Enhancement of catalytic activity by homo-dispersing S2O82–-Fe2O3 nanoparticles on SBA-15 through ultrasonic adsorption

Article abstract of DOI:10.1016/S1872-2067(17)63007-9

Mesoporous superacids S₂O₈^2–-Fe₂O₃/SBA-15 (SFS) with active nanoparticles are prepared by ultrasonic adsorption method. This method is adopted to ensure a homo-dispersed nanoparticle active phase, large specific surface area and many acidic sites. Compared with bulk S₂O₈^2–-Fe₂O₃, Br?nsted acid catalysts and other reported catalysts, SFS with an Fe₂O₃ loading of 30% (SFS-30) exhibits an outstanding activity in the probe reaction of alcoholysis of styrene oxide by methanol with 100% yield. Moreover, SFS-30 also shows a more excellent catalytic performance than bulk S₂O₈^2–-Fe₂O₃ towards the alcoholysis of other ROHs (R = C₂H₅-C₄H₉). Lewis and Br?nsted acid sites on the SFS-30 surfaces are confirmed by pyridine adsorbed infrared spectra. The highly efficient catalytic activity of SFS-30 may be attributed to the synergistic effect from the nano-effect of S₂O₈^2–-Fe₂O₃ nanoparticles and the mesostructure of SBA-15. Finally, SFS-30 shows a good catalytic reusability, providing an 84.1% yield after seven catalytic cycles.

Full text of DOI:10.1016/S1872-2067(17)63007-9

Chinese Journal of Catalysis 39 (2018) 955–963
a v a i l a b l e a t w w w . s c i e n c e d i r e c t . c o m
j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / c h n j c
Article
2–
Enhancement of catalytic activity by homo‐dispersing S2O8 ‐Fe2O3
nanoparticles on SBA‐15 through ultrasonic adsorption
Qingyan Chua,b, Jing Chena,Wenhua Houc,*, Haoxuan Yud,Ping Wanga,d,Rui Liua,
Guangliang Songa,Hongjun Zhua,#, Pingping Zhaod
a College of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, Jiangsu, China
b Research institute of QILU petrochemical company, SINOPEC, Zibo 255400, Shandong, China
c Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, Jiangsu, China
d School of Chemical Engineering, Shandong University of Technology, Zibo 255049, Shandong, China
A R T I C L E I N F O
A B S T R A C T
Article history:
Mesoporous superacids S2O82–‐Fe2O3/SBA‐15 (SFS) with active nanoparticles are prepared by ul‐
trasonic adsorption method. This method is adopted to ensure a homo‐dispersed nanoparticle ac‐
tive phase, large specific surface area and many acidic sites. Compared with bulk S2O82–‐Fe2O3,
Brönsted acid catalysts and other reported catalysts, SFS with an Fe2O3 loading of 30% (SFS‐30)
exhibits an outstanding activity in the probe reaction of alcoholysis of styrene oxide by methanol
with 100% yield. Moreover, SFS‐30 also shows a more excellent catalytic performance than bulk
S2O82–‐Fe2O3 towards the alcoholysis of other ROHs (R = C2H5‐C4H9). Lewis and Brönsted acid sites
on the SFS‐30 surfaces are confirmed by pyridine adsorbed infrared spectra. The highly efficient
catalytic activity of SFS‐30 may be attributed to the synergistic effect from the nano‐effect of
S2O82–‐Fe2O3 nanoparticles and the mesostructure of SBA‐15. Finally, SFS‐30 shows a good catalytic
reusability, providing an 84.1% yield after seven catalytic cycles.
Received 23 November 2017
Accepted 29 December 2017
Published 5 May 2018
Keywords:
Mesoporous superacid
Nanoparticle
Nano effect
S2O82–‐Fe2O3/SBA‐15
Acidic site
Ultrasonic adsorption
Alcoholysis
© 2018, Dalian Institute of Chemical Physics, Chinese Academy of Sciences.
