In situ growth of Pt3Ni nanoparticles on an A-site deficient perovskite with enhanced activity for the oxygen reduction reaction

Article abstract of DOI:10.1039/c7ta00349h

A novel A-site deficient perovskite, La_0.9Mn_0.9Pt_0.075Ni_0.025O_3-δ, is developed as a catalyst for the oxygen reduction reaction in alkaline solution. Pt₃Ni nanoparticles are exsolved in situ on the surface upon reduction. The catalytic activity improves significantly after exsolution. This improvement is attributed to the synergy between the host perovskite and the nanoparticles.

Full text of DOI:10.1039/c7ta00349h

View Article Online
View Journal
Journal of
M at erials Chemistry A
Accepted Manuscript
This article can be cited before page numbers have been issued, to do this please use: Y. Gao, J. WANG,
Y. Lyu, K. Lam and F. Ciucci, J. Mater. Chem. A, 2017, DOI: 10.1039/C7TA00349H.
Volume
4
Number
1
7
January 2016 Pages 1–330
This is an Accepted Manuscript, which has been through the
Royal Society of Chemistry peer review process and has been
accepted for publication.
Journal of
Materials Chemistry A
Accepted Manuscripts are published online shortly after
Materials for energy and sustainability
www.rsc.org/MaterialsA
acceptance, before technical editing, formatting and proof reading.
Using this free service, authors can make their results available
to the community, in citable form, before we publish the edited
article. We will replace this Accepted Manuscript with the edited
and formatted Advance Article as soon as it is available.
You can find more information about Accepted Manuscripts in the
author guidelines.
Please note that technical editing may introduce minor changes
to the text and/or graphics, which may alter content. The journal’s
standard Terms & Conditions and the ethical guidelines, outlined
in our author and reviewer resource centre, still apply. In no
event shall the Royal Society of Chemistry be held responsible
for any errors or omissions in this Accepted Manuscript or any
consequences arising from the use of any information it contains.
ISSN 2050-7488
PAPER
Kun Chang, Zhaorong Chang et al.
Bubble-template-assisted synthesis of hollow fullerene-like
MoS nanocages as a lithium ion battery anode material
2
rsc.li/materials-a

Page 1 of 6
Jo uP rl ne aa sl eo fd oM na ot et r ai ad l jsu sCt hme am r gi si nt rs y A
View Article Online
DOI: 10.1039/C7TA00349H
Journal Name
COMMUNICATION
In situ growth of Pt Ni nanoparticles on A-site deficient perovskite
3
with enhanced activity for oxygen reduction reaction
a
a
a
a
a,b
Yang Gao, Jian Wang, Yu-Qi Lyu, Kwunyu Lam and Francesco Ciucci
Received 00th January 20xx,
Accepted 00th January 20xx
DOI: 10.1039/x0xx00000x
www.rsc.org/
A novel A-site deficient perovskite La0.9Mn0.9Pt0.075Ni0.025O3-δ is by designing a novel and active oxygen catalyst utilizing this
developed as a catalyst for oxygen reduction reaction in alkaline promising approach.
solution. Pt Ni nanoparticles are exsolved in situ on the surface
upon reduction. The catalytic activity improves significantly after We developed a novel LaMnO
exsolution. This improvement is attributed to the synergy between chemical formula La0.9Mn0.9Pt0.075Ni0.025
3
3
(LMO)-based material with the
3-δ (LMPN). LMPN is
3
capable of exsolving Pt Ni alloy nanoparticles upon reduction in
O
the host perovskite and the nanoparticles.
hydrogen and its ORR catalytic activity increases significantly
after nanoparticle egress. We chose LMO as the parent material
The sluggish activity of oxygen reduction reaction (ORR) is a
critical bottleneck of numerous electrochemical devices, such as
fuel cells and metal-air batteries. To improve the efficiency of
these devices, tremendous research efforts have been devoted
to the development of efficient and cost-effective oxygen
catalysts. Among such catalysts, perovskite oxides (with
19
due to its relatively good catalytic activity and stability upon
1, 2
20
reduction. The Pt/Ni molar ratios were set at 3:1 in order to
21
promote the formation of highly active Pt
3
Ni nanoparticles.
