Tailored Electron Transfer Pathways in Aucore /Ptshell -Graphene Nanocatalysts for Fuel Cells

Nedjeljko Seselj, Christian Engelbrekt, Yi Ding, Hans Aage Hjuler, Jens Ulstrup, Jingdong Zhang*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

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Abstract

Aucore/Ptshell–graphene catalysts (G-Cys-Au@Pt) are prepared through chemical and surface chemical reactions. Au–Pt core–shell nanoparticles (Au@Pt NPs) covalently immobilized on graphene (G) are efficient electrocatalysts in low-temperature polymer electrolyte membrane fuel cells. The 9.5 ± 2 nm Au@Pt NPs with atomically thin Pt shells are attached on graphene via L-cysteine (Cys), which serves as linkers controlling NP loading and dispersion, enhancing the Au@Pt NP stability, and facilitating interfacial electron transfer. The increased activity of G-Cys-Au@Pt, compared to non-chemically immobilized G-Au@Pt and commercial platinum NPs catalyst (C-Pt), is a result of (1) the tailored electron transfer pathways of covalent bonds integrating Au@Pt NPs into the graphene framework, and (2) synergetic electronic effects of atomically thin Pt shells on Au cores. Enhanced electrocatalytic oxidation of formic acid, methanol, and ethanol is observed as higher specific currents and increased stability of G-Cys-Au@Pt compared to G-Au@Pt and C–Pt. Oxygen reduction on G-Cys-Au@Pt occurs at 25 mV lower potential and 43 A gPt−1 higher current (at 0.9 V vs reversible hydrogen electrode) than for C–Pt. Functional tests in direct fomic acid, methanol and ethanol fuel cells exhibit 95%, 53%, and 107% increased power densities for G-Cys-Au@Pt over C–Pt, respectively.
Original languageEnglish
Article number1702609
JournalAdvanced Energy Materials
Volume18
Issue number13
Number of pages12
ISSN1614-6832
DOIs
Publication statusPublished - 2018

Keywords

  • Au-Pt core-shell
  • Electron pathway
  • Fuel cells
  • Graphene

Cite this

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title = "Tailored Electron Transfer Pathways in Aucore /Ptshell -Graphene Nanocatalysts for Fuel Cells",
abstract = "Aucore/Ptshell–graphene catalysts (G-Cys-Au@Pt) are prepared through chemical and surface chemical reactions. Au–Pt core–shell nanoparticles (Au@Pt NPs) covalently immobilized on graphene (G) are efficient electrocatalysts in low-temperature polymer electrolyte membrane fuel cells. The 9.5 ± 2 nm Au@Pt NPs with atomically thin Pt shells are attached on graphene via L-cysteine (Cys), which serves as linkers controlling NP loading and dispersion, enhancing the Au@Pt NP stability, and facilitating interfacial electron transfer. The increased activity of G-Cys-Au@Pt, compared to non-chemically immobilized G-Au@Pt and commercial platinum NPs catalyst (C-Pt), is a result of (1) the tailored electron transfer pathways of covalent bonds integrating Au@Pt NPs into the graphene framework, and (2) synergetic electronic effects of atomically thin Pt shells on Au cores. Enhanced electrocatalytic oxidation of formic acid, methanol, and ethanol is observed as higher specific currents and increased stability of G-Cys-Au@Pt compared to G-Au@Pt and C–Pt. Oxygen reduction on G-Cys-Au@Pt occurs at 25 mV lower potential and 43 A gPt−1 higher current (at 0.9 V vs reversible hydrogen electrode) than for C–Pt. Functional tests in direct fomic acid, methanol and ethanol fuel cells exhibit 95{\%}, 53{\%}, and 107{\%} increased power densities for G-Cys-Au@Pt over C–Pt, respectively.",
keywords = "Au-Pt core-shell, Electron pathway, Fuel cells, Graphene",
author = "Nedjeljko Seselj and Christian Engelbrekt and Yi Ding and Hjuler, {Hans Aage} and Jens Ulstrup and Jingdong Zhang",
year = "2018",
doi = "10.1002/aenm.201702609",
language = "English",
volume = "18",
journal = "Advanced Energy Materials",
issn = "1614-6832",
publisher = "Wiley - V C H Verlag GmbH & Co. KGaA",
number = "13",

}

Tailored Electron Transfer Pathways in Aucore /Ptshell -Graphene Nanocatalysts for Fuel Cells. / Seselj, Nedjeljko; Engelbrekt, Christian; Ding, Yi; Hjuler, Hans Aage; Ulstrup, Jens; Zhang, Jingdong.