Published by Elsevier B.V. All rights reserved.
1. Introduction
ceived extensive attention because of their strong acidity, ease
of separation, low corrosivity, stability, reusability and envi‐
Acid catalysts play an important role for various chemical
reactions of industrial interest. Conventional acids (i.e., H2SO4,
H3PO4 and p‐toluenesulfonic acid) exhibit a high catalytic activ‐
ity; however, significant risks are associated with their han‐
dling, containment, disposal as well as the issue of equipment
corrosion [1,2]. For these reasons, new stringent environmen‐
tal legislations against the use of these conventional acids in
industrial applications have been implemented in many coun‐
tries. Consequently, in recent years, solid superacids have re‐
ronmental friendliness [3–6]. Particularly, SO42–‐MxOy superac‐
ids (i.e., SO42–‐ZrO2, SO42–‐TiO2 and SO42–‐SnO2) have been the
subject of many investigations because of their good catalytic
performance and low waste generation [7,8]. Compared with
SO42–‐MxOy, S2O82–‐MxOy with stronger acidities and catalytic
activities have begun to attract interest. However, only a few
kinds of MxOy compounds, such as ZrO2 and Al2O3, have been
studied. Therefore, the exploration of metal oxides is of great
value. In addition, Fe‐doped superacids are well known for
* Corresponding author. Tel/Fax: +86‐25‐58137480; E‐mail: whou@nju.edu.cn
# Corresponding author. E‐mail: zhuhj@njtech.edu.cn
This work was supported by the National Key Research and Development Program of China (2016YFB0301703), the Joint Innovation and Research
Funding‐prospective Joint Research Projects (BY2016005‐06), and the National Natural Science Foundation of China (21506118).
DOI: 10.1016/S1872‐2067(17)63007‐9 | http://www.sciencedirect.com/science/journal/18722067 | Chin. J. Catal., Vol. 39, No. 5, May 2018

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Qingyan Chu et al. / Chinese Journal of Catalysis 39 (2018) 955–963
their good catalytic activity and stability in several industrial
and environmental processes [9,10].
Fe2O3/SBA‐15. During calcination, the temperature was in‐
creased at a rate of 1 °C/min, starting from 50 °C. A (NH4)2S2O8
aqueous solution was slowly added to the Fe2O3/SBA‐15 to
afford (NH4)2S2O8‐Fe2O3/SBA‐15, which was also dried at 45 °C
for 12 h and calcined at 500 °C for 4 h after a heating ramp that
started at 50 °C with a rate of temperature increase of 2 °C/min
to obtain S2O82–‐Fe2O3/SBA‐15 (SFS‐x, x = 10, 20, 25, 35, 40, 45).
The Fe2O3 loading of x% was calculated according to Eq. (1).
The Fe(NO3)3·9H2O/(NH4)2S2O8 molar ratio was 1:1.
A research focus has been how to overcome the low surface
area and porosity of bulk superacids to improve their specific
surface area and enhance the catalytic activity of the active
phase. Nowadays, with the development of nano‐technology,
various nanomaterials have been extensively used, including
nanoparticles and nanocomposites, and have drawn considera‐
ble attention because of their high temperature sensitivity, high
ductility, large surface area, high strain resistance, and low
electrical resistivity [11,12]. How to turn materials into nano‐
particles is a challenging topic. As an efficient and practical
technology for the preparation of nano‐materials, the ultrason‐
ic technique has the advantages of introducing local stress in‐
tensities and ensuring a reproducible state of dispersions [13].
In addition, mesoporous silica materials have been identified as
possible catalyst supports, particularly SBA‐15, which have
ordered hexagonally mesopores, thick channels, big pore di‐
ameters, and large surface areas [14–19].