LMPN was first synthesized via the sol-gel method and then
o
2
reduced in H at 500 C for 30 min in order to promote the
3
nominal chemical formula ABO , where A is an alkaline earth
formation of nanoparticles. Experimental details are given in
the electronic supplementary information. The resulting
metal or rare earth metal and B is a transition metal) have
shown great potential due to their compositional flexibility,
structural stability, relative low cost, and high area-specific
material is called Pt
and ‘r’ means ‘reduced’. Pt
3
Ni/rLMPN where ‘/’ indicates ‘exsolved on’
Ni bimetallic alloy nanoparticles are
3
3
, 4
activity. However, the measured activity of perovskite oxides
is still inferior to state-of-the-art precious metal-based
shown to egress directly from the bulk of the material during
reduction (Figure 1a). The nanoparticles grow evenly on the
surface as protrusions attached to the host material with an
average diameter of ~20 nm, as shown by the scanning electron
microscopy (SEM) images (Figure 1b and Figure S1). During
reduction, the material undergoes a structural phase change
5
catalysts. Scientists have found that the performance of
perovskites in solid oxide cells can be greatly enhanced by
decorating their surface with catalytic metal nanoparticles.6-9
Recent studies have shown that substituting transition metals
(
M) into the B-site of a perovskite with a moderate A-site
deficiency (A1-x ) can facilitate the in situ exsolution of
metal nanoparticles.
developed following this strategy, where exsolution ultimately
(
(
Figure 1c). The X-ray diffraction (XRD) refinements of LMPN
Figure 1d) and Pt Ni/rLMPN (Figure 1e) suggest that the
1-y y 3
B M O
3
1
0, 11
Numerous materials have been
lattice’s structures transform from being rhombohedral (PDF
22, 23
0
1-073-8342) to orthorhombic (PDF 01-087-2014).
More
11-15
leads to an improved activity.
However, perovskites
importantly, the refinement reveals the emergence, upon
reduction, of an additional cubic phase (PDF 96-101-1114, space
group Fm-3m, lattice parameter a = 3.88 Å) with an ~8% area
decorated with either infiltrated or exsolved metal
nanoparticles have been little used as room-temperature
16-18
oxygen catalysts.
The goal of this article is to bridge this gap
ratio, suggesting the formation of a new phase, i.e., Pt
Elemental analysis based on X-ray photoelectron spectroscopy
XPS) supports these results. The amounts of surface Pt and Ni
3
Ni metal.
(
increase after reduction, suggesting the exsolution from the
bulk to the surface (Table S1). For comparison, we also studied
the Pt singly doped LMO, i.e., La0.9Mn0.9Pt0.1O3-δ (LMP), as well
as undoped LMO. Their reduced counterparts are named as
Pt/rLMP and rLMO, respectively. The morphology of Pt/rLMP is
a.Department of Mechanical and Aerospace Engineering, The Hong Kong University
of Science and Technology, Hong Kong, SAR China.
Department of Chemical and Biomolecular Engineering, The Hong Kong
University of Science and Technology, Hong Kong, SAR China.
Electronic Supplementary Information (ESI) available: [details of any supplementary
information available should be included here]. See DOI: 10.1039/x0xx00000x
b.
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 1
Please do not adjust margins

Jo uP rl ne aa sl eo fd oM na ot et r ai ad l jsu sCt hme am r gi si nt rs y A
Page 2 of 6
COMMUNICATION
Journal Name
View Article Online
DOI: 10.1039/C7TA00349H
Fig. 1 (a) Schematic illustration of the exsolution process of LMPN. (b) SEM images of Pt
and Pt Ni/rLMPN. XRD patterns and corresponding refinements of (d) LMPN and (e) Pt
the experimental data, red lines are calculated patterns, and green lines are the residuals. The vertical bars in (d) and (e) indicate
the peaks of the refined perovskite (blue) and Pt Ni alloy (magenta) crystal structures.
