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Protonic conduction

The concept of the reversed fuel cell, as shown schematically, consists of two parts. One is the already discussed direct oxidation fuel cell. The other consists of an electrochemical cell consisting of a membrane electrode assembly where the anode comprises Pt/C (or related) catalysts and the cathode, various metal catalysts on carbon. The membrane used is the new proton-conducting PEM-type membrane we developed, which minimizes crossover. [Pg.220]

Polymer Electrolyte Fuel Cell. The electrolyte in a PEFC is an ion-exchange (qv) membrane, a fluorinated sulfonic acid polymer, which is a proton conductor (see Membrane technology). The only Hquid present in this fuel cell is the product water thus corrosion problems are minimal. Water management in the membrane is critical for efficient performance. The fuel cell must operate under conditions where the by-product water does not evaporate faster than it is produced because the membrane must be hydrated to maintain acceptable proton conductivity. Because of the limitation on the operating temperature, usually less than 120°C, H2-rich gas having Htde or no ([Pg.578]

Ren, X. Springer, T. E. and Gottesfeld, S. (1998). Direct Methanol Fuel Cell Transport Properties of the Polymer Electrolyte Membrane and Cell Performance. Vol. 98-27. Proc. 2nd International Symposium on Proton Conducting Membrane Euel Cells. Pennington, NJ Electrochemical Society. [Pg.644]

Jacobs et al. [59,925,926] (Fig. 17). While this scheme conveniently summarizes many features of the observed behaviour, a number of variations or modifications of the mechanisms indicated have been proposed. Maycock and Pai Vemeker [924,933] emphasize the possible role of point defects and suggest, on the evidence of conductivity measurements, that the initial step may be the transfer of either a proton or an electron. Boldyrev et al. [46] suggest that proton conduction permits rapid migration of HC104 within the reactant and this undergoes preferential decomposition in distorted regions. More recently, the ease of proton transfer and the mobilities of other species in or on AP crystals have been investigated by a.c. [360] and d.c. [934] conductivity measurements. Owen et al. [934] could detect no surface proton conductivity and concluded that electron transfer was the initial step in decomposition. At the present time, these inconsistencies remain unresolved. [Pg.199]

T.I. Politova, V.A. Sobyanin, and V.D. Belyaev, Ethylene hydrogenation in electrochemical cell with solid proton-conducting electrolyte, Reaction Kinetics and Catalysis Letters 41(2), 321-326 (1990). [Pg.13]

N. Kurita, N. Fukatsu, K. Ito, and T. Ohashi, Protonic Conduction Domain of Indium-Doped Calcium Zirconate,/. Electrochem. Soc. 142(5), 1552-1559 (1995). [Pg.107]

Figure 9.32. Experimental set-up (a) Machinable ceramic holders and two proton conducting pellets showing the location of catalyst, counter and reference electrodes, (b) Twenty four pellet unit, (c) High-pressure reactor, gas feed and analysis unit.43 Reprinted with permission from the American Chemical Society. Figure 9.32. Experimental set-up (a) Machinable ceramic holders and two proton conducting pellets showing the location of catalyst, counter and reference electrodes, (b) Twenty four pellet unit, (c) High-pressure reactor, gas feed and analysis unit.43 Reprinted with permission from the American Chemical Society.
For last few years, extensive studies have been carried out on proton conducting inorganic/organic hybrid membranes prepared by sol-gel process for PEMFC operating with either hydrogen or methanol as a fuel [23]. A major motivation for this intense interest on hybrid membranes is high cost, limitation in cell operation temperature, and methanol cross-... [Pg.80]

But when the contents of Nafion ionomer was increased from 30 to 45 % to find out the better electrode structures, the Pt-Ru/SRaw, which had showed the lowest single cell performance, became the best electro-catalyst. By this result one can conclude that as long as the structure of the electrode can be optimized for the each of new electro-catalysts, the active metal size is a more important design parameter rather than inter-metal distances. Furthermore, when the electro-catalysts are designed, the principal parameters should be determined in the consideration of the electrode structures which affect on the electron conduction, gas permeability, proton conductivity, and so on. [Pg.640]

