Hydroxyl-rich ceria hydrate nanoparticles enhancing the alcohol electrooxidation performance of Pt catalysts

Article abstract of DOI:10.1039/c7ta09071d

The exploration of anode catalysts with high activity and stability for direct alcohol fuel cells (DAFCs) has been a big challenge for decades. Metal oxides, such as CeO₂ with oxygen vacancies, are widely investigated in the promotion of Pt-based electrocatalysts for alcohol oxidation. Hydroxyl-rich CeO₂·xH₂O, which is capable of affording OH groups directly for reacting with CO to re-activate the nearby metal catalyst, may surpass CeO₂ in alcohol electrooxidation reactions. Herein, small CeO₂·xH₂O nanoparticles with plenty of surface OH groups have been prepared by a tert-butylamine-assisted solvothermal method, and then ultrasonically mixed with Pt/CNTs (CNTs = carbon nanotubes). As a proof-of-concept experiment, the CeO₂·xH₂O/Pt/CNT catalyst containing the tert-butylamine-modified CeO₂·xH₂O nanoparticles achieves a high peak current density of 2304 mA mg^-1 for methanol oxidation in the alkaline medium, which is remarkably higher than those of the calcined counterpart (CeO₂/Pt/CNTs, 814 mA mg^-1) and Pt/CNTs (520 mA mg^-1). After a chronoamperometry test for 1200 s, the retained current density of CeO₂·xH₂O/Pt/CNTs (570 mA mg^-1) is also much higher than those of CeO₂/Pt/CNTs (163 mA mg^-1) and Pt/CNTs (10 mA mg^-1). The advantage of CeO₂·xH₂O nanoparticles over CeO₂ nanoparticles has been further confirmed by ethylene glycol and glycerol oxidation reactions, and they have also been found to be effective over other alcohol oxidation catalysts such as Pt/C, Pd/C and PtRu/C. Therefore, this strategy may provide an alternative for the design of anode catalysts in DAFCs with high performance and low cost.

Full text of DOI:10.1039/c7ta09071d

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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
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J oP ul er na as el od f oM na ot et rai ad lj su Cs th me ma ri gs ti nr ys A
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DOI: 10.1039/C7TA09071D
Journal Name
ARTICLE
Hydroxyl-riched Ceria Hydrate Nanoparticles Enhancing the
Alcohol Electrooxidation Performance of Pt Catalysts
Received 00th January 20xx,
Accepted 00th January 20xx
a
a
a
b
a
a
a
Zhen-Yu Li, Jian Zhou , Long-Shu Tang, Xin-Pu Fu, Hang Wei, Mei Xue, Yong-Liang Zhao, Chun-
b
c
a
d
Jiang Jia, Xue-Mei Li, Hai-Bin Chu* and Yan Li
The exploration of anode catalysts with high activity and stability for direct alcohol fuel cell (DAFC) has been
a big challenge for decades. Metal oxides, such as CeO with oxygen vacancies, are widely investigated in the
promotion of Pt-based electrocatalysts for alcohol oxidation. Hydroxyl-riched CeO ·xH O, which is capable of
affording OH groups directly for reacting with CO to re-activate the nearby metal catalyst, may surpass CeO
in alcohol electrooxidation reactions. Herein, small CeO ·xH O nanoparticles with plenty of surface OH
groups have been prepared by a tert-butylamine-assisted solvothermal method, and then ultrasonic mixed
with Pt/CNTs (CNTs = carbon nanotubes). As a proof-of-concept experiment, the CeO ·xH O/Pt/CNTs catalyst
containing the tert-butylamine-modified CeO ·xH O nanoparticles achieves a high peak current density of
304 mA/mg for methanol oxidation in the alkaline medium, which is remarkably higher than those of the
DOI: 10.1039/x0xx00000x
www.rsc.org/
2
2
2
2
2
2
2
2
2
2
2
calcined counterpart (CeO
2
/Pt/CNTs, 814 mA/mg) and Pt/CNTs (520 mA/mg). After chronoamperometry test
·xH O/Pt/CNTs (570 mA/mg) is also much higher than those of
/Pt/CNTs (163 mA/mg) and Pt/CNTs (10 mA/mg). The advantage of CeO ·xH O nanoparticles over CeO
for 1200s, the retained current density of CeO
CeO
2
2
2
2
2
2
nanoparticles has been further confirmed by ethylene glycol and glycerol oxidation reactions, and also found
effective on other alcohol oxidation catalysts such as Pt/C, Pd/C and PtRu/C. Therefore, this strategy may
provide an alternative for the design of anode catalysts in DAFC with high performance and low cost.
2 3 2 2 2 2
RuO , WO , ZrO , MgO, SnO , TiO , NiO and MnO , have been
Introduction
Direct alcohol fuel cell (DAFC) has acquired extensive attention as a applied to promote the electro-catalytic performance of Pt catalysts
6
portable energy devices because of their multitudinous virtues such toward alcohol oxidation. In particular, due to its unique reversible
as high energy density, high energy utilization efficiency, easy valence change and high concentration of oxygen vacancies, CeO
2
is
1
-5
storage, low price and environmental compatibility.
Unfortunately, their widespread commercial application has been stability of Pt-based electro-catalysts toward alcohol oxidation.
prevented with the challenges of sluggish reaction kinetics and The formation of OH groups on the surface of CeO by dissociating
normally employed as a co-catalyst for promoting the activity and
1
6-18
2
6
serious carbonaceous poisoning of anode catalysts. One of the water molecules may contribute to the efficient removal of the
effective solutions to these challenges can be alloying Pt with other poisoning intermediates on Pt surface during alcohol
6
19
metals, including Ru, Sn, Ti, Ta, Cr, Mo, W, Re, Fe, Os, Co, Ni, Pd, Ag electrooxidation. Moreover, the CeO
2
can tune the electric
These bimetallic or ternary catalysts have shown structure of Pt and change the d-band center of Pt by charge
7
-15
and Cu.
20
promoted reactivities by alleviating Pt poisoning during alcohol transfer.
oxidation. Alternatively, numerous metal oxides, including CeO2,
Hydroxyl groups have shown great impact on heterogeneous
catalysis and electrocatalysis of oxidation reactions. During alcohol
oxidation on metal nanoparticles, the adsorbed hydroxyl can act as
a Brønsted base to activate O-H and C-H bonds of alcohol, which
means assisting in the deprotonation and dehydrogenation of
2
1, 22
alcohol to form the product of aldehyde and acid.