3
Ni/rLMPN. (c) Lattice structure of LMPN
3
3
Ni/rLMPN, where the x marks represent
3
3
similar to that of Pt Ni/rLMPN, and small nanoparticles grown
on the surface in an analogous fashion (Figure S2). An identical
reduction-driven phase transition is observed for both Pt/rLMP
and rLMO (Figure S3). A similar secondary phase attributable to
Pt metal is also found in Pt/rLMP with a larger lattice parameter
a = 3.91 Å.
We further examined the crystal structures of Pt
Pt/rLMP using transmission electron microscopy (TEM). Small
Pt Ni particles with a diameter of ~20 nm are embedded in the
host perovskite material (Figure 2a). A magnified Pt Ni
3
Ni/rLMPN and
3
3
nanoparticle with visible lattice fringes is presented in Figure 2b.
The lattice parameter of the nanoparticle is examined by fast
Fourier transform (FFT) and the fringes are visualized through
inverse fast Fourier transform (IFFT). The plane distance for
adjacent fringes is measured to be 2.18 Å, where this value is in
good agreement with reported data for the (111) oriented plane
of Pt
3
Ni (i.e., 2.19 Å2 and 2.2 Å ). Analogous quantities are
1
24
observed for Pt/rLMP (Figure 2c and d). The plane distance is
measured to be 2.22 Å, a value in accordance with the Pt (111)
2
5
plane distance (2.23 Å ). We also calculated the plane distance
from the lattice parameter a (as obtained from XRD refinement) Fig. 2 (a) TEM micrograph of Pt
of the secondary phases formed after exsolution. The are visible. (b) High resolution TEM images of the Pt
3
Ni/rLMPN where nanoparticles
Ni
corresponding results are calculated to be 2.24 Å for nanoparticle with visible lattice fringes. The upper right inset
Pt Ni/rLMPN and 2.26 Å for Pt/rLMP. These values contribute (within the white frame) shows the FFT of the selected area,
3
3
to the evidence that Pt
reduction.
3
Ni and Pt nanoparticles form during while the lower right inset (within the red circle) depicts the
2
| J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 3 of 6
Jo uP rl ne aa sl eo fd oM na ot et r ai ad l jsu sCt hme am r gi si nt rs y A
Journal Name
COMMUNICATION
saturated 0.1
mol L KOH solution with a scan rate of 5 mV s and loading of
0.4 mg cm . (b) Specific activity of LMO, rLMO, Pt/rLMP, and
corresponding IFFT (magnified 3 times) with selected fringes. (c) Fig. 3 (a) ORR current densities at 1600 rpm in O
and (d) analogous data for Pt/rLMP.
2
View Article Online
−
1
DOI: 10.1039/C7TA00349H
−1
−
2
~
The ORR activity were tested with a rotating disk electrode set- Pt Ni/rLMPN at 0.9, 0.8, and 0.7 V vs. RHE. (c) and (d)
3
up in 0.1M KOH solution. The as-prepared perovskites were Corresponding Tafel plots and slopes. the same color scheme is
mixed with VXC-72 conductive carbon black (VC) at a 5:1 mass used across all panels.