Figure 15. Extent of methanol crossover through different ETFE proton-conducting membranes. Comparison with the behavior ofNafion 117 ( ). Figure 15. Extent of methanol crossover through different ETFE proton-conducting membranes. Comparison with the behavior ofNafion 117 ( ).
Apart from the problems of low electrocatalytic activity of the methanol electrode and poisoning of the electrocatalyst by adsorbed intermediates, an overwhelming problem is the migration of the methanol from the anode to the cathode via the proton-conducting membrane. The perfluoro-sulfonic acid membrane contains about 30% of water by weight, which is essential for achieving the desired conductivity. The proton conduction occurs by a mechanism (proton hopping process) similar to what occurs... [Pg.107]

S. R. Narayanan, A. Kindler, B. Jeffries-Nakamura, W. Chun, H. Frank, M. Smart, S. Surampudi, and G. Halpert, in Proc. of the First International Symposium on Proton Conducting Membrane Fuel Cells, Ed. by S. Gottesfield, G. Halpert, and A. R. Landgrebe, The Electrochemical Society, Pennington, NJ, PV 95-23, 1995, pp. 261-266. [Pg.118]

A considerable decrease in platinum consumption without performance loss was attained when a certain amount (30 to 40% by mass) of the proton-conducting polymer was introduced into the catalytically active layer of the electrode. To this end a mixture of platinized carbon black and a solution of (low-equivalent-weight ionomeric ) Nafion is homogenized by ultrasonic treatment, applied to the diffusion layer, and freed of its solvent by exposure to a temperature of about 100°C. The part of the catalyst s surface area that is in contact with the electrolyte (which in the case of solid electrolytes is always quite small) increases considerably, due to the ionomer present in the active layer. [Pg.365]

Inzelt, G., M. Pineri, 1. W. Schultze, and M. A. Vorotyntsev, Electron and proton conducting polymers recent developments and prospects, Electrochim. Acta, 45, 2403 (2000). [Pg.466]

Electrolytes for Electrochromic Devices Liquids are generally used as electrolytes in electrochemical research, but they are not well suited for practical devices (such as electrochromic displays, fuel cells, etc.) because of problems with evaporation and leakage. For this reason, solid electrolytes with single-ion conductivity are commonly used (e.g., Nafion membranes with proton conductivity. In contrast to fuel cells in electrochromic devices, current densities are much lower, so for the latter application, a high conductivity value is not a necessary requirement for the electrolyte. [Pg.626]

Implementation of Pt/C catalysts in PEFC technology using recast Nafion as a proton conducting and bonding agent [Raistrick, 1986 Wilson and Gottesfeld, 1992]. [Pg.3]

Nagle, J. F., Theory of passive proton conductance in lipid bilayers, J. Bioenerg. Biomem. 19, 413—426 (1987). [Pg.273]


See other pages where Protonic conduction is mentioned: [Pg.636]    [Pg.157]    [Pg.120]    [Pg.92]    [Pg.107]    [Pg.470]    [Pg.542]    [Pg.217]    [Pg.81]    [Pg.81]    [Pg.34]    [Pg.577]    [Pg.60]    [Pg.61]    [Pg.72]    [Pg.107]    [Pg.114]    [Pg.118]    [Pg.364]    [Pg.434]    [Pg.435]    [Pg.456]    [Pg.5]    [Pg.519]    [Pg.520]    [Pg.74]    [Pg.209]    [Pg.416]   
See also in sourсe #XX -- [ Pg.251 ]

See also in sourсe #XX -- [ Pg.56 , Pg.58 , Pg.237 , Pg.243 , Pg.246 , Pg.251 ]




