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Meng-tsun Lin - One of the best experts on this subject based on the ideXlab platform.
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Suppressing Methanol Crossover with a deposited quaternary Pt-based catalyst on the Nafion surface
International Journal of Hydrogen Energy, 2014Co-Authors: Chieh-hao Wan, Meng-tsun Lin, Chien-heng LinAbstract:Abstract A Pt49–Ru35–Ir6–Os10 alloy layer is deposited on the Nafion membrane surface using the impregnation-reduction (IR) method to mitigate Methanol Crossover. The Methanol Crossover in a membrane electrode assembly (MEA) with a deposited Pt–Ru–Ir–Os layer is compared with a MEA without any layer on the proton exchange membrane (PEM). The deposited Pt49–Ru35–Ir6–Os10 layer functions like a catalytically active layer, a Methanol barrier, and an electrode all at the same time. This layer yields up to a 30% suppression of Methanol Crossover and a 15% improvement in fuel cell voltage performance (@170 mA cm−2) at 80 °C. The porous metal alloy layer with a high surface area of the Pt–Ru layer suppresses Methanol Crossover by the catalytic activity of the deposited layer. The presence of the solid Pt49–Ru35–Ir6–Os10 layer on the Nafion membrane surface reduces the proton conductivity of the PEM (from 10.75 to 4.22 mS cm−1), and degrades the output of the cell voltage performance (from 0.350 to 0.335 V at 90 mA cm−2 of current density) at 60 °C, even though Methanol Crossover is reduced (from 6928 ppm to 4415 ppm (CO2 concentration at cathode exhaust is proportional to Methanol Crossover)).
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mitigating Methanol Crossover with self assembled pt35 ru65 catalyst on nafion surface
Journal of Power Sources, 2013Co-Authors: Chieh-hao Wan, Meng-tsun LinAbstract:Abstract In this paper, 5 bi-layers of poly (allylamine hydrochloride) (PAH)/polystyrene sulfonic acid sodium salt (PSS) containing Pt35–Ru65 catalyst are self-assembled on the Nafion membrane surface through the layer-by-layer technique to mitigate Methanol Crossover. This composite Nafion membrane coated with Pt35–Ru65 catalyst with loading of 0.46 μg cm−2 and layer thickness of 87.5 nm on both surfaces suppresses the Methanol Crossover by 22% (on average), improves the power density by 48% (@0.30 V) and the potential by 22% (@62.5 mA cm−2) at 80 °C. The Pt35–Ru65 catalyst in the PAH/PSS bi-layers serves multiple roles at the same time – a catalytically active layer, a Methanol barrier and an electrode. In addition, the PAH/PSS bi-layers also acts as a Methanol barrier. These roles contribute to the suppression of Methanol Crossover and improvement of the output performance. Compared with Pt–Ru directly deposited on Nafion surface, the deposition of Pt35–Ru65 in this study has less negative impact on the cell performance because 1) lesser and thinner deposited Pt35–Ru65 is used, 2) the Pt35–Ru65 layer deposited on the additional PAH/PSS bi-layers does not reduce the proton conductivity of Nafion membrane.
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Mitigating Methanol Crossover with self-assembled Pt35–Ru65 catalyst on Nafion surface
Journal of Power Sources, 2013Co-Authors: Chieh-hao Wan, Meng-tsun LinAbstract:Abstract In this paper, 5 bi-layers of poly (allylamine hydrochloride) (PAH)/polystyrene sulfonic acid sodium salt (PSS) containing Pt35–Ru65 catalyst are self-assembled on the Nafion membrane surface through the layer-by-layer technique to mitigate Methanol Crossover. This composite Nafion membrane coated with Pt35–Ru65 catalyst with loading of 0.46 μg cm−2 and layer thickness of 87.5 nm on both surfaces suppresses the Methanol Crossover by 22% (on average), improves the power density by 48% (@0.30 V) and the potential by 22% (@62.5 mA cm−2) at 80 °C. The Pt35–Ru65 catalyst in the PAH/PSS bi-layers serves multiple roles at the same time – a catalytically active layer, a Methanol barrier and an electrode. In addition, the PAH/PSS bi-layers also acts as a Methanol barrier. These roles contribute to the suppression of Methanol Crossover and improvement of the output performance. Compared with Pt–Ru directly deposited on Nafion surface, the deposition of Pt35–Ru65 in this study has less negative impact on the cell performance because 1) lesser and thinner deposited Pt35–Ru65 is used, 2) the Pt35–Ru65 layer deposited on the additional PAH/PSS bi-layers does not reduce the proton conductivity of Nafion membrane.