In this context, we have developed homo‐dispersed
S2O82–‐Fe2O3 (SF) nanoparticles supported on SBA‐15
(S2O82–‐Fe2O3/SBA‐15, SFS) with a large specific surface area by
ultrasonic adsorption method. The prepared mesoporous su‐
peracid showed better catalytic activities than bulk
S2O82–‐Fe2O3, Brönsted acid catalysts and the other catalysts
reported for the probe reaction of alcoholysis of styrene oxide.
In addition, the structure, surface acidity, and activity of the
superacid catalysts were evaluated.
x(%) = WFe2O3/WSBA‐15 × 100%
(1)
2.2. Catalyst characterization
X‐ray fluorescence spectrometry (XRF) was recorded on a
ZSX‐100e. The surface morphology of the catalyst was ob‐
served using a FEI Sirion 200 field‐emission scanning electron
microscope (SEM) and a JEM‐1200EX transmission electron
microscope (TEM). The Fourier transform infrared (FT‐IR)
spectra were recorded on a Nicolet 360 FT‐IR instrument (KBr
discs) in the 4,000–400 cm–1 region. X‐ray diffraction (XRD)
patterns were collected on the X’Pert Pro Multipurpose dif‐
fractometer using a Cu Kα radiation source at RT from 0.5° to
5.0° (small angle) and 5° to 50° (wide angle). Measurements
were conducted using a voltage of 40 kV, and a current setting
of 20 mA for small angle XRD and 40 mA for wide angle XRD. N2
adsorption‐desorption isotherms and specific surface areas
were measured at 196 ˚C using a Micromeritics ASAP 2020
surface area and porosity analyzer. The X‐ray photoelectron
spectroscopy (XPS) measurements were performed on a RBD
upgraded PHI‐5000C ESCA system (Perkin‐Elmer, Norwalk, CT,
USA) with Mg Kα radiation (hν = 1253.6 eV), where binding
energies were calibrated by using the containment carbon (C 1s
= 284.6 eV). The infrared spectra of adsorbed pyridine (pyri‐
dine‐IR spectra) were obtained on a PE Frontier FT‐IR spec‐
trometer [20].
2. Experimental
2.1. Catalyst preparation
All alcohols were analytical grade and purchased from
SINOPHARM Chemical Reagent Co., Ltd. Styrene oxide (99%),
(NH4)2S2O8 (98%) and Fe(NO3)3·9H2O (98%) were supplied
from Energy Chemical. SBA‐15 was obtained by Nanjing
XFNANO Materials Tech Co., Ltd.
2.3. Catalytic tests
The SFS solid superacids were prepared using the UA
method (Fig. 1). The Fe(NO3)3 aqueous solution was slowly
added to the SBA‐15, then the mixture was evenly dispersed in
an ultrasonic bath for 15 min. The Fe(NO3)3/SBA‐15 was dried
at 45 °C for 12 h, and calcined at 550 °C for 6 h to obtain the
A comparison of the catalytic performances of superacid
catalysts tested in the probe reaction of alcoholysis of styrene
oxide with MeOH was performed in a 50‐mL flask (Scheme 1).
Typically, styrene oxide (1.60 g, 13.3 mmol), MeOH (3.00 g,
93.6 mmol), and the catalyst (10.0 mg) were added to the re‐
actor and stirred at 40 °C. The reaction mixture was sampled
periodically, and the samples were analyzed by gas chroma‐
tography (Agilent Technologies 7820A GC system, Palo Alto,
CA, USA). Under the operating conditions adopted, the product
was 2‐methoxyl‐2‐phenylethanol with 100% selectivity, as
identified by the analysesof 1H NMR and 13C NMR. The catalyst
activity and stability were measured in detail.
OR
O
SF/SFS-30 (cat.)
40 oC
+ ROH
OH
Fig. 1. Well‐ordered mesoporous S2O82–‐Fe2O3/SBA‐15 prepared by
ultrasonic adsorption and dry‐calcination.
Scheme 1. The probe reaction of alcoholysis of styrene oxide.