ratio to study the intrinsic activity while compensating for their
3
, 4
poor electrical conductivity. Experimental details are given in The reduction has dramatically improved the ORR activity of the
the ESI. The ORR activity increased significantly after exsolution starting materials.6, 10, 24 In particular, the superior activity of
(
Figure 3a). The onset potential shifts positively from 0.77 V vs. Pt
the reversible hydrogen electrode (RHE) for LMO to 0.92 V for of Pt
Pt Ni/rLMPN. The limiting current density of Pt Ni/rLMPN also is not clear if this higher activity can be solely attributed to the
increases a lot and is close to that of the commercial Pt/C (5.3 presence of the nanoparticles or the synergy between the
3
Ni/rLMPN compared with Pt/rLMP is likely due to the egress
35
3
Ni, which is catalytically more active than Pt. However, it
3
3
-
2
-2
mA cm to 5.4 mA cm ) at 0.3 V. The specific activity is used as egressed Pt
an indicator for the intrinsic activity, where the ORR current we prepared the Pt
densities at low over potentials are normalized with the surface rLMO and VC with identical Pt and rLMO mass loadings as
area of the loaded perovskites.
the as-synthesized perovskite samples was analyzed using the activity than Pt
3
Ni and the perovskite. In order to resolve this issue,
3
Ni (Figure S6) and physically mixed it with
4
, 26
The specific surface area of Pt
3
Ni/rLMPN (mass ratio 5:1 with VC). Pt
Ni+rLMO, which is in turn inferior to
Ni/rLMPN (Figure S7a). These results suggest that perovskite
and Pt Ni synergistically contribute to the ORR activity, and this
Ni nanoparticles are in situ
Ni/rLMPN, it is 13 times higher than that of the exsolved. Figure 4a shows the ORR activity of Pt Ni/rLMPN at
3
Ni shows a lower
3
N
2
adsorption/desorption isotherms (Figure S4). All the Pt
3
2
perovskites have a similar specific surface area of around 3 m
g . The specific activity increases dramatically after exsolution, effect is stronger when the Pt
and, for Pt
3
-1
3
3
3
original LMO at 0.9 V (Figure 3b). Figure 3c and 3d shows the various rotating speeds, and the corresponding Koutecky–
corresponding Tafel plots and Tafel slopes. A small slope is Levich plot is given in Figure S8. The electron transfer number is
2
7, 28
28
another indicator of the high ORR kinetics after exsolution.
calculated to be ~3.9. The electron transfer numbers and
In particular, such slope drops from 147 mV dec (original LMO) peroxide (HO Ni/rLMPN, rLMO, Pt Ni, and
-) yields of Pt
Ni+rLMO are also obtained via rotating ring-disk electrode
Ni/rLMPN is measurement (Figure S7). The perovskite samples show a
highly active. For comparison with literature values, the ORR similar quasi 4-electron pathway and the reacted O is mainly
catalytic activity of some commonly used perovskite-based converted into H O. In contrast, the Pt Ni and Pt Ni/rLMO
-1
2
3
3
-
1
to 76 mV dec (Pt
3
Ni/rLMPN), a value close to that of Pt/C (61 Pt
3
-
1
mV dec ),). This result further confirms that Pt
3
2
2
3
3
materials are also listed in Table S2. Most of these materials samples have lower electron transfer numbers and higher
exhibit a relatively low onset potentials (in the ~0.7-0.9 V range) peroxide percentages. These results further validate the
-
1
36, 37
and large Tafel slopes (~70-170 mv dec ). These activities are synergetic effect.
The strong connection, high dispersion,
16-18, 29-34
inferior to Pt
the stability of the most active Pt
Pt/C (Figure S5). The onset and half-wave potentials of
Pt Ni/rLMPN drop less than ~0.03 V after 1000 cycles, while that
3
Ni/rLMPN.
In addition, we also compared and small particle size obtained from in situ growth are
Ni/rLMPN with commercial beneficial and effectively increase the measured activity.1
0, 38
3
3
of Pt/C drops by ~0.12 V. All of these results make Pt
as well as its derivatives promising ORR catalysts.