During CO
oxidation, the OH groups at the transition metal-OH-Pt interface
2
3
2
readily react with CO adsorbed nearby to form CO . During alcohol
electrooxidation involved with metal oxide promoter, the OH
groups adsorbed on the metal oxide assist the removal of the
poisoning intermediates from neighboring Pt particles, resulting in
the improved electrochemical activity and stability of the
2
4
catalysts. Compared with the huge number of reports about metal
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ARTICLE
oxide promoted catalysts, the direct exploring metal hydroxide or
Journal Name
0.1480 g CeCl
3
·7H
2
O was added to the solvents of 9.0 mL EG
hydrate in the alcohol electrooxidation reactions has been reported and 1.0 mL deionized water with vigorous magnetic stirring for 10
2
5-29
less frequently.
have been used for the electro-catalytic oxidation of methanol.
Recently, Huang et al. introduced highly defective Ni(OH)
nanostructures to prepare Pt/Ni(OH)
with high activity and exceptional durability toward methanol centrifugation and washed several times by water and ethanol, and
In the years around 2000, Ni(OH)
2
and Co(OH)
2
5, 26
min. Subsequently, 6 mL of tert-butylamine was added into the
solution under continuous stirring for 90 min. The yellow solution
was then transferred into a Teflon-lined autoclave and heated at
2
2
2
/graphene electrocatalysts 180 °C for 8 h. The yellow precipitates were separated by
30
oxidation oxidation (MOR). Ni(OH)
decisive roles in oxidative removal of carbonaceous poison on Pt nanoparticles. The CeO
sites. furnace with a heating rate of 4 °C/min and then calcined at 400 °C
2
has been found to play then dried at 60 °C to get the products of as-prepared CeO
2 2
·xH O
2
·xH O nanoparticles were placed in a muffle
2
in air for 2h to obtain the CeO
stated.
2
nanoparticles unless otherwise
Combining the advantages of CeO
2
and hydroxyl groups, we
reason that hydroxyl-riched CeO ·xH O nanoparticles may possess
2
2
significant promoting effect for alcohol electrooxidation catalysts. Preparation of Pt/CNTs + CeO
Herein, we have prepared CeO ·xH O nanoparticles by amine- catalysts
assisted solvothermal method. The comprehensive characterization
and comparison of the as-prepared CeO ·xH O particles and the
calcined CeO reveals that the CeO ·xH O nanoparticles have
abundant surface OH groups and a high content of Ce ions. By a
facile ultrasonic mixing process, CeO ·xH O nanoparticles can be
2 2 2
·xH O and Pt/CNTs + CeO hybrid
2
2
2 2
In a typical process, 5.0 mg Pt/CNTs and 1.5 mg CeO ·xH O was
2
2
dispersed into the 1.5 mL mixed solution of ethanol, water and
nafion (v/v/v = 20:79:1) to form the uniform ink containing Pt/CNTs
2
2
2
3
+
+
2 2
CeO ·xH O hybrid catalysts under ultrasonic treatment for 1 h.
2
2
The ink containing Pt/CNTs + CeO
the similar process.
2
hybrid catalysts was prepared via
efficiently dispersed on the Pt/CNTs (CNT = carbon nanotubes)
catalyst. This simple physical mixing method not only well keeps the
connection between Pt and CNTs, but also generates plenty of CNT-
Materials Characterization
3
1-34
Pt-CeO
2
·xH
2
O interfaces.
As a result, the catalytic activity and
The obtained products were characterized with XRD
stability of the Pt/CNTs catalyst for the electrooxidation of (Empyrean XD-3 with Cu K α radiation, λ =1.5406 Å), TEM and
methanol, ethylene glycol (EG) and glycerol is remarkably improved HRTEM (Tecnai F20, 200 kV), STEM (Tecnai F30, 300 kV), SEM
by the CeO
of CeO ·xH
nanoparticles. Besides, this easy method via ultrasonic mixing with conducted on a Netzsch STA 409PC instrument from 25 to 900 °C at
CeO ·xH O nanoparticles adapts to many kinds of catalysts such as a heating rate of 10 °C/min under an air atmosphere.
2
·xH
2
O nanoparticles. Importantly, the promoting effect (Hitachi S-4800), FT-IR spectrometer (Nicolet Magna-IR 750), XPS
2
2
O nanoparticles is superior than that of calcined CeO
2
(Kratos Axis Ultra). Thermogravimetric analysis (TGA) was
2
2
commercial Pt/C, Pd/C and PtRu/C for enhancing their
electrocatalytic activities towards alcohol oxidation.
Electrochemical measurement
The electrochemical test were performed on a CHI760
electrochemical workstation with
a standard three-electrode
Experimental
configuration. We used a 3 mm glassy carbon electrode coated with
catalyst as a working electrode, the Ag/AgCl and Pt wire as the
reference and counter electrode. The solution of 1.0 M KOH and 1.0
M KOH + 1.0 M alcohol solution was constantly stirred and purged
Materials
Carbon nanotubes (diameter: 10-20 nm) were purchased from
Shenzhen Nanotech Port Co., Ltd. (China). 1-butyl-3-methyl
with ultrapure N
the catalysts were recorded within a potential range from -1.0 to
.2 V at a scan rate of 200 mV/s in 1.0 M KOH solution. The cyclic
voltammograms (CVs) of electrochemical oxidation of alcohol
methanol, EG and glycerol) on the catalysts were measured in an
-saturated solution of 1.0 M KOH + 1.0 M alcohol within a
2
gas. The electrochemical surface areas (ECSA) of
imidazolium tetrafluoroborate ([BMIM]BF
Henan Lihua Pharmaceutical Co. Ltd. (China). The Commercial
Ce(OH) (Aldrich) and the commercial Pt/C, PtRu/C and Pd/C
4
) was purchased from
0
4
catalysts (Johnson Matthey) were all used as received if not
mentioned. Other chemical reagents were of analytical grade and
used as received.
(
N
2
potential range from -0.9 to 0.2 V at a scan rate of 20 mV/s. The
chronoamperometric (CA) curves were obtained in the 1.0 M KOH +
Preparation of Pt/CNTs catalyst
1
3
.0 M CH OH at -0.3 V. The linear sweeping voltammetry (LSV) was
The Pt/CNTs catalyst was prepared by a modified method we
3
5
measured in the range of -0.8 to 0.2 V at a scan rate of 1 mV/s.The
polarization curves were obtained in the range of -0.9 to 0.4 V at a
scan rate of 1 mV/s. The CO striping test was carried out in 1.0 M
KOH solution in the range of -0.9 to 0.2 V. The electrochemical
impedance spectra (EIS) were obtained over a frequency range
from 1 to 100000 Hz with an AC voltage amplitude of 5.0 mV.
reported before. Firstly, 40 mg CNTs were added to the mixed
solvent of 40 mL EG and 20 mL deionized water. The suspension
was then sonicated for 10 min, after which 1.3 g [BMIM]BF
wt% of the solution) was added. The suspension was sonicated for
another 15 min, after which 25 mg K PtCl was added. Then the
4
(2.0
2
6
reaction mixtures were kept stirring at 140 °C for 4 h. The black
precipitates were separated by centrifugation and washed several
times by water, ethanol and acetone, and finally dried at 80 °C to
get the Pt/CNTs catalyst.
