Selective hydrogenation of Ti–Zr–Ni alloys
We prepared series of Ti–Zr–Ni samples by melt-spinning and subsequent thermal treatment at 700 °C for 2 h in dynamic 10 −5 mbar vacuum in order to obtain mixture of crystalline C14 Laves and α, β-(Ti, Zr) phases. These samples were exposed to hydrogen gas at 300 °C and 50 bar for 1000 min. The mass...
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Published in | International journal of hydrogen energy Vol. 36; no. 4; pp. 3056 - 3061 |
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Main Authors | , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Kidlington
Elsevier Ltd
01.02.2011
Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | We prepared series of Ti–Zr–Ni samples by melt-spinning and subsequent thermal treatment at 700
°C for 2
h in dynamic 10
−5
mbar vacuum in order to obtain mixture of crystalline C14 Laves and α, β-(Ti, Zr) phases. These samples were exposed to hydrogen gas at 300
°C and 50
bar for 1000
min. The mass% of H was obtained gravimetrically and volumetrically. When approximately 1% of air was present in the Sievert device we found relatively narrow area in Ti–Zr–Ni phase diagram, so-called zero-zone, where hydrogen amounts in crystalline samples varied between 0 and 0.8
mass%. Surprisingly, icosahedral quasicrystalline (i-QC) samples showed no selective hydrogenation and absorbed more than 1.5
mass% H in the interval of compositions, where the i-phase is formed. XPS analysis revealed that the oxide layer thickness is similar after melt-spinning and thermal treatment for both type of samples, i.e. from inside and outside of the zero-zone. However, after hydrogenation the zero-zone samples had 5-times thicker surface oxide layer. In order to find, whether this is correlated to different electronic structure, DOS near E
F was examined by
1H NMR. In parallel, thermal desorption of hydrogen was performed in order to reveal, if H-bonding sites are correlated to different hydrogenation behaviour of various samples. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0360-3199 1879-3487 |
DOI: | 10.1016/j.ijhydene.2010.11.116 |