3
Ni/rLMPN
Fig. 4 (a) ORR current densities of Pt
rotating speeds. (b) ORR current densities of Pt
mixed with carbon in different ratios at 1600 rpm. (c) ORR
current densities of Pt Ni/rLMPN and Pt Ni/rLMPN2 with
3
Ni/rLMPN at different
3
Ni/rLMPN
3
3
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 3
Please do not adjust margins

Jo uP rl ne aa sl eo fd oM na ot et r ai ad l jsu sCt hme am r gi si nt rs y A
Page 4 of 6
COMMUNICATION
Journal Name
different carbon ratios at 1600 rpm. (d) Total mass activity and
Pt mass activity of selected samples.
Acknowledgements
The authors gratefully acknowledge HKUST for providing start-
up funds, and the Research Grants Council of Hong Kong for
support through the Project 16207615.
View Article Online
DOI: 10.1039/C7TA00349H
We further studied the influence of catalysts loading and the
mass activity to optimize the performance and test its suitability
in potential applications. The impact of perovskite loading was
studied by testing the ORR activity of Pt
different mass ratios (Figure 4b). The effect of Pt
investigated by doubling the amount of Pt Ni into perovskite.
3-δ (LMPN2), reduced it to make
Ni/rLMPN2, and tested its activity (Figure 4c). We normalized
the kinetic current densities measured at 0.9V vs RHE with Sci., 2011, 4, 114-130.
. J. Suntivich, K. J. May, H. A. Gasteiger, J. B. Goodenough and
Y. Shao-Horn, Science, 2011, 334, 1383-1385.
. J. Suntivich, H. A. Gasteiger, N. Yabuuchi, H. Nakanishi, J. B.
3
Ni/rLMPN+VC with
Notes and references
3
Ni loading was
1
. J. S. Lee, S. Tai Kim, R. Cao, N. S. Choi, M. Liu, K. T. Lee and J.
Cho, Adv. Energy Mater., 2011, 1, 34-50.
. F. Jaouen, E. Proietti, M. Lefèvre, R. Chenitz, J.-P. Dodelet, G.
Wu, H. T. Chung, C. M. Johnston and P. Zelenay, Energ. Environ.
3
We made La0.8Mn0.8Pt0.15Ni0.05
O
2
Pt
3
3
respect to the total mass of the catalyst and the mass of Pt
Figure 4d). The mass ratio of Pt versus the total catalyst loading
is calculated from the stoichiometry of the formula, i.e., 0.06 for
pure Pt Ni/rLMPN and 0.12 for pure Pt Ni/rLMPN2, as given in
the ESI. The Pt
activity, ascribed to the improved electrical connection and
(
4
Goodenough and Y. Shao-Horn, Nat. Chem., 2011, 3, 546-550.
3
3
5
. D. Chen, C. Chen, Z. M. Baiyee, Z. Shao and F. Ciucci, Chem.
3
Ni/rLMPN+VC (1:1) has the highest total mass Rev., 2015, 115, 9869-9921.
6
. Y. Nishihata, J. Mizuki, T. Akao, H. Tanaka, M. Uenishi, M.
Kimura, T. Okamoto and N. Hamada, Nature, 2002, 418, 164-167.
39
surface utilization.
significantly for Pt Ni/rLMPN2 in comparison to Pt
due to the higher Pt
Pt
The total mass activity increases
Ni/rLMPN,
Ni coverage (Figure S9). In contrast,
7
8
. J. A. Farmer and C. T. Campbell, Science, 2010, 329, 933-936.
. D. M. Bierschenk, E. Potter-Nelson, C. Hoel, Y. Liao, L. Marks,
3
3
40
3
K. R. Poeppelmeier and S. A. Barnett, J. Power Sources, 2011, 196,
3
Ni/rLMPN with the carbon ratio of 1:3 has the highest Pt 3089-3094.
9
. A. Atkinson, S. Barnett, R. J. Gorte, J. Irvine, A. J. McEvoy, M.
Mogensen, S. C. Singhal and J. Vohs, Nat. Mater., 2004, 3, 17-27.
0. D. Neagu, G. Tsekouras, D. N. Miller, H. Menard and J. T.
Irvine, Nat. Chem., 2013, 5, 916-923.