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Mitigating Methanol Crossover using Pt–Ru catalyst coated on commercial membrane of ethanesulfonyl fluoride through layer-by-layer technique
Thin Solid Films, 2013Co-Authors: Chieh-hao Wan, Yu Jheng, Meng-tsun LinAbstract:Abstract In this study, 10 bilayers of poly (allylamine hydrochloride) (PAH)/polystyrene sulfonic acid sodium salt (PSS) with Pt 47 –Ru 53 catalyst are self-assembled on both sides of the commercial membrane of ethanesulfonyl fluoride via layer-by-layer technique to mitigate Methanol Crossover. The Pt 47 –Ru 53 alloy catalyst is dispersed in the PAH/PSS bi-layers through the reduction of the Pt and Ru ions in the PSS. Experimental results show that the Pt 47 –Ru 53 catalyst with an average particle size of 5 nm and a layer thickness of 1.31 μm, which is similar to the thickness of 10 PAH/PSS bi-layers, is coated onto both sides of the commercial membrane of ethanesulfonyl fluoride. Compared to untreated commercial membrane of ethanesulfonyl fluoride at 60 °C, this composite membrane, with Pt 47 –Ru 53 loading of 16.5 μg cm − 2 , suppresses Methanol Crossover by 12% (on average) and improves output voltage and power density by 18% and 46% (@79 mA cm − 2 ), respectively. The Pt 47 –Ru 53 catalyst in the PAH/PSS bi-layers oxidizes the crossed-over Methanol and produces extra current. It also reduces the mixed potential effect in the cathode. The 10 PAH/PSS bi-layers with low Methanol permeability function like a Methanol barrier, blocking the crossed-over Methanol. Combining these effects, the self-assembly of the PAH/PSS containing Pt 47 –Ru 53 alloy onto the commercial membrane of ethanesulfonyl fluoride can effectively improve output voltage and power density and can suppress Methanol Crossover.
Chieh-hao Wan - One of the best experts on this subject based on the ideXlab platform.
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Suppressing Methanol Crossover with a deposited quaternary Pt-based catalyst on the Nafion surface
International Journal of Hydrogen Energy, 2014Co-Authors: Chieh-hao Wan, Meng-tsun Lin, Chien-heng LinAbstract:Abstract A Pt49–Ru35–Ir6–Os10 alloy layer is deposited on the Nafion membrane surface using the impregnation-reduction (IR) method to mitigate Methanol Crossover. The Methanol Crossover in a membrane electrode assembly (MEA) with a deposited Pt–Ru–Ir–Os layer is compared with a MEA without any layer on the proton exchange membrane (PEM). The deposited Pt49–Ru35–Ir6–Os10 layer functions like a catalytically active layer, a Methanol barrier, and an electrode all at the same time. This layer yields up to a 30% suppression of Methanol Crossover and a 15% improvement in fuel cell voltage performance (@170 mA cm−2) at 80 °C. The porous metal alloy layer with a high surface area of the Pt–Ru layer suppresses Methanol Crossover by the catalytic activity of the deposited layer. The presence of the solid Pt49–Ru35–Ir6–Os10 layer on the Nafion membrane surface reduces the proton conductivity of the PEM (from 10.75 to 4.22 mS cm−1), and degrades the output of the cell voltage performance (from 0.350 to 0.335 V at 90 mA cm−2 of current density) at 60 °C, even though Methanol Crossover is reduced (from 6928 ppm to 4415 ppm (CO2 concentration at cathode exhaust is proportional to Methanol Crossover)).
