Pt submonolayers on metal nanoparticles - Novel electrocatalysts for H 2 oxidation and O2 reduction

K. Sasaki; Y. Mo; J. X. Wang; M. Balasubramanian; F. Uribe; J. McBreen; R. R. Adzic

doi:10.1016/S0013-4686(03)00518-8

Pt submonolayers on metal nanoparticles - Novel electrocatalysts for H ₂ oxidation and O₂ reduction

K. Sasaki, Y. Mo, J. X. Wang, M. Balasubramanian, F. Uribe, J. McBreen, R. R. Adzic

Emerging and Solid-State Batteries

Research output: Contribution to journal › Conference article › peer-review

162 Scopus citations

Abstract

Novel electrocatalysts based on Pt submonolayer deposits on Ru and Au nanoparticles, and on a Au(111) surface, have been prepared by two new methods for noble metal monolayer deposition. These were tested for H₂ and H₂/CO oxidation and O₂ reduction kinetics. Our recently reported methods for controlled submonolayer-to-multilayer deposition of Pt involve spontaneous deposition of Pt on Ru and Pt deposition by redox replacement of a Cu upd monolayer on Au. The Pt mass-specific activity for H₂ oxidation of the PtRu₂₀ electrocatalyst was found to be three to four times higher than that of commercial catalysts at 25°C. The CO tolerance appears to be also higher than those of commercial catalysts under conditions of rotating disk experiments. Fuel cell tests at 80°C have shown practically the same activity of the PtRu₂₀ electrocatalyst for H₂ oxidation as that of the catalyst containing a 10× larger Pt loading. Extended X-ray absorption fine structure spectroscopy measurements showed that Pt is coordinated with three to four Ru atoms in this catalyst, with a bond length of 2.68 Å between Pt and Ru as in PtRu alloys. A Pt_0.75Pd_0.25 monolayer on Au/C is a very active electrocatalyst for O₂ reduction that equals the activity of a Pt/C catalyst with a 2.5 times larger Pt loading. The activity of a Pt monolayer on Au(1 1 1) is also considerable. A single Tafel slope of -110 mV for the Pt _0.75Pd_0.25/Au/C catalyst, and a -120 mV for Au(1 1 1), may indicate a smaller adsorption of OH on Pt and Pt_0.75Pd _0.25 on Au in comparison with bulk or nano Pt. Further work utilizing a Pt monolayer on metal nanoparticles seems to be a promising approach for both reduction of noble metal loading and designing electrocatalysts with improved properties.

Original language	English
Pages (from-to)	3841-3849
Number of pages	9
Journal	Electrochimica Acta
Volume	48
Issue number	25-26
DOIs	https://doi.org/10.1016/S0013-4686(03)00518-8
State	Published - Nov 15 2003
Event	Electrocatalysis: From Theory to Industrial Applications - Como, Italy Duration: Sep 22 2002 → Sep 24 2002

Funding

This work is supported by US Department of Energy, Divisions of Chemical and Material Sciences, under the Contract No. DE-AC02-98CH10886.

Keywords

Au nanoparticles
CO tolerance
H oxidation
O reduction
Pt monolayer
Ru nanoparticles

Access to Document

10.1016/S0013-4686(03)00518-8

Cite this

@article{1090176d6a3e4f8e90f6b6d637d029ae,

title = "Pt submonolayers on metal nanoparticles - Novel electrocatalysts for H 2 oxidation and O2 reduction",

abstract = "Novel electrocatalysts based on Pt submonolayer deposits on Ru and Au nanoparticles, and on a Au(111) surface, have been prepared by two new methods for noble metal monolayer deposition. These were tested for H2 and H2/CO oxidation and O2 reduction kinetics. Our recently reported methods for controlled submonolayer-to-multilayer deposition of Pt involve spontaneous deposition of Pt on Ru and Pt deposition by redox replacement of a Cu upd monolayer on Au. The Pt mass-specific activity for H2 oxidation of the PtRu20 electrocatalyst was found to be three to four times higher than that of commercial catalysts at 25°C. The CO tolerance appears to be also higher than those of commercial catalysts under conditions of rotating disk experiments. Fuel cell tests at 80°C have shown practically the same activity of the PtRu20 electrocatalyst for H2 oxidation as that of the catalyst containing a 10× larger Pt loading. Extended X-ray absorption fine structure spectroscopy measurements showed that Pt is coordinated with three to four Ru atoms in this catalyst, with a bond length of 2.68 {\AA} between Pt and Ru as in PtRu alloys. A Pt0.75Pd0.25 monolayer on Au/C is a very active electrocatalyst for O2 reduction that equals the activity of a Pt/C catalyst with a 2.5 times larger Pt loading. The activity of a Pt monolayer on Au(1 1 1) is also considerable. A single Tafel slope of -110 mV for the Pt 0.75Pd0.25/Au/C catalyst, and a -120 mV for Au(1 1 1), may indicate a smaller adsorption of OH on Pt and Pt0.75Pd 0.25 on Au in comparison with bulk or nano Pt. Further work utilizing a Pt monolayer on metal nanoparticles seems to be a promising approach for both reduction of noble metal loading and designing electrocatalysts with improved properties.",

keywords = "Au nanoparticles, CO tolerance, H oxidation, O reduction, Pt monolayer, Ru nanoparticles",

author = "K. Sasaki and Y. Mo and Wang, {J. X.} and M. Balasubramanian and F. Uribe and J. McBreen and Adzic, {R. R.}",

year = "2003",

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volume = "48",

pages = "3841--3849",

journal = "Electrochimica Acta",

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note = "Electrocatalysis: From Theory to Industrial Applications ; Conference date: 22-09-2002 Through 24-09-2002",

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TY - JOUR

T1 - Pt submonolayers on metal nanoparticles - Novel electrocatalysts for H 2 oxidation and O2 reduction

AU - Sasaki, K.