Results and discussion
The solvothermal approach was used to synthesize CeO
2 2
·xH O
Synthesis of CeO
2
·xH
2
O Nanoparticles and CeO
2
nanoparticles
nanoparticles, in which CeCl ·7H O was used as the cerium
3
2
2
| J. Name., 2012, 00, 1-3
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Journal Name
ARTICLE
-
1
precursor, ethylene glycol and water was explored as solvent, and of CeO
2
·xH
2
O around 3390 cm could be assigned to the
-
symmetrical stretching vibration of the OH group, indicating the
tert-butylamine would undergo hydrolysis to produce OH . Figs. 1a
37
abundance of OH group in CeO
2
·xH
2
O nanoparticles. The intensity
, which
and 1b display the representative TEM and HRTEM images of
of this band decreases sharply in the IR spectrum of CeO
2
2 2
CeO ·xH O nanoparticles. These nanoparticles exhibit uniform size
Fig. 2 (a) TEM and (b) HRTEM images of the Pt/CNTs + CeO
catalyst. (c) SEM image and EDX element mapping images of Pt (d)
and Ce (e) of the Pt/CNTs + CeO ·xH O catalyst. (f) STEM image of
the Pt/CNTs + CeO ·xH O catalyst and element mapping images of
2 2
·xH O
2
2
Fig. 1 (a) TEM and (b) HRTEM images of CeO ·xH O nanoparticles
2
2
2
2
obtained by tert-butylamine-assisted solvothermal method. The
inset image in Fig. 1a is the size distribution histogram of CeO ·xH
particles. (c) XRD patterns, (d) micro-FTIR spectra, (e) Ce 3d XPS
spectra and (f) O 1s XPS spectra of the as-prepared CeO ·xH O and
calcined CeO nanoparticles.
Pt (g) and Ce (h) obtained from the rectangle region marked in (f).
2
2
O
2
2
means that the majority of OH groups were lost during calcination.
2
-1
-1
Meanwhile, the bands around 1649 cm and 1355 cm may come
3
7
2 2
from the water in CeO ·xH O nanoparticles. And the bands around
-
1
-1
1
556 cm and 1066 cm could be attributed to the bending and
of 5.6 ±1.1 nm in the range of 3.0 - 9.0 nm (inset of Fig. 1a). HRTEM twisting vibration of -NH group in tert-butylamine adsorbed on
2
image (Fig. 1b) shows that most of the particles have clear lattice the surface of CeO ·xH O nanoparticles. These bands also become
2
2
3
8
fringes. The interplane distance of 0.31 nm corresponds to (111) weak in the spectrum of CeO2. Thus, FTIR demonstrates that OH
plane of CeO ·xH O. After calcining the CeO ·xH O nanoparticles at group and tert-butylamine may co-exist with large quantity on the
2
2
2
2
4
00 °C, CeO
2
2 2
nanoparticles were obtained. As shown in Fig. S1a, the surface of CeO ·xH O nanoparticles. And after calcination, only a
morphology of CeO nanoparticles is similar with that of CeO ·xH O small amount of these two species is left on the surface of CeO2
2
2
2
nanoparticles, but the mean diameter of the particles increases to nanoparticles. TGA shows that the weight loss of CeO ·xH O
2
2
8
.0 ± 1.6 nm. The lattice spacings found in Fig. S1b are 0.31 and 0.26 nanoparticles in the range of 30 - 500 °C is about 14.26% (Fig. S2),
nm, which could be ascribed to the (111) and (200) planes of CeO
which is close to the theoretical value of water molecules lost from
The XRD patterns (Fig. 1c) of both CeO ·xH O and CeO2 CeO ·1.6H O. However, the weight loss of CeO nanoparticles in the
2
.
2
2
2
2
2
nanoparticles reflect the typical diffraction peaks of ceria with same temperature range is only 2.25%. XPS analysis is used to
fluorite structure (JCPDS 34-0394). However, the diffraction further investigate the surface state of the as prepared CeO ·xH O
2
2
2 2 2
intensities of CeO ·xH O nanoparticles are much weaker than those and calcined CeO nanoparticels. As shown in Fig. 1e, the
of CeO nanoparticles. And the (200), (222), (400) and (331) peaks deconvoluted spectra for the Ce 3d peak of the two particles are
2
3
+
4+
of CeO
2
could hardly be found in the pattern of CeO
2
·xH
2
O
compared. Ce ions can exist in the oxidation states of Ce and Ce
3
6
nanoparticles, which is in agreement with the reported result. As in CeO ·xH O and CeO . The peaks around 880.5, 884.4, 898.8 and
shown in Fig. 1d, the micro-FTIR spectra of CeO
nanoparticles possess similar adsorption bands. The strongest band Ce . The calculated Ce content of as-prepared CeO ·xH O
2
2
2
3
+
2
·xH
2
O and CeO
2
903.2 eV can be ascribed to Ce , while other peaks are ascribed to
4
+ 39
3+
2
2
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Journal Name
2 2 2
Fig. 3 Electrochemical performance of Pt/CNTs + CeO ·xH O, Pt/CNTs + CeO , and Pt/CNTs for alcohol oxidation reaction. (a) CV
curves of the catalysts in 1.0 M KOH with a scan rate of 200 mV/s. (b) CV curves of the catalysts in 1.0 M KOH + 1.0 M CH OH with a
3
3
scan rate of 20 mV/s. (c) Chronoamperometric curves of the catalysts in 1.0 M KOH + 1.0 M CH OH at -0.3 V. (d) CV curves of the
catalysts in 1.0 M KOH + 1.0 M EG with a scan rate of 20 mV/s. (e) CV curves of the catalysts in 1.0 M KOH + 1.0 M glycerol with a
scan rate of 20 mV/s. (f) The mass activities of the catalysts for methanol, EG and glycerol electro-oxidation.