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mitigating Methanol Crossover with self assembled pt35 ru65 catalyst on nafion surface
Journal of Power Sources, 2013Co-Authors: Chieh-hao Wan, Meng-tsun LinAbstract:Abstract In this paper, 5 bi-layers of poly (allylamine hydrochloride) (PAH)/polystyrene sulfonic acid sodium salt (PSS) containing Pt35–Ru65 catalyst are self-assembled on the Nafion membrane surface through the layer-by-layer technique to mitigate Methanol Crossover. This composite Nafion membrane coated with Pt35–Ru65 catalyst with loading of 0.46 μg cm−2 and layer thickness of 87.5 nm on both surfaces suppresses the Methanol Crossover by 22% (on average), improves the power density by 48% (@0.30 V) and the potential by 22% (@62.5 mA cm−2) at 80 °C. The Pt35–Ru65 catalyst in the PAH/PSS bi-layers serves multiple roles at the same time – a catalytically active layer, a Methanol barrier and an electrode. In addition, the PAH/PSS bi-layers also acts as a Methanol barrier. These roles contribute to the suppression of Methanol Crossover and improvement of the output performance. Compared with Pt–Ru directly deposited on Nafion surface, the deposition of Pt35–Ru65 in this study has less negative impact on the cell performance because 1) lesser and thinner deposited Pt35–Ru65 is used, 2) the Pt35–Ru65 layer deposited on the additional PAH/PSS bi-layers does not reduce the proton conductivity of Nafion membrane.
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Mitigating Methanol Crossover with self-assembled Pt35–Ru65 catalyst on Nafion surface
Journal of Power Sources, 2013Co-Authors: Chieh-hao Wan, Meng-tsun LinAbstract:Abstract In this paper, 5 bi-layers of poly (allylamine hydrochloride) (PAH)/polystyrene sulfonic acid sodium salt (PSS) containing Pt35–Ru65 catalyst are self-assembled on the Nafion membrane surface through the layer-by-layer technique to mitigate Methanol Crossover. This composite Nafion membrane coated with Pt35–Ru65 catalyst with loading of 0.46 μg cm−2 and layer thickness of 87.5 nm on both surfaces suppresses the Methanol Crossover by 22% (on average), improves the power density by 48% (@0.30 V) and the potential by 22% (@62.5 mA cm−2) at 80 °C. The Pt35–Ru65 catalyst in the PAH/PSS bi-layers serves multiple roles at the same time – a catalytically active layer, a Methanol barrier and an electrode. In addition, the PAH/PSS bi-layers also acts as a Methanol barrier. These roles contribute to the suppression of Methanol Crossover and improvement of the output performance. Compared with Pt–Ru directly deposited on Nafion surface, the deposition of Pt35–Ru65 in this study has less negative impact on the cell performance because 1) lesser and thinner deposited Pt35–Ru65 is used, 2) the Pt35–Ru65 layer deposited on the additional PAH/PSS bi-layers does not reduce the proton conductivity of Nafion membrane.
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Suppressing Methanol Crossover with Nanometer-Sized Pt 3 Sn Particles Self-Assembled on a Nafion Membrane Surface
2013Co-Authors: Chien-heng Lin, Chieh-hao WanAbstract:In this paper, 5 and 10 poly(allylamine hydrochloride) (PAH)/poly(styrene sulfonic acid sodium salt) (PSS) bi-layers with dispersed Pt3Sn alloy nano-particles are self-assembled onto both sides of the Nafion-117 membrane to suppress Methanol Crossover. The Pt3Sn alloy in PAH/PSS bi-layers are synthesized by the reduction of Pt and Sn ions in PSS with NaBH4. The UV-visible spectroscopy was used to monitor the PAH/PSS self-assembly bi-layers. The Methanol Crossover in membrane electrode assembly (MEA) was determined by measuring the CO2 concentration at cathode exhaust using a CO2 sensor. The results confirm that the Pt and Sn deposited in PAH/PSS bi-layers exist in a Pt-Sn alloy phase with atomic ratio of 3:1 (Pt:Sn). The layer thicknesses of 5 and 10 PAH/PSS bi-layers containing Pt-Sn alloy are 150nm and 300nm, respectively. The MEA, with 5 PAH/PSS bi-layers containing PtSn alloy nano-particles (average particle size is 17 nm) catalyst, suppress Methanol Crossover by 50% and slightly improve the output current by 6% (@0.40V). This is because the presence of Pt-Sn alloy and PAH/PSS bi-layers itself functions like a catalytic active layer and Methanol barrier that react and block the crossed-over Methanol. These dual roles contribute to the suppression of Methanol Crossover and performance improvement. However, the thickness effect is evident for the 10 PAH/PSS bi-layers sample and results in the decrease of cell performance by 19%, while suppressing Methanol Crossover by 50%.
