Structural transformations and adsorption properties of PtNi nanoalloy thin film electrocatalysts prepared by magnetron co-sputtering
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F17%3A10371505" target="_blank" >RIV/00216208:11320/17:10371505 - isvavai.cz</a>
Result on the web
<a href="http://dx.doi.org/10.1016/j.electacta.2017.08.062" target="_blank" >http://dx.doi.org/10.1016/j.electacta.2017.08.062</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1016/j.electacta.2017.08.062" target="_blank" >10.1016/j.electacta.2017.08.062</a>
Alternative languages
Result language
angličtina
Original language name
Structural transformations and adsorption properties of PtNi nanoalloy thin film electrocatalysts prepared by magnetron co-sputtering
Original language description
PtNi thin film catalysts provide higher activity and enhanced Pt efficiency in the oxygen reduction reaction (ORR) in comparison to pure Pt catalysts. We explored the structural transformations and degradation mechanisms in such films by cyclic voltammetry (CV), electrochemical atomic force microscopy (EC-AFM), and electrochemical infrared reflection absorption spectroscopy (EC-IRRAS) using CO as a probe. The model catalysts were prepared by magnetron sputtering, and the results were compared to reference experiments on Pt(111). Freshly prepared catalysts show two characteristic IR bands in the on-top CO region. The signal at lower wavenumbers is assigned to isolated CO on Pt sites. Based on density functional theory (DFT) calculations, we suggest that another blue-shifted CO band can be attributed to dicarbonyls on low-coordinated Pt centers, generated by the leaching of surface Ni. This band vanishes upon cycling to 1.1 V versus the reversible hydrogen electrode (V-RHE) and the catalyst shows a weak decrease in grain size in AFM. A dramatic change of the film structure is observed upon potential cycling to 1.2 V-RHE. CV indicates the formation of [110] and [100] steps and AFM points to a strong decrease in particle size. Simultaneously, EC-IRRAS shows the appearance of a new, strongly red-shifted CO band. Based on DFT, we assign these changes to a transient enrichment of Ni in the (sub) surface region. Upon cycling to higher potential, Ni is completely leached from the surface region, and large Pt particles are formed.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10305 - Fluids and plasma physics (including surface physics)
Result continuities
Project
Result was created during the realization of more than one project. More information in the Projects tab.
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2017
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Electrochimica Acta
ISSN
0013-4686
e-ISSN
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Volume of the periodical
251
Issue of the periodical within the volume
10. října
Country of publishing house
GB - UNITED KINGDOM
Number of pages
15
Pages from-to
427-441
UT code for WoS article
000413004200046
EID of the result in the Scopus database
2-s2.0-85028540223