(
28.12%) is much higher than that in CeO
2
nanoparticles (7.48%). CeO
The higher Ce content reflects the higher concentration of oxygen catalysts in 1.0 M KOH and 1.0 M methanol solution. The forward
vacancies in the as-prepared CeO ·xH O nanoparticles, which may oxidation peak current density of the Pt/CNTs + CeO ·xH O catalyst
benefit for the anti-poisoning ability of Pt-based alcohol reaches as high as 2304 mA/mg, which is 2.8 times and 4.4 times of
2 2 2
·xH O or CeO nanoparticles. Fig. 3b compares CVs of the three
3
+
2
2
2
2
4
0
electrooxidation catalysts. As illustrated in Fig. 3f, the XPS spectra those from Pt/CNTs + CeO
of O 1s show the existence of OH groups (around 534.5 eV) in as- respectively. On the other hand, Table S1 illustrates that mass
prepared CeO ·xH O nanoparticles, and this component decreases activity of the Pt/CNTs + CeO ·xH O catalyst is far beyond the Pt-
in the calcined CeO nanoparticles, which is consistent with the FTIR based catalyst with metal oxides,
and TGA results .
Next, we use home-made Pt/CNTs material as a model alcohol
electrooxidation catalyst to investigate the effect of CeO ·xH
nanoparticles. The Pt/CNTs catalyst was prepared by an ionic-liquid-
assisted method. As shown in Fig. S3, Pt nanoparticles with a size
of 1.5-3.0 nm are uniformly grown on carbon nanotubes. The
Pt/CNTs catalyst was then mixed with CeO
obtain the Pt/CNTs + CeO ·xH O catalyst by ultrasonicating them
together in solution. TEM image (Fig. 2a) of the Pt/CNTs +
CeO ·xH O sample reveals that CeO ·xH O nanoparticles
2
(814 mA/mg) and Pt/CNTs (520 mA/mg),
2
2
2
2
3
1,41,42
and it is comparable to the
best Pt-alloy catalyst. Therefore, the novel Pt/CNTs + CeO ·xH
architecture may become an attractive catalyst for MOR in alkaline
2
medium. Meanwhile, the onset potential of Pt/CNTs + CeO ·xH O
2
7
2
2
O
2
2
2
O
shifts negatively to a lower potential (-0.546 V) as compared with
3
5
Pt/CNTs + CeO (-0.530 V) and Pt/CNTs (-0.513 V). This indicates
2
MOR occurs more easily on the Pt/CNTs + CeO ·xH O catalyst than
2
2
43
on the Pt/CNTs + CeO
and backward oxidation peak current densities, which is denoted as
/I , can be considered as an index to estimate the poison
resistance of catalyst for MOR.
CeO ·xH O catalyst is 2.57, which is higher than that of Pt/CNTs +
2
and Pt/CNTs catalysts. The ratio of forward
2 2
·xH O nanoparticles to
2
2
I
f b
4
4,45
The I /I value for Pt/CNTs +
f
b
2
2
2
2
2
2
homogeneously anchor on the surface of Pt/CNTs with few
dissociative particles. Furthermore, from the HRTEM image (Fig. 2b),
one can easily find the neighboring nanoparticles with the lattice
fringes of 0.23 nm and 0.31 nm, which are corresponding to the Pt
CeO2 (2.32) and Pt/CNTs (1.68). Furthermore, the durability of
catalysts toward MOR was tested by chronoamperograms. As
shown in Fig. 3c, the current densities rapidly decrease in the initial
stage for all the catalysts. However, after 1200 s, the retained
current density of Pt/CNTs + CeO ·xH O (570 mA/mg) is still much
(
2 2
111) plane and CeO ·xH O (111) plane, respectively. The SEM
2
2
image and the corresponding EDX element mapping images of Pt
and Ce (Figs. 2c-e) show the homogeneous distribution of Pt and Ce
in the Pt/CNTs + CeO ·xH O sample. The STEM image and
corresponding element mapping of Pt and Ce (Fig. 2f-h) further
demonstrate the CeO ·xH O nanoparticles are close to the Pt
nanoparticles .
The electrocatalytic performance of the three catalysts
Pt/CNTs + CeO ·xH O, Pt/CNTs +CeO and Pt/CNTs is initial
higher than those of Pt/CNTs + CeO
2
(163 mA/mg) and Pt/CNTs (10
mA/mg). The remaining proportions for the three catalysts are
4.7%, 30.2% and 4.9%, respectively. It is evidently obvious that
Pt/CNTs + CeO ·xH O exhibits higher stability than Pt/CNTs + CeO
2
2
2
3
2
2
2
2
4
and Pt/CNTs. Besides, the electrocatalytic activity of the Pt/CNTs +
CeO ·xH O catalyst are higher than those of Pt/CNTs + CeO and
2
2
2
Pt/CNTs catalysts even in acid medium (Fig. S4), though the
promotion effect of CeO ·xH O nanoparticles is not as high as that
2
2
2
2
2
evaluated by CVs in N -saturated 1.0 M KOH. As shown in Fig. 3a,
the ECSAs of the Pt/CNTs increase after the introduction of
2
in alkaline medium.
4
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Besides, the electrocatalytic activities of the three catalysts are 60 °C) is obviously superior than those catalysts with calcined CeO
compared for other alcohols, including EG and glycerol. For EG (Fig. S9a). Based on the thermogravimetric analysis (Fig. S9b), the
electrooxidation reaction (Fig. 3d), the forward oxidation peak total weight loss for each CeO sample calcined at different
2
2
temperature can be detected in the temperature range from 30 °C
to 500 °C. Finally, the relationship of calcination temperature and
the weight loss of CeO ·xH O nanoparticles as well as the mass
2 2
activity of the composite catalyst is clearly illustrated in Fig. 4b. The
largest weight loss (14.26%) is obtained from the as-preapred
CeO
current density (2309 mA/mg). And the peak current density
decreases with the weight loss of the corresponding CeO ·xH
nanoparticles. The peak current density of Pt/CNTs + CeO with the
nanoparticles calcined at 400 °C is only 814 mA/mg, accompanied
by the small weight loss (2.25%). The weight loss of the CeO ·xH
nanoparticles mainly come from the water molecules, whose
content is related with the amount of the surface OH groups. It may
2 2
be concluded that the the OH groups in CeO ·xH O nanoparticles
2 2
·xH O nanoparticles, which corresponds to the highest peak
2
2
O
2
Fig. 4 (a) The third cycle peak current density of Pt/CNTs +
CeO ·xH O containing different ratio of CeO ·xH O nanoparticles for
methanol oxidation. (b)The weight loss (black square) in the range
of 30 - 500 °C for the CeO ·xH O calcined at different temperature,
and the peak current density (red sphere) of Pt/CNTs + CeO ·xH O
2
2
2
2
2
2
O
2
2
2
2
containing the corresponding CeO
methanol oxidation.
