Core@shell PtAuAg@PtAg Hollow Nanodendrites as Effective Electrocatalysts for Methanol and Ethylene Glycol Oxidation

Article abstract of DOI:10.1021/acs.inorgchem.1c01254

Pt-based catalysts with core@shell structures are widely used in alcohol oxidations due to their excellent catalytic performance. In this work, we synthesized a series of core@shell PtAuAg@PtAg hollow nanodendrites (HNDs) with different compositions by a simple seed-mediated method. The PtAuAg@PtAg HNDs with a hollow core and dendritic shell exhibit excellent catalytic performance for ethylene glycol oxidation reaction (EGOR) and methanol oxidation reaction (MOR). Among these, Pt38Au29Ag33 HNDs have the highest mass activity (12364.0 mA mgPt-1/3278.0 mA mgPt-1) for EGOR and MOR, which is 4.2 times and 5.3 times higher than that of commercial Pt/C (2941.0 mA mgPt-1/617.6 mA mgPt-1), respectively. More importantly, after successive cyclic voltammetry tests, the retained mass activities of Pt38Au29Ag33 HNDs are 3913.8 mA mgPt-1 and 348.3 mA mgPt-1, which are much higher than that of commercial Pt/C as well. The excellent catalytic performance of PtAuAg@PtAg HNDs can be attributed to the structure of HNDs, which can greatly increase the surface area and active sites, as well as the electronic and synergistic effects among Pt, Au, and Ag. This research may provide new ideas for the development of high-efficiency hollow catalytic materials for EGOR and MOR.

Full text of DOI:10.1021/acs.inorgchem.1c01254

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Core@shell PtAuAg@PtAg Hollow Nanodendrites as Effective
Electrocatalysts for Methanol and Ethylene Glycol Oxidation
Zhuolin Li, Fei Gao, Bin Zou, Zhengying Wu,* Yangping Zhang, and Yukou Du*
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ABSTRACT: Pt-based catalysts with core@shell structures are widely used in alcohol
oxidations due to their excellent catalytic performance. In this work, we synthesized a series
of core@shell PtAuAg@PtAg hollow nanodendrites (HNDs) with different compositions
by a simple seed-mediated method. The PtAuAg@PtAg HNDs with a hollow core and
dendritic shell exhibit excellent catalytic performance for ethylene glycol oxidation reaction
(EGOR) and methanol oxidation reaction (MOR). Among these, Pt38Au29Ag33 HNDs
have the highest mass activity (12364.0 mA mgPt−1/3278.0 mA mgPt−1) for EGOR and
MOR, which is 4.2 times and 5.3 times higher than that of commercial Pt/C (2941.0 mA
mgPt−1/617.6 mA mgPt−1), respectively. More importantly, after successive cyclic
voltammetry tests, the retained mass activities of Pt38Au29Ag33 HNDs are 3913.8 mA
mgPt−1 and 348.3 mA mgPt−1, which are much higher than that of commercial Pt/C as well.
The excellent catalytic performance of PtAuAg@PtAg HNDs can be attributed to the
structure of HNDs, which can greatly increase the surface area and active sites, as well as
the electronic and synergistic effects among Pt, Au, and Ag. This research may provide new
ideas for the development of high-efficiency hollow catalytic materials for EGOR and MOR.
Therefore, Pt-based catalysts that combine the advantages of
core@shell, hollow and dendritic structures may show a
satisfied catalytic performance for EGOR and MOR.
