Three-dimensional crumpled graphene as an electro-catalyst support for formic acid electro-oxidation

Article abstract of DOI:10.1039/c5ta09956k

Three-dimensional crumpled graphene (PRGO) was synthesized from graphene oxide (GO) solution by the spay drying method and employed as the support material for the Pd catalyst. The as-prepared catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), tunnel electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The electro-catalytic activity and stability toward formic acid oxidation were investigated using cyclic voltammetry (CV) and chronoamperometry (CA), which indicated that the Pd/PRGO catalyst exhibits a larger electrochemically active surface area and mass activity as well as higher long term-stability in comparison to the commercial Pd/C and Pd/RGO catalysts. The enhanced catalytic performance is attributed to the high specific surface area of the 3D formation and utilization efficiency of Pd during the oxidation of formic acid.

Full text of DOI:10.1039/c5ta09956k

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ARTICLE
Three-dimensional crumpled graphene as an electro-catalyst
support for formic acid electro-oxidation
Received 00th January 20xx,
Accepted 00th January 20xx
a
b
a
a
Yang Zhou,* Xian-Chao Hu, Qizhe Fan, and He-Rui Wen*
DOI: 10.1039/x0xx00000x
Three-dimensional crumpled graphene (PRGO) was synthesized from graphene oxide (GO) solution with spay drying
method and employed as the support material for Pd catalyst. The as-prepared catalysts were characterized by X-ray
diffraction (XRD), scanning electron microscopy (SEM), tunnel electron microscopy (TEM) and X-ray photoelectron
spectroscopy (XPS). The electro-catalytic activity and stability toward formic acid oxidation was investigated with cyclic
voltammetry (CV) and chronoamperometry (CA), which indicated that Pd/PRGO catalyst exhibits larger electrochemically
active surface area and mass activity as well as higher long term-stability in comparison to the commercial Pd/C and
Pd/RGO catalysts. The enhanced catalytic performance is attributed to the high specific surface area of the 3D formation
and utilization efficiency of Pd during the oxidation of formic acid.
www.rsc.org/
1
1
and graphene have been extensively investigated for the
support materials in fuel cells due to its high specific surface
area and conductivity. Especially, graphene (GR) has gained
much attention as the support materials in DFAFC because of
its high electron conductivity, large surface area, sufficient
1
. Introduction
Recently, formic acid has attracted great attentions as a
promising alternative fuel for liquid fuel cells because of its
many advantages, such as reduced toxicity, higher kinetic
activity and lower fuel crossover through Nafion membranes
12
porosity and thermal stability. For example, Zhong et al.
reported that the Pd nano-leaves supported on the reduced
graphene oxide (RGO) exhibited excellent electro-catalytic
13
1
,2
than methanol. It has been proved that the Pd catalyst
exhibits excellent activity and stability towards the formic acid
electro-oxidation (FAEO) compared with those of the Pt
catalyst, which has relatively lower cost and higher resistance
performance towards the formic acid oxidation. But two-
dimensional (2D) layered graphene have a tendency to form
aggregation during the drying stage due to the π ꢀ π stacking
and van der Waals attraction. The stacking of 2D GR-based
3
,4
to CO poisoning.
However, further investigations have
14
demonstrated that the Pd catalyst has its drawbacks such as
poor stability due to dissolution during the FAEO.
Consequently, the activity and stability of the Pd-based
catalysts still need further improvements to meet the demand
of the direct formic acid fuel cell (DFAFC).
sheets leads to reduce the specific surface area and utilization
efficiency of Pd. Therefore, many efforts are needed to
prevent severe stacking in 2D GR-based sheets.
Spray drying is widely used to prepare powders because
of its many advantages, such as high efficiency, low
preparation temperature and the fact that it can be scaled up
One of the best strategies to obtain alternative
economical catalysts with desired performance is to effectively
control the size and morphology of Pd nanostructure with a
large specific surface area. Previous studies have proven that
15
to ton quantities. Herein, we report an efficient synthesis of
3D structured graphene with a porous structure from
graphene oxide (GO) by spray drying. The fabricated 3D
structured graphene decorated with Pd catalyst displays higher
electro-catalytic activity and durability than 2D structured
graphene decorated with Pd catalyst in DFAFC.
