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Synthesis and Characterization of Catalytically Active Au Core—Pd Shell Nanoparticles Supported on Alumina

[Image: see text] A two-step seeded-growth method was refined to synthesize Au@Pd core@shell nanoparticles with thin Pd shells, which were then deposited onto alumina to obtain a supported Au@Pd/Al(2)O(3) catalyst active for prototypical CO oxidation. By the strict control of temperature and Pd/Au m...

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Autores principales: Feng, Yanyue, Schaefer, Andreas, Hellman, Anders, Di, Mengqiao, Härelind, Hanna, Bauer, Matthias, Carlsson, Per-Anders
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2022
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9609311/
https://www.ncbi.nlm.nih.gov/pubmed/36221959
http://dx.doi.org/10.1021/acs.langmuir.2c01834
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author Feng, Yanyue
Schaefer, Andreas
Hellman, Anders
Di, Mengqiao
Härelind, Hanna
Bauer, Matthias
Carlsson, Per-Anders
author_facet Feng, Yanyue
Schaefer, Andreas
Hellman, Anders
Di, Mengqiao
Härelind, Hanna
Bauer, Matthias
Carlsson, Per-Anders
author_sort Feng, Yanyue
collection PubMed
description [Image: see text] A two-step seeded-growth method was refined to synthesize Au@Pd core@shell nanoparticles with thin Pd shells, which were then deposited onto alumina to obtain a supported Au@Pd/Al(2)O(3) catalyst active for prototypical CO oxidation. By the strict control of temperature and Pd/Au molar ratio and the use of l-ascorbic acid for making both Au cores and Pd shells, a 1.5 nm Pd layer is formed around the Au core, as evidenced by transmission electron microscopy and energy-dispersive spectroscopy. The core@shell structure and the Pd shell remain intact upon deposition onto alumina and after being used for CO oxidation, as revealed by additional X-ray diffraction and X-ray photoemission spectroscopy before and after the reaction. The Pd shell surface was characterized with in situ infrared (IR) spectroscopy using CO as a chemical probe during CO adsorption–desorption. The IR bands for CO ad-species on the Pd shell suggest that the shell exposes mostly low-index surfaces, likely Pd(111) as the majority facet. Generally, the IR bands are blue-shifted as compared to conventional Pd/alumina catalysts, which may be due to the different support materials for Pd, Au versus Al(2)O(3), and/or less strain of the Pd shell. Frequencies obtained from density functional calculations suggest the latter to be significant. Further, the catalytic CO oxidation ignition-extinction processes were followed by in situ IR, which shows the common CO poisoning and kinetic behavior associated with competitive adsorption of CO and O(2) that is typically observed for noble metal catalysts.
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spelling pubmed-96093112022-10-28 Synthesis and Characterization of Catalytically Active Au Core—Pd Shell Nanoparticles Supported on Alumina Feng, Yanyue Schaefer, Andreas Hellman, Anders Di, Mengqiao Härelind, Hanna Bauer, Matthias Carlsson, Per-Anders Langmuir [Image: see text] A two-step seeded-growth method was refined to synthesize Au@Pd core@shell nanoparticles with thin Pd shells, which were then deposited onto alumina to obtain a supported Au@Pd/Al(2)O(3) catalyst active for prototypical CO oxidation. By the strict control of temperature and Pd/Au molar ratio and the use of l-ascorbic acid for making both Au cores and Pd shells, a 1.5 nm Pd layer is formed around the Au core, as evidenced by transmission electron microscopy and energy-dispersive spectroscopy. The core@shell structure and the Pd shell remain intact upon deposition onto alumina and after being used for CO oxidation, as revealed by additional X-ray diffraction and X-ray photoemission spectroscopy before and after the reaction. The Pd shell surface was characterized with in situ infrared (IR) spectroscopy using CO as a chemical probe during CO adsorption–desorption. The IR bands for CO ad-species on the Pd shell suggest that the shell exposes mostly low-index surfaces, likely Pd(111) as the majority facet. Generally, the IR bands are blue-shifted as compared to conventional Pd/alumina catalysts, which may be due to the different support materials for Pd, Au versus Al(2)O(3), and/or less strain of the Pd shell. Frequencies obtained from density functional calculations suggest the latter to be significant. Further, the catalytic CO oxidation ignition-extinction processes were followed by in situ IR, which shows the common CO poisoning and kinetic behavior associated with competitive adsorption of CO and O(2) that is typically observed for noble metal catalysts. American Chemical Society 2022-10-12 2022-10-25 /pmc/articles/PMC9609311/ /pubmed/36221959 http://dx.doi.org/10.1021/acs.langmuir.2c01834 Text en © 2022 The Authors. Published by American Chemical Society https://creativecommons.org/licenses/by/4.0/Permits the broadest form of re-use including for commercial purposes, provided that author attribution and integrity are maintained (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Feng, Yanyue
Schaefer, Andreas
Hellman, Anders
Di, Mengqiao
Härelind, Hanna
Bauer, Matthias
Carlsson, Per-Anders
Synthesis and Characterization of Catalytically Active Au Core—Pd Shell Nanoparticles Supported on Alumina
title Synthesis and Characterization of Catalytically Active Au Core—Pd Shell Nanoparticles Supported on Alumina
title_full Synthesis and Characterization of Catalytically Active Au Core—Pd Shell Nanoparticles Supported on Alumina
title_fullStr Synthesis and Characterization of Catalytically Active Au Core—Pd Shell Nanoparticles Supported on Alumina
title_full_unstemmed Synthesis and Characterization of Catalytically Active Au Core—Pd Shell Nanoparticles Supported on Alumina
title_short Synthesis and Characterization of Catalytically Active Au Core—Pd Shell Nanoparticles Supported on Alumina
title_sort synthesis and characterization of catalytically active au core—pd shell nanoparticles supported on alumina
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9609311/
https://www.ncbi.nlm.nih.gov/pubmed/36221959
http://dx.doi.org/10.1021/acs.langmuir.2c01834
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