1. INTRODUCTION
The development of direct methanol fuel cells (DMFCs)1,2
and direct ethylene glycol fuel cells (DEGFCs),3 with the
characteristics of lower price, fast heat generation, high energy,
convenient transportation, and low operating temperature, is
an important way to alleviate the energy crisis.4−6 Among
these, the anode catalyst is a key component related to the
performance of DMFCs and DEGFCs.7 Pt catalysts have been
considered as the most effective anode catalytic materials for
ethylene glycol oxidation reaction (EGOR) and methanol
oxidation reaction (MOR),8−10 which can promote the
cleavage of C−C bonds in EGOR and MOR,11 but pure Pt
catalysts have the disadvantage of a strong interaction between
active sites on the catalyst surface and CO intermediates,12−15
which limits the development of Pt catalysts for EGOR and
MOR. In order to overcome the shortcomings of pure Pt
catalysts and give full play to the catalytic advantages of Pt, it is
particularly important to construct Pt-based catalysts with
good catalytic performance.16
The strategy of introducing transition metals into Pt
nanomaterials to improve the catalytic performance of the
catalyst has been widely reported.31−35 Among various Pt-
based catalysts, Au36−38 and Ag39 have attracted a lot of
attention. For example, dendrite-like PtAg alloyed nanocrystals
alleviate the poisoning of CO intermediates and show better
catalytic activity.40 Ag has been proved to be a good auxiliary
metal, which plays a very important role in increasing the
maximum current density and reducing the onset potential of
alcohol oxidation,41,42 which improves the catalytic perform-
ance of the catalysts for EGOR and MOR. Moreover, the
introduction of Au and Ag into Pt nanomaterials will cause
changes in the electronic structure of Pt, which changes the
adsorption energy of alcohol molecules and CO intermedi-
ates.35,43,44 Because the electronic and synergistic effects
41among Au, Ag, and Pt alleviate the adsorption of CO
intermediates by the catalyst45 and improve the catalytic
Adjusting the structure and morphology of the Pt-based
catalysts has been proven to be an effective way to modify the
catalytic performance of the catalysts.17−20 Recently, Pt-based
catalysts with core@shell structures have been extensively
studied due to their geometric and electronic effects.21−23 In
addition, the core@shell structure has an uneven surface which
increases surface defects and active sites.24,25 Except for that,
hollow26,27 structure and dendritic28,29 structure are widely
used in Pt-based catalysts because they can increase the
specific surface area and active sites of nanomaterials.30
Received: April 24, 2021
Published: June 16, 2021
https://doi.org/10.1021/acs.inorgchem.1c01254
© 2021 American Chemical Society
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Scheme 1. Schematic for Preparing PtAuAg@PtAg HNDs via a Simple Seed-Mediated Strategy
powder and sonicated for 1 h. The mixture was dispersed in 5 μL of
Nafion and 995 μL of isopropanol to form a catalytic ink, and the ink
was dropped on the glass carbon electrode, and then, the test was
performed after the ink air-dried naturally. The modified electrode
was subjected to cyclic voltammetry (CV) tests in the solution of 1 M
KOH, 1 M KOH + 1 M ethylene glycol, and 1 M KOH + 1 M
methanol at the potential ranging from −0.6 to 0.6 V. The
electrochemical behavior of EGOR and MOR is measured by CA
at 0.3 and 0.15 V, respectively. In addition, an EIS test was carried out
in 1 M KOH + 1 M ethylene glycol and 1 M KOH + 1 M methanol at
−0.25 and −0.15 V, respectively.
performance of the catalyst, the Pt-based catalyst can meet the
needs of a high catalytic performance.
In order to utilize the advantages of core@shell, hollow and
dendritic structures, and achieve the purpose of introducing Au
and Ag into Pt-based nanomaterials to optimize the perform-
ance of the catalyst, a simple seed-mediated strategy was
adopted in this work to successfully produce a series of
PtAuAg@PtAg hollow nanodendrites (HNDs) with different
compositions. Benefiting from the advantages of geometric and
electronic effects of HNDs, Pt38Au29Ag33 HNDs exhibit
excellent catalytic activity (4.2 and 5.3 times higher than
commercial Pt/C) and long-term durability in alkaline
ethylene glycol solution and methanol solution, which
indicates that PtAuAg@PtAg HNDs would have a broad
application prospect.
