high current efficiency, especially at the lower pH-values of the electrolyte, due to the significant overpotential displayed by most electrode materials for the OER. 6 However, OER remains a side reaction during chlorine evolution, affecting directly the purity of the Cl 2 produced. 6,7 So, electrode selectivity for the ClER re...

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Section: Tafel Linesmentioning

confidence: 72%

Chlorine evolution reaction at Ti/(RuO2+Co3O4) electrodes

Silva¹,

Boodts²,

Faria³

2003

J. Braz. Chem. Soc.

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“…It is related to the deposition of the oxide as a very fine crystallite structure during the thermal decomposition of the precursors, due to the non-intimate mixing between the individual components. [11][12][13][14] Figure 4 also shows that, after extensive oxygen evolution (Tafel experiments), the values of q a slightly increase. This behavior is explained by Boodts and collaborators [11][12][13][14][15][16] as a result of an increase of the degree coverage of the electrode surface by the active species OH, resulting from water discharge, leading to additional activation of the surface sites.…”

Section: Electrochemical Measurementsmentioning

confidence: 80%

“…Therefore, dlog i/pH = 0. As pointed by Boodts and collaborators, [11][12][13][14][15][16] the observed reaction order is that at constant overpotential [n(H + ) h ] and not at constant potential [n(H + ) E ], since the reference electrode used was the hydrogen electrode in the same solution. The chemically significant reaction order is n(H + ) E which is related to n(H + ) h by the equation:…”

Section: Electrochemical Measurementsmentioning

confidence: 98%

“…With a value of 60 mV The reaction mechanism is invariant with overpotential and oxide composition, as shown by the Tafel slope and the reaction order. Trasatti and collaborators 14 suggested that the value of 60 mV decade -1 for a Tafel slope is related to the formation of intermediate S-OH as an unstable species, which rearranges via a surface reaction (spillover). The step reaction and Tafel slope for the mechanism is shown in Table 1.…”

Section: Electrochemical Measurementsmentioning

confidence: 99%

“…10 A third component can be added to the electrocatalyst layer to modify the electrochemical and electrocatalytical properties of the electrodes. Boodts and Trasatti [11][12][13][14][15][16] have carried out systematic investigations of the physicochemical and electrochemical properties of ternary DSA electrodes using PtO 2 , CeO 2 and SnO 2 as the third component. The methodology used by these authors is to substitute TiO 2 by one of these oxides in the 30 mol % RuO 2 + 70 mol %TiO 2 or 30 mol % IrO 2 + 70 mol % TiO 2 systems.…”

Section: Introductionmentioning

confidence: 99%

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Surface Characterization and Electrocatalytic Properties of the Ti/Ir0.3Ti(0.7-x)Pb x O2-Coated Electrodes for Oxygen Evolution Reaction in Acidic Media

Oliveira-Sousa¹,

Lima‐Neto²

2002

J. Braz. Chem. Soc.

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Neste trabalho é feita uma investigação sistemática de caracterização morfológica e da atividade eletrocatalítica de eletrodos de Ti revestidos com camadas de Ir 0.3 Ti (0.7-x) Pb x O 2 (0 £ x £ 0,7), usando a reação de desprendimento de oxigênio (RDO), em meio de H 2 SO 4 0,5 mol dm -3 , como modelo. Os eletrodos foram preparados pela decomposição térmica de IrCl 3 , TiCl 3 e Pb(NO 3 ) 2 a 600 °C por 1 h usando Ti como suporte. A difração de raios-X mostrou que a camada é cristalina e permitiu identificar a presença dos correspondentes óxidos nas camadas. A caracterização da morfologia superficial das amostras, antes e após uso sob desprendimento de oxigênio (experimento de Tafel), foi feita por microscopia eletrônica de varredura (MEV). As análises das micrografias mostram que a RDO promove a dissolução da camada de óxido, indicando que o mecanismo de desativação destes eletrodos está associado à dissolução da camada. Os voltamogramas cíclicos obtidos em H 2 SO 4 0.5 mol dm -3 a 20 mV s -1 , à temperatura ambiente, mostram que o par redox Ir 3+ /Ir 4+ controla a eletroquímica superficial dos eletrodos. Os valores de carga anódica são relacionados à área ativa dos eletrodos e mostram que esta aumenta com teor de Pb na camada, atingindo um máximo em 50% de Pb. Após a RDO, a área superficial das camadas aumenta. Os valores dos coeficientes de Tafel são independentes do teor de Pb na camada com valores de aproximadamente 60 mV decada -1 , sugerindo que somente sítios de Ir são ativos para a RDO. Os valores de corrente normalizadas (i/q a ) mostram alguma inibição da RDO quando TiO 2 é substituído por PbO 2 , sugerindo que esse óxido pode ser uma boa escolha para melhorar a seletividade do sistema. A ordem de reação com relação à concentração de íons H + é zero a sobrepotencial e força iônica constantes. Os valores da inclinação de Tafel e ordem de reação indicam que a RDO ocorre por um único mecanismo.In this work a systematic investigation was carried out of the surface characterization and electrocatalytic activity of Ti/Ir 0.3 Ti (0.7-x) Pb x O 2 -coated electrodes (0 £ x £ 0.7), using the oxygen evolution reaction (OER) in 0.5 mol dm -3 H 2 SO 4 as model. The electrodes were prepared by thermal decomposition of IrCl 3 , TiCl 3 and Pb(NO 3 ) 2 at 600 °C for 1 h using Ti as support. X-ray diffraction shows that the layers are crystalline and that the corresponding metal oxides are present. The surface morphology of the samples, before and after use under extensive oxygen evolution (Tafel experiment), was characterized by Scanning Electron Microscopy and the micrograph analyses show that the OER promotes the dissolution of the oxide layer. The redox processes occurring on the surface were characterized by cyclic voltammetry at 20 mV s -1 in 0.5 mol dm -3 aqueous H 2 SO 4 , at room temperature, and were controlled by the Ir 3+ /Ir 4+ couple. The measured anodic voltammetric charge is related to the active area of the electrode showing that the replacement of TiO 2 by PbO 2 increases the surface area with the highe...

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Recent Development of Oxygen Evolution Electrocatalysts in Acidic Environment

et al. 2021

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a-d) Reproduced with permission. [61] Copyright 2017, Springer Nature. e) Possible OER routes on Zn 0.2 Co 0.8 O 2 with LOM mechanism. [59] Copyright 2019, Springer Nature. f) Scheme representing the proposed OER mechanism on the surface of La 2 LiIrO 6 in acid. Reproduced with permission. [66] Copyright 2016, Nature Publishing Group. g) The mechanism suggested for amorphous iridium oxide and leached perovskites with participation of activated oxygen in the reaction forming oxygen vacancies. Reproduced with permission. [51] Copyright 2018, Springer Nature.

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Electrocatalytic properties of ternary oxide mixtures of composition Ru0.3Ti(0.7−x)CexO2: oxygen evolution from acidic solution

Cited by 133 publications

References 8 publications

Chlorine evolution reaction at Ti/(RuO2+Co3O4) electrodes

Chlorine evolution reaction at Ti/(RuO2+Co3O4) electrodes

Surface Characterization and Electrocatalytic Properties of the Ti/Ir0.3Ti(0.7-x)Pb x O2-Coated Electrodes for Oxygen Evolution Reaction in Acidic Media

Recent Development of Oxygen Evolution Electrocatalysts in Acidic Environment

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