Du, Jia; Quinson, Jonathan; Zhang, Damin; Wang, Baiyu; Wiberg, Gustav K H; Pittkowski, Rebecca K; Schröder, Johanna; Simonsen, Søren B; Kirkensgaard, Jacob J K; Li, Yao; Reichenberger, Sven; Barcikowski, Stephan; Jensen, Kirsten M Ø; Arenz, Matthias (2022). Nanocomposite Concept for Electrochemical In Situ Preparation of Pt-Au Alloy Nanoparticles for Formic Acid Oxidation. JACS Au, 2(7), pp. 1757-1768. ACS Publications 10.1021/jacsau.2c00335
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Herein, we report a straightforward approach for the in situ preparation of Pt-Au alloy nanoparticles from Pt + xAu/C nanocomposites using monometallic colloidal nanoparticles as starting blocks. Four different compositions with fixed Pt content and varying Pt to Au mass ratios from 1:1 up to 1:7 were prepared as formic acid oxidation reaction (FAOR) catalysts. The study was carried out in a gas diffusion electrode (GDE) setup. It is shown that the presence of Au in the nanocomposites substantially improves the FAOR activity with respect to pure Pt/C, which serves as a reference. The nanocomposite with a mass ratio of 1:5 between Pt and Au displays the best performance during potentiodynamic tests, with the electro-oxidation rates, overpotential, and poisoning resistance being improved simultaneously. By comparison, too low or too high Au contributions in the nanocomposites lead to an unbalanced performance in the FAOR. The combination of operando small-angle X-ray scattering (SAXS), scanning transmission electron microscopy (STEM) elemental mapping, and wide-angle X-ray scattering (WAXS) reveals that for the nanocomposite with a 1:5 mass ratio, a conversion between Pt and Au from separate nanoparticles to alloy nanoparticles occurs during continuous potential cycling in formic acid. By comparison, the nanocomposites with lower Au contents, for example, 1:2, exhibit less in situ alloying, and the concomitant performance improvement is less pronounced. On applying identical location transmission electron microscopy (IL-TEM), it is revealed that the in situ alloying is due to Pt dissolution and re-deposition onto Au as well as Pt migration and coalescence with Au nanoparticles.
Item Type: |
Journal Article (Original Article) |
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Division/Institute: |
09 Interdisciplinary Units > Microscopy Imaging Center (MIC) 08 Faculty of Science > Department of Chemistry, Biochemistry and Pharmaceutical Sciences (DCBP) |
UniBE Contributor: |
Du, Jia, Wiberg, Gustav Karl Henrik, Schröder, Johanna, Arenz, Matthias |
Subjects: |
500 Science > 570 Life sciences; biology 500 Science > 540 Chemistry |
ISSN: |
2691-3704 |
Publisher: |
ACS Publications |
Language: |
English |
Submitter: |
Pubmed Import |
Date Deposited: |
04 Aug 2022 12:02 |
Last Modified: |
30 May 2023 11:14 |
Publisher DOI: |
10.1021/jacsau.2c00335 |
PubMed ID: |
35911453 |
BORIS DOI: |
10.48350/171684 |
URI: |
https://boris.unibe.ch/id/eprint/171684 |
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