3. RESULTS AND DISCUSSION
In order to optimize the catalytic performance of Pt-based
catalysts, the method of synthesizing PtAuAg @ PtAg HNDs
was used in this work. The processes of using a seed-mediated
method to synthesize catalysts are shown in Scheme 1, in
which PVP is used as the surfactant to control the morphology
of the catalyst, and AA is used as the reducing agent (Figure
S1). The HNDs with special structure were synthesized by
galvanic replacement reaction among Ag seeds and PtCl62− and
2. EXPERIMENTAL SECTION
2.1. Chemicals. Dehydrate trisodium citrate (Na3C6H5O7·2H2O,
AR), chloroauric acid (HAuCl4, AR), silver nitrate (AgNO3, AR),
chloroplatinic acid (H2PtCl6, AR), potassium hydroxide (KOH, AR),
acetone (C3H6O, AR), ethanol (C2H5OH, AR), ethylene glycol
((CH2OH)2, AR), methanol (CH3OH, AR), and PVP [(C6H9NO)n,
Mw = 30,000] were purchased from Sinopharm Chemicals Reagent
Co., Ltd, China. Tannic acid (C76H52O46, 95%) and Nafion were
purchased from Sigma−Aldrich, and L-ascorbic acid (C6H8O6, AR)
was purchased from Shanghai Macklin Biochemical Co., Ltd. Double-
distilled water was used throughout the experiments.
2.2. Characterizations. The synthesized catalyst was first
detected using an HT7700 transmission electron microscope under
an acceleration voltage of 120 kV. The structure information of the
sample was tested by X-ray diffraction (XRD) with Cu Kα as the
radiation source (λ = 1.54056 Å). The surface chemical state of the
product is characterized by X-ray photoelectron spectroscopy (XPS),
which is operated on a Thermo Scientific EXCALAB 250 XI electron
spectrometer using 300 W Al Kα radiation. Scanning electron
microscopy energy-dispersive X-ray energy spectroscopy (SEM-EDS)
was tested with an EVO18 scanning electron microscope.
2.3. Synthesis of PtAuAg@PtAg HNDs. In this work, Ag seeds
were first synthesized using the previously reported synthesis
strategy.46 In the standard synthesis, 100 mg of PVP and 5 mL of
the prepared (2.0 mM) Ag seed were sequentially added to a reaction
flask containing 5 mL of deionized water. After stirring vigorously at
60 °C for 20 min, 1.4 mL (7.7 mM) of H2PtCl6 and 1.1 mL (9.7 mM)
of HAuCl4 were sequentially added to the vial and continued stirring
vigorously at 60 °C. After 20 min, AA (20.0 mg) was added to the vial
and continued stirring for 1 h. Pt38Au29Ag33 HNDs were washed
several times with ethanol and acetone after being collected by
centrifugation. For the synthesis of Pt60Au13Ag27 HNDs, the amount
of HAuCl4 was changed from 1.1 to 0.5 mL, and the amount of
H2PtCl6 was changed from 1.4 to 2.8 mL. For the synthesis of
Pt45Au17Ag38 HNDs, the amount of HAuCl4 added was changed from
1.1 to 0.5 mL.
2.4. Electrochemical Measurements. The synthesized anode
catalyst had been tested using an electrochemical workstation
CHI660E to determine its catalytic performance. We adopted a
three-electrode system consisting of a Pt wire (counter electrode),
glassy carbon electrode (working electrode, diameter: 3.0 mm), and
Ag/AgCl electrode (reference electrode). Before the test, according to
the mass ratio of Pt/C = 1:4, the catalysts were mixed with carbon
−
AuCl4 at 60 °C using Ag seeds as the sacrificial template
(Figure S2). The synthesized PtAuAg@PtAg HNDs were first
subjected to a series of characterization. Among these, the
morphology of Pt38Au29Ag33 HNDs was measured by trans-
mission electron microscopy (TEM). The results are shown in
Figures 1A−C and S3A. Pt38Au29Ag33 HNDs exist in the form
of uniformly dispersed HNDs with an average particle size of
60.6 nm (Figure S4). The dendritic structure and hollow
structure of HNDs increase the surface-to-volume ratio of the
catalyst, which means the improvement of the catalytic
performance of the catalyst. The SEM-EDS image of
Pt38Au29Ag33 HNDs is shown in Figure 1D. The atomic ratio
of Pt/Au/Ag is 38.2/28.7/33.1, indicating that Au and Ag have
been successfully introduced into the Pt-based catalysts. The
crystal structures of Pt38Au29Ag33 HNDs were analyzed by
XRD (Figure 1E), and the XRD diffraction peaks of
Pt38Au29Ag33 HNDs slightly shifted from the standard XRD
diffraction peaks of Pt, Au, and Ag, confirming the alloying
among Pt, Au, and Ag.47 The surface chemical composition
and valence state of Pt38Au29Ag33 HNDs were studied by XPS.
