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Evolution of the PtNi Bimetallic Alloy Fuel Cell Catalyst under Simulated Operational Conditions
- Source :
- ACS Applied Materials & Interfaces. 12:17602-17610
- Publication Year :
- 2020
- Publisher :
- American Chemical Society (ACS), 2020.
-
Abstract
- Comprehensive understanding of the catalyst corrosion dynamics is a prerequisite for the development of an efficient cathode catalyst in proton-exchange membrane fuel cells. To reach this aim, the behavior of fuel cell catalysts must be investigated directly under reaction conditions. Herein, we applied a strategic combination of in situ/online techniques: in situ electrochemical atomic force microscopy, in situ grazing incidence small angle X-ray scattering, and electrochemical scanning flow cell with online detection by inductively coupled plasma mass spectrometry. This combination of techniques allows in-depth investigation of the potential-dependent surface restructuring of a PtNi model thin film catalyst during potentiodynamic cycling in an aqueous acidic electrolyte. The study reveals a clear correlation between the upper potential limit and structural behavior of the PtNi catalyst, namely, its dealloying and coarsening. The results show that at 0.6 and 1.0 VRHE upper potentials, the PtNi catalyst essentially preserves its structure during the entire cycling procedure. The crucial changes in the morphology of PtNi layers are found to occur at 1.3 and 1.5 VRHE cycling potentials. Strong dealloying at the early stage of cycling is substituted with strong coarsening of catalyst particles at the later stage. The coarsening at the later stage of cycling is assigned to the electrochemical Ostwald ripening process.
- Subjects :
- Ostwald ripening
Materials science
Alloy
02 engineering and technology
Electrolyte
engineering.material
010402 general chemistry
021001 nanoscience & nanotechnology
Electrochemistry
01 natural sciences
0104 chemical sciences
Corrosion
Catalysis
symbols.namesake
Chemical engineering
engineering
symbols
General Materials Science
Thin film
0210 nano-technology
Bimetallic strip
Subjects
Details
- ISSN :
- 19448252 and 19448244
- Volume :
- 12
- Database :
- OpenAIRE
- Journal :
- ACS Applied Materials & Interfaces
- Accession number :
- edsair.doi.dedup.....062f094547a83c33cef3e678076001ce