1. J.-h. Myung, D. Neagu, D. N. Miller and J. T. Irvine, Nature,
mass activity due to the lower loading, even higher than Pt/C.
To further improve the catalytic activity of this special class of
materials, more work is needed to optimally select the parent
materials, exsolved metals, and doping levels. Highly active
1
1
metal or metal alloy nanoparticles with smaller particle size, 2016.
1
2
1
2. Y. Gao, D. Chen, M. Saccoccio, Z. Lu and F. Ciucci, Nano Energy,
016, 27, 499-508.
3. Y. Zhu, W. Zhou, R. Ran, Y. Chen, Z. Shao and M. Liu, Nano
better dispersion, and a strong connection with the parent
perovskite material may ultimately lead to improved
performance over state-of-the-art catalysts.
Lett., 2015, 16, 512-518.
1
4. Y.-F. Sun, Y.-Q. Zhang, J. Chen, J.-H. Li, Y.-T. Zhu, Y.-M. Zeng, B.
Apart from the remarkable performance of Pt
ORR activity of LMO also slightly increases after reduction
Figure 3a), possibly due to the structural transition and the
3
Ni/rLMPN, the S. Amirkhiz, J. Li, B. Hua and J.-L. Luo, Nano Lett., 2016, 16, 5303-
5
1
309.
5. Z. Du, H. Zhao, S. Yi, Q. Xia, Y. Gong, Y. Zhang, X. Cheng, Y. Li,
(
L. Gu and K. ꢀwierczek, ACS nano, 2016, 10, 8660-8669.
41
reduction. According to the XPS (Figure S10) and iodometric
titration (Table S3), the average valence state of Mn decreases
1
6. B. Hua, M. Li, Y.-F. Sun, Y.-Q. Zhang, N. Yan, J. Chen, T.
Thundat, J. Li and J.-L. Luo, Nano Energy, 2016.
after reduction. It is expected that the concentration of oxygen 17. Y. Zhu, W. Zhou, Y. Chen, J. Yu, X. Xu, C. Su, M. O. Tadꢁ and Z.
Shao, Chem. Mater., 2015, 27, 3048-3054.
8. X. Han, F. Cheng, T. Zhang, J. Yang, Y. Hu and J. Chen, Adv.
Mater., 2014, 26, 2047-2051.
9. J. Sunarso, A. A. Torriero, W. Zhou, P. C. Howlett and M.
Forsyth, J. Phys. Chem. C, 2012, 116, 5827-5834.
vacancies increases consequently, positively affecting the
1
2
6
oxygen reaction activity. We also measured the oxygen
evolution reaction (OER) activity of the materials (Figure S11).
The OER activity shows a moderate improvement after
1
reduction, and is explained using molecular orbital theory. As 20. T. Nakamura, G. Petzow and L. Gauckler, Mater. Res. Bull.,
1
2
2
979, 14, 649-659.
1. S. H. SY, J. Mater. Chem. A, 2014, 2, 19778-19787.
2. S. Sengodan, S. Choi, A. Jun, T. H. Shin, Y.-W. Ju, H. Y. Jeong, J.
Shin, J. T. Irvine and G. Kim, Nat. Mater., 2014.
3. J. T. Mefford, W. G. Hardin, S. Dai, K. P. Johnston and K. J.
the surface Mn valence state drops, the e
g
occupancy in the Mn
3
d orbital rises from 0.95 to 1.59, a value closer to the OER
3
activity volcano peak.
2
Stevenson, Nat. Mater., 2014, 13, 726-732.
Conclusions
24. X. Huang, Z. Zhao, L. Cao, Y. Chen, E. Zhu, Z. Lin, M. Li, A. Yan,
A. Zettl and Y. M. Wang, Science, 2015, 348, 1230-1234.
In conclusion, we have developed an A-site deficient perovskite
material LMPN and exsolved Pt
reduction. The ORR activity of Pt
2
5. M. A. Hoque, F. M. Hassan, D. Higgins, J. Y. Choi, M. Pritzker,
3
Ni nanoparticles using in situ S. Knights, S. Ye and Z. Chen, Adv. Mater., 2015, 27, 1229-1234.