As shown in Figure S5A, the binding energy of the two strong
peaks in the Pt 4f graph is 70.6 and 73.9 eV, which corresponds
to Pt 4f7/2 and Pt 4f5/2 of Pt (0), respectively, indicating that
PtCl62− is reduced to Pt0. Figure S5B,C shows that AuCl4− and
Ag+ are reduced to Au0 and Ag0, respectively, indicating that
Au, Ag, and Pt in Pt38Au29Ag33 HNDs mainly exist in metallic
states.48 The high-resolution transmission electron microscopy
(HRTEM) images (Figure 1F,G) show that the prepared
Pt38Au29Ag33 HNDs have a lattice spacing of 0.230 nm and
0.233 nm, corresponding to the (111) planes of face center
cubic (fcc) PtAg alloys and fcc PtAuAg alloys, respectively,
which proves that Pt38Au29Ag33 HNDs have core@shell
structures. Line scan analysis (Figure 1H) explains the element
distribution of Pt38Au29Ag33 HNDs. Pt and Ag are distributed
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Figure 1. Representative images of (A) HAADF-STEM, (B) TEM, (C) HRTEM, (D) SEM-EDS spectrum, (E) XRD, (F,G) HRTEM, (H) line
scan analysis, and (I) element mapping of Pt38Au29Ag33 HNDs.
throughout the HNDs, while Au is mainly distributed in the
core of HNDs. Combining the results of TEM (Figure 1B) and
element mapping patterns (Figure 1I), it shows that
Pt38Au29Ag33 HNDs have a PtAuAg hollow core and a PtAg
dendritic shell. The electronic effects between the PtAuAg core
and the PtAg shell, as well as the large surface area of the
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Figure 2. TEM images of (A) Pt60Au13Ag27 HNDs and (B) Pt45Au17Ag38 HNDs. SEM-EDS spectra of (C) Pt60Au13Ag27 HNDs and (D)
Pt45Au17Ag38 HNDs. XRD patterns of (E) Pt60Au13Ag27 HNDs and (F) Pt45Au17Ag38 HNDs.
catalysts are beneficial to improving the electrocatalytic
performance of the catalysts.
Pt60Au13Ag27 HNDs and Pt45Au17Ag38 HNDs were synthe-
sized only by changing the composition of the precursor
without changing other conditions. The TEM images show
that Pt60Au13Ag27 HNDs (Figures 2A and S3B) and
Pt45Au17Ag38 HNDs (Figure 2B) exhibit similar HND
structures to Pt38Au29Ag33 HNDs. The SEM-EDS spectra of
Pt60Au13Ag27 HNDs and Pt45Au17Ag38 HNDs are shown in
Figure 2C,D; the atomic ratios of Pt/Au/Ag are 59.7/13.1/
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Figure 3. (A) CV curves and the corresponding (B) ECSA value histograms of Pt38Au29Ag33, Pt60Au13Ag27, and Pt45Au17Ag38 HNDs and
commercial Pt/C operating in 1 M KOH. (C) CV curves and corresponding (D) mass/specific activity histograms of Pt38Au29Ag33, Pt60Au13Ag27,
and Pt45Au17Ag38 HNDs and commercial Pt/C operated in 1 M KOH + 1 M ethylene glycol.
27.2 and 45.4/16.6/38.0, respectively. The XRD patterns of
Pt60Au13Ag27 HNDs (Figure 2E) and Pt45Au17Ag38 HNDs
(Figure 2F) are similar to those of Pt38Au29Ag33 HNDs. The
XRD diffraction peaks of HNDs are located among the
standard XRD diffraction peaks of Au, Ag, and Pt, indicating
the formation of the PtAuAg alloy phase. The XPS images of
Pt60Au13Ag27 HNDs (Figure S6) and Pt45Au17Ag38 HNDs
(Figure S7) show that Pt, Au, and Ag in HNDs mainly exist in
the metallic state.