5
various Pd catalysts including Pd nanowire networks, Pd
6
nanorods with high-index facets, concave Pd nanocubes and
7
8
tetra-hexahedral Pd nanocrystals have extremely high activity
towards the oxidation of ethanol and formic acid. Nevertheless,
it is well known that the catalytic activity of metal catalyst is
also related to the support materials besides the size and 2. Experimental
shapes of metal nanostructure. Various carbon materials such
9 10
as carbon nanotube (CNT), carbon black, carbon nanofibers
2.1 Synthesis of electro-catalysts
Graphene oxide was prepared by the oxidation reaction of
graphite powder (99.9 % purity, Alfa Aesar, USA) using a
16,17
modified Hummers’ method.
In a typical synthesis, 1 g of
graphite powder was put into 23 mL of concentrated H SO4
2
under magnetic stirring in an ice bath. The temperature of the
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mixture was kept below 20 °C. The mixture was then stirred at of the catalysts on the oxidation of methanol was studied in
5 °C for 2 h. 46 mL of deionized water was added and the 0.5 M H SO aqueous solution containing 1.0 M HCOOH at a
temperature was maintained at 96 °C for 15 min. After 46 mL scan rate of 50 mV s .
of deionized water and 46 mL of 30 wt % H solution were
3
2
4
-1
2 2
O
added to the solution, the mixture was filtered and washed
with 1 M HCl and distilled water until the rinse water became
neutral. The product was finally freeze-dried, which was
denoted as GO.
3
. Results and Discussion
3
.1 Structure and Morphology
The XRD patterns of the as-prepared samples are shown in Fig.
1a and b. The diffraction peak at 11° is characteristic of the GO
plane, suggesting the transformation to 2D layered
For the fabrication of 3D structured graphene, 1000 mL
-1
aqueous suspensions of GO at concentrations of 0.25 mg mL
were prepared. After being ultrasonicated for 30 min, the
combined solution were handled by spray drying using SD1000
1
8
graphene.
characteristic peak of the (002) plane is obviously found to
decrease in the PRGO support. In addition, the 2 values of the
002) peak for the PRGO is obviously shifted to lower
After spay-drying treatment, the graphene
3
spray dryer (EYELA) under the blower flux of 0.7 m ∙min ,
-1
-
1
θ
feeding speed of 300 mL∙h and inlet temperature of 200
The as-prepared product was designated as PRGO.
℃.
(
diffraction angles in comparison with the GO. This behavior is
related with the aggregation and restacking of graphene
Subsequently, Pd/PRGO catalyst was prepared through
the improved liquid phase reduction method. In a typical
procedure, 50 mg of the as-prepared PGO support and 23.5 mL
1
9
sheets being effectively prevented by spay-drying treatment.
The diffraction peaks at 40.6°, 46.2°, 67.8° and 81.4° are
corresponded to the (111), (200), (220) and (311) lattice planes
of 5 mM PdCl solution was dispersed in 50 mL of water by
2
sonication. After the pH was adjusted to nearly 9 using 1 M
Na CO solution, a freshly prepared 10 mL of 0.1 M NaBH
4
2
0
of the fcc crystalline Pd [JCPDS no. 46-1043], respectively.
2
3
According to Debye–Scherrer's formula, the crystal sizes of Pd
nanoparticles are respectively calculated to be 6.3 and 4.8 nm
solution was added to the solution, followed by stirring for 2 h.
The resulting solution was filtered, washed, and dried at 85 °C
for 10 h in a vacuum oven, yielding 20 wt % Pd loading on the
supports. For comparison, Pd supported on GO catalyst with
the same Pd loading amounts was prepared by the same
2
1
for Pd/RGO and Pd/PRGO catalysts.
procedure above, which was denoted as Pd/RGO.
A
commercial 10 wt % Pd/C (JM Pd/C) was purchased from
Johnson Matthy Co., Ltd. and used as contrast samples.
