Apparent enthalpies of activation of electrodic oxygen reduction at platinum in different current density regions—I. Acid solution

Šepa, D. B.; Vojnović, M.V.; Vračar, Lj.M.; Damjanović, A.

doi:10.1016/0013-4686(86)80067-6

Cited by 83 publications

(80 citation statements)

References 17 publications

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“…The value of the Tafel slope obtained (b = 55 mv dec -1 ) indicates Temkin adsorption isotherm [35][36][37]. The limiting current, I l is much higher (by a factor of more than 10 3 times) than that of the exchange current, I o [34,31].…”

Section: Resultsmentioning

confidence: 99%

Electrocatalytic reduction of oxygen at vapor phase polymerized poly(3,4-ethylene- dioxidethiophene) modified glassy carbon electrode

Wondimu¹,

Admassie²

2012

Bull. Chem. Soc. Eth.

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ABSTRACT. We successfully polymerized poly (3,4-ethylenedioxidethiophene) by vapor phase polymerization technique on rotating glassy carbon disk electrode. The catalytic activity of this electrode towards oxygen reduction reaction was investigated and showed remarkable activity. Rotating disk voltammetry was used to study the kinetics of oxygen reduction reaction by plotting Levich, Koutecky Levich and Tafel plots. It was found that the reduction was mixed diffusion and kinetic controlled. The O2 reduction underwent through four electron transfer reaction. The Tafel slope was obtained as 55 mV/dec. The limiting current density was higher by a factor of more than 10 3 times the exchange current density.

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Section: Resultsmentioning

confidence: 99%

Electrocatalytic reduction of oxygen at vapor phase polymerized poly(3,4-ethylene- dioxidethiophene) modified glassy carbon electrode

Wondimu¹,

Admassie²

2012

Bull. Chem. Soc. Eth.

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“…The provided above currents may be considered as exchange current of reaction (14). An analogous experimental effect is also observed in acidic media [33,44]. But in this case reaction (14) shall be transformed by accounting for a change of composition and structure of SBNO nanoclusters in acidic media [45].…”

Section: Discussion Of Orr Redox Cycle On Pt-electrodesmentioning

confidence: 99%

“…Reaction (14) corresponds to quasi-equilibrium state of oxygen electrode which, according to the experimental data, is set within 0.95-1.0 V (versus RHE) interval both in alkaline [9,25,26] and in acidic [33] electrolytes. By taking into account that ratio of surface states s,d Pt…”

Section: Discussion Of Orr Redox Cycle On Pt-electrodesmentioning

confidence: 99%

Oxygen-Containing Nanoclusters on the Surface of Pt-Electrodes and Oxygen Reduction Reaction in Alkaline Medium

Trunov

2018

International Journal of Electrochemistry

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Analysis of the role of oxygen-containing nanoclusters in oxygen reduction reaction (ORR) on Pt-electrodes in alkaline media is provided on the basis of the concept of electrochemical processes with slowed stage of consecutive heterogeneous chemical reaction (ConHCR). Under the ConHCR concept, the main factor determining the ORR characteristics is energetic inhomogeneity of electrode surface (EIES) according to Temkin. A new concept, according to which EIES is determined by the Gibbs energy of formation of oxygen-containing surface structures with inclusions of surface defects of the platinum crystal structure, s,d Pt, is formulated. A correlation between the level of EIES of Pt-electrodes and packing density of s,d Pt atoms on the surface of Pt(hkl) monocrystals is determined. The concept, according to which the stationary potential of ORR process is considered as a "mixed potential" of two reactions (electrochemical reduction of surface atom

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“…The values of i 0 were estimated at potential = 0 from the linear extrapolation of a Tafel slope of about -2.3 × 2RT/F (Langmuir region), which corresponded to the potential range of approximately 0.7-0.85 V vs. RHE (Sepa et al, 1986;Kabbabi et al, 1994;Limjeerajarus et al, 2009). Calculation of i 0 was performed in this potential range in order to avoid the effect of adsorbed oxygen-containing species, which caused the decrease in ORR rate by inhibiting the O 2 gas from the reaction site.…”

Section: Effect Of Homogenization Time On Structure Ofmentioning

confidence: 99%

Modeling for PEFC MEAs Based on Reaction Rate on Pt Surface and Microstructures of Catalyst Layers

Limjeerajarus

Nishiyama

Ohashi

et al. 2009

J. Chem. Eng. Japan

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A polymer electrolyte fuel cell membrane electrode assembly (PEFC MEA) model that focuses on the structural and reaction parameters of catalyst layers has been developed. The reaction and structural parameters were modeled independently by considering the oxygen reduction reaction (ORR) activity in terms of current per unit active surface area of Pt [A cm -2 -Pt]. The catalyst layer models were constructed based on an assumption of cylindrical secondary pore structure, which was verified by measuring the primary pore size using mercury porosimetry. We found that penetration of Nafion ® electrolyte into the primary pores of Pt/C catalysts was restricted, and thus diffusion and reaction in primary pores became negligible. Moreover, the experimental results demonstrated that for the same catalyst, ORR activity remained almost constant, irrespective of the agglomerate size (i.e., 2.7 × × × × × 10 -6 A cm -2 -Pt at 60°C for Pt/C TEC10E50E in this study). This supported our idea that reaction parameters and structural parameters should be considered independently in PEFC modeling. The cell performance predicted with the developed model was satisfactorily accurate as compared to that obtained from experiments. As a result, the modeling developed in this study can be used to construct simple PEFC models that yield results with good accuracy and can be a useful tool for the development of PEFCs in future.

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Apparent enthalpies of activation of electrodic oxygen reduction at platinum in different current density regions—I. Acid solution

Cited by 83 publications

References 17 publications

Electrocatalytic reduction of oxygen at vapor phase polymerized poly(3,4-ethylene- dioxidethiophene) modified glassy carbon electrode

Electrocatalytic reduction of oxygen at vapor phase polymerized poly(3,4-ethylene- dioxidethiophene) modified glassy carbon electrode

Oxygen-Containing Nanoclusters on the Surface of Pt-Electrodes and Oxygen Reduction Reaction in Alkaline Medium

Modeling for PEFC MEAs Based on Reaction Rate on Pt Surface and Microstructures of Catalyst Layers

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