Transport in Proton Exchange Membranes for Fuel Cell Applications

PDF Publication Title:

Transport in Proton Exchange Membranes for Fuel Cell Applications ( transport-proton-exchange-membranes-fuel-cell-applications )

Next Page View | Return to Search List

Text from PDF Page: 001

materials Article Transport in Proton Exchange Membranes for Fuel Cell Applications—A Systematic Non-Equilibrium Approach Angie L. Rangel-Cárdenas and Ger J. M Koper * Chemical Engineering, Delft University of Technology, 2629 HZ Delft, The Netherlands; *;Tel.:+31-15-278-8218 Academic Editor: Haolin Tang Received: 20 March 2017; Accepted: 19 May 2017; Published: 25 May 2017 Abstract: We hypothesize that the properties of proton-exchange membranes for fuel cell applications cannot be described unambiguously unless interface effects are taken into account. In order to prove this, we first develop a thermodynamically consistent description of the transport properties in the membranes, both for a homogeneous membrane and for a homogeneous membrane with two surface layers in contact with the electrodes or holder material. For each subsystem, homogeneous membrane, and the two surface layers, we limit ourselves to four parameters as the system as a whole is considered to be isothermal. We subsequently analyze the experimental results on some standard membranes that have appeared in the literature and analyze these using the two different descriptions. This analysis yields relatively well-defined values for the homogeneous membrane parameters and estimates for those of the surface layers and hence supports our hypothesis. As demonstrated, the method used here allows for a critical evaluation of the literature values. Moreover, it allows optimization of stacked transport systems such as proton-exchange membrane fuel cell units where interfacial layers, such as that between the catalyst and membrane, are taken into account systematically. Keywords: non-equilibrium; interfacial effects; transport properties; coupling effects; transport coefficient matrix; PEM fuel cell; proton conductivity; water permeability; hydrogen permeability; diffusivity; electro-osmotic drag PACS: 82.47.-a 1. Introduction Proton-conducting, polymer electrolyte membranes (PEM), play an important role in fuel cell applications as they serve not only the function of separation between the anode and cathode sides, but also act as a solid electrolyte allowing the transport of charge. The most common material used for these applications is NafionTM (DuPont, Wilmington, DE, USA), which consists of a tetrafluoroethylene (TFE) backbone and perfluoroalkyl ether (PFA) side chains terminated in sulfonic acid groups [1,2]. The combination of the hydrophobicity of the backbone with the hydrophilicity of the sulfonic acid functional group in one macromolecule confers NafionTM the properties necessary for this application. Given the evident importance of PEM membranes, a plethora of studies on their different properties has been done over the last few decades. However, it proves difficult to reach a consensus on their meaning as research aimed at understanding the underlying phenomena describing the behavior of membrane properties is performed in many different ways and under different conditions which often do not match the reality of a membrane in an operating fuel cell. Within this framework, and from Materials 2017, 10, 576; doi:10.3390/ma10060576

PDF Image | Transport in Proton Exchange Membranes for Fuel Cell Applications

PDF Search Title:

Transport in Proton Exchange Membranes for Fuel Cell Applications

Original File Name Searched:


DIY PDF Search: Google It | Yahoo | Bing

Molecular Hydrogen: Clinically researched and proven as a antioxidant and more... More Info

Molecular Hydrogen Machine: Cart mounted molecular hydrogen machine for infusing antioxidant hydrogen into oils and making high value skin creams... More Info

Infinity Supercritical 10L CO2 Extractor: Supercritical CO2 Hemp Oil Extraction for Full Spectrum Botanical Oil which retains the terpenes and other valuable plant components during extraction. System runs silent with small footprint of 24 inches by 48 inches... More Info

Infinity Supercritical has developed the most profitable Supercritical CO2 Extraction Machines. Our CO2 terpene extraction system rapidly produces shelf-ready oils which make more money. Perfect for hemp oil extraction using environmentally friendly CO2 extraction equipment. Manufactures efficient oil extraction systems and machines for natural terpenes, flavorings, fragrance, hemp, beer hops, lavender and other botanicals. New for 2021 includes Molecular Hydrogen Skin Cream Machine for production of high value cosmetic skin cream. Silent technology includes supercritical co2, oil-to-oil extraction using induction magnetic mixing, and eco friendly hydrodynamic cavitation water as the solvent in our closed-looped systems. The process can also be used for electrowinning, e-waste recycling, and lithium battery recycling, gold mining electronic wastes, precious metals. CO2 can also be used in a reverse fuel cell with nafion to make a gas-to-liquids fuel, such as methanol, ethanol and butanol or ethylene. Supercritical CO2 has also been used for treating nafion to make it more effective catalyst. SCO2 can remove water from wood as an alternative to conventional kiln drying.

CONTACT TEL: 608-238-6001 Email: (Standard Web Page)