2
.2 Characterizations
The phases present in the synthesized materials were
identified using XRD (Panalytical X'Pert Pro, Cu Kα1 radiation
source (λ = 0.1541 nm), voltage of 40 kV, current of 40 mA).
The morphology and structure of the products were
characterized using FE-SEM (Hitachi S-4700 II) and TEM (Tecnai
G2 F30) with Energy-dispersive X-ray spectroscopic (EDS). XPS
was carried out on Kratos AXIS Ultra DLD. All XPS spectra were
corrected using the C 1s line at 284.6 eV. Curve fitting and
background subtraction were accomplished.
Fig.1 (a) XRD patterns of GO and PRGO; (b) XRD patterns of
Pd/PRGO and Pd/RGO
2.3 Electrochemical measurements
The electrochemical measurements were performed using a
three-electrode cell with an Ivium electrochemical workstation
at room temperature. For electrode preparation, 2 mg of
electrocatalysts were ultrasonically mixed in 200 μl of ethanol-
water solution to form a homogeneous ink followed by
dropping 2 μl of the electrocatalyst ink onto the surface of a
glassy carbon electrode (GCE, with a diameter of 3 mm), and 5
μl of Nafion solution of 1.0% (DuPont, USA) in ethanol was
added to fix the electrocatalyst on the GCE surface. Glassy
carbon (GC) disk electrode served as the substrate for the
support. Prior to use, the GC electrode was polished using
aqueous alumina suspension. And then the catalyst suspension
was pipetted using a micropipettor onto the GC surface to
Fig.2 SEM images of (a-b) PRGO and (c-d) GO
-2
make a Pd loading of about 0.056 mg cm . A Pt foil and
saturated calomel electrode (SCE) were used as counter and
reference electrodes, respectively. The electrocatalytic activity
The structure and morphology of the different samples
were analyzed by the scanning electron microscopy (SEM) and
2
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tunnel electron microscopy (TEM). Fig. 2 displays SEM images
of GO and PRGO with different magnifications. SEM images
(Fig. 2a and b) illustrates that the as-prepared PRGO has a 3D
morphology, which appear as crumpled paper balls with
diameters of about 3-5 μm. Fig 2c and d are the SEM images of
GO, it can be seen that 2D layered graphene sheets tend to
form aggregation and stacking. Fig.3 presents TEM images and
particle size distributions of Pd/PRGO and Pd/RGO catalysts. It
can be seen from the TEM images that Pd particles on the
PRGO support are smaller and more uniformly dispersed than
those on the GO supports. The average sizes of particles in the
Pd/PRGO and Pd/RGO catalysts are estimated from their
histograms as being approximately 4.6 and 6.8nm, respectively,
which are consistent with the results of XRD. In order to
further investigate the structure and morphology of Pd
nanoparticles on the surface of PRGO, the high-resolution TEM Fig. 5 FTIR spectra for PRGO and GO
(HR-TEM) were carried out. Fig. 4a exhibits a lattice spacing of
0
.23 nm with the lattice orientation of (111) of Pd, which
According to the FTIR spectra of GO and PRGO (Fig. 5), the
-
1
-1
indicates that Pd nanoparticles with an average size of 3-5 nm characteristic peaks at 3450 cm , 1620 cm , 1400 cm and
-1
-1
are dispersed on the surface of PRGO consistent with the XRD 1083 cm are corresponded to –OH
，C=C and C=O functional
result. Energy-dispersive X-ray (EDX) analysis was also groups, respectively, indicating that the existence of carboxyl
performed to study the chemical composition of Pd/PRGO and hydroxyl groups on the graphene oxide surface. After
catalyst. The existence of O element is considered to the spaying-dry treatment, all the characteristic peaks remain
oxygenated groups of PRGO. The EDS spectra of Pd/PRGO (Fig. unchanged, which indicate that spaying-dry has not an effect
4b) confirms that the Pd loading concentration of 19.65 %, on the surface composition of GO. X-ray photoelectron
which is close to actual loading amounts of Pd.
spectroscopy (XPS) was carried out in order to further evaluate
the chemical composition of Pd/RGO and Pd/PRGO catalysts.