The catalytic performance of carbon-supported PtAuAg@
PtAg HNDs and commercial Pt/C for EGOR and MOR under
alkaline conditions49,50 was evaluated. Electrochemically active
surface area (ECSA) is an important means to evaluate the
catalytic performance of catalysts, which can be obtained by
analyzing the CV curve of the catalyst in 1 M KOH (Figure
3A,B). The method of calculating ECSA using the CV curve is
shown in the following equation: ECSA = Q/(m × 210), where
Q(C) is the charge in the Hupd adsorption/desorption area
obtained after the double-layer correction, m is the mass of Pt,
and 210 (μC cm−2) is the charge required for monolayer
adsorption of hydrogen on the Pt surface. From the CV curves
of Pt38Au29Ag33 HNDs, it can be found that the reduction peak
of Pt oxide is located at −0.333 V, which is positively shifted
by 0.104 V compared with the reduction peak of commercial
Pt/C oxide, which confirms that the alloying of Au, Ag, and Pt
can promote the reduction of Pt oxide.51 The ECSA values of
Pt38Au29Ag33, Pt60Au13Ag27, and Pt45Au17Ag38 HNDs and
commercial Pt/C are 37.3, 35.8, 33.3, and 57.1 m2 g−1,
respectively. In order to prove that HNDs have obvious
catalytic activity for EGOR, CV tests were performed on
Pt38Au29Ag33, Pt60Au13Ag27, and Pt45Au17Ag38 HNDs and
commercial Pt/C in a 1 M KOH + 1 M ethylene glycol.
The results are shown in Figure 3C. The CV curves of the
catalysts show two obvious current peaks. The forward current
peak and the reverse current peak were caused by the oxidation
of ethylene glycol and the oxidation of intermediates produced
during the reaction, respectively.52 The Pt38Au29Ag33 HNDs
had the highest forward current peak with mass activity of
12,364.0 mA mgPt−1, which was 1.4, 1.8, and 4.2 times higher
than Pt60Au13Ag27 HNDs (8770.0 mA mgPt−1), Pt45Au17Ag38
HNDs (6710.0 mA mgPt−1), and commercial Pt/C (2941.0
mA mgPt−1), respectively. More importantly, Pt38Au29Ag33
HNDs have shown better catalytic activity for EGOR than
the reported Pt-based catalysts (Table S1). The calculation of
specific activity further shows the catalytic activity of the
catalyst, and the result is shown in Figure 3D. Pt38Au29Ag33
HNDs had the highest specific activity of 33.2 mA cm−2, which
was 1.36, 1.64, and 6.4 times higher than Pt60Au13Ag27 HNDs
(24.5 mA cm−2), Pt45Au17Ag38 HNDs (20.1 mA cm−2), and
commercial Pt/C (5.2 mA cm−2), respectively. According to
the results of mass/specific activity, Pt38Au29Ag33 HNDs have
shown satisfactory catalytic activity for EGOR. The mechanism
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Figure 4. (A,B) CA curves and the corresponding histograms of Pt38Au29Ag33, Pt60Au13Ag27, and Pt45Au17Ag38 HNDs and commercial Pt/C in 1 M
KOH + 1 M ethylene glycol at 0.3 V for 4000 s. (C) 500 successive sweeping CV curves and the (D) retained mass activity histograms of
Pt38Au29Ag33, Pt60Au13Ag27, and Pt45Au17Ag38 HNDs and commercial Pt/C measured in 1 M KOH + 1 M ethylene glycol. (E) EIS spectra of the
four tested catalysts in 1 M KOH + 1 M ethylene glycol at −0.25 V.
of EGOR is shown in the following equations. As can been
(CH2 − OH)2(ads) → CH2OH(CHO)
(2)
2−
seen in the reaction evolution processes, C2O4 is the main
CH2OH(CHO) → CHO(COO−)
product.47,53
(3)
CHO(COO−) → (COO−)2
(CH2 − OH)2 → (CH2 − OH)2(ads)
(1)
(4)
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Figure 5. (A) CV curves and corresponding (B) mass/specific activity histograms of Pt38Au29Ag33, Pt60Au13Ag27, and Pt45Au17Ag38 HNDs and
commercial Pt/C operated in 1 M KOH + 1 M methanol. (C) 500 successive sweeping CV curves and the (D) retained mass activity histograms of
Pt38Au29Ag33, Pt60Au13Ag27, and Pt45Au17Ag38 HNDs and commercial Pt/C measured in 1 M KOH + 1 M methanol. (E) CA curves of the four
tested catalysts in 1 M KOH + 1 M methanol at 0.15 V for 4000 s. (F) EIS spectra of the four tested catalysts in 1 M KOH + 1 M methanol at
−0.15 V.
