Electroreduction of oxygen on Co-based catalysts: determination of the parameters affecting the two-electron transfer reaction in an acid medium

Marcotte, S.; Villers, Dominique; Guillet, Nicolas; Roué, Lionel; Dodelet, J. P.

doi:10.1016/j.electacta.2004.07.029

Cited by 120 publications

(90 citation statements)

References 43 publications

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“…Also, the bell-shaped curve of the ring current is characteristic of hydrogen peroxide produced on non-noble metal catalysts and activated carbon. 20 The number of electrons transferred (n) and the percentage of hydrogen peroxide produced (% H 2 O 2 ) can be determined by the following equations: 20,21 where N, I D , and I R are the collection efficiency, disk current, and ring current, respectively. We assumed the collection efficiency to be a constant at an estimated value of 0.25 for all the catalysts studied.…”

Section: Resultsmentioning

confidence: 99%

“…The electrocatalytic activity of the modified carbon was studied using the rotating ring disk electrode (RRDE) technique. [18][19][20][21] Briefly, a rotating ring disk electrode from Pine Instruments employing a glassy carbon disk (5 mm o.d.) and Pt ring (5.52 mm i.d., 7.16 o.d.)…”

Section: Experimental Approachmentioning

confidence: 99%

“…The net faradic current was obtained by subtracting the background capacitive current from the N 2 CV. 20 All measurements were obtained with a bipotentiostat (model AFRDE from Pine Instruments).…”

Section: Experimental Approachmentioning

confidence: 99%

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O₂ Reduction on Graphite and Nitrogen-Doped Graphite: Experiment and Theory

Sidik¹,

Anderson²,

Subramanian³

et al. 2006

J. Phys. Chem. B

609

488

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An experimental and theoretical study of electroreduction of oxygen to hydrogen peroxide is presented. The experimental measurements of nitrided Ketjenblack indicated an onset potential for reduction of approximately 0.5 V (SHE) compared to the onset potential of 0.2 V observed for untreated carbon. Quantum calculations on cluster models of nitrided and un-nitrided graphite sheets show that carbon radical sites formed adjacent to substitutional N in graphite are active for O 2 electroreduction to H 2 O 2 via and adsorbed OOH intermediate. The weak catalytic effect of untreated carbon is attributed to weaker bonding of OOH to the H atom-terminated graphite edges. Substitutional N atoms that are far from graphite sheet edges will be active, and those that are close to the edges will be less active. Interference from electrochemical reduction of H atoms on the reactive sites is considered, and it is shown that in the potential range of H 2 O 2 formation the reactive sites are not blocked by adsorbed H atoms.

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Section: Resultsmentioning

confidence: 99%

Section: Experimental Approachmentioning

confidence: 99%

See 1 more Smart Citation

O₂ Reduction on Graphite and Nitrogen-Doped Graphite: Experiment and Theory

Sidik¹,

Anderson²,

Subramanian³

et al. 2006

J. Phys. Chem. B

609

488

View full text Add to dashboard Cite

show abstract

“…Therefore, an adsorption model must be incorporated into the reaction system. For oxygen and peroxide, the Langmuir adsorption coefficients, K o,2 and K p,2 , may be defined as: [15] where θ o,2 and θ p,2 are the surface fractions of oxygen and peroxide respectively on the sites involved in indirect ORR pathway (site 2), θ v,2 is the surface availability of this adsorption site, and C o , C p are oxygen and peroxide concentrations near the surface. If the reactions two and three are first order with respect to the surface species (θ o,2 and θ p,2 ) the rate laws can be re-written:…”

Section: Resultsmentioning

confidence: 99%

“…Previous RRDE studies of non-precious metal catalysts for oxygen reduction 1,[12][13][14][15][16][17] generally show an increase in peroxide generation by one to two percent per 0.1 mg/cm 2 decrease in loading. 1,13,17,18 This suggests that peroxide detection at the ring could be artificially low because inner layers may further reduce peroxide to water, decreasing peroxide at the ring and increasing total disk current.…”

mentioning

confidence: 99%

Analysis of Adsorption Effects on a Metal-Nitrogen-Carbon Catalyst Using a Rotating Ring-Disk Study

Leonard

Barton

2014

J. Electrochem. Soc.

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A steady-state, rotating ring disk study of the oxygen reduction reaction (ORR) was conducted in acid environment using a pyrolyzed metal/nitrogen/carbon (MNC) electrocatalyst. Analysis of peroxide generation indicates that ORR proceeds both via a direct fourelectron pathway to water at high potentials and an indirect peroxide pathway at low potentials. Above 0.6 V vs RHE, the direct four-electron pathway to water without a desorbing intermediate dominates oxygen reduction because peroxide generation is inhibited due to site availability. In contrast, at potentials below 0.6 V, oxygen reduction begins to shift to the indirect peroxide pathway due to fast kinetics and higher site availability. The net peroxide generation remains relatively low over the entire range due to reduction of peroxide to water.

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Time to move beyond transition metal — N — C catalysts for oxygen reduction

Garsuch

Bonakdarpour

Liu

et al. 2010

Handbook of Fuel Cells

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FeNC and CoNC electrocatalysts have been studied for many years by numerous research groups. Various synthesis routes, involving different precursors, different temperatures, etc., have been employed, but “successful” catalysts share the common features of Fe or Co, N, and C and a heat‐treatment step to around 800 °C. It is our contention that the thermodynamics, not the details of the precursors or synthesis steps, determines the local atomic arrangement of Fe, N, and C or Co, N, and C in these catalysts after heating and, as such, the catalysts prepared by all researchers in this field are basically the same. In this article, compelling evidence for this contention is presented. These catalysts, presumably all, share the same advantages, which include reasonable activity, and disadvantages, which include short lifetime. Therefore, the study of FeNC and CoNC catalysts is overpopulated by researchers, and most should probably shift their focus to the search for new nonnoble metal catalysts involving other elements in the periodic table.

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Electroreduction of oxygen on Co-based catalysts: determination of the parameters affecting the two-electron transfer reaction in an acid medium

Cited by 120 publications

References 43 publications

O₂ Reduction on Graphite and Nitrogen-Doped Graphite: Experiment and Theory

O₂ Reduction on Graphite and Nitrogen-Doped Graphite: Experiment and Theory

Analysis of Adsorption Effects on a Metal-Nitrogen-Carbon Catalyst Using a Rotating Ring-Disk Study

Time to move beyond transition metal — N — C catalysts for oxygen reduction

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Electroreduction of oxygen on Co-based catalysts: determination of the parameters affecting the two-electron transfer reaction in an acid medium

Cited by 120 publications

References 43 publications

O2 Reduction on Graphite and Nitrogen-Doped Graphite: Experiment and Theory

O2 Reduction on Graphite and Nitrogen-Doped Graphite: Experiment and Theory

Analysis of Adsorption Effects on a Metal-Nitrogen-Carbon Catalyst Using a Rotating Ring-Disk Study

Time to move beyond transition metal — N — C catalysts for oxygen reduction

Contact Info

Product

Resources

About

O₂ Reduction on Graphite and Nitrogen-Doped Graphite: Experiment and Theory

O₂ Reduction on Graphite and Nitrogen-Doped Graphite: Experiment and Theory