Applications of NMR Techniques in the Development and Operation of Proton Exchange Membrane Fuel Cells

Yan, Liuming; Hu, Yunxia; Zhang, Xiaoming; Yue, Baohua

doi:10.1016/bs.arnmr.2015.11.003

Cited by 17 publications

(19 citation statements)

References 202 publications

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“…If impedance spectroscopy is used for studying ion transport across a sample, NMR spectroscopy provides specific information about local dynamics of ions. Both the pulsed field gradient NMR (PFG-NMR) method and different spin-relaxation techniques can be used for investigation of diffusion coefficients [ 72 , 76 , 79 ]. The relationship between the conductivity ( σ i ) and the diffusion coefficient D i for any given ions i is established by the Nernst–Einstein equation [ 90 , 91 , 92 ]: D i = RT / z i 2 F 2 σ i , where z i is the charge of ion i , F is the Faraday constant, and R is the gas constant.…”

Section: Ionic Transport In Solids and Membranesmentioning

confidence: 99%

“…Unlike impedance spectroscopy, NMR allows one to describe molecular mobility [ 78 ]. This provides an undeniable advantage, especially when studying transfer processes in ion-exchange membranes, in which the mobility of solvent molecules plays an important role [ 23 , 79 , 80 ]. Significant advantages are provided by the joint analysis of data obtained using impedance and NMR spectroscopy.…”

Section: Introductionmentioning

confidence: 99%

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Ionic Mobility in Ion-Exchange Membranes

Стенина

Yaroslavtsev

2021

Membranes

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Membrane technologies are widely demanded in a number of modern industries. Ion-exchange membranes are one of the most widespread and demanded types of membranes. Their main task is the selective transfer of certain ions and prevention of transfer of other ions or molecules, and the most important characteristics are ionic conductivity and selectivity of transfer processes. Both parameters are determined by ionic and molecular mobility in membranes. To study this mobility, the main techniques used are nuclear magnetic resonance and impedance spectroscopy. In this comprehensive review, mechanisms of transfer processes in various ion-exchange membranes, including homogeneous, heterogeneous, and hybrid ones, are discussed. Correlations of structures of ion-exchange membranes and their hydration with ion transport mechanisms are also reviewed. The features of proton transfer, which plays a decisive role in the membrane used in fuel cells and electrolyzers, are highlighted. These devices largely determine development of hydrogen energy in the modern world. The features of ion transfer in heterogeneous and hybrid membranes with inorganic nanoparticles are also discussed.

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Section: Ionic Transport In Solids and Membranesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Ionic Mobility in Ion-Exchange Membranes

Стенина

Yaroslavtsev

2021

Membranes

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“…Pulsed Field Gradient (PFG) NMR is a common and accurate method for measuring the water diffusion coefficient in Nafion ™ membranes [53]. The water self-diffusion coefficient in pristine and aged membrane samples were here determined as a function of the water uptake.…”

Section: Liquid State 1 H-nmrmentioning

confidence: 99%

Time-resolved monitoring of composite Nafion™ XL membrane degradation induced by Fenton's reaction

Robert

Kaddouri

Perrin

et al. 2021

Journal of Membrane Science

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This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

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“…Therefore, measuring nuclear spin-lattice relaxation rates can provide information regarding the interaction of molecules with their chemical environments. 43 In an effort to examine the rotational movement of hydrogen and sodium, we performed spin-lattice relaxation experiments.…”

Section: Hydrogen and Sodium Ion Rotational Motion Rates In Polyamidementioning

confidence: 99%

Unravelling Water and Salt transport in Polyamide with Nuclear Magnetic Resonance Spectroscopy

Abbaszadeh

Choi

Chen

et al. 2022

Preprint

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Unraveling water and salt transport in polyamide is of growing importance as the use of reverse osmosis membranes grows in many industries. Here, using solid-state nuclear magnetic resonance (NMR) spectroscopy, we measure the translational diffusion coefficients using pulsed-field gradient NMR, examine ion dynamics with NMR relaxometry, and determine activation energy barriers of hydrogen and sodium ions in ion-exchanged polyamide using variable-temperature NMR. We identify two predominant diffusion components within the spectra associated with bound and unbound hydrogen and sodium ions. We show that the diffusion coefficient of the bound hydrogen ions decreases by 46% while the free hydrogen diffusion coefficient remained constant as the salinity of the mixture increases from 1 M to 2 M. Conversely, the diffusion coefficient of bounded sodium did not change while the unbounded sodium diffusion coefficient decreased by 38% as the salinity of the mixture increases from 1 M to 2 M. Through examining the spin-lattice relaxation time (T1) at various temperatures we reveal that the sodium and hydrogen ion motion decreases with an increase in salinity, and we also report the associated activation energy. We believe these molecular-scale measurements can aid in extending the solution-diffusion model of reverse osmosis membranes.

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Applications of NMR Techniques in the Development and Operation of Proton Exchange Membrane Fuel Cells

Cited by 17 publications

References 202 publications

Ionic Mobility in Ion-Exchange Membranes

Ionic Mobility in Ion-Exchange Membranes

Time-resolved monitoring of composite Nafion™ XL membrane degradation induced by Fenton's reaction

Unravelling Water and Salt transport in Polyamide with Nuclear Magnetic Resonance Spectroscopy

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