2
·xH
2
O
nanoparticles for
play important roles in the promotion effect of electrocatalytic
activities of Pt/CNTs toward MOR.
In order to investigate the promotion mechanism, the LSV and
polarization curves were obtained to evaluate the electrocatalytic
activity. As shown in Fig. 5a, the onset potentials of MOR are -0.517
V, -0.501 V and -0.492 V, and current densities are 687 mA/mg, 372
current density of Pt/CNTs + CeO
nearly 1.7 and 2.2 times of those of Pt/CNTs + CeO
and Pt/CNTs (1464 mA/mg). Moreover, the onset potential of
Pt/CNTs + CeO ·xH O catalyst is -0.539 V, which has negatively
shifted comparing with Pt/CNTs + CeO (-0.519 V) and Pt/CNTs (-
.505V). For glycerol electrooxidation reaction, Fig. 3e shows the
2
·xH
2
O is 3245 mA/mg, which is
2
(1883 mA/mg)
2
2
mA/mg and 112 mA/mg for Pt/CNTs + CeO
and Pt/CNTs catalysts, respectively. It shows that the Pt/CNTs +
CeO ·xH O catalyst possesses more negative onset potential and
higher current density compared with Pt/CNTs and Pt/CNTs + CeO
which confirms the outstanding electrocatalytic activity of Pt/CNTs
2 2 2
·xH O, Pt/CNTs + CeO
2
0
2 2
peak current density of Pt/CNTs + CeO ·xH
O is 1880 mA/mg, which
(1324
mA/mg) and Pt/CNTs (952 mA/mg). Furthermore, the onset
potential of Pt/CNTs + CeO ·xH O catalyst (-0.517V) is also lower
than those of Pt/CNTs + CeO (-0.505 V) and Pt/CNTs (-0.497 V)
catalysts. Consequently, it can be concluded that the activity of the
Pt/CNTs + CeO ·xH O catalyst is superior than Pt/CNTs + CeO and
2
2
,
is nearly 1.4 and 2.0 times of those from Pt/CNTs + CeO
2
2
2
0,31
+
CeO
MOR for all the catalysts. The equilibrium potentials of MOR are -
.735 V, -0.785 V and -0.850 V for Pt/CNTs, Pt/CNTs + CeO and
Pt/CNTs CeO ·xH O catalysts, suggesting that Pt/CNTs
CeO ·xH O catalyst exhibits the most negative equilibrium potential
for MOR among the three catalysts. Furthermore, the Tafel slope of
2
·xH
2
O catalyst.
Fig. 5b shows the polarization curves of
2
2
2
0
2
+
2
2
+
2
2
2
Pt/CNTs catalysts for alcohol (methanol, EG or glycerol)
electrooxidation reaction (Fig. 3f).
2
2
-1
Pt/CNTs + CeO
2 2
·xH O is 122 mV dec (Fig. 5c), which is much
Moreover, the promotion effect of CeO
2
·xH
2
O nanoparticles
-1
smaller than those of Pt/CNTs + CeO
2
(130 mV dec ) and Pt/CNTs
toward alcohol electrooxidation reaction is also applicable to other
catalysts. The mass activities of the commercial Pt/C, Pd/C and
PtRu/C catalysts can be remarkably enhanced by the introduction of
CeO
electrocatalytic activities of metal/carbon + CeO
higher than those of the metal/carbon + CeO counterparts. These
2
results demonstrate the highly versatility of CeO ·xH O
2
·xH
2
O
nanoparticles (Figs. S5-7). Meanwhile, the
2
·xH O are much
2
2
2
nanoparticles to increase the electrocatalytic activities of Pt-based
and Pd-based catalysts toward alcohol oxidation.
2 2
The addition ratio of CeO ·xH O nanoparticles to Pt/CNTs is a
crucial factor to obtain the optimal electrocatalytic activities. CV
measurement of each ratio was repeated for three times. The
typical CV curves of each ratio are shown in Fig. S8. And Fig. 4a
shows the effect of different ratio on the mass activity increases
with the increasement of the amount of CeO
the range of 0-30%. The mass activity reaches the maximum value
of 1547 mA/mg when 30% CeO ·xH O nanoparticles are mixed with
Pt/CNTs. However, the mass activity drops when more CeO ·xH
nanoparticles are introduced, which may be due to the coverage of
2 2
·xH O nanoparticles in
2
2
2
2
O
Fig. 5 (a) LSV curves and (b) polarization curves of Pt/CNTs,
Pt/CNTs + CeO and Pt/CNTs + CeO ·xH O in N -purged 1.0 M
KOH and 1.0 M CH OH solution at a scan rate of 1 mV/s. (c)
Tafel plots derived in the potential range of -0.5 to -0.45 V. (d)
2
EIS of Pt/CNTs, Pt/CNTs + CeO and Pt/CNTs + CeO ·xH O in N -
2
2
2
2
too many CeO
nanoparticles.
2 2
·xH O nanoparticles on the surface of Pt
3
To clarify the effect of OH groups on CeO
we calcine the as-prepared CeO ·xH O nanoparticles at different
temperatures for two hours. It can be found that the mass activity
of Pt/CNTs + CeO ·xH O with the as-prepared CeO ·xH O (dried at
2 2
·xH O nanoparticles,
2
2
2
2
2
purged 1.0 M KOH solution for the potential at -0.5 V with the
inset showing the magnification of high frequency region.
2
2
2
2
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ARTICLE
Journal Name
5
0
catalytic activity toward MOR. Besides, as stated above, the as-
3
+
2 2 2
prepared CeO ·xH O possess much higher Ce content than CeO ,
which may further facilitate the charge transfer from CeO
Pt nanoparticles.
2 2
·xH O to
To measure the anti-CO poisoning of the three catalysts, the
CO striping voltammograms were carried on the catalysts in KOH
solution. As shown in Fig. 6b, the onset potential for CO oxidation of
Pt/CNTs + CeO
Pt/CNTs (-0.459 V) and Pt/CNTs + CeO
2
·xH
2
O (-0.502 V) shifts negatively as compared to
(-0.466 V), indicating that
2 2
·xH O may weaken the affinity of adjacent Pt nanoparticles for
2
CeO2
CO.
9,51
Furthermore, this catalyst possesses a larger CO oxidation
peak area than the other two catalysts, which could be attributed to
52-55
the larger ECSA of Pt/CNTs + CeO
may also contribute to the high electrocatalytic performance of
Pt/CNTs + CeO ·xH O catalyst toward MOR. These results prove that
Pt/CNTs + CeO ·xH O has higher reaction activity than the other
two catalysts in oxidation of CO, which may be due to a large
2
·xH
2
O catalyst.