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Alumina proton conduction

Ambipolar proton-electron conductivity

Ammonia synthesis, proton-conducting

Anhydrous Proton-Conducting Polymers for High-Temperature PEMFCs

Anhydrous proton-conducting

Anhydrous proton-conducting polymer

Brouwer Diagram Representation of Mixed Proton Conductivity

CCL, proton conductivity

CL, proton conductivity

Catalyst layers protonic conductivity

Charge Mobility and Conductivity of Protons

Composite polymer electrolytes proton-conduction mechanism

Conductivity in Proton Conductors

Conductivity mechanisms and models in anhydrous protonic conductors

Conductivity mixed proton/electronic

Conductivity protonic

Conductivity protonic

Conductivity, electrical proton

Configuration of Proton-Conducting Membrane Reactors

Defect Chemistry in Proton-Conducting Perovskites

Defect Structures of Proton-conducting Oxides

Developments of Proton-Conducting SOFCs

Dielectric relaxation protonic conduction

Direct current proton conductivity measurements

Effective Proton Conductivity

Effective catalyst layer proton conductivity

Electrical conductivity proton-conducting oxides

Electrochromic devices proton-conducting polymer

Electrode proton conductivity

Electrolyte proton conducting

Electrolyzer with proton-conducting membranes

Electronic/protonic conductivity

Fluoropolymers proton conductivity

Frequency dependent conductivity, microwave dielectric relaxation and proton dynamics

Fuel cells Proton conducting

Fuel cells proton-conducting separators

Fuel cells proton-conductive membranes

Fuel proton conductivity

High-temperature polymer electrolyte fuel proton conductivity mechanism

High-temperature proton-conducting

High-temperature proton-conducting membranes

Highly ionic hydroxides unexpected proton conductivity in Mg(OH)2 and homologues

Hybrid proton conductive membrane

Hybrid proton-conducting membranes

Intermediate-Temperature SOFCs Using Proton-Conducting Perovskite

Ionic liquids proton-conducting

Manganese oxide, proton conduction

Measuring the true proton conductivity

Mechanisms of Proton Conduction (Undoped, Cubic Perovskites)