Qingyan Chu et al. / Chinese Journal of Catalysis 39 (2018) 955–963
957
3. Results and discussion
3.1. Catalyst characterization
The morphology of the solid superacid SF was characterized
by SEM and TEM. As shown from the SEM images (Fig. 2(a)),
the crystal structure of SF was formed by the coordination of
Fe2O3 and S2O82– at high temperature (Fig. 2(b)). Moreover, the
lattice structures of SF could be clearly seen from the TEM im‐
ages (Fig. 2(c) and 2(d)). The clear lattice fringes with two in‐
terval spacings of 0.405 and 0.30 nm corresponded to the crys‐
tallographic planes of monoclinic SF, in accordance with the
XRD peaks at 29.7o and 21.5o (Fig. 4(c)). Elemental mappings
were taken to gain insights into the distribution of SF (Fig.
2(e)). Furthermore, the XRF analysis showed the element con‐
tent of SF was 41.8% O, 34.8% Fe, 22.1% S.
The morphology analysis of SFS‐30 is shown in Fig. 3. The
external structure of SFS‐30 (Fig. 3(a) and 3(b)) was similar to
that of SBA 15. The TEM images clearly revealed the inner
mesoporous channels in which SF nanoparticles of approxi‐
mately 6 × 8 nm were uniformly distributed (Fig. 3(c)). Moreo‐
ver, the clear lattice fringe with an interval spacing of 0.44 nm
(Fig. 3(d)) corresponded to the crystallographic planes of
monoclinic SFS‐30, in agreement with the XRD peak at 20.3o
(Fig. 4(d)). To gain insights into the distribution of SFS‐30, ele‐
mental mappings were taken (Fig. 3(e)). It could be seen that
the four elements of O, Fe, S and Si were evenly distributed in
the prepared catalytic material, which showed that the active
components were uniformly dispersed in SBA‐15, and no ag‐
gregation occurred. Furthermore, the XRF analysis showed the
element content of SFS‐30 was 42.9% O, 18.5% Fe, 5% S, and
32.7% Si.
Fig. 3. (a) SEM images of SFS‐30; (b–d) TEM images of SFS‐30; TEM
images (e) and elemental mapping (f) of the composite SFS‐30.
in the range of 900–1300 cm–1, which were attributed to the S
=O or S–O bonds in the acid structures of the catalysts [21,22].
In this range, the peaks at 995, 1113 and 1127 cm–1 were as‐
signed to the stretching vibration of S–O. Meanwhile, the band
at 1227 cm–1 was assigned to the stretching vibration of S=O.
The attribution of these characteristic vibration peaks was in
The FT‐IR spectra of Fe2O3 and SF are shown in Fig. 4(a).
Compared with Fe2O3, SF showed the emergence of new bands
2–
accordance with the reported S2O8 ion of solid superacids
[2,23–26]. This result indicated a very strong interaction of
surface persulfate species with Fe(III) species, which was the
significant reason for the formation of the active acid center on
the surface of SF [27,28].
The FT‐IR spectra characterizing SBA‐15 and SFS‐30 are
shown in Fig. 4(b). The band at 964 cm–1 was related to the
characteristic stretching vibration of Si‐OH of SBA‐15 [29,30]. It
was apparent that the absorption band at 964 cm–1 moved to
968 cm–1 and became weaker after loading SF on the pore sur‐
face of SBA‐15. This effect was attributed to the stretching vi‐
bration of Si–OH being perturbed by Fe3+ in a neighboring posi‐
tion [28,31]. The special bands in the range of 900–1300 cm–1,
attributed to the S=O or S–O bonds, were covered by the band
at 1091 cm–1, which was attributed to the asymmetric stretch‐
ing vibration of Si–O–Si in the SBA‐15 [32,33]. However, it was
obvious that the band at 1097 cm–1 broadened compared with
the band at 1091 cm–1, which indicated the successful loading
of SF nanoparticles on the SBA‐15.
