Electrocatalysts for polymer electrolyte fuel cell (PEFC) cathodes were prepared using Au-Pt core-shell nanoparticles. Polyvinylpyrrolidone (PVP)-protected core-shell nanoparticles were synthesized by simultaneous aqueous-phase reduction of Au and Pt, and they were deposited on carbon black support material. The catalyst powder was thermally processed in air to remove PVP, since the protecting polymers prevent nanoparticles from directly contacting the support material as well as reactant molecules. To avoid sintering during the thermal treatment, the effects of temperature and processing time on sintering were carefully examined. It was found that PVP was selectively oxidized and removed at 170 °C in air without notable damages to the other components of the catalyst. Stability of the core-shell catalyst in water was improved after the removal of PVP. The oxidation state of the Pt shell was found to be very close to zero. The thus-prepared Au-Pt core-shell catalyst for a PEFC cathode exhibited mass activity that was 20% higher than that of pure Pt catalyst.

References

References
1.
Zhao
,
D.
, and
Xu
,
B.-Q.
,
2006
, “
Platinum Covering of Gold Nanoparticles for Utilization Enhancement of Pt in Electrocatalysts
,”
Phys. Chem. Chem. Phys.
,
8
(
43
), pp.
5106
5114
.10.1039/b610269g
2.
Rolison
,
D. R.
,
2003
, “
Catalytic Nanoarchitectures—The Importance of Nothing and the Unimportance of Periodicity
,”
Science
,
299
(
5613
), pp.
1698
1701
.10.1126/science.1082332
3.
Zeng
,
J.
,
Yang
,
J.
,
Lee
,
J. Y.
, and
Zhou
,
W.
,
2006
, “
Preparation of Carbon-Supported Core-Shell Au-Pt Nanoparticles for Methanol Oxidation Reaction: The Promotional Effect of the Au Core
,”
J. Phys. Chem. B
,
110
(
48
), pp.
24606
24611
.10.1021/jp0640979
4.
Li
,
X.
,
Liu
,
J.
,
He
,
W.
,
Huang
,
Q.
, and
Yang
,
H.
,
2010
, “
Influence of the Composition of Core-Shell Au-Pt Nanoparticle Electrocatalysts for the Oxygen Reduction Reaction
,”
J. Colloid Interface Sci.
,
344
(
1
), pp.
132
136
.10.1016/j.jcis.2009.12.019
5.
Song
,
C.
,
Ge
,
Q.
, and
Wang
,
L.
,
2005
, “
DFT Studies of Pt/Au Bimetallic Clusters and Their Interactions With the CO Molecule
,”
J. Phys. Chem. B
,
109
(
47
), pp.
22341
22350
.10.1021/jp0546709
6.
Wang
,
C.
,
Dennis
,
v. d. V.
,
More
,
K. L.
,
Zaluzec
,
N. J.
,
Peng
,
S.
,
Sun
,
S.
,
Daimon
,
H.
,
Wang
,
G.
,
Greeley
,
J.
,
Pearson
,
J.
,
Paulikas
,
A. P.
,
Karapetrov
,
G.
,
Strmcnic
,
D.
,
Markovic
,
N. M.
, and
Stamenkovic
, V
. R.
,
2011
, “
Multimetallic Au/FePt3 Nanoparticles as Highly Durable Electrocatalyst
,”
Nano Lett.
,
11
(
3
), pp.
919
926
.10.1021/nl102369k
7.
Jin
,
Y. D.
,
Shen
,
Y.
, and
Dong
,
S. J.
,
2004
, “
Electrochemical Design of Ultrathin Platinum-Coated Gold Nanoparticle Monolayer Films as a Novel Nanostructured Electrocatalyst for Oxygen Reduction
,”
J. Phys. Chem. B
,
108
(
24
), pp.
8142
8147
.10.1021/jp0375517
8.
Tang
,
H.
,
Chen
,
J. H.
,
Wang
,
M. Y.
,
Nie
,
L. H.
,
Kuang
,
Y. F.
, and
Yao
,
S. Z.
,
2004
, “
Controlled Synthesis of Platinum Catalysts on Au Nanoparticles and Their Electrocatalytic Property for Methanol Oxidation
,”
Appl. Catal. A: General
,
275
(
1–2
), pp.
43
48
.10.1016/j.apcata.2004.07.018
9.
Zhang
,
J.
,
Lima
,
F. H. B.
,
Shao
,
M. H.
,
Sasaki
,
K.
,
Wang
,
J. X.
,
Hanson
,
J.
, and
Adzic
,
R. R.
,
2005
, “
Platinum Monolayer on Nonnoble Metal-Noble Metal Core-Shell Nanoparticle Electrocatalysts for O2 Reduction
,”
J. Phys. Chem. B
,
109
(
48
), pp.