Fig. 6 shows the XPS spectra of C 1s and Pd 3d photoemission
from Pd/RGO and Pd/PRGO catalysts, respectively. As shown in
Fig. 6, the main peak fitting at 284.7 eV is attributed to the C-C
bond, the other small peaks are attributed to the – COOH
(
288.9 eV), -C-O-C- (286.8 eV) and – C-OH (285.6 eV) functional
2
2
groups, which is consistent with the result of IR spectra. In
addition, two main characteristic peaks with binding energies
of 335.6 and 340.9 eV are characteristic of the metallic Pd ,
and the other two peaks at 337.2 and 342.9 eV can be
2
+
23
assigned to Pd in PdO and Pd(OH) -like species, suggesting
2
the presence of Pd mainly exists in the form of the metallic
state
Fig. 3 TEM images of (a) Pd/PRGO, (b) Pd/RGO, (c) and (d) Pd
particle size distributions of Pd/PRGO and Pd/RGO
Fig. 4 high resolution (a) TEM image and (b) EDX spectrum of Fig. 6 XPS spectra of C1s for (a) Pd/RGO and (b) Pd/PRGO
Pd/PRGO catalyst
catalysts, Pd 3d for (c) Pd/RGO and (d) Pd/PRGO
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.2 Activity toward formic acid oxidation
Fig. 7 a) Cyclic voltammetric curves of Pd/PRGO, Pd/RGO and
-1
JM Pd/C in 0.5 M H SO at the scan rate of 20 mV s ; b) Cyclic
4
2
Fig. 8 Chronoamperometric curves of Pd/PRGO, Pd/RGO and
JM Pd/C at 0.1 V in 0.5 M H SO + 1 M HCOOH solution
voltammetric curves of Pd/PRGO, Pd/RGO and JM Pd/C in 0.5
-1
2
4
M H SO + 1 M HCOOH solution at the scan rate of 50 mV s
2
4
The long-term stability and durability of three catalysts
were further investigated by chronoamperometry tests (Fig. 8).
All catalysts display an initial obvious current decay before
The electro-catalytic activity of Pd/PRGO catalyst towards
formic acid was investigated and further compared with JM
Pd/C and Pd/RGO catalysts. First, the electrochemical active
surface area (ECSA) of three catalysts were estimated by the
reaching
a quasi-equilibrium steady state because of
dissolution and the formation of the poisonous species COabs
.
cyclic voltammogram (CV) recorded in a N -saturated solution
2
-1
The current decay rates of Pd/PRGO and Pd/RGO are much
slower than JM Pd/C due to the presence of residual oxygen
functional groups on graphene sheets can promote the
of 0.5 M H SO at a scanning rate of 20 mV s (Fig. 7a). The
2
4
ECSA can be calculated by the integrated area in the range -
.2 to 0.1 V attributed to the hydrogen adsorption/desorption
regions after double-layer correction and assuming a value of
0
3
1,32
oxidation of COads on the active Pd sites.
In addition, the
-
2
24-27 Pd/PRGO catalyst exhibits higher current density and long-
term performance compared with the Pd/RGO catalyst. This
2
10 μC cm for the adsorption of a hydrogen monolayer.
2
The calculated values of Pd/PRGO (40.9 m g ) are the highest
-1
2
in comparison with those of Pd/RGO (28.3 m g ) and JM Pd/C
-1
result confirms that the 2D catalyst has a low abilities and
catalytic properties due to the stacked layers of the GR sheets.
2
20.0 m g ), which is due to the introduction of 3D structured
-1
(
graphene, thereby enhancing the dispersion of Pd
2
nanoparticles on the surface of PRGO.
2
4
. Conclusions
The catalytic performance of three catalysts towards
formic acid oxidation was investigated in 0.5 M H SO
In summary, we have presented a spay-drying approach to
2
4
containing 1 M HCOOH. It is well known that the prominent synthesize a three-dimensional crumpled graphene material.
peak range from 0.1 to 0.2
is ascribed to the Owing to the unique textual features, a 3D structured
dehydrogenation reaction (direct pathway, HCOOH
CO2 graphene supported Pd catalyst shows a greater catalytic
2H + 2e), while the weak peak at approximately 0.6 V is surface area, greater electro-catalytic activity and greater
related to the dehydration reaction (indirect way, HCOOH steady-state current than Pd/RGO and JM Pd/C catalysts
V
+
+
+
28,29
COads + H
2
O
CO
2
+ 2H + 2e).
