Impedance studies of hydrogen evolution on NiP alloys
The hydrogen evolution reaction (HER) was studied on electrodeposited NiP alloys containing 7, 20 and 28 at.% P. Potentiodynamic, potentiostatic and impedance spectroscopy measurements were performed in 0.1 M H 2SO 4 solution. Kinetic parameters of the HER were derived from the analysis of polarisa...
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Published in | Electrochimica acta Vol. 47; no. 13; pp. 2065 - 2069 |
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Main Authors | , |
Format | Journal Article Conference Proceeding |
Language | English |
Published |
Oxford
Elsevier Ltd
25.05.2002
Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | The hydrogen evolution reaction (HER) was studied on electrodeposited NiP alloys containing 7, 20 and 28 at.% P. Potentiodynamic, potentiostatic and impedance spectroscopy measurements were performed in 0.1 M H
2SO
4 solution. Kinetic parameters of the HER were derived from the analysis of polarisation and impedance data. Crystalline Ni7P alloy showed higher rate of the HER than amorphous Ni20P and Ni28P samples. However, this difference was small. The evident increase of the rate of the HER was observed for the crystalline Ni7P upon anodic prepolarisation. Under these circumstances the nature of the HER was changed and very high values of interfacial capacitance and much lower values of Tafel slope were found. These high values of interfacial capacitance can be assigned to the onset of a porous phosphate film on the alloy surface. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0013-4686 1873-3859 |
DOI: | 10.1016/S0013-4686(02)00074-9 |