نتایج جستجو برای: catalyst layer

تعداد نتایج: 325011  

2006
Monika Mihailovici Ben Schweizer

Abstract: We study a pore scale model for the catalyst layer on the cathode side of a fuel cell, where hydrogen and oxygen combine at catalyst sites. Our model distinguishes microscopically the phases of rigid structure, electrolyte, pore-space, and catalyst. The oxygen concentration and the protonic potential are described by diffusion equations with reaction terms on the catalyst’s surface. F...

The shape and geometry of the flow field have considerable effects on the transfer rate of the reactants toward the catalyst layer and consequently the performance of the polymer electrolyte membrane (PEM) fuel cell. In this study, a novel PEM fuel cell with pin-type flow field is proposed in order to reduce the wake regions, increase the oxygen transfer rate into the catalyst layer and the cur...

2016
William K. Epting

Polymer electrolyte fuel cells (PEFCs) are a promising technology for environmentally friendly automobiles, among other applications. However, performance losses due to oxygen transport hindrances in the PEFC’s cathode continue to be an issue in widespread commercialization. This dissertation focuses on the transport of oxygen through the thickness of the PEFC cathode, and the effect of the cat...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1392

a novel acrylic acid-functionalized fe3o4 magnetic nanoparticle with a core-shell structure was developed for utilization as a heterogeneous organosuperacid in chemical transformations. the structural, surface, and magnetic characteristics of the nanosized catalyst were investigated by various techniques such as transmission electron microscopy (tem), thermogravimetric analysis (tga), and ft-ir...

Journal: :iranian journal of hydrogen and fuel cell 0
hossein fathi department of mehcanical engineering, shahid bahonar university of kerman, kerman, iran seyed hossein mansouri department of mechanical engineering, shahid bahonar university of kerman, kerman, iran amir raoof department of earth sciences, utrecht university, utrecht, netherlands

the produced liquid water in cathode catalyst layer (ccl) has significant effect on the operation of proton exchange membrane fuel cell (pemfc). to investigate this effect, the transport of oxygen in ccl in the presence of immiscible liquid water is studied applying a two-dimensional pore scale model. the ccl was reconstructed as an agglomerated system. to explore the wettability effects, diffe...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز - دانشکده علوم 1391

in this thesis, we exploit a simple and suitable method for immobilization of copper(ii) complex of 4?-phenyl-terpyridine on activated multi-walled carbon nanotubes [amwcnts-o-cu(ii)-phtpy]. this nanostructure was characterized by various physico-chemical techniques. to ensure the efficiency and fidelity of copper species, the implementation of three-component strategies in click-chemistry all...

Journal: :journal of nanostructures 2014
p. heydari a. r. asgharpour m. nazoktabar m. zahedinejad

in this paper metal-assisted chemical etching has been applied to pattern porous silicon regions and silicon nanohole arrays in submicron period simply by using positive photoresist as a mask layer. in order to define silicon nanostructures, metal-assisted chemical etching (mace) was carried out with silver catalyst. provided solution (or materiel) in combination with laser interference lithogr...

Journal: :Nanoscale 2016
Placidus B Amama Ahmad E Islam Sammy M Saber Daniel R Huffman Benji Maruyama

There is significant interest in broadening the type of catalyst substrates that support the growth of high-quality carbon nanotube (CNT) carpets. In this study, ion beam bombardment has been utilized to modify catalyst substrates for CNT carpet growth. Using a combination of contact angle measurements (CAMs) and X-ray reflectivity (XRR) for the first time, new correlations between the physicoc...

In this article, a two dimensional pore scale model of polymeric fuel cell, which is promising of a clean and renewable energy production, is presented here. Let reactive gases behave as an ideal gas; inhomogeneous anisotropic structure of the gas diffusion layer, is contemplated as a random generated circular porous media. Lattice Boltzmann method is applied to inquire the fluid flow and mass ...

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