58 research outputs found
Current Understanding of Chemical Degradation Mechanisms of Perfluorosulfonic Acid Membranes and their Mitigation Strategies: A Review
International audienc
Mitigation of Fuel Cell Membrane Degradation with Metal Oxide/Nafion Nanofiber Interlayers
International audienc
Electrospun Nanofibre Composite Polymer Electrolyte Fuel Cell and Electrolysis Membranes
International audienceLarge-scale commercialisation of Proton Exchange Membrane Fuel Cell (PEMFC) technology for automotive and stationary applications demands the development of a robust, durable and cost-effective materials. In this regard, ionomer membranes being present at the core of PEMFCs are required to maintain elevated proton conductivity, high mechanical strength and low gas permeability during the lifespan of the fuel cell. These challenges are addressed by investigating novel nano-structured membrane materials possessing long-range spatial organisation of ionic and hydrophobic domains at the micro-and nano-scales. Electrospinning, a versatile and easily up-scalable tool for the preparation of nanofibrous polymers and ceramics with targeted architectures, is being extensively applied for the development of nanostructured electrolyte membranes. This review describes the most important advances in the use of electrospun materials for the preparation of new generation fuel cell proton conducting membranes. It also highlights the challenges to be overcome and the new directions and future application fields of composite nanofibre-based membranes in the broader context of energy materials
N° 71. — Spectroscopie de vibration de l'ion H
Le spectre de vibration de l’ion H5O2+ est donné de même que celui de D5O2+ pour les deux composés cristallisés HClO4, 2 H2O et DClO4, 2 D2O à — 180°. Des attributions sont proposées sur la base d’un modèle trans à liaison hydrogène symétrique. L’étude en coordonnées normales par la méthode de WILSON en négligeant les constantes d’interaction angle-valence conduit pour les vibrations de classe Bu de l’ion H5O2+ à des constantes de force dont certaines sont comparées à celles de H3O+. La vibration de déformation angulaire entre OH terminaux à 1 680 cm-1 est fortement couplée à la vibration de valence asymétrique du pont
Strong metal–support interaction improves activity and stability of Pt electrocatalysts on doped metal oxides
International audienceNiobium and antimony doped tin oxide loose-tubes decorated with Pt nanoparticles present outstanding mass activity and stability, exceeding those of a reference carbon-based electrocatalyst. Physico-chemical characterisation and in particular X-ray photoelectron spectroscopy demonstrate that this observation can be ascribed to the strong metal-support interaction promoting electroactivity and Pt anchoring on doped metal oxide supports
Platinum‐Rare Earth Alloy Electrocatalysts for the Oxygen Reduction Reaction: A Brief Overview
International audienc
High-Purity Hydrogen Generation via Dehydrogenation of Organic Carriers: A Review on the Catalytic Process
International audienceHigh purity hydrogen delivery for stationary and mobile applications using fuel cells is a subject of rapidly growing interest. As a consequence, the development of efficient storage technologies and processes for hydrogen supply is of primary importance. Promising hydrogen storage techniques rely on the reversibility and high selectivity of liquid organic hydrogen carriers (LOHCs), for example methylcyclohexane, decalin, dibenzyltoluene or dodecahydrocabazole. LOCHs have high gravimetric and volumetric hydrogen density, and involve low risk and capital investment because they are largely compatible with the current transport infrastructure used for fossil fuels. A further advantage comes from the high purity (close to 100%) of the hydrogen generated by dehydrogenation, suitable to directly feed fuel cells without the need for bulky purification modules. Partial dehydrogenation (PDH) of liquid fuels has recently emerged as a transition technology for hydrogen delivery purposes. The principle is to extract from fossil fuels a small fraction of the available hydrogen, which can be used for fuel cell applications, while the dehydrogenated hydrocarbon mixture maintains suitable properties for its use as fuel. With this technology, the large energy demand of dehydrogenation processes can be satisfied by implementing a heat exchanger between the engine and the dehydrogenation reactor, overcoming one of the main constraints associated with the use of organic liquids as hydrogen carriers. This method qualifies itself as a transition technology towards more electrified transportations, in which the main propulsion is still obtained by fuel combustion, although the electrical utilities or auxiliary propulsion are powered by fuel cells. This paper provides a review of the effort that has been directed towards the utilization of organic liquids as hydrogen carriers, with particular focus on the design of the catalytic dehydrogenation process and on the recent approach of fuel partial dehydrogenation. High-Purity Hydrogen Generation via Dehydrogenation of Organic Carriers: A Review on the Catalytic Process | Request PDF. Available from: https://www.researchgate.net/publication/324426955_High-Purity_Hydrogen_Generation_via_Dehydrogenation_of_Organic_Carriers_A_Review_on_the_Catalytic_Process [accessed Jul 03 2018]
Scaling Behavior of Nafion with Different Model Parameterizations in Dissipative Particle Dynamics Simulations
International audienc
Design of Heterogeneities and Interfaces with Nanofibres in Fuel Cell Membranes
International audienc
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