Mechanisms of Proton Conduction in Perovskite-Type Oxides

Membrane lateral proton conduction

Membrane proton conductivity and

Membrane reactor proton-conducting membranes

Membrane/ionomer proton conductivity

Membrane/ionomer proton conductivity advantage

Membrane/ionomer proton conductivity conduction mechanism

Membrane/ionomer proton conductivity current density

Membrane/ionomer proton conductivity effect

Membrane/ionomer proton conductivity measurements

Membrane/ionomer proton conductivity water content

Membrane/ionomer proton conductivity water uptake

Mitochondrial membranes, proton conductance

Mixed electronic and protonic conductivity

Mixed proton conducting membranes

Mixed protonic-electronic conducting

Mixed protonic-electronic conducting materials

Mixed protonic-electronic conducting membrane

Mixed protonic-electronic conducting perovskite membrane

Mixed proton—electron conducting

Mixed proton—electron conducting materials

Mixed proton—electron conducting oxide

Nafion proton conducting, structure

Nafion proton conductivity

Nanoporous proton-conducting membranes

PEMFC proton conductivity

PROTON CONDUCTING

PROTON CONDUCTING

Perfluorosulfonic acid proton-conducting

Perovskite oxides proton conductivity

Perovskite proton conduction

Perovskite proton conductivities

Perovskite proton-conducting ceramic membrane

Perovskite protonic-electronic conductivity

Perovskite-type materials proton conducting ceramics

Perovskites proton conductivity

Phase transitions proton conductivity

Poly proton-conducting polymer

Polybenzimidazole proton conduction

Polybenzimidazole proton conductivity

Polyelectrolytes protonic conduction

Polymer electrolyte membrane proton conductivity

Proton Conducting Ceramic Fuel Cells

Proton Conducting Electrolytes and Their Application in Fuel Cells

Proton Conducting Mechanism during Fuel Cell Operation

Proton Conduction in Aqueous Environments

Proton Conduction in Biology

Proton Conduction in Cerium- and Zirconium-Based Perovskite Oxides

Proton Conduction in Fuel Cells

Proton Conductivity as a Function of Composition and Temperature

Proton Conductivity at Low Temperature

Proton Conductivity in Acceptor-Doped Simple Perovskites, ABO

Proton Conductivity in Nafion

Proton Conductivity in Perovskite Oxides

Proton Hole Mixed Conduction

Proton conductance

Proton conductance

Proton conducting gels

Proton conducting materials, quantum

Proton conducting membrane reactor

Proton conducting membranes, aromatic

Proton conducting membranes, aromatic polymers

Proton conducting polymer electrolytes

Proton conducting polymer electrolytes acid

Proton conducting polymer electrolytes imidazole

Proton conducting polymer electrolytes poly

Proton conducting polymer electrolytes preparation

Proton conducting polymer electrolytes properties

Proton conducting polymeric

Proton conducting polymeric membrane

Proton conducting solid oxide fuel cells

Proton conducting solids

Proton conduction

Proton conduction

Proton conduction behavior

Proton conduction complications

Proton conduction enhancing

Proton conduction in PEMs

Proton conduction in zeolites

Proton conduction measurement

Proton conduction mechanism

Proton conduction mechanism hydronium ions

Proton conduction mechanism hydrophilic sulfonic acid group

Proton conduction mechanism hydrophobic polymer

Proton conduction mechanism in concentrated acidic aqueous solutions

Proton conduction mechanism in n solid acidic hydrates

Proton conduction mechanism water channel network

Proton conduction oxygen deficiency

Proton conduction pore-scale models

Proton conduction stability

Proton conduction, lateral

Proton conductive matrix

Proton conductive membrane

Proton conductive oxide

Proton conductivity

Proton conductivity Grotthuss mechanism

Proton conductivity acid-base

Proton conductivity diffusion

Proton conductivity electrochemical impedance

Proton conductivity grain boundaries

Proton conductivity hydrogen bonds

Proton conductivity in oxides

Proton conductivity influence

Proton conductivity measurements

Proton conductivity permanent

Proton conductivity protons

Proton conductivity protons

Proton conductivity results

Proton conductivity spectroscopy

Proton conductivity vehicle mechanism

Proton conductivity/conductor

Proton conductors classification and conductivity

Proton electrical conductivity mechanisms

Proton exchange membrane fuel cells electron conductivity

Proton limiting conductances

Proton membranes, conductivity

Proton transport pore conductance model

Proton-Conducting Analogues

Proton-Conducting Pd Membranes

Proton-Conducting Solid Electrolytes

Proton-Electron Conducting Oxides

Proton-conducting ceramic

Proton-conducting ceramic membrane hydrogen production

Proton-conducting ceramic membrane reactors

Proton-conducting ceramic membranes

Proton-conducting channel

Proton-conducting dense ceramic

Proton-conducting dense ceramic membranes

Proton-conducting gel polymer

Proton-conducting gel polymer electrolyte

Proton-conducting material

Proton-conducting membrane for fuel cells

Proton-conducting membranes

Proton-conducting membranes amphoteric polymers

Proton-conducting membranes ionic liquid applications

Proton-conducting oxides

Proton-conducting perovskites

Proton-conducting polymer membran

Proton-conducting polymers

Proton-conducting polymers and

Proton-conducting separators

Proton-switch conduction

Protonic and Electronic Conductivity in the Catalyst Layer

Protonic conducting

Protonic conducting

Protonic conduction hydration dependence

Protonic conduction in alkali metal zeolites

Protonic conduction in tin zeolites

Protonic conductivities, of composite

Protonic conductivities, of composite membranes

Protonic salts molar conductivity

Radiation-grafted fuel cell membranes proton conductivity

Rate of proton conductance

Regulation of Proton Conduction

Relative humidity proton conductivity

Role of water in proton conductance

SPEEK membranes proton conductivity

SPTES polymer membranes proton conductivities

Siloxanic proton-conducting

Siloxanic proton-conducting membranes

Solitons Coming Alive in Surface Proton Conduction

Superionic protonic conductivity

Surface Proton Conduction Why Bother

Surface Proton Conduction in Biology and at Monolayers

Switching protonic conductivity

Translocation mechanism, proton conductance

Verification of protonic conduction

Water protonic conduction

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