Humidity and Temperature Dependences of Oxygen Transport Resistance of Nafion Thin Film on Platinum Electrode

Kudo, Kenji; Jinnouchi, Ryosuke; Morimoto, Yu

doi:10.1016/j.electacta.2016.04.023

Cited by 167 publications

(221 citation statements)

References 58 publications

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“…Iden et al [27] proposed an alternative in-situ method based on gas crossover through the membrane to study hydrogen vs. oxygen transport resistances near the platinum surface. Also, ex-situ approaches using Nafion thin films cast on platinum electrodes have been demonstrated [28,29]. Finally, in one of the earlier studies, Yoon and Weber [30] modeled the extra resistance and demonstrated that due to isolated catalyst particles, the effective diffusion pathlength for the oxygen increased, which is somewhat similar to the analysis of Debe [31] who examined it from a probability perspective.…”

Section: Figure 1: Schematic Of Oxygen Diffusion Losses In a Fuel-celsupporting

confidence: 57%

Investigating fuel-cell transport limitations using hydrogen limiting current

Spingler

Phillips

Schuler

et al. 2017

International Journal of Hydrogen Energy

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Reducing mass-transport losses in polymer-electrolyte fuel cells (PEFCs) is essential to increase their power density and reduce overall stack cost. At the same time, cost also motivates the reduction in expensive precious-metal catalysts, which results in higher local transport losses in the catalyst layers. In this paper, we use a hydrogen-pump limitingcurrent setup to explore the gas-phase transport losses through PEFC catalyst layers and various gas-diffusion and microporous layers. It is shown that the effective diffusivity in the gas-diffusion layers is a strong function of liquid saturation. In addition, it is shown how the catalyst layer unexpectedly contributes significantly to the overall measured transport resistance. This is especially true at low catalyst loadings. It is also shown how the various losses can be separated into different mechanisms including diffusional processes and massdependent and independent ones, where the data suggests that a large part of the transport resistance in CLs cannot be attributed to a gas-phase diffusional process. The technique is promising for deconvoluting transport losses in PEFCs.2

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Section: Figure 1: Schematic Of Oxygen Diffusion Losses In a Fuel-celsupporting

confidence: 57%

Investigating fuel-cell transport limitations using hydrogen limiting current

Spingler

Phillips

Schuler

et al. 2017

International Journal of Hydrogen Energy

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“…This work is another indirect evidence that the origin of the OPL is related to oxygen transport in Nafion. Kudo et al [6] showed that the dominant part of the oxygen transport resistivity in the thin Nafion film is due to Pt/ionomer interface.…”

Section: Introductionmentioning

confidence: 99%

The effect of Nafion film on the cathode catalyst layer performance in a low–Pt PEM fuel cell

Kulikovsky

2019

Electrochemistry Communications

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A single-pore model for performance of the cathode catalyst layer (CCL) in a PEM fuel cell is developed. The model takes into account oxygen transport though the CCL depth and through the thin Nafion film, separating the pore from Pt/C species. Analytical solution to model equations reveals the limiting current density j lim N due to oxygen transport through the Nafion film. Further, j lim N linearly depends of the CCL thickness, i.e., the thinner the CCL, the lower j lim N . This result may explain unexpected lowering of low-Pt loaded catalyst layers performance, which has been widely discussing in literature.

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“…These effects are often discussed with strong interaction between platinum and the ionomer [9,10]. Sulfonic acid groups in ionomers are confirmed to specifically adsorb on the Pt surfaces and block the active sites of oxygen reduction reaction (ORR), and polytetrafluoroethylene(PTFE)-like main chains in ionomers are considered to be folded on the Pt surfaces and form a dense layer near the Pt surfaces, which hinders the oxygen transport to the Pt surfaces [11,12].…”

Section: Introductionmentioning

confidence: 99%

MgO-Templated Mesoporous Carbon as a Catalyst Support for Polymer Electrolyte Fuel Cells

2018

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An MgO-templated mesoporous carbon, CNovel ® , was employed as a catalyst support for the cathode of polymer electrolyte fuel cells (PEFCs) after modifying its dimensional, crystalline, surface and porous structures and the electrochemical oxygen reduction reaction (ORR) activities were examined by the thin-film rotating disk electrode (RDE) method and as well as the membrane electrode assembly (MEA) method. Although the catalytic activity of Pt on CNovel ® was comparable with that on a non-porous carbon, Vulcan ® , in the RDE configuration without Nafion ® , Pt/CNovel showed a considerably higher activity than Pt/Vulcan in the MEA condition with Nafion ® . The mechanism inducing this difference was discussed from the results of electrochemical surface area and sulfonic coverage measurements which suggested that Pt particles on inside pores of CNovel ® are not covered with Nafion ® ionomer while protons can still reach those Pt particles through water network. The MEA performance in the middle and high current-density regions was drastically improved by heat-treatment in air, which modified the pore structure to through-pored ones.

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Humidity and Temperature Dependences of Oxygen Transport Resistance of Nafion Thin Film on Platinum Electrode

Cited by 167 publications

References 58 publications

Investigating fuel-cell transport limitations using hydrogen limiting current

Investigating fuel-cell transport limitations using hydrogen limiting current

The effect of Nafion film on the cathode catalyst layer performance in a low–Pt PEM fuel cell

MgO-Templated Mesoporous Carbon as a Catalyst Support for Polymer Electrolyte Fuel Cells

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