Electrochemical studies of DMFC anodes with different ionomer content

Kim, Joon-Hee; Ha, Heung Yong; Oh, In‐Hwan; Hong, Seung‐Chyul; Kim, H.N.; Lee, Ho‐In

doi:10.1016/j.electacta.2004.02.069

Cited by 42 publications

(18 citation statements)

References 15 publications

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“…The ionomer is used in order to increase the ionic conductivity of the electrode [ 32 -34 ] and improving the adhesion between the membrane material and the electrode layer. In the acidic MEAs Nafion ® dispersion is used and the optimum ionomer-carbon ratio depends on the carbon support of the catalyst particles: for carbon black (Vulcan) the optimized value for anodes is between 25-40 wt% [35][36][37][38] and in our experiments the aim is for 30 wt% ionomer. As for the less porous nano carbon supports (CNT and GNF) only limited optimization has been performed, however, in preliminary studies it has been found that higher (over 50 wt%)…”

Section: Direct Alcohol Fuel Cellmentioning

confidence: 99%

The correlation of electrochemical and fuel cell results for alcohol oxidation in acidic and alkaline media

Santasalo-Aarnio

Tuomi

Jalkanen

et al. 2013

Electrochimica Acta

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Section: Direct Alcohol Fuel Cellmentioning

confidence: 99%

The correlation of electrochemical and fuel cell results for alcohol oxidation in acidic and alkaline media

Santasalo-Aarnio

Tuomi

Jalkanen

et al. 2013

Electrochimica Acta

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“…However, when new carbon supported catalysts are tested in fuel cells, the usual approach is to use optimum compositions found for commercial carbon black (Vulcan) catalysts. The optimum ionomer-carbon ratio for these catalysts has been studied several times for DMFC MEAs in the past [29] [30][31] [32]. The optimum depends on the exact metal to carbon ratio and the method of MEA fabrication, but it is usually between 25-40 wt % of the total dry mass of the electrode.…”

Section: Introductionmentioning

confidence: 99%

The effect of Nafion content in a graphitized carbon nanofiber-based anode for the direct methanol fuel cell

Kanninen

Borghei

Ruiz

et al. 2012

International Journal of Hydrogen Energy

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The performance and stability of a direct methanol fuel cell (DMFC) with membrane electrode assemblies (MEA) using different Nafion ® contents (30, 50 and 70 wt % or MEA30, MEA50 and MEA70, respectively) and graphitized carbon nanofiber (GNF) supported PtRu catalyst at the anode was investigated by a constant current measurement of 9 days (230 h) in a DMFC and characterization with various techniques before and after this measurement. Of the pristine MEAs, MEA50 reached the highest power and current densities. During the 9-day measurement at a constant current, the performance of MEA30 decreased the most (-124 µV h -1 ), while the MEA50 was almost stable (-11 µV h -1 ) and performance of MEA70 improved (+115 µV h -1 ). After the measurement, the MEA50 remained the best MEA in terms of performance. The optimum anode Nafion content for commercial Vulcan carbon black supported PtRu catalysts is between 20 and 40 wt %, so the GNF-supported catalyst requires more Nafion to reach its peak power. This difference is explained by the tubular geometry of the catalyst support, which requires more Nafion to form a penetrating proton conductive network than the spherical Vulcan.Mass transfer limitations are mitigated by the porous 3D structure of the GNF catalyst layer and possible changes in the compact Nafion filled catalyst layers during constant current production.2

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“…A further increase in the Nafion content of the anode may further increase the DMFC performance. For example, for a DMFC anode with 3 mg of PtRu (53.3 wt.% PtRu/C) per cm 2 , the optimal Nafion content was reported as 60 wt.% [30]. Our catalyst loading on carbon being lower, and thus our catalyst layer thickness being more important, the optimal Nafion content may be even higher than 60 wt.%.…”

Section: R P and R P Values For Stenciled Vs Sprayed Anodesmentioning

confidence: 99%

“…The influence of the ionomer content in the catalysts layers on the DMFC performance has been studied for carbon supported [30] and unsupported [2,30,31] Pt-Ru catalysts. The performance of a DMFC is dependent on the Nafion content.…”

Section: R P and R P Values For Stenciled Vs Sprayed Anodesmentioning

confidence: 99%

DMFC electrode preparation, performance and proton conductivity measurements

et al. 2008

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A method that involves stenciling electrodes using dry powders for fuel cells is described and compared to anodes and cathodes prepared by the traditional spraying method using catalyst inks. Methods to determine the proton conductivity of the DMFC anode layer are also discussed. The stenciling method allows for the preparation of highly reproducible membrane electrode assemblies (MEAs) utilizing little waste material. MEAs can be prepared in a controlled manner using the stenciling technique. The resulting morphology of the as-prepared electrodes is observed to be dependent on the preparation method, while the thickness of the once hot-pressed catalyst layers appears to be independent of the preparation method. Stenciled anodes of the same catalyst loading were found to show a lower proton resistance (R p ) than sprayed anodes. However, the lower R p value was not sufficient to result in a measurable increase in the performance of a direct methanol fuel cell (DMFC); as in fact, the average steady-state DMFC performance was found to be the same using sprayed or stenciled electrodes. The DMFC performance was found to be strongly dependent on the Nafion content and large increases in the Nafion content were needed to increase the DMFC performance measurably. Even though thick electrodes were prepared in this work, the R p values of the stenciled anodes were found to be comparable to results reported in the literature for much thinner electrodes made using high metal catalyst loadings on carbon. This observation is most probably due to the higher Nafion content used in this work.

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Electrochemical studies of DMFC anodes with different ionomer content

Cited by 42 publications

References 15 publications

The correlation of electrochemical and fuel cell results for alcohol oxidation in acidic and alkaline media

The correlation of electrochemical and fuel cell results for alcohol oxidation in acidic and alkaline media

The effect of Nafion content in a graphitized carbon nanofiber-based anode for the direct methanol fuel cell

DMFC electrode preparation, performance and proton conductivity measurements

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