The large ECSA
2
2
2
2
20, 21
amount of OH groups existing on the surface of CeO
To further unveil the effect of OH groups on the promotion
effect of CeO ·xH O, the calcined CeO nanoparticles have first been
2 2
·xH O.
2
2
2
stirred in the 1.0 M NaOH solution for 1h, and then mixed with
Pt/CNTs. This catalyst shows obviously higher mass activity toward
2
Fig. 6 (a) The Pt 4f XPS spectra of the Pt/CNTs, Pt/CNTs+CeO ,
and Pt/CNTs+CeO ·xH O. (b) CO stripping curves of Pt/CNTs,
2
2
MOR than Pt/CNTs + CeO
commercial Ce(OH) nanoparicles were also conducted. On
introducing the commerial Ce(OH) nanoparicles, the mass activity
of Pt/CNTs toward MOR increases from 533 mA/mg to 1031 mA/mg
(Fig. S11). This result confirms the promotion effect of Ce(OH)
2
(Fig. S10). Control experiments with
Pt/CNTs +CeO
catalyst in 1.0 M KOH. (c) A schematic diagram to illustrate the
critical function of OH groups in the Pt/CNTs + CeO ·xH O
2 2 2
, Pt/CNTs+CeO ·xH O and commercial Pt/C
4
4
2
2
catalyst for the removal of CO during methanol
electrooxidation.
4
nanoparicles on Pt/CNTs catalyst for MOR. However, the current
density is far lower than that of the Pt/CNTs with above-mentioned
CeO
O can method. In order to reveal the role of tert-butylamine, the
reflect their lower overpotential and the faster reaction kinetics of commercial Ce(OH) was first stirred in the tert-butylamine solution,
MOR than the other two catalysts, which is consistent with LSV isolated by centrifugation and then mixed with Pt/CNTs. The mass
curves and CV curves. Besides, the charge transfer resistance of the activity of Pt/CNTs with tert-butylamine-modified Ce(OH) further
three catalysts were verified by electrochemical impedance spectra increases to 1551 mA/mg in MOR, nearly 1.5 times of that of
EIS). Fig. 5d shows the Nyquist plots of Pt/CNTs, Pt/CNTs +CeO
and Pt/CNTs + commercial Ce(OH) . These experiments prove that both
Pt/CNTs + CeO ·xH
O catalysts in 1.0 M KOH. The resistance value in OH groups and tert-butylamine modification contribute to the high
2 2
·xH O nanoparicles synthesized by tert-butylamine-assisted
-
1
(
2 2
169 mV dec ). The smaller Tafel slope of Pt/CNTs + CeO ·xH
4
31
4
(
2
4
2
2
the high frequency region is small and even could be ignored. As is electrocatalytic activity of Pt/CNTs + CeO
2 2
·xH O catalyst toward
known to all, the diameter of the semicircle in the low frequency MOR.
area can be used to determine the charge transfer resistance of
Through the above investigations, we have established the
CeO ·xH O nanoparticles with abundant OH groups possess superb
catalyst, and the smaller diameter means the smaller electron
2
2
46
transfer resistance of MOR. The diameter of Pt/CNTs + CeO ·xH O
2
2
promotion effect for Pt-based catalysts toward MOR in alkaline
medium. The overall reaction and electrocatalytic pathways for
MOR on Pt nanoparticles in alkaine media can be expressed in
is much smaller than those of the Pt/CNTs and Pt/CNTs + CeO
catalysts, declaring that Pt/CNTs + CeO ·xH O catalyst possesses
2
2
2
smaller charge transfer resistance, further demonstrating the
catalytic activity of Pt/CNTs can be efficiently enhanced by
8,30
reactions (1) and (2), respectively.
-
-
4
6,47
CH OH + 6OH
→
CO + 5H O + 6e
(1)
→
CeO
2
·xH
Furthermore, the XPS data of Pt 4f lines for the Pt/CNTs,
Pt/CNTs + CeO , and Pt/CNTs + CeO ·xH O was obtained to compare
2
O.
3
2
2
CH
3
OH + Pt
→
Pt-(CH
3
O)ads
→
2
Pt-(CH O)ads→ Pt-(CHO)ads
2
2
2
Pt-COads
(2)
the surface chemical composition evolution of Pt nanoparticles. As
shown in Fig. 6a, the Pt 4f peak can be separated into two different
The poisoning intermediates such as CH O and CO may adsorb
3
0
2+
0
7/2
on the Pt active sites, leading to the decrease of activity of the
catalyst. The promotion effect of CeO ·xH O nanoparticles may
chemical-shifted components Pt and Pt . The peak of Pt 4f in
the Pt/CNTs (71.34 eV) is positively shifted to 71.55 eV and 71.63 eV,
respectively, after ultrasonic mixing with CeO2 and CeO ·xH O
2
2
result from the following aspect: (i) Upon ultrasonic mixing with
CeO ·xH O nanoparticles, the electronic structure of Pt
2
2
2
2
nanoparticles. This significant change of binding energy is an
indicative of electron transfer between Pt nanoparticles and
nanoparticles could be changed by electron transfer from
CeO ·xH O to Pt, which may effectively reduce the adsorption
possibility of poisoning intermediates (such as CO) on Pt
4
8,49
2
2
CeO
2
·xH
2
O nanoparticles.
Moreover, from the deconvolution of
0
the XPS profiles, the content of Pt in Pt/CNTs + CeO ·xH O catalyst
20
2
2
nanoparticles.
(ii) The abundant OH group in CeO ·xH O
2 2
is determined to be 66.8%, which is higher than those in Pt/CNTs +
0
nanoparticles may directly accelerate MOR via the following
CeO2 (65.2%) and Pt/CNTs (58.4%). The higher content of Pt in
8
pathways.
2 2
Pt/CNTs + CeO ·xH O catalyst may contribute to their higher
6
| J. Name., 2012, 00, 1-3
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J oP ul er na as el od f oM na ot et ra i ad lj su Cs th me ma ri gs ti nr ys A
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DOI: 10.1039/C7TA09071D
Journal Name
ARTICLE
Pt-(CH
3
O)ads + CeO
2
-xOH → Pt-(CH3-xO) + CeO
2
+ xH
2
O
(3)
(4)
measurements. Z.L. performed the TGA and spectra analysis.
X.F. and C.J. performed the TPD analysis. Z.L. and X.L.
performed TEM and SEM studies. Z.L., J.Z., H.W. and H.C.
performed mechanism studies. Z.L., J.Z. and H.C. co-wrote the
paper. All authors discussed the results and commented on
the manuscript.