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Mitigating Methanol Crossover using Pt–Ru catalyst coated on commercial membrane of ethanesulfonyl fluoride through layer-by-layer technique
Thin Solid Films, 2013Co-Authors: Chieh-hao Wan, Yu Jheng, Meng-tsun LinAbstract:Abstract In this study, 10 bilayers of poly (allylamine hydrochloride) (PAH)/polystyrene sulfonic acid sodium salt (PSS) with Pt 47 –Ru 53 catalyst are self-assembled on both sides of the commercial membrane of ethanesulfonyl fluoride via layer-by-layer technique to mitigate Methanol Crossover. The Pt 47 –Ru 53 alloy catalyst is dispersed in the PAH/PSS bi-layers through the reduction of the Pt and Ru ions in the PSS. Experimental results show that the Pt 47 –Ru 53 catalyst with an average particle size of 5 nm and a layer thickness of 1.31 μm, which is similar to the thickness of 10 PAH/PSS bi-layers, is coated onto both sides of the commercial membrane of ethanesulfonyl fluoride. Compared to untreated commercial membrane of ethanesulfonyl fluoride at 60 °C, this composite membrane, with Pt 47 –Ru 53 loading of 16.5 μg cm − 2 , suppresses Methanol Crossover by 12% (on average) and improves output voltage and power density by 18% and 46% (@79 mA cm − 2 ), respectively. The Pt 47 –Ru 53 catalyst in the PAH/PSS bi-layers oxidizes the crossed-over Methanol and produces extra current. It also reduces the mixed potential effect in the cathode. The 10 PAH/PSS bi-layers with low Methanol permeability function like a Methanol barrier, blocking the crossed-over Methanol. Combining these effects, the self-assembly of the PAH/PSS containing Pt 47 –Ru 53 alloy onto the commercial membrane of ethanesulfonyl fluoride can effectively improve output voltage and power density and can suppress Methanol Crossover.
Sung Hyun Kim - One of the best experts on this subject based on the ideXlab platform.
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Methanol Crossover through ptru nafion composite membrane for a direct Methanol fuel cell
International Journal of Hydrogen Energy, 2007Co-Authors: E.h. Jung, Un Ho Jung, Tae-hyun Yang, D.h. Peak, Doo-hwan Jung, Sung Hyun KimAbstract:Abstract This study examined Methanol Crossover through PtRu/Nafion composite membranes for the direct Methanol fuel cell. For this purpose, 0.03, 0.05 and 0.10 wt% PtRu/Nafion composite membranes were fabricated using a solution impregnation method. The composite membrane was characterized by inductively coupled plasma-mass spectroscopy and thermo-gravimetric analysis. The Methanol permeability and proton conductivity of the composite membranes were measured by gas chromatography and impedance spectroscopy, respectively. In addition, the composite membrane performance was evaluated using a single cell test. The proton conductivity of the composite membrane decreased with increasing number of PtRu particles embedded in the pure Nafion membrane, while the level of Methanol permeation was retarded. From the results of the single cell test, the maximum performance of the composite membrane was approximately 27% and 31% higher than that of the pure Nafion membrane at an operating temperature of 30 and 45 °C, respectively. The optimum loading of PtRu was determined to be 0.05 wt% PtRu/Nafion composite membrane.The PtRu particles embedded in the Nafion membrane act as a barrier against Methanol Crossover by the chemical oxidation of Methanol on embedded PtRu particles and by reducing the proton conduction pathway.