Ni/rLMPN improved 26. J. Suntivich, H. A. Gasteiger, N. Yabuuchi and Y. Shao-Horn, J.
Electrochem. Soc., 2010, 157, B1263-B1268.
3
dramatically after exsolution due to the synergy between the
2
7. Y. Liang, Y. Li, H. Wang, J. Zhou, J. Wang, T. Regier and H. Dai,
Nat. Mater., 2011, 10, 780-786.
8. Y. Gao, H. Zhao, D. Chen, C. Chen and F. Ciucci, Carbon, 2015,
room temperature may be developed following a similar 94, 1028-1036.
approach to the one undertaken in this work.
29. J. I. Jung, H. Y. Jeong, J. S. Lee, M. G. Kim and J. Cho, Angew.
Chem. Int. Edit., 2014, 53, 4582-4586.
parent perovskite and the active Pt
3
Ni nanoparticles. A number
of novel materials with high activity towards oxygen catalysis at
2
4
| J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 5 of 6
Jo uP rl ne aa sl eo fd oM na ot et r ai ad l jsu sCt hme am r gi si nt rs y A
Journal Name
COMMUNICATION
3
0. W. S. Kim, G. Anoop, H. J. Lee, S. S. Lee, J. H. Kwak, H. J. Lee
View Article Online
DOI: 10.1039/C7TA00349H
and J. Y. Jo, J. Catal., 2016, 344, 578-582.
3
2
3
1. W. Zhou and J. Sunarso, J. Phys. Chem. Lett., 2013, 4, 2982-
988.
2. K. A. Stoerzinger, W. Lꢂ, C. Li, T. Venkatesan and Y. Shao-Horn,
J. Phys. Chem. Lett., 2015, 6, 1435-1440.
3
3. Y. Zhu, W. Zhou, J. Yu, Y. Chen, M. Liu and Z. Shao, Chem.
Mater., 2016, 28, 1691-1697.
4. B. Hua, Y. Q. Zhang, N. Yan, M. Li, Y. F. Sun, J. Chen, J. Li and J.
L. Luo, Adv. Funct. Mater., 2016, 26, 4106-4112.
5. V. R. Stamenkovic, B. Fowler, B. S. Mun, G. Wang, P. N. Ross,
C. A. Lucas and N. M. Marković, Science, 2007, 315, 493-497.
6. Y. Zhou, K. Neyerlin, T. S. Olson, S. Pylypenko, J. Bult, H. N.
3
3
3
Dinh, T. Gennett, Z. Shao and R. O'Hayre, Energ. Environ. Sci.,
2
3
3
010, 3, 1437-1446.
7. Z. Wen, J. Liu and J. Li, Adv. Mater., 2008, 20, 743-747.
8. S. H. Joo, S. J. Choi, I. Oh, J. Kwak, Z. Liu, O. Terasaki and R.
Ryoo, Nature, 2001, 412, 169-172.
9. E. Fabbri, R. Mohamed, P. Levecque, O. Conrad, R. d. Kꢃtz and
T. J. Schmidt, ACS Catal., 2014, 4, 1061-1070.
3
4
3
4
0. M. Shao, A. Peles and K. Shoemaker, Nano Lett., 2011, 11,
714-3719.
1. D. Chen, J. Wang, Z. Zhang, Z. Shao and F. Ciucci, Chem.
Commun., 2016, 52, 10739-10742.
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 5
Please do not adjust margins

Journal of Materials Chemistry A
Page 6 of 6
View Article Online
DOI: 10.1039/C7TA00349H
A perovskite material with in situ exsolved Pt Ni nanoparticles is applied for oxygen reduction
3
reaction catalysis with dramatically improved activity.