Oxygen evolution at RuO2(x)+Co3O4(1−x) electrodes from acid solution

Silva, Leonardo M. Da; Boodts, Julien Françoise Coleta; Faria, Luiz A. De

doi:10.1016/s0013-4686(00)00716-7

Cited by 164 publications

(104 citation statements)

References 17 publications

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Section: Analysis Of the Electrocatalytic Activitysupporting

confidence: 55%

“…Figure 8A shows maximum apparent electrocatalytic activity for the ClER is observed in the 50-100 mol% RuO 2 range, differently from the OER for which maximum apparent and true electrocatalytic activity is observed in the 20-40 mol% RuO 2 range. 17 These results support that the more active electrodes for the ClER are the least active for the OER, supporting coating with 50-100 mol% RuO 2 contents present a better selectivity for chlorine production.The inset in Figure 8B shows a sudden increase in j/q aratio with the introduction of only 10mol% RuO 2 . This finding is in good agreement with results reported by Shalaginov et al 15 , who found that doping titaniumsupported cobalt oxide films (Co 3 O 4 ) with small amounts of ruthenium leads to a significant increase of the electrocatalytic activity for ClER.…”

supporting

confidence: 55%

“…This behaviour is rather different from the OER, for which a strong dependence on potential and nominal electrode composition was observed, 17 showing the ClER is a much less complex electrode process. …”

Section: Tafel Linesmentioning

confidence: 73%

“…A strategy to compatibilise the lower cost of the spinel oxides with their instability under acid conditions is the formation of mixed rutile + spinel oxides. [17][18][19] Recent studies of the OER on Ti/[RuO 2 +Co 3 O 4 ] coatings by Da Silva et al 17,20,21 showed these mixed oxides present interesting fundamental properties; stabilise the spinel under acid conditions and show an increase of the true electrocatalytic activity. Now we report the results of a detailed investigation of the kinetics and electrocatalytic properties of the Ti/[RuO 2 +Co 3 O 4 ] system for the ClER.…”

Section: Introductionmentioning

confidence: 99%

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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: Analysis Of the Electrocatalytic Activitysupporting

confidence: 55%

supporting

confidence: 55%

Section: Tafel Linesmentioning

confidence: 73%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

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

Silva¹,

Boodts²,

Faria³

2003

J. Braz. Chem. Soc.

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show abstract

“…The promising applications of RuO 2 range from electronic advancement in integrated circuit, film resistors, ferroelectric films to high-temperature superconducting thin films in forming a buffer layer [3][4][5]. The oxygen evolution reaction (OER) occurs at a suitable reaction rate on noble metals (e.g., Pt, Au, Ir, Ru and Ag), while metal oxides (RuO 2 and IrO 2 ) are generally more active electrocatalysts for this reaction than metal electrodes [6][7][8]. RuO 2 as active and stable anodes can be used for chlorine generation in the chlor-alkali industry, oxygen or hydrogen evolution in water electrolysis [9,10], CO 2 reduction in photocatalysis, and CO oxidation in sensors [1,11,12].…”

Section: Introductionmentioning

confidence: 99%