Self-assembled polyelectrolyte multilayered films on Nafion with lowered methanol cross-over for DMFC applications

Deligöz, Hüseyin; Yılmaztürk, Serpil; Karaca, Tuba; Özdemi̇r, Hasan; Koç, Serkan Naci; Öksüzömer, M.A. Faruk; Durmuş, Ali; Gürkaynak, M. Ali

doi:10.1016/j.memsci.2008.10.055

Cited by 70 publications

(37 citation statements)

References 24 publications

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“…In order to derive Equation (11), the following expression is obtained applying the condition n = 1 to Equation (4) …”

Section: Appendixmentioning

confidence: 99%

“…For kinetic studies, the electrocatalysts are usually covered by a protonic conductor membrane to reproduce the conditions observed in the fuel cell. In most cases a unique membrane was used [4][5][6][7][8][9][10], but recently new arrangements with a multilayer membrane were proposed [11][12][13]. However, the formalism for an appropriate interpretation of these results has not been developed yet.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Kinetic Study of the Hydrogen Oxidation Reaction on Membrane Coated Electrodes. Part I: Theoretical Aspects

Marozzi¹,

Chialvo²,

Chialvo

2009

TOELECJ

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Abstract:A generalized theoretical analysis of the kinetics of the hydrogen oxidation reaction under the VolmerHeyrovsky-Tafel mechanism on an electrode covered by polymeric films is presented. The treatment includes the diffusion of the molecular hydrogen through the electrolyte solution, as well as through the different layers and interfaces. On the light of the resulting expressions, the applicability of the Levich-Koutecky diagrams for the determination of the kinetic current densities was critically analyzed.

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“…In order to derive Equation (11), the following expression is obtained applying the condition n = 1 to Equation (4) …”

Section: Appendixmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Kinetic Study of the Hydrogen Oxidation Reaction on Membrane Coated Electrodes. Part I: Theoretical Aspects

Marozzi¹,

Chialvo²,

Chialvo

2009

TOELECJ

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“…Based on the optimized DMFC structure, a passive DMFC fed with 20 M methanol exhibits a peak power density of 42 mW cm -2 at 25°C, and no obvious performance degradation after over 90 h continuous operation at a constant current density of 40 mA cm -2 . [12][13][14][15][16]. Therefore, in order to take advantage of the high energy density of methanol, high concentration methanol should be stored in the fuel cartridge and in the meantime, the methanol concentration should be diluted to an appropriate level at the aCL [17,18] when the passive DMFC works.…”

Section: Introductionmentioning

confidence: 99%

Development of a Self‐Adaptive Direct Methanol Fuel Cell Fed with 20 M Methanol

Guo¹,

Zhang²,

Jiang³

et al. 2013

Fuel Cells

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A passive and self‐adaptive direct methanol fuel cell (DMFC) directly fed with 20 M of methanol is developed for a high energy density of the cell. By using a polypropylene based pervaporation film, methanol is supplied into the DMFC's anode in vapor form. The mass transport of methanol from the cartridge to the anodic catalyst layer can be controlled by varying the open ratio of the anodic bipolar plate and by tuning the hydrophobicity of anodic diffusion layer. An effective back diffusion of water from the cathode to the anode through Nafion film is carried out by using an additive microporous layer in the cathode that consists of 50 wt.% Teflon and KB‐600 carbon. Accordingly, the water back diffusion not only ensures the water requirement for the methanol oxidation reaction but also reduces water accumulation in the cathode and then avoids serious water flooding, thus improving the adaptability of the passive DMFC. Based on the optimized DMFC structure, a passive DMFC fed with 20 M methanol exhibits a peak power density of 42 mW cm–2 at 25 °C, and no obvious performance degradation after over 90 h continuous operation at a constant current density of 40 mA cm–2.

