Nanocomposite Concept for Electrochemical In Situ Preparation of Pt-Au Alloy Nanoparticles for Formic Acid Oxidation.

Autor:	Du J; Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, 3012 Bern, Switzerland., Quinson J; Department of Chemistry, University of Copenhagen, 2100 Copenhagen, Denmark.; Department of Biochemical and Chemical Engineering, University of Aarhus, 8200 Aarhus, Denmark., Zhang D; Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, 3012 Bern, Switzerland., Wang B; Department of Chemistry, University of Copenhagen, 2100 Copenhagen, Denmark., Wiberg GKH; Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, 3012 Bern, Switzerland., Pittkowski RK; Department of Chemistry, University of Copenhagen, 2100 Copenhagen, Denmark., Schröder J; Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, 3012 Bern, Switzerland., Simonsen SB; Department of Energy Conversion and Storage, Technical University of Denmark, 2800 Lyngby, Denmark., Kirkensgaard JJK; Department of Food Science, University of Copenhagen, 1958 Frederiksberg, Denmark.; Niels-Bohr-Institute, University of Copenhagen, 2100 Copenhagen, Denmark., Li Y; Technical Chemistry I and Center of Nanointegration Duisburg Essen (CENIDE), University of Duisburg-Essen, 45141 Essen, Germany., Reichenberger S; Technical Chemistry I and Center of Nanointegration Duisburg Essen (CENIDE), University of Duisburg-Essen, 45141 Essen, Germany., Barcikowski S; Technical Chemistry I and Center of Nanointegration Duisburg Essen (CENIDE), University of Duisburg-Essen, 45141 Essen, Germany., Jensen KMØ; Department of Chemistry, University of Copenhagen, 2100 Copenhagen, Denmark., Arenz M; Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, 3012 Bern, Switzerland.
Jazyk:	angličtina
Zdroj:	JACS Au [JACS Au] 2022 Jul 06; Vol. 2 (7), pp. 1757-1768. Date of Electronic Publication: 2022 Jul 06 (Print Publication: 2022).
DOI:	10.1021/jacsau.2c00335
Abstrakt:	Herein, we report a straightforward approach for the in situ preparation of Pt-Au alloy nanoparticles from Pt + x Au/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. Competing Interests: The authors declare no competing financial interest. (© 2022 The Authors. Published by American Chemical Society.)
Databáze:	MEDLINE
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