AU - Mo, Y.

AU - Wang, J. X.

AU - Balasubramanian, M.

AU - Uribe, F.

AU - McBreen, J.

AU - Adzic, R. R.

PY - 2003/11/15

Y1 - 2003/11/15

N2 - Novel electrocatalysts based on Pt submonolayer deposits on Ru and Au nanoparticles, and on a Au(111) surface, have been prepared by two new methods for noble metal monolayer deposition. These were tested for H2 and H2/CO oxidation and O2 reduction kinetics. Our recently reported methods for controlled submonolayer-to-multilayer deposition of Pt involve spontaneous deposition of Pt on Ru and Pt deposition by redox replacement of a Cu upd monolayer on Au. The Pt mass-specific activity for H2 oxidation of the PtRu20 electrocatalyst was found to be three to four times higher than that of commercial catalysts at 25°C. The CO tolerance appears to be also higher than those of commercial catalysts under conditions of rotating disk experiments. Fuel cell tests at 80°C have shown practically the same activity of the PtRu20 electrocatalyst for H2 oxidation as that of the catalyst containing a 10× larger Pt loading. Extended X-ray absorption fine structure spectroscopy measurements showed that Pt is coordinated with three to four Ru atoms in this catalyst, with a bond length of 2.68 Å between Pt and Ru as in PtRu alloys. A Pt0.75Pd0.25 monolayer on Au/C is a very active electrocatalyst for O2 reduction that equals the activity of a Pt/C catalyst with a 2.5 times larger Pt loading. The activity of a Pt monolayer on Au(1 1 1) is also considerable. A single Tafel slope of -110 mV for the Pt 0.75Pd0.25/Au/C catalyst, and a -120 mV for Au(1 1 1), may indicate a smaller adsorption of OH on Pt and Pt0.75Pd 0.25 on Au in comparison with bulk or nano Pt. Further work utilizing a Pt monolayer on metal nanoparticles seems to be a promising approach for both reduction of noble metal loading and designing electrocatalysts with improved properties.

AB - Novel electrocatalysts based on Pt submonolayer deposits on Ru and Au nanoparticles, and on a Au(111) surface, have been prepared by two new methods for noble metal monolayer deposition. These were tested for H2 and H2/CO oxidation and O2 reduction kinetics. Our recently reported methods for controlled submonolayer-to-multilayer deposition of Pt involve spontaneous deposition of Pt on Ru and Pt deposition by redox replacement of a Cu upd monolayer on Au. The Pt mass-specific activity for H2 oxidation of the PtRu20 electrocatalyst was found to be three to four times higher than that of commercial catalysts at 25°C. The CO tolerance appears to be also higher than those of commercial catalysts under conditions of rotating disk experiments. Fuel cell tests at 80°C have shown practically the same activity of the PtRu20 electrocatalyst for H2 oxidation as that of the catalyst containing a 10× larger Pt loading. Extended X-ray absorption fine structure spectroscopy measurements showed that Pt is coordinated with three to four Ru atoms in this catalyst, with a bond length of 2.68 Å between Pt and Ru as in PtRu alloys. A Pt0.75Pd0.25 monolayer on Au/C is a very active electrocatalyst for O2 reduction that equals the activity of a Pt/C catalyst with a 2.5 times larger Pt loading. The activity of a Pt monolayer on Au(1 1 1) is also considerable. A single Tafel slope of -110 mV for the Pt 0.75Pd0.25/Au/C catalyst, and a -120 mV for Au(1 1 1), may indicate a smaller adsorption of OH on Pt and Pt0.75Pd 0.25 on Au in comparison with bulk or nano Pt. Further work utilizing a Pt monolayer on metal nanoparticles seems to be a promising approach for both reduction of noble metal loading and designing electrocatalysts with improved properties.

KW - Au nanoparticles

KW - CO tolerance

KW - H oxidation

KW - O reduction

KW - Pt monolayer

KW - Ru nanoparticles

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U2 - 10.1016/S0013-4686(03)00518-8

DO - 10.1016/S0013-4686(03)00518-8

M3 - Conference article

AN - SCOPUS:0141919412

SN - 0013-4686

VL - 48

SP - 3841

EP - 3849

JO - Electrochimica Acta

JF - Electrochimica Acta

IS - 25-26

T2 - Electrocatalysis: From Theory to Industrial Applications

Y2 - 22 September 2002 through 24 September 2002

ER -