Scalable Synthesis of Carbon-Supported Platinum–Lanthanide and −Rare-Earth Alloys for Oxygen Reduction

Claudie Roy, Brian P. Knudsen, Christoffer M. Pedersen, Amado Velazquez-Palenzuela, Leif H. Christensen, Christian Danvad Damsgaard, Ifan E. L. Stephens, Ib Chorkendorff*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

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Abstract

Platinum–rare-earthalloys have proven to be both active and stable under accelerated stability tests in their bulk polycrystalline form. However, a scalable method for the synthesis of a high-surface-area supported catalyst of these alloys has so far not been presented. Herein we discuss the thermodynamics relevant for the reduction conditions of the rare earths to form alloys with platinum. We show how the tolerance for water and oxygen severely limits the synthesis parameters and how under certain conditions the thermal reduction of YCl3 with H2 is possible from 500 °C. From the insight gained, we synthesized a PtxY/C catalyst by modifying a Pt/C catalyst and confirmed alloy formation by both X-ray diffraction and X-ray photoelectron spectroscopy measurements.These reveal crystalline intermetallic phases and the metallic state of yttrium. Without any optimization of the method, the catalyst has an improved mass activity in comparison to the unmodified catalyst,proving the viability of the method. Initial work based on thermodynamic equilibrium calculations on reduction time show promise in controlling the phase formed by tuning the parameters of time, temperature, and gas composition.
Original languageEnglish
JournalA C S Catalysis
Volume8
Pages (from-to)2071-2080
ISSN2155-5435
DOIs
Publication statusPublished - 2018

Keywords

  • Synthesis
  • Rare earths
  • Platinum
  • Alloy
  • Oxygen reduction reaction
  • Proton exchange membrane fuel cell
  • Nanoparticles

Cite this

@article{e09918da362a44759cde7e986b0326c6,
title = "Scalable Synthesis of Carbon-Supported Platinum–Lanthanide and −Rare-Earth Alloys for Oxygen Reduction",
abstract = "Platinum–rare-earthalloys have proven to be both active and stable under accelerated stability tests in their bulk polycrystalline form. However, a scalable method for the synthesis of a high-surface-area supported catalyst of these alloys has so far not been presented. Herein we discuss the thermodynamics relevant for the reduction conditions of the rare earths to form alloys with platinum. We show how the tolerance for water and oxygen severely limits the synthesis parameters and how under certain conditions the thermal reduction of YCl3 with H2 is possible from 500 °C. From the insight gained, we synthesized a PtxY/C catalyst by modifying a Pt/C catalyst and confirmed alloy formation by both X-ray diffraction and X-ray photoelectron spectroscopy measurements.These reveal crystalline intermetallic phases and the metallic state of yttrium. Without any optimization of the method, the catalyst has an improved mass activity in comparison to the unmodified catalyst,proving the viability of the method. Initial work based on thermodynamic equilibrium calculations on reduction time show promise in controlling the phase formed by tuning the parameters of time, temperature, and gas composition.",
keywords = "Synthesis, Rare earths, Platinum, Alloy, Oxygen reduction reaction, Proton exchange membrane fuel cell, Nanoparticles",
author = "Claudie Roy and Knudsen, {Brian P.} and Pedersen, {Christoffer M.} and Amado Velazquez-Palenzuela and Christensen, {Leif H.} and Damsgaard, {Christian Danvad} and Stephens, {Ifan E. L.} and Ib Chorkendorff",
year = "2018",
doi = "10.1021/acscatal.7b03972",
language = "English",
volume = "8",
pages = "2071--2080",
journal = "A C S Catalysis",
issn = "2155-5435",
publisher = "American Chemical Society",

}

Scalable Synthesis of Carbon-Supported Platinum–Lanthanide and −Rare-Earth Alloys for Oxygen Reduction. / Roy, Claudie; Knudsen, Brian P.; Pedersen, Christoffer M.; Velazquez-Palenzuela, Amado ; Christensen, Leif H.; Damsgaard, Christian Danvad; Stephens, Ifan E. L.; Chorkendorff, Ib.

In: A C S Catalysis, Vol. 8, 2018, p. 2071-2080.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Scalable Synthesis of Carbon-Supported Platinum–Lanthanide and −Rare-Earth Alloys for Oxygen Reduction

AU - Roy, Claudie

AU - Knudsen, Brian P.

AU - Pedersen, Christoffer M.

AU - Velazquez-Palenzuela, Amado

AU - Christensen, Leif H.

AU - Damsgaard, Christian Danvad

AU - Stephens, Ifan E. L.

AU - Chorkendorff, Ib

PY - 2018

Y1 - 2018

N2 - Platinum–rare-earthalloys have proven to be both active and stable under accelerated stability tests in their bulk polycrystalline form. However, a scalable method for the synthesis of a high-surface-area supported catalyst of these alloys has so far not been presented. Herein we discuss the thermodynamics relevant for the reduction conditions of the rare earths to form alloys with platinum. We show how the tolerance for water and oxygen severely limits the synthesis parameters and how under certain conditions the thermal reduction of YCl3 with H2 is possible from 500 °C. From the insight gained, we synthesized a PtxY/C catalyst by modifying a Pt/C catalyst and confirmed alloy formation by both X-ray diffraction and X-ray photoelectron spectroscopy measurements.These reveal crystalline intermetallic phases and the metallic state of yttrium. Without any optimization of the method, the catalyst has an improved mass activity in comparison to the unmodified catalyst,proving the viability of the method. Initial work based on thermodynamic equilibrium calculations on reduction time show promise in controlling the phase formed by tuning the parameters of time, temperature, and gas composition.

AB - Platinum–rare-earthalloys have proven to be both active and stable under accelerated stability tests in their bulk polycrystalline form. However, a scalable method for the synthesis of a high-surface-area supported catalyst of these alloys has so far not been presented. Herein we discuss the thermodynamics relevant for the reduction conditions of the rare earths to form alloys with platinum. We show how the tolerance for water and oxygen severely limits the synthesis parameters and how under certain conditions the thermal reduction of YCl3 with H2 is possible from 500 °C. From the insight gained, we synthesized a PtxY/C catalyst by modifying a Pt/C catalyst and confirmed alloy formation by both X-ray diffraction and X-ray photoelectron spectroscopy measurements.These reveal crystalline intermetallic phases and the metallic state of yttrium. Without any optimization of the method, the catalyst has an improved mass activity in comparison to the unmodified catalyst,proving the viability of the method. Initial work based on thermodynamic equilibrium calculations on reduction time show promise in controlling the phase formed by tuning the parameters of time, temperature, and gas composition.

KW - Synthesis

KW - Rare earths

KW - Platinum

KW - Alloy

KW - Oxygen reduction reaction

KW - Proton exchange membrane fuel cell

KW - Nanoparticles

U2 - 10.1021/acscatal.7b03972

DO - 10.1021/acscatal.7b03972

M3 - Journal article

VL - 8

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JO - A C S Catalysis

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SN - 2155-5435

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