Consequently, it can be toward formic acid electro-oxidation. The improved catalytic
concluded from Fig. 7b that the formic acid oxidation on these activity of the Pd/PRGO catalyst is most likely due to the high
Pd-based electrocatalysts is mainly through the direct electron specific surface area of the 3D formation together with and
3
0
transfer pathway. It can also be seen from Fig. 7b that the utilization efficiency of Pd during the oxidation of formic acid.
-1
mass specific current of Pd/PRGO catalyst is 1112 mA∙mg Pd, We believe that the 3D structured graphene has promising
-1
which is about 1.6 times that of Pd/RGO (683 mA∙mg Pd) and applications as a catalyst support in fuel cells and its
-1
2
.8 times that of JM Pd/C catalyst (386 mA∙mg Pd). In applications can be extended to other fields such as catalysis,
addition, the onset potential of formic acid oxidation on the sensors and energy storage.
Pd/PRGO shifts negatively 50 mV compared to JM Pd/C and
Pd/RGO. The higher formic acid oxidation current and lower
Acknowledgements
onset potential indicate that Pd/PRGO catalyst has much
better electrocatalytic activity due to its larger ECSA and the The research was financially supported by the Jiangxi Ganpo
presence of PRGO enhances the utilization efficiency of Pd 555 Project for Excellent Talents, National Natural Science
during the oxidation of formic acid.
Foundation of China (No. 51404110 and 21506187), Jiangxi
Natural Science Foundation of China (No. 20151BAB213011) ,
researching fund of Jiangxi University of Science and Technolo
gy ( NSFJ2015-G08)
4
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2
2
2
2
6. H. Zhao, J. Yang, L. Wang, C. G. Tian, B. J. Jiang and H. G. Fu,
Chemical Communications, 2011, 47, 2014-2016.
Notes and references
1.
D. Bin, B. B. Yang, F. F. Ren, K. Zhang, P. Yang and Y. K. Du, J
Mater Chem A, 2015, , 14001-14006.
7. C. X. Guo, L. Y. Zhang, J. W. Miao, J. T. Zhang and C. M. Li,
3
Adv Energy Mater, 2013,
8. R. S. Li, Z. Wei, T. Huang and A. S. Yu, Electrochimica Acta,
011, 56, 6860-6865.
9. M. S. El-Deab, A. M. Mohammad, G. A. El-Nagar and B. E.
El-Anadouli, Journal of Physical Chemistry C, 2014, 118
2457-22464.
0. R. F. Wang, S. J. Liao and S. Ji, Journal of Power Sources,
008, 180, 205-208.
3, 167-171.
2
.
H. D. Jang, S. K. Kim, H. Chang, J. H. Choi, B. G. Cho, E. H. Jo,
J. W. Choi and J. X. Huang, Carbon, 2015, 93, 869-877.
. Y. Z. Lu and W. Chen, Journal of Physical Chemistry C, 2010,
2
3
1
14, 21190-21200.
V. Mazumder, M. F. Chi, M. N. Mankin, Y. Liu, O. Metin, D.
H. Sun, K. L. More and S. H. Sun, Nano Lett, 2012, 12
102-1106.
,
4.
2
,
3
3
3
1
2
5.
J. J. Wang, Y. G. Chen, H. Liu, R. Y. Li and X. L. Sun,
1. J. Kua and W. A. Goddard, Journal of the American
Chemical Society, 1999, 121, 10928-10941.
Electrochemistry Communications, 2010, 12, 219-222.
6
. N. Tian, Z. Y. Zhou and S. G. Sun, Chemical Communications,
009, DOI: 10.1039/b819751b, 1502-1504.
J. W. Zhang, L. Zhang, S. F. Xie, Q. Kuang, X. G. Han, Z. X. Xie
and L. S. Zheng, Chemistry-a European Journal, 2011, 17
915-9919.