The EIS test is also an important method for electrochemical
performance evaluation, in which the diameter is an important
tool to evaluate the conductivity of the electrocatalyst.54 The
diameter impedance arc (DIA) of the three kinds of HNDs
was much smaller than that of commercial Pt/C (Figure 4E).
Among these, Pt38Au29Ag33 HNDs had the smallest DIA,
indicating that Pt38Au29Ag33 HNDs had the best electrical
conductivity.
Catalysts with excellent catalytic performance need to have
excellent durability in addition to high catalytic activity. This is
because the durability determines the service life of the
catalyst, which is an important factor affecting the actual
commercial application of the catalyst. The four catalysts were
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tested for 4000 s by CA in a 1 M KOH + 1 M ethylene glycol
at a voltage of 0.3 V. The results are shown in Figure 4A,B.
Since the catalyst was inevitably poisoned and dissolved during
the test, the current density gradually decreased at the
beginning of the test and then stabilized. The retained mass
activity of Pt38Au29Ag33 HNDs was 885.0 mA mgPt−1, which
was 3.1, 5.2, and 14.1 times higher than that of Pt60Au13Ag27
HNDs (285.7 mA mgPt−1), Pt45Au17Ag38 HNDs (168.2 mA
mgPt−1), and commercial Pt/C (62.9 mA mgPt−1), respectively.
In order to further analyze the durability of the catalysts, 500
successive sweeping CV tests were carried out for the four
catalysts in 1 M KOH +1 M ethylene glycol. The mass activity
of the catalysts tended to be stable after gradually decreasing
with the test (Figures 4C and S8), and the retained mass
activity is shown in Figure 4D. Among the four catalysts,
Pt38Au29Ag33 HNDs (3913.8 mA mgPt−1) had the highest
retained mass activity. In summary, Pt38Au29Ag33 HNDs show
excellent durability and catalytic activity toward EGOR.
In order to further illustrate the excellent catalytic
performance of the PtAuAg@PtAg HNDs, the CV tests were
performed on Pt38Au29Ag33, Pt60Au13Ag27, and Pt45Au17Ag38
HNDs and commercial Pt/C in 1 M KOH + 1 M methanol.
The results of CV tests are shown in Figure 5A,B. Among
these, the mass activity of Pt38Au29Ag33 HNDs was 3278.0 mA
mgPt−1, which was 1.2 times higher than that of Pt60Au13Ag27
HNDs (2802.5 mA mgPt−1), 1.7 times higher than that of
Pt45Au17Ag38 HNDs (1923.5 mA mgPt−1), and 5.3 times higher
than that of commercial Pt/C (617.6 mA mgPt−1).
Pt38Au29Ag33 HNDs show better catalytic activity for MOR
than the reported Pt-based catalysts (Table S2). The specific
activity of Pt38Au29Ag33 HNDs was 8.8 mA cm−2, which was
1.1, 1.5, and 8.1 times higher than that of Pt60Au13Ag27 and
Pt45Au17Ag38 HNDs and commercial Pt/C, respectively. The
reaction evolution processes for MOR are presented in the
following equations, where the main products are CO2.53
which was 1.3, 3.7, and 11.4 times higher than that of
Pt60Au13Ag27 HNDs (329.8 mA mgPt−1), Pt45Au17Ag38 HNDs
(115.3 mA mgPt−1), and commercial Pt/C (37.9 mA mgPt−1),
respectively. In conclusion, Pt38Au29Ag33 HNDs have excellent
catalytic performance for MOR under alkaline conditions.