Pt-COads + CeO -xOH → Pt-(COOH) + CeO -(x-1)OH
2
ads
2
Pt-(COOH)ads + CeO -xOH → CO + CeO -(x-1)OH + H O
(5)
2
2
2
2
On the contrary, CeO
groups by dissociating water molecules on their surface. One of
the functions of OH groups is to react with CO adsorbed on the
2
nanoparticles indirectly afforded OH
16
2
3
neighboring Pt particles (Fig. 6c and reactions 4-5). Furthermore,
the abundant OH groups on CeO ·xH O nanoparticles may also
facilitate the deprotonation and dehydrogenation processes of
2
2
Notes and references
2
2
methanol adsorbents on Pt (reaction 3). Meanwhile, the
dissociation of OH groups from CeO ·xH O nanoparticles
2
2
1.
2.
M. Liu, R. Zhang and W. Chen, Chem. Rev., 2014, 114
5
,
simultaneously produced coordinatively unsaturated Ce sites, which
117-5160.
-
are capable of adsorbing OH from the alkaline solution to
5
6
C. Hu, H. Cheng, Y. Zhao, Y. Hu, Y. Liu, L. Dai and L. Qu, Adv.
Mater., 2012, 24, 5493-5498.
regenerate OH groups. The fast regeneration of OH groups
assures the high catalytic stability of the Pt/CNTs + CeO ·xH O
2
2
2
2
3
4
.
.
Y. Y. Chu, J. Cao, Z. Dai and X. Y. Tan, J. Mater. Chem. A,
catalysts. (ii) The OH groups on the surface of CeO
·xH
O
2
014, 2, 4038.
nanoparticles may be stabilized by the tert-butylamine molecules,
which ensures the high content of OH groups during the alcohol
electrooxidation process. Therefore, the high concentration of OH
groups and tert-butylamine molecules have played synergistic
effect on the CeO ·xH O-enhanced catalytic activity and stability of
A. L. Wang, X. J. He, X. F. Lu, H. Xu, Y. X. Tong and G. R. Li,
Angew. Chem. Int. Ed., 2015, 54, 3669-3673.
5
6
.
.
M. K. Debe, Nature, 2012, 486, 43-51.
N. Kakati, J. Maiti, S. H. Lee, S. H. Jee, B. Viswanathan and
Y. S. Yoon, Chem. Rev., 2014, 114, 12397-12429.
S. Lu, K. Eid, D. Ge, J. Guo, L. Wang, H. Wang and H. Gu,
Nanoscale, 2017, 9, 1033-1039.
2
2
Pt-based catalysts toward alcohol electrooxidation.
7
8
.
.
L. Huang, Y. Han, X. Zhang, Y. Fang and S. Dong, Nanoscale,
Conclusion
2
017, 9, 201-207.
In summary, tert-butylamine-modified CeO
2
·xH
2
O nanoparticles 9.
with abundant OH groups have been synthesized for the
remarkable enhancement of electrocatalytic performance of 10.
Pt/CNTs catalyst toward methanol, EG and glycerol oxidation.
Characterization results clearly show the difference between the as- 11.
L. Wang and Y. Yamauchi, J. Am. Chem. Soc., 2013, 135,
16762-16765.
S. Lu, K. Eid, M. Lin, L. Wang, H. Wang and H. Gu, J. Mater.
Chem. A, 2016, 4, 10508-10513.
Z. Zhang, Z. Luo, B. Chen, C. Wei, J. Zhao, J. Chen, X.
Zhang, Z. Lai, Z. Fan, C. Tan, M. Zhao, Q. Lu, B. Li, Y. Zong,
C. Yan, G. Wang, Z. J. Xu and H. Zhang, Adv. Mater., 2016,
28, 8712-8717.
G. Zhang, Z. Yang, W. Zhang and Y. Wang, J. Mater. Chem.
A, 2016, 4, 3316-3323.
prepared CeO
2
·xH
2
O nanoparticles and calcined CeO
2
nanoparticles.
The OH groups on CeO
2
·xH O nanoparticles have been found to be
the key factor for the promotion of the catalytic activity and
stability of Pt/CNTs, through accelerating the deprotonation and 12.
dehydrogenation of alcohol as well as stripping poisonous
intermediates from Pt nanoparticles. Moreover, via stabilizing OH 13.
groups, the tert-butylamine molecules also contribute to the
2
Y. Liu, D. Li, V. R. Stamenkovic, S. Soled, J. D. Henao and S.
Sun, ACS catal., 2011, 1, 1719-1723.
enhancement of the electrocatalytic performance of Pt/CNTs 14.
Y.-Y. Feng, L.-X. Bi, Z.-H. Liu, D.-S. Kong and Z.-Y. Yu, J.
Catal., 2012, 290, 18-25.
2 2
catalyst. Importantly, this method by incorporation CeO ·xH O
nanoparticles to enhance the electrocatalytic performance is not 15.
only facile, but also adapts to other kinds of alcohol electroxidation
catalysts such as commercial Pt/C, Pd/C and PtRu/C. We believe our 16.
H.-H. Li, Q.-Q. Fu, L. Xu, S.-Y. Ma, Y.-R. Zheng, X.-J. Liu and
S.-H. Yu, Energy Environ. Sci., 2017, 10, 1751-1756.
Y. Zhou, Y. Gao, Y. Liu and J. Liu, J. Power Sources, 2010,
195, 1605-1609.
work may also inspire the rational design of other electrocatalysts,
such as water oxidation catalysts, with high performance.
17.
D. R. Ou, T. Mori, H. Togasaki, M. Takahashi, F. Ye and J.
Drennan, Langmuir, 2011, 27, 3859-3866.
H. Huang and X. Wang, J. Mater. Chem. A, 2014, 2, 6266-
1
1
2
8.
9.
0.
6
291.
H. Xu, A.-L. Wang, Y.-X. Tong and G.-R. Li, ACS Catal., 2016,
, 5198-5206.
Acknowledgements
The research work is supported by the National Natural
Science Foundation of China (21561023, 51501094,
6
L. Zhang and Y. Shen, ChemElectroChem, 2015, 2, 887-895.
B. N. Zope, D. D. Hibitts, M. Neurock and R. J. Davis,
Science, 2010, 330, 74-78.
2
1161013), the Natural Science Foundation of Inner Mongolia 21.
Autonomous Region of China (2017JQ03) and the Program of
High-level Talents of Inner Mongolia University (21300- 22.
155104).
M. S. Ide and R. J. Davis, Acc. Chem. Res., 2014, 47, 825-
8
33.
5
2
3.
G. X. Chen, G. Fu, P. N. Duchesne, L. Gu, Y. P. Zheng, X. F.
Weng, M. S. Chen, P. Zhang, C. W. Pao, J. F. Lee and N. F.