22701
22704
.10.1021/jp055634c
10.
Mani
,
P.
,
Srivastava
,
R.
, and
Strasser
,
P.
,
2011
, “
Dealloyed Binary PtM3 (M = Cu, Co, Ni) and Ternary PtNi3M (M = Cu, Co, Fe, Cr) Electrocatalysts for the Oxygen Reduction Reaction: Performance in Polymer Electrolyte Membrane Fuel Cells
,”
J. Power Sources
,
196
(
2
), pp.
666
673
.10.1016/j.jpowsour.2010.07.047
11.
Oezaslan
,
M.
,
Hasche
,
F.
, and
Strasser
,
P.
,
2012
, “
PtCu3, PtCu, and Pt3Cu Alloy Nanoparticle Electrocatalysts for Oxygen Reduction Reaction in Alkaline and Acidic Media
,”
J. Electrochem. Soc.
,
159
(
4
), pp.
B444
B454
.10.1149/2.106204jes
12.
Garcia-Gutierrez
,
D. I.
,
Gutierrez-Wing
,
C. E.
,
Giovanetti
,
L.
,
Ramallo-Lopez
,
J. M.
,
Requejo
,
F. G.
, and
Jose-Yacaman
,
M.
,
2005
, “
Temperature Effect on the Synthesis of Au-Pt Bimetallic Nanoparticles
,”
J. Phys. Chem. B
,
109
(
9
), pp.
3813
3821
.10.1021/jp048114a
13.
Wang
,
W.
,
Wang
,
R.
,
Ji
,
S.
,
Feng
,
H.
,
Wang
,
H.
, and
Lei
,
Z.
,
2010
, “
Pt Overgrowth on Carbon Supported PdFe Seeds in the Preparation of Core-Shell Electrocatalysts for the Oxygen Reduction Reaction
,”
J. Power Sources
,
195
(
11
), pp.
3498
3503
.10.1016/j.jpowsour.2009.12.015
14.
Wanjala
,
B. N.
,
Luo
,
J.
,
Loukrakpam
,
R.
,
Fang
,
B.
,
Mott
,
D.
,
Njoki
,
P. N.
,
Engelhard
,
M.
,
Naslund
,
H. R.
,
Wu
,
J. K.
,
Wang
,
L.
,
Malis
,
O.
, and
Zhong
,
C.-J.
,
2010
, “
Nanoscale Alloying, Phase-Segregation, and Core-Shell Evolution of Gold-Platinum Nanoparticles and Their Electrocatalytic Effect on Oxygen Reduction Reaction
,”
Chem. Mater.
,
22
(
14
), pp.
4282
4294
.10.1021/cm101109e
15.
Cochell
,
T.
, and
Manthiram
,
A.
,
2012
, “
Pt@PdxCuy/C Core-Shell Electrocatalysts for Oxygen Reduction Reaction in Fuel Cells
,”
Langmuir
,
28
(
2
), pp.
1579
1587
.10.1021/la202610z
16.
Jang
,
J.-H.
,
Kim
,
J.
,
Lee
,
Y.-H.
,
Kim
,
I. Y.
,
Park
,
M.-H.
,
Yang
,
C.-W.
,
Hwang
,
S.-J.
, and
Kwon
,
Y.-U.
,
2011
, “
One-Pot Synthesis of Core Shell-Like Pt3Co Nanoparticle Electrocatalyst With Pt-Enriched Surface for Oxygen Reduction Reaction in Fuel Cells
,”
Energy Environ. Sci.
,
4
(
12
), pp.
4947
4953
.10.1039/c1ee01825f
17.
Toshima
,
N.
,
Yonezawa
,
T.
, and
Kushihashi
,
K.
,
1993
, “
Polymer-Protected Palladium-Platinum Bimetallic Clusters: Preparation, Catalytic Properties and Structural Consderations
,”
J. Chem. Soc., Faraday Trans.
,
89
(
14
), pp.
2537
2543
.10.1039/ft9938902537
18.
Toshima
,
N.
,
Naohama
,
H.
,
Yoshimoto
,
T.
, and
Okamoto
,
Y.
,
2011
, “
One-Pot Simultaneous Synthesis of Au-Pt Core-Shell Nanoparticles Protected by a Nafion Ionomer in an Aqueous Solution
,”
Chem. Lett.
,
40
, pp.
1095
1097
.10.1246/cl.2011.1095
19.
Alayoglu
,
S.
,
Nilekar
,
A. U.
,
Mavrikakis
,
M.
, and
Eichhorn
,
B.
,
2008
, “
Ru-Pt Core-Shell Nanoparticles for Preferential Oxidation of Carbon Monoxide in Hydrogen
,”
Nature Mater.
,
7
(
4
), pp.
333
338
.10.1038/nmat2156
You do not currently have access to this content.