4. CONCLUSIONS
In summary, this work used a seed-mediated method to
synthesize a series of PtAuAg@PtAg HNDs with different
atomic ratios via regulating the compositions of metal
precursors. Among these, because HNDs have a hollow core
and dendritic shell that can expose many active sites, as well as
the synergistic and electronic effects among Pt, Ag, and Au can
alleviate the poisoning of CO intermediates to the active sites
of Pt-based catalysts, Pt38Au29Ag33 HNDs show remarkable
catalytic activity (the mass activities are 12364.0 and 3278.0
mA mgPt−1) and durability (the retained mass activities are
3913.8 and 348.3 mA mgPt−1) for EGOR and MOR.
Pt45Au17Ag38 HNDs and Pt60Au13Ag27 HNDs also show better
catalytic performance comparable to commercial Pt/C. The
design and synthesis of PtAuAg@PtAg HNDs provide a
promising idea for the synthesis of anode catalytic materials
with excellent catalytic performance for EGOR and MOR.
ASSOCIATED CONTENT
■
sı
* Supporting Information
The Supporting Information is available free of charge at
https://pubs.acs.org/doi/10.1021/acs.inorgchem.1c01254.
TEM images, size distribution histogram, XPS spectra,
500 successive sweeping CV curves, and histogram of
CA curves of samples, and electrocatalytic activity
comparisons for EGOR and MOR with previously
synthesized catalysts (PDF)
CH3OH → CO(ads) + 4H+ + 4e−
CO(ads) + 2OH− → CO2 + H2O + 2e−
OH− → OH(ads) + e−
AUTHOR INFORMATION
(5)
■
Corresponding Authors
(6)
Zhengying Wu − Jiangsu Key Laboratory for Environment
Functional Materials, School of Materials Science and
Engineering, Suzhou University of Science and Technology,
Suzhou 215009, China; orcid.org/0000-0002-9561-
6275; Email: zywu@mail.usts.edu.cn
(7)
CO(ads) + 2OH(ads) → CO2 + H2O
(8)
Yukou Du − College of Chemistry, Chemical Engineering and
Materials Science, Soochow University, Suzhou 215123, PR
China; orcid.org/0000-0002-9161-1821; Email: duyk@
suda.edu.cn
The EIS test results of the four catalysts are shown in Figure
5F. The DIA of Pt38Au29Ag33, Pt60Au13Ag27, and Pt45Au17Ag38
HNDs was much smaller than that of commercial Pt/C;
among these, the DIA of Pt38Au29Ag33 HNDs was the smallest,
which show that Pt38Au29Ag33 HNDs had the smallest
electron-transfer hindrance and best conductivity. The results
of combining EIS and CV curves show that Pt38Au29Ag33
HNDs had excellent catalytic activity for MOR. In order to test
the durability of the PtAuAg@PtAg HNDs in alkaline
methanol solution, 500 successive sweeping CV tests were
carried out on the four catalysts, as shown in Figures 5C,D and
S9. In alkaline methanol solution, Pt38Au29Ag33 HNDs had the
highest retained mass activity, and the retained mass activity of
Pt38Au29Ag33 HNDs was 348.3 mA mgPt−1. In addition,
Pt38Au29Ag33, Pt60Au13Ag27, and Pt45Au17Ag38 HNDs and
commercial Pt/C were tested in 1 M KOH + 1 M methanol
at 0.15 V for 4000 s by CA. As shown in Figures 5E and S10,
the current density first decreased slowly and then tended to
Authors
Zhuolin Li − College of Chemistry, Chemical Engineering and
Materials Science, Soochow University, Suzhou 215123, PR
China
Fei Gao − College of Chemistry, Chemical Engineering and
Materials Science, Soochow University, Suzhou 215123, PR
China
Bin Zou − College of Chemistry, Chemical Engineering and
Materials Science, Soochow University, Suzhou 215123, PR
China
Yangping Zhang − College of Chemistry, Chemical
Engineering and Materials Science, Soochow University,
Suzhou 215123, PR China
be stable. Among these, the retained mass activity of
Complete contact information is available at:
https://pubs.acs.org/10.1021/acs.inorgchem.1c01254
−1
Pt38Au29Ag33 HNDs was the highest at 431.2 mA mgPt
,
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Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
The authors thank the National Natural Science Foundation of
China (grant nos. 51873136 and 52073199), the Natural
Science Foundation of the Jiangsu Higher Education
Institutions of China (18KJA150008), the Natural Science
Foundation of Jiangsu Province (BK20181428).
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