Zheng, Science, 2014, 344, 495-499.
Author contributions
2
4.
H. Huang, J. Zhu, D. Li, C. Shen, M. Li, X. Zhang, Q. Jiang, J.
Zhang and Y. Wu, J. Mater. Chem. A, 2017, 5, 4560-4567.
A. A. EL-Shafei, J. Electroanal. Chem., 1999, 471, 89-95.
H.C. conceived the project and designed the experiments. Z. L.
and L.T. conducted material synthesis and electrochemical 25.
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 7
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DOI: 10.1039/C7TA09071D
ARTICLE
Journal Name
2
6.
M. Jafarian, M. G. Mahjani, H. Heli, F. Gobal, H. 53.
Khajehsharifi and M. H. Hamedi, Electrochim. Acta, 2003,
A. L. Wang, H. Xu, J. X. Feng, L. X. Ding, Y. X. Tong and G. R.
Li, J. Am. Chem. Soc., 2013, 135, 10703-10709.
H. Wang, K. Jiang, Q. Chen, Z. Xie and W. B. Cai, Chem
Commun , 2016, 52, 374-377.
T.-T. Zhao, H. Wang, X. Han, K. Jiang, H. Lin, Z. Xie and W.-B.
Cai, J. Mater. Chem. A, 2016, 4, 15845-15850.
H. Su, K. X. Zhang, B. Zhang, H. H. Wang, Q. Y. Yu, X. H. Li,
M. Antonietti and J. S. Chen, J. Am. Chem. Soc., 2017, 139,
811-818.
4
8, 3423-3429.
54.
55.
2
7.
8.
Y. Wang, D. Zhang, W. Peng, L. Liu and M. Li, Electrochim.
Acta, 2011, 56, 5754-5758.
2
J. Zhong, D. Bin, B. Yan, Y. Feng, K. Zhang, J. Wang, C.
Wang, Y. Shiraishi, P. Yang and Y. Du, RSC Adv., 2016, 6, 56.
2722-72727.
7
29.
30.
31.
W. Huang, X. Y. Ma, H. Wang, R. Feng, J. Zhou, P. N.
Duchesne, P. Zhang, F. Chen, N. Han, F. Zhao, J. Zhou, W. B.
Cai and Y. Li, Adv. Mater., 2017, 29, 1703057.
W. Huang, H. Wang, J. Zhou, J. Wang, P. N. Duchesne, D.
Muir, P. Zhang, N. Han, F. Zhao, M. Zeng, J. Zhong, C. Jin, Y.
Li, S. T. Lee and H. Dai, Nat. Commun., 2015, 6, 10035.
L. Yu and J. Xi, Int. J. Hydrogen Energy, 2012, 37, 15938-
15947.
3
3
2.
3.
L. Yu and J. Xi, Electrochim. Acta, 2012, 67, 166-171.
J. Xi, J. Wang, L. Yu, X. Qiu and L. Chen, Chem. Commun,
2007, 1656-1658.
34.
35.
36.
37.
38.
39.
40.
41.
J. Wang, X. Deng, J. Xi, L. Chen, W. Zhu and X. Qiu, J. Power
Sources, 2007, 170, 297-302.
H. Chu, Y. Shen, L. Lin, X. Qin, G. Feng, Z. Lin, J. Wang, H.
Liu and Y. Li, Adv. Funct. Mater., 2010, 20, 3747-3752.
K. Tang, J. Zhang, W. Wang, S. Wang, J. Guo and Y. Yang,
CrystEngComm, 2015, 17, 2690-2697.
T. Wang and D.-C. Sun, Mater. Res. Bull., 2008, 43, 1754-
1760.
I. Kanesasaka, M. Izumi, M. Mitsuishi and K. Kawai, Bull.
Chem. Soc. Jpn., 1981, 54, 1600-1605.
Q. Tan, C. Du, Y. Sun, L. Du, G. Yin and Y. Gao, Nanoscale,
2
015, 7, 13656-13662.
Q. Tan, C. Du, Y. Sun, G. Yin and Y. Gao, J. Mater. Chem. A,
014, 2, 1429-1435.
2
X. Yang, X. Wang, G. Zhang, J. Zheng, T. Wang, X. Liu, C.
Shu, L. Jiang and C. Wang, Int. J. Hydrogen Energy, 2012,
3
7, 11167-11175.
H. Huang and X. Wang, Phys. Chem. Chem. Phys., 2013,
5, 10367-10375.
4
2.
3.
1
4
X. Cui, P. Xiao, J. Wang, M. Zhou, W. Guo, Y. Yang, Y. He, Z.
Wang, Y. Yang, Y. Zhang and Z. Lin, Angew. Chem. Int. Ed.,
2
017, 56, 4488-4493.
H. Fan, M. Cheng, Z. Wang and R. Wang, Nano Res., 2016,
0, 187-198.
A. Serrà, E. Gómez, I. V. Golosovsky, J. Nogués and E.
Vallés, J. Mater. Chem. A, 2016, 4, 7805-7814.
D.-M. Gu, Y.-Y. Chu, Z.-B. Wang, Z.-Z. Jiang, G.-P. Yin and Y.
Liu, Appl. Catal. B: Environ., 2011, 102, 9-18.
B. Kaur, R. Srivastava and B. Satpati, ACS Catal., 2016, 6,
44.
45.
46.
47.
48.
49.
1
2
654-2663.
J. Xi, J. Wang, L. Yu, X. Qiu and L. Chen, Chem. Commun.,
007, 1656-1658.
2
D. Higgins, M. A. Hoque, M. H. Seo, R. Wang, F. Hassan, J.-
Y. Choi, M. Pritzker, A. Yu, J. Zhang and Z. Chen, Adv. Funct.
Mater., 2014, 24, 4325-4336.
5
0.
1.
Y. Liu, C. Liu, X. Yu, H. Osgood and G. Wu, Phys. Chem.
Chem. Phys., 2016, 19, 330-339.
Q. Liu, K. Jiang, J. Fan, Y. Lin, Y. Min, Q. Xu and W.-B. Cai,
Electrochim. Acta, 2016, 203, 91-98.
5
52.
L. Zhang, L. X. Ding, H. Chen, D. Li, S. Wang and H. Wang,
Small, 2017, 13, 1604000.
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| J. Name., 2012, 00, 1-3
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Journal of Materials Chemistry A
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DOI: 10.1039/C7TA09071D
CeO ·xH O nanoparticles with abundant surface OH groups can remarkably promote
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the alcohol electrooxidation activity of Pt/CNT catalysts.