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Methanol Crossover through PtRu/Nafion composite membrane for a direct Methanol fuel cell
International Journal of Hydrogen Energy, 2007Co-Authors: E.h. Jung, Un Ho Jung, Tae-hyun Yang, D.h. Peak, Doo-hwan Jung, Sung Hyun KimAbstract:Abstract This study examined Methanol Crossover through PtRu/Nafion composite membranes for the direct Methanol fuel cell. For this purpose, 0.03, 0.05 and 0.10 wt% PtRu/Nafion composite membranes were fabricated using a solution impregnation method. The composite membrane was characterized by inductively coupled plasma-mass spectroscopy and thermo-gravimetric analysis. The Methanol permeability and proton conductivity of the composite membranes were measured by gas chromatography and impedance spectroscopy, respectively. In addition, the composite membrane performance was evaluated using a single cell test. The proton conductivity of the composite membrane decreased with increasing number of PtRu particles embedded in the pure Nafion membrane, while the level of Methanol permeation was retarded. From the results of the single cell test, the maximum performance of the composite membrane was approximately 27% and 31% higher than that of the pure Nafion membrane at an operating temperature of 30 and 45 °C, respectively. The optimum loading of PtRu was determined to be 0.05 wt% PtRu/Nafion composite membrane.The PtRu particles embedded in the Nafion membrane act as a barrier against Methanol Crossover by the chemical oxidation of Methanol on embedded PtRu particles and by reducing the proton conduction pathway.
Robert F. Savinell - One of the best experts on this subject based on the ideXlab platform.
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Real‐Time Mass Spectrometric Study of the Methanol Crossover in a Direct Methanol Fuel Cell
Journal of The Electrochemical Society, 1996Co-Authors: J.‐t. Wang, S. Wasmus, Robert F. SavinellAbstract:The products of Methanol Crossover through the acid‐doped polybenzimidazole polymer electrolyte membrane (PBI PEM) to the cathode of a prototype direct Methanol fuel cell (DMFC) were analyzed using multipurpose electrochemical mass spectrometry (MPEMS) coupled to the cathode exhaust gas outlet. It was found that the Methanol crossing over reacts almost quantitatively to at the cathode with the platinum of the cathode acting as a heterogeneous catalyst. The cathode open‐circuit potential is inversely proportional to the amount of formed. A poisoning effect on the oxygen reduction also was found. Methods for the estimation of the Methanol Crossover rate at operating fuel cells are suggested.
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real time mass spectrometric study of the Methanol Crossover in a direct Methanol fuel cell
Journal of The Electrochemical Society, 1996Co-Authors: J T Wang, S. Wasmus, Robert F. SavinellAbstract:The products of Methanol Crossover through the acid‐doped polybenzimidazole polymer electrolyte membrane (PBI PEM) to the cathode of a prototype direct Methanol fuel cell (DMFC) were analyzed using multipurpose electrochemical mass spectrometry (MPEMS) coupled to the cathode exhaust gas outlet. It was found that the Methanol crossing over reacts almost quantitatively to at the cathode with the platinum of the cathode acting as a heterogeneous catalyst. The cathode open‐circuit potential is inversely proportional to the amount of formed. A poisoning effect on the oxygen reduction also was found. Methods for the estimation of the Methanol Crossover rate at operating fuel cells are suggested.
Akhila Kumar Sahu - One of the best experts on this subject based on the ideXlab platform.
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A Nafion-Ceria Composite Membrane Electrolyte for Reduced Methanol Crossover in Direct Methanol Fuel Cells
Energies, 2017Co-Authors: Parthiban Velayutham, Akhila Kumar Sahu, Sridhar ParthasarathyAbstract:An alternative Nafion composite membrane was prepared by incorporating various loadings of CeO 2 nanoparticles into the Nafion matrix and evaluated its potential application in direct Methanol fuel cells (DMFCs). The effects of CeO 2 in the Nafion matrix were systematically studied in terms of surface morphology, thermal and mechanical stability, proton conductivity and Methanol permeability. The composite membrane with optimum filler content (1 wt. % CeO 2 ) exhibits a proton conductivity of 176 mS·cm −1 at 70 °C, which is about 30% higher than that of the unmodified membrane. Moreover, all the composite membranes possess a much lower Methanol Crossover compared to pristine Nafion membrane. In a single cell DMFC test, MEA fabricated with the optimized composite membrane delivered a peak power density of 120 mW·cm −2 at 70 °C, which is about two times higher in comparison with the pristine Nafion membrane under identical operating conditions.