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“…This may be exploited as an approach for hindering the crossover effect since it should reduce cell depolarization and cathode poisoning. [15][16][17][18] …”

Section: Introductionmentioning

confidence: 99%

“…This may be exploited as an approach for hindering the crossover effect since it should reduce cell depolarization and cathode poisoning. [15][16][17][18] Experimental LbL films were assembled onto Nafion ® membranes. The LbL films were obtained via ionic attraction of oppositely charged materials, by alternate immersion of the Nafion ® membrane into the chitosan and PVS dispersions (HCl solution, pH 2, 1.6 g L −1 ) for 1 min.…”

mentioning

confidence: 99%

Self-assembled films from chitosan and poly(vinyl sulfonic acid) on Nafion® for direct methanol fuel cell

Vinhola¹,

Facci²,

Dias³

et al. 2012

J. Braz. Chem. Soc.

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Filmes de quitosana/poli(ácido vinilsulfônico) (PVS) foram depositados sobre membranas de Nafion ® a partir do método camada por camada (LbL), visando o seu uso em células a combustível de metanol direto (DMFC). Métodos computacionais e espectros de infravermelho com transformada de Fourier (FTIR) sugerem a formação de um par iônico entre o grupo sulfônico do PVS e o grupo amino protonado da quitosana, o qual promove o crescimento dos filmes LbL sobre a membrana de Nafion ® , assim como impede parcialmente a passagem de metanol. Experimentos de cronopotenciometria e varredura linear de potencial foram realizados a fim de se investigar a passagem de metanol através das membranas de Nafion ® e quitosana/PVS/Nafion ® em uma célula a diafragma. Os valores de resistência iônica associada ao transporte de prótons nas membranas de Nafion ® e quitosana/PVS/Nafion ® são próximos, de acordo com as medidas de impedância elétrica devido à pequena espessura do filme LbL. Assim, espera-se um melhor desempenho da DMFC, uma vez que a resistência do filme automontado é insignificante comparada ao resultado associado à passagem de metanol através das membranas.Chitosan/poly(vinyl sulfonic acid) (PVS) films have been prepared on Nafion ® membranes by the layer-by-layer (LbL) method for use in direct methanol fuel cell (DMFC). Computational methods and Fourier transform infrared (FTIR) spectra suggest that an ionic pair is formed between the sulfonic group of PVS and the protonated amine group of chitosan, thereby promoting the growth of LbL films on the Nafion ® membrane as well as partial blocking of methanol. Chronopotentiometry and potential linear scanning experiments have been carried out for investigation of methanol crossover through the Nafion ® and chitosan/PVS/Nafion ® membranes in a diaphragm diffusion cell. On the basis of electrical impedance measurements, the values of proton resistance of the Nafion ® and chitosan/PVS/Nafion ® membranes are close due to the small thickness of the LbL film. Thus, it is expected an improved DMFC performance once the additional resistance of the self-assembled film is negligible compared to the result associated with the decrease in the crossover effect.Keywords: chitosan, direct methanol fuel cell, proton exchange membrane, crossover effect, methanol permeability IntroductionDirect methanol fuel cells (DMFCs) are the most promising portable, stationary power sources with application in several fields. In these cells, methanol and air are continually injected into the anode and cathode compartments, respectively, thus providing energy with high efficiency. Methanol has been largely employed as fuel once it is abundant and inexpensive. Even though DMFCs produce carbon dioxide, which is released into the atmosphere, their high efficiency guarantees low pollution as compared to other power sources. [1][2][3] One drawback of DMFCs is the so-called crossover effect, through which methanol leaves the anodic compartment and crosses the proton exchange membrane (PEM), thereby promoting cell de...

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Self-assembled polyelectrolyte multilayered films on Nafion with lowered methanol cross-over for DMFC applications

Cited by 70 publications

References 24 publications

Kinetic Study of the Hydrogen Oxidation Reaction on Membrane Coated Electrodes. Part I: Theoretical Aspects

Kinetic Study of the Hydrogen Oxidation Reaction on Membrane Coated Electrodes. Part I: Theoretical Aspects

Development of a Self‐Adaptive Direct Methanol Fuel Cell Fed with 20 M Methanol

Self-assembled films from chitosan and poly(vinyl sulfonic acid) on Nafion® for direct methanol fuel cell

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