Electrochemical study of hydrogen absorption in polycrystalline palladium

The hydrogen reactions on polycrystalline Pd in 0.1 M NaOH at 25°C have been studied by using transients at constant potential, and by impedance spectroscopy and X-ray diffraction techniques. At potentials, E<sub>s</sub>, more positive than the reversible potential, E<sub>r</sub...

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Autores principales: Salvarezza, Roberto Carlos, Montemayor, M. C., Fatas, E., Arvia, Alejandro Jorge
Formato: Articulo
Lenguaje:Inglés
Publicado: 1991
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Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/119924
https://www.sciencedirect.com/science/article/abs/pii/002207289185186S
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id I19-R120-10915-119924
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Ciencias Exactas
Química
Hydrogen absorption
Polycrystalline palladium
spellingShingle Ciencias Exactas
Química
Hydrogen absorption
Polycrystalline palladium
Salvarezza, Roberto Carlos
Montemayor, M. C.
Fatas, E.
Arvia, Alejandro Jorge
Electrochemical study of hydrogen absorption in polycrystalline palladium
topic_facet Ciencias Exactas
Química
Hydrogen absorption
Polycrystalline palladium
description The hydrogen reactions on polycrystalline Pd in 0.1 M NaOH at 25°C have been studied by using transients at constant potential, and by impedance spectroscopy and X-ray diffraction techniques. At potentials, E<sub>s</sub>, more positive than the reversible potential, E<sub>r</sub>, for the H<sub>2</sub> evolution reaction, the current-time response and the impedance data indicate H atom diffusion into the bulk Pd. The X-ray diffraction pattern of electrodes cathodized during 20 min at these potentials are similar to those obtained for Pd. At Es < Er, the current transients exhibit a current maximum which increases as E<sub>s</sub> moves in the negative direction. The Nyquist plot for the rising part of the transients indicates the H atom diffusion into the bulk metal and H<sub>2</sub> evolution on the Pd surface at high frequencies. The X-ray diffraction pattern of the electrodes cathodized at E<sub>s</sub> < E<sub>r</sub>, shows the presence of the βPdH phase and Pd. The experimental results indicate that different reactions take place simultaneously in this potential range: (i) H<sub>s</sub> evolution, (ii) H diffusion into the bulk Pd, (iii) nucleation and diffusion-controlled growth of the βPdH phase. Taking into account the contribution of these reactions, a model, which is able to reproduce the experimental current transients, is presented.
format Articulo
Articulo
author Salvarezza, Roberto Carlos
Montemayor, M. C.
Fatas, E.
Arvia, Alejandro Jorge
author_facet Salvarezza, Roberto Carlos
Montemayor, M. C.
Fatas, E.
Arvia, Alejandro Jorge
author_sort Salvarezza, Roberto Carlos
title Electrochemical study of hydrogen absorption in polycrystalline palladium
title_short Electrochemical study of hydrogen absorption in polycrystalline palladium
title_full Electrochemical study of hydrogen absorption in polycrystalline palladium
title_fullStr Electrochemical study of hydrogen absorption in polycrystalline palladium
title_full_unstemmed Electrochemical study of hydrogen absorption in polycrystalline palladium
title_sort electrochemical study of hydrogen absorption in polycrystalline palladium
publishDate 1991
url http://sedici.unlp.edu.ar/handle/10915/119924
https://www.sciencedirect.com/science/article/abs/pii/002207289185186S
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AT fatase electrochemicalstudyofhydrogenabsorptioninpolycrystallinepalladium
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