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Surfactant templated nanoporous carbon-Nafion hybrid membranes for direct Methanol fuel cells with reduced Methanol Crossover
Journal of Membrane Science, 2017Co-Authors: V. Parthiban, Srinu Akula, Akhila Kumar SahuAbstract:Abstract In the path to improve the efficiency of direct Methanol fuel cell (DMFC), development of an alternative membrane with reduced Methanol cross over is the great deal of current interest. Herein, we configured a novel nanoporous carbon - Nafion hybrid membrane which reduces the Methanol Crossover by 50% compared to the pristine Nafion membrane. Firstly, nanoporous carbon (NPC) is synthesized through a surfactant template route using sodium dodecyl sulfate (SDS) which direct well-established pore geometry in the NPC during synthesis. NPC acts as effective filler to Nafion polymer matrix by restricting the Methanol Crossover in a hybrid membrane in return helps in enhancing DMFC output power density. Proton conductivity, Methanol Crossover, microscopic analysis along with durability in the cell mode is systematically studied to find potential application of derived hybrid membrane towards DMFC. The DMFC comprising Nafion-NPC hybrid membrane delivers the peak power density of 171 mW cm-2 at 70 °C under ambient pressure which is about three folds higher than pristine Nafion membrane under identical operating conditions. Hence, the current investigation intended to find remarkable scope for the future DMFC technology development.
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Proton Conducting Nafion-Sulfonated Graphene Hybrid Membranes for Direct Methanol Fuel Cells with Reduced Methanol Crossover
Energy & Fuels, 2015Co-Authors: V. Parthiban, Srinu Akula, S. Gouse Peera, Nazrul Islam, Akhila Kumar SahuAbstract:Sulfonic acid functionalized graphene (S-graphene) is explored as a potential inorganic filler as well as a solid acid proton conducting medium to realize a hybrid membrane with Nafion for a direct Methanol fuel cell (DMFC). The simple, but effective, functionalization of graphene is performed by sulfonic acid containing aryl radicals to increase the number of sulfonate groups per unit volume of graphene domain. Nafion–S-graphene hybrid membranes increase compactness of ionic domains and enhanced proton conductivity while restricting the Methanol Crossover across the membrane. DMFCs with a Nafion–S-graphene (1 wt %) hybrid membrane deliver a peak power density of 118 mW cm–2 at a load current density of 450 mA cm–2 while operating at 70 °C under an ambient pressure. By contrast, operating under identical conditions, a peak power density of 54 mW cm–2 at a load current density of 241 mA cm–2 is obtained with the pristine recast Nafion membrane. The Nafion–S-graphene hybrid membranes are extremely beneficia...
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PVA-PSSA Membrane with Interpenetrating Networks and its Methanol Crossover Mitigating Effect in DMFCs
Journal of The Electrochemical Society, 2008Co-Authors: Akhila Kumar Sahu, G. Selvarani, S. Pitchumani, Parthasarathi Sridhar, A. K. Shukla, N. Narayanan, Abhishek Banerjee, N. ChandrakumarAbstract:A membrane with interpenetrating networks between poly�vinyl alcohol� �PVA� and poly�styrene sulfonic acid� �PSSA� coupled with a high proton conductivity is realized and evaluated as a proton exchange membrane electrolyte for a direct Methanol fuel cell �DMFC�. Its reduced Methanol permeability and improved performance in DMFCs suggest the new blend as an alternative membrane to Nafion membranes. The membrane has been characterized by powder X-ray diffraction, scanning electron microscopy, time-modulated differential scanning calorimetry, and thermogravimetric analysis in conjunction with its mechanical strength. The maximum proton conductivity of 3.3 � 10−2 S/cm for the PVA–PSSA blend membrane is observed at 373 K. From nuclear magnetic resonance imaging and volume localized spectroscopy experiments, the PVA–PSSA membrane has been found to exhibit a promising Methanol impermeability, in DMFCs. On evaluating its utility in a DMFC, it has been found that a peak power density of 90 mW/cm2 at a load current density of 320 mA/cm2 is achieved with the PVA–PSSA membrane compared to a peak power density of 75 mW/cm2 at a load current density of 250 mA/cm2 achievable for a DMFC employing Nafion membrane electrolyte while operating under identical conditions; this is attributed primarily to the Methanol Crossover mitigating property of the PVA–PSSA membrane.