Kinetic Model of Platinum Dissolution in PEMFCs

Darling, Robert M.; Meyers, James F.

doi:10.1149/1.1613669

Cited by 670 publications

(640 citation statements)

References 6 publications

(7 reference statements)

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“…As small particles possess high surface-area-to-volume ratio, they tend to grow to lower their surface free energy [37,38]. On the other hand, under potential cycling, Pt particles encounter a Pt dissolution/re-deposition process [9,39,40]. During the positive scan, Pt surface atoms are oxidized and some of them dissolve into the electrolyte, while at the negative scan the surface atoms are reduced and the Pt ions re-deposit onto the surface [9,39,40].…”

Section: Fuel Cell Durabilitymentioning

confidence: 99%

“…On the other hand, under potential cycling, Pt particles encounter a Pt dissolution/re-deposition process [9,39,40]. During the positive scan, Pt surface atoms are oxidized and some of them dissolve into the electrolyte, while at the negative scan the surface atoms are reduced and the Pt ions re-deposit onto the surface [9,39,40]. Since the atoms at edges and corners (defects) on the Pt surface are low coordinated, they have strong affinity to oxygenated species generated in the electrode reaction, and they are more apt to undergo the Pt dissolution process compared to the face atoms.…”

Section: Fuel Cell Durabilitymentioning

confidence: 99%

See 1 more Smart Citation

Effect of particle size on the activity and durability of the Pt/C electrocatalyst for proton exchange membrane fuel cells

Zhang

Zhong

et al. 2012

Applied Catalysis B: Environmental

166

110

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a b s t r a c tCarbon supported Pt (Pt/C) with various average particle sizes ranging from sub 3 nm to 6.5 nm were in situ prepared and characterized at the cathode of proton exchange membrane fuel cells (PEMFCs). A clear Pt particle size effect on both the catalytic activity for oxygen reduction reaction (ORR) and the durability of the electrocatalyst was revealed. With the Pt particle size increase, both the surface specific activity and the electrochemical stability of Pt/C improved; however, the mass specific activity of Pt/C is balanced by the electrochemical surface area loss. The reduced occupation of corner and edge atoms on the Pt surface during the Pt particle size increase is believed to weaken the adsorption of the oxygenated species on Pt, and thereafter releases more available active sites for ORR and also renders the Pt surface a stronger resistance against potential cycling. It is therefore proposed that by designing the Pt microstructure with more face atoms on the surface, cathode electrocatalyst with both improved activity and enhanced durability would be developed for PEMFCs.

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Section: Fuel Cell Durabilitymentioning

confidence: 99%

Section: Fuel Cell Durabilitymentioning

confidence: 99%

Effect of particle size on the activity and durability of the Pt/C electrocatalyst for proton exchange membrane fuel cells

Zhang

Zhong

et al. 2012

Applied Catalysis B: Environmental

166

110

View full text Add to dashboard Cite

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“…It is known that the corrosion rate of carbon itself is low even under PEFC operating conditions, but the rate is accelerated by Pt catalyst loading with increasing temperature and potential [2,[7][8][9]. The corrosion of the carbon support leads to agglomeration (sintering) and/or a detachment of Pt nanoparticles from the surface, together with a reduction of the electronic conductance in the CL [1,[10][11][12][13][14][15][16][17]. Thus, the ECA for the ORR decreases significantly.…”

Section: Introductionmentioning

confidence: 99%

Oxygen Reduction Reaction Activity and Durability of Pt Catalysts Supported on Titanium Carbide

et al. 2015

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Abstract:We have prepared Pt nanoparticles supported on titanium carbide (TiC) (Pt/TiC) as an alternative cathode catalyst with high durability at high potentials for polymer electrolyte fuel cells. The Pt/TiC catalysts with and without heat treatment were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). Hemispherical Pt nanocrystals were found to be dispersed uniformly on the TiC support after heat treatment at 600 °C in 1% H2/N2 (Pt/TiC-600 °C). The electrochemical properties (cyclic voltammetry, electrochemically active area (ECA), and oxygen reduction reaction (ORR) activity) of Pt/TiC-600 °C and a commercial Pt/carbon black (c-Pt/CB) were evaluated by the rotating disk electrode (RDE) technique in 0.1 M HClO4 solution at 25 °C. It was found that the kinetically controlled mass activity for the ORR on Pt/TiC-600 °C at 0.85 V (507 A g ). Moreover, the durability of Pt/TiC-600 °C examined by a standard potential step protocol (E = 0.9 V↔1.3 V vs. RHE, holding 30 s at each E) was much higher than that for c-Pt/CB. OPEN ACCESSCatalysts 2015, 5 967

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“…5,15 Mathematical models were developed by hypothesizing several surface species and their rates for formation and reduction. 5,[16][17][18] The effect of parameters in the models on voltammograms was discussed, or the models were validated by appropriate selection of parameters that reproduce experimental voltammograms. Even by the latest model, however, some features in the cyclic voltammograms (CVs) and oxide growth rate are still not well reproduced.…”

Section: Introductionmentioning

confidence: 99%

Kinetics of Oxide Formation and Reduction at Pt Catalyst in Polymer Electrolyte Fuel Cells

Suzuki

Morimoto

2016

Electrochemistry

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The rates of oxide formation and reduction at platinum catalyst in polymer electrolyte fuel cells were measured potentiostatically with various potential histories to reveal the kinetics of the reactions. Reaction rates during potential holds after an anodic or a cathodic sweep were examined as a function of potential and PtOH-equivalent oxide coverage. At 500 and 600 mV vs. RHE, the oxide coverage increased or decreased with increasing time depending on the potential history; this result indicates that the surfaces with different potential histories have different surface states. Oxide reduction rates were compared by changing potential and duration for oxide formation to attain the same coverage before the reduction. Oxide formed at a higher potential for a shorter period of time was easier to reduce than oxide formed at a lower potential for a longer period of time. This indicates that the oxide-formation potential and/or oxide-formation time are factors to determine the oxide reduction rate.

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Kinetic Model of Platinum Dissolution in PEMFCs

Cited by 670 publications

References 6 publications

Effect of particle size on the activity and durability of the Pt/C electrocatalyst for proton exchange membrane fuel cells

Effect of particle size on the activity and durability of the Pt/C electrocatalyst for proton exchange membrane fuel cells

Oxygen Reduction Reaction Activity and Durability of Pt Catalysts Supported on Titanium Carbide

Kinetics of Oxide Formation and Reduction at Pt Catalyst in Polymer Electrolyte Fuel Cells

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