N. Tian, Z. Y. Zhou, N. F. Yu, L. Y. Wang and S. G. Sun,
Journal of the American Chemical Society, 2010, 132
580-+.
Z. Z. Zhu, Z. Wang and H. L. Li, Applied Surface Science,
008, 254, 2934-2940.
2. S. Sharma, A. Ganguly, P. Papakonstantinou, X. P. Miao, M.
X. Li, J. L. Hutchison, M. Delichatsios and S. Ukleja, Journal
of Physical Chemistry C, 2010, 114, 19459-19466.
2
7.
,
9
8.
,
7
9
1
1
1
1
.
2
0. H. Y. Qian, H. J. Huang and X. Wang, Journal of Power
Sources, 2015, 275, 734-741.
1. D. Liu, Q. H. Guo, H. Q. Hou, O. Niwa and T. Y. You, Acs
Catalysis, 2014,
2.M. J. Allen, V. C. Tung and R. B. Kaner, Chem Rev, 2010, 110
32-145.
4, 1825-1829.
,
1
3. o. Zhong, D. Bin, F. Ren, C. Wang, C. Zhai, P. Yang and Y. Du,
Colloids and Surfaces A: Physicochemical and Engineering
Aspects, 2016, 488, 6.
14. J. Y. Luo, H. D. Jang, T. Sun, L. Xiao, Z. He, A. P. Katsoulidis,
M. G. Kanatzidis, J. M. Gibson and J. X. Huang, Acs Nano,
2
011,
5. Y. Zhou;, X. Hu;, Y. Xiao; and Q. Shu, Electrochimica Acta,
013, 111, 588-592.
5, 8943-8949.
1
2
1
6. H. WS; and O. RE, J Am Chem Soc, 1958, 80, 1339.
7. L. J. Cote, F. Kim and J. X. Huang, Journal of the American
Chemical Society, 2009, 131, 1043-1049.
1
1
1
2
2
2
2
2
2
8. Y. C. Li, L. Zhang, Z. F. Hub and J. C. Yu, Nanoscale, 2015,
7,
1
0896-10902.
9. J. Zhao, Z. S. Liu, H. Q. Li, W. B. Hu, C. Z. Zhao, P. Zhao and
D. L. Shi, Langmuir, 2015, 31, 2576-2583.
0. R. R. Yue, H. W. Wang, D. Bin, J. K. Xu, Y. K. Du, W. S. Lu and
J. Guo, J Mater Chem A, 2015, 3, 1077-1088.
1. X. C. Hu, Y. Zhou, H. R. Wen and H. M. Zhong, Journal of the
Electrochemical Society, 2014, 161, F583-F587.
2. A. Halder, S. Sharma, M. S. Hegde and N. Ravishankar,
Journal of Physical Chemistry C, 2009, 113, 1466-1473.
3. Y. Li, X. B. Fan, J. J. Qi, J. Y. Ji, S. L. Wang, G. L. Zhang and F.
B. Zhang, Nano Res, 2010, 3, 429-437.
4. A. Pozio, M. De Francesco, A. Cemmi, F. Cardellini and L.
Giorgi, Journal of Power Sources, 2002, 105, 13-19.
5. F. H. B. Lima and E. A. Ticianelli, Electrochimica Acta, 2004,
49, 4091-4099.
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ARTICLE
The threeꢀdimensional crumpled
graphene (PRGO) was
synthesized from graphene oxide
GO) solution with spay drying
a
b
Yang Zhou,* Xian-Chao Hu,
a
a
Qizhe Fan, and He-Rui Wen*
Page No 01. – Page No 05.
(
Three-dimensional
graphene as an electro-catalyst
support for formic acid
electro-oxidation
crumpled
method and employed as the
support material for Pd catalyst.
The
asꢀprepared
Pd/PRGO
catalyst exhibits the mass specific
ꢀ1
current is 1112 mA·mg Pd,
which is about 1.6 times that of
ꢀ1
Pd/RGO (683 mA·mg Pd) and
2
.8 times that of JM Pd/C catalyst
ꢀ1
(386 mA·mg Pd).