In: Advanced Energy Materials, Vol. 18, No. 13, 1702609, 2018.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Tailored Electron Transfer Pathways in Aucore /Ptshell -Graphene Nanocatalysts for Fuel Cells

AU - Seselj, Nedjeljko

AU - Engelbrekt, Christian

AU - Ding, Yi

AU - Hjuler, Hans Aage

AU - Ulstrup, Jens

AU - Zhang, Jingdong

PY - 2018

Y1 - 2018

N2 - Aucore/Ptshell–graphene catalysts (G-Cys-Au@Pt) are prepared through chemical and surface chemical reactions. Au–Pt core–shell nanoparticles (Au@Pt NPs) covalently immobilized on graphene (G) are efficient electrocatalysts in low-temperature polymer electrolyte membrane fuel cells. The 9.5 ± 2 nm Au@Pt NPs with atomically thin Pt shells are attached on graphene via L-cysteine (Cys), which serves as linkers controlling NP loading and dispersion, enhancing the Au@Pt NP stability, and facilitating interfacial electron transfer. The increased activity of G-Cys-Au@Pt, compared to non-chemically immobilized G-Au@Pt and commercial platinum NPs catalyst (C-Pt), is a result of (1) the tailored electron transfer pathways of covalent bonds integrating Au@Pt NPs into the graphene framework, and (2) synergetic electronic effects of atomically thin Pt shells on Au cores. Enhanced electrocatalytic oxidation of formic acid, methanol, and ethanol is observed as higher specific currents and increased stability of G-Cys-Au@Pt compared to G-Au@Pt and C–Pt. Oxygen reduction on G-Cys-Au@Pt occurs at 25 mV lower potential and 43 A gPt−1 higher current (at 0.9 V vs reversible hydrogen electrode) than for C–Pt. Functional tests in direct fomic acid, methanol and ethanol fuel cells exhibit 95%, 53%, and 107% increased power densities for G-Cys-Au@Pt over C–Pt, respectively.

AB - Aucore/Ptshell–graphene catalysts (G-Cys-Au@Pt) are prepared through chemical and surface chemical reactions. Au–Pt core–shell nanoparticles (Au@Pt NPs) covalently immobilized on graphene (G) are efficient electrocatalysts in low-temperature polymer electrolyte membrane fuel cells. The 9.5 ± 2 nm Au@Pt NPs with atomically thin Pt shells are attached on graphene via L-cysteine (Cys), which serves as linkers controlling NP loading and dispersion, enhancing the Au@Pt NP stability, and facilitating interfacial electron transfer. The increased activity of G-Cys-Au@Pt, compared to non-chemically immobilized G-Au@Pt and commercial platinum NPs catalyst (C-Pt), is a result of (1) the tailored electron transfer pathways of covalent bonds integrating Au@Pt NPs into the graphene framework, and (2) synergetic electronic effects of atomically thin Pt shells on Au cores. Enhanced electrocatalytic oxidation of formic acid, methanol, and ethanol is observed as higher specific currents and increased stability of G-Cys-Au@Pt compared to G-Au@Pt and C–Pt. Oxygen reduction on G-Cys-Au@Pt occurs at 25 mV lower potential and 43 A gPt−1 higher current (at 0.9 V vs reversible hydrogen electrode) than for C–Pt. Functional tests in direct fomic acid, methanol and ethanol fuel cells exhibit 95%, 53%, and 107% increased power densities for G-Cys-Au@Pt over C–Pt, respectively.

KW - Au-Pt core-shell

KW - Electron pathway

KW - Fuel cells

KW - Graphene

U2 - 10.1002/aenm.201702609

DO - 10.1002/aenm.201702609

M3 - Journal article

VL - 18

JO - Advanced Energy Materials

JF - Advanced Energy Materials

SN - 1614-6832

IS - 13

M1 - 1702609

ER -