Proton-conducting Membranes (proton-conducting + membrane)

Distribution by Scientific Domains


Selected Abstracts


Plasma Sputtering Deposition of PEMFC Porous Carbon Platinum Electrodes,

FUEL CELLS, Issue 2 2008
H. Rabat
Abstract A novel method is proposed to fabricate the active catalytic layers of proton exchange membrane fuel cells (PEMFC). A plasma sputtering technique is used to deposit a porous columnar carbon film (column diameter of 20,nm) followed by the catalyst (platinum) deposition directly on the proton-conducting membrane. The study of Pt diffusion shows that the optimised catalysed layers correspond to low plasma pressure operation (0.5,Pa) below a platinum loading limit of about 90,,g,cm,2. The initial carbon porosity is then maintained and Pt nanoparticles are present in all parts of the carbon layer. A membrane electrode assembly (MEA) is then achieved by alternate depositions of carbon and platinum onto both sides of the membrane. The results show the importance of the porous carbon structure. A significant increase in the catalyst efficiency is observed compared to a commercial fuel cell when measuring open circuit voltage. [source]


Polybenzimidazole-Based Membranes as a Real Alternative to Nafion for Fuel Cells Operating at Low Temperature,

ADVANCED MATERIALS, Issue 7 2008
Piercarlo Mustarelli
Filler up! Composite proton-conducting membranes, based on polybenzimidazole (PBI) and imidazole-derivatized silica are presented. The addition of even small amounts (,10 wt %) of filler causes an outstanding improvement in the permanent proton conductivity by a factor <103. The preparation of PBI composite membranes with basic functionalities is a promising way to make possible their use in PEMFCs operating around 120,°C, that is, the temperature required for automotive applications. [source]


Novel UV-induced photografting process for preparing poly(tetrafluoroethylene)-based proton-conducting membranes

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 13 2007
Masaharu Asano
Abstract A novel process comprising the UV-induced photografting of styrene into poly(tetrafluoroethylene) (PTFE) films and subsequent sulfonation has been developed for preparing proton-conducting membranes. Although under UV irradiation the initial radicals were mainly generated on the surface of the PTFE films by the action of photosensitizers such as xanthone and benzoyl peroxide, the graft chains were readily propagated into the PTFE films. The sulfonation of the grafted films was performed in a chlorosulfonic acid solution. Fourier transform infrared and scanning electron microscopy were used to characterize the grafted and sulfonated membranes. With a view to use in fuel cells, the proton conductivity, water uptake, and mechanical properties of the prepared membranes were measured. Even through the degree of grafting was lower than 10%, the proton conductivity in the thickness direction of the newly prepared membranes could reach a value similar to that of a Nafion membrane. In comparison with ,-ray radiation grafting, UV-induced photografting is very simple and safe and is less damaging to the membranes because significant degradation of the PTFE main chains can be avoided. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2624,2637, 2007 [source]