Suppression of Hysteresis in Absorption of Hydrogen by a Pd-Au Alloy Full article
| Journal |
Physical Review E
ISSN: 2470-0045 , E-ISSN: 2470-0053 |
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| Output data | Year: 2020, Volume: 101, Number: 4, Article number : 042130, Pages count : 9 DOI: 10.1103/physreve.101.042130 | ||||
| Tags | TOTAL-ENERGY; PALLADIUM; THERMODYNAMICS; SOLUBILITY; TRANSITION; DYNAMICS; GOLD; SIZE | ||||
| Authors |
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| Affiliations |
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Funding (1)
| 1 | Federal Agency for Scientific Organizations | 0303-2016-0001 |
Abstract:
Hydrogen absorption by Pd exhibits hysteresis loops (provided the temperature is not too high) and represents one of the classical examples of first-order phase transitions in metals. Experiments indicate that addition of even a small amount of Au is able to suppress hysteresis. From this perspective, we analyze the energetics of hydrogen in a Pd-Au alloy by using extensive density-functional-theory (DFT) calculations. The dependence of the hydrogen binding energy on the number (n) of Au atoms forming an adsorption site is found to be appreciably nonlinear. With the DFT input for statistical calculations, we reproduce special features of the hydrogen absorption isotherms and explain the rapid decrease of the corresponding critical temperature with increasing Au fraction. The key factor here is that the phase transition is related primarily to absorption in sites formed only by Pd. With increasing Au amount, the fraction of such sites rapidly decreases, the distance between H atoms located there becomes on average larger, the interaction between them becomes weaker, and accordingly the driving force for the phase transition decreases. It is of interest that all these effects can be illustrated by taking only the configurations with n≤2 into account. This means that in the context under consideration the fine details of the dependence of the hydrogen binding energy on n are in fact not too important.
Cite:
Mamatkulov M.
, Zhdanov V.P.
Suppression of Hysteresis in Absorption of Hydrogen by a Pd-Au Alloy
Physical Review E. 2020.
V.101. N4. 042130
:1-9. DOI: 10.1103/physreve.101.042130
WOS
Scopus
РИНЦ
AN
PMID
OpenAlex
Suppression of Hysteresis in Absorption of Hydrogen by a Pd-Au Alloy
Physical Review E. 2020.
V.101. N4. 042130
:1-9. DOI: 10.1103/physreve.101.042130
WOS
Scopus
РИНЦ
AN
PMID
OpenAlex
Files:
Full text from publisher
Dates:
| Submitted: | Sep 4, 2019 |
| Accepted: | Mar 23, 2020 |
| Published print: | Apr 23, 2020 |
| Published online: | Apr 23, 2020 |
Identifiers:
| Web of science: | WOS:000527889100006 |
| Scopus: | 2-s2.0-85084606181 |
| Elibrary: | 43286111 |
| Chemical Abstracts: | 2020:1374685 |
| PMID: | 32422748 |
| OpenAlex: | W3018032781 |