The XRD patterns of Fe2O3 and SF in the wide‐angle region
of 3°–60° are shown in Fig.4(c). The prepared Fe2O3 exhibited
all the well‐resolved characteristic peaks of the Fe2O3 crystallite
(JCPDS card No. 33‐0664) with the six peaks displayed at 2θ =
24.1°, 33.1°, 35.6°, 40.8°, 49.4° and 54.0°. Six new peaks ap‐
Fig. 2. (a) SEM images of SF; (b–d) TEM images of SF; TEM images (e)
and elemental mapping (f) of the composite SF.

958
Qingyan Chu et al. / Chinese Journal of Catalysis 39 (2018) 955–963
(b)
(a)
964
100
100
80
60
40
20
0
80
968
60
995
1270
1238
1073
1085
40
20
1091
1113
SBA-15
SFS-30
1127
Fe2O3
SF
1097
0
3500 3000 2500 2000 1500 1000
500
3500 3000 2500 2000 1500 1000 500
Wavenumbers (cm–1)
Wavenumber (cm–1)
Fe2O3
SF
(d)
(c)
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
2/(O
)
SFS-30
SBA-15
10
20
30
40
50
60
10
20
30
40
50
60
O
2/( )
2/()
Fig. 4. FT‐IR spectra of Fe2O3, SF (a), SBA‐15 and SFS‐30 (b); XRD of Fe2O3, SF (c), SBA‐15 and SFS‐30 (d).
peared in the diffraction pattern of SF after (NH4)2S2O8 adsorp‐
tion and calcination. The six peaks displayed at 2θ = 14.7°,
20.2°, 21.5°, 24.7°, 29.7° and 32.5° were well matched with the
standard JCPDS card No. 33‐0679, and resulted from the inter‐
action of Fe2O3 with (NH4)2S2O8.
The XRD patterns of SBA‐15 and SFS‐30 in the small and
wide‐angle regions are shown in Fig. 4(d). The small angle
(0.4°–10°) XRD patterns were similar for SBA‐15 and SFS‐30
and showed that S2O82–‐Fe2O3 was very well dispersed and did
not damage the mesoporous structure of SBA‐15. However,
there were significant differences in the wide‐angle XRD pat‐
tern (10°–60°). SFS‐30 clearly exhibited six new peaks at 2θ =
14.7°, 20.3°, 21.5°, 24.7°, 29.7° and 32.5° (JCPDS card No.
33‐0679), which corresponded to the XRD of SF, and which did
not appear in the XRD of SBA‐15. Such results indicated the
successful loading of SF nanoparticles on SBA‐15.
To investigate the chemical states of Fe and S in the samples,
XPS measurements were performed. Fig. 5(a) and 5(b) shows
the Fe 2p and S 2p XPS spectra of SFS‐30. The SFS‐30 contained
two peaks at 706.75 and 720.07 eV (Fig. 5(a)), which could be
assigned to the Fe3+ species. The S6+ species was revealed by
the binding energy of 169 eV in Fig. 5(b) [26].
The N2 adsorption‐desorption isotherms of SFS‐30 are
shown in Fig. 5(c). According to IUPAC classifications [34], the
isotherms exhibited a type IV pattern and both showed a clear
loop (H1 hysteresis loop) in the relative pressure range of
0.4–0.8. The presence of a hysteresis loop, which arose from
capillary condensation, indicated the presence of regular mes‐
oporous channels in the materials. This further confirmed that
SFS‐30 retained the intact and ordered mesoporous structure
of SBA‐15 after S2O82–‐Fe2O3 loading. The parameters describ‐
ing the textural properties and catalytic activities of bulk SF and
SFS‐30 are summarized in Table 1. The BET surface area and
pore volume of SFS‐30 were obviously larger than those of SF.
In addition, Fig. 5(c) shows the N2 adsorption‐desorption iso‐
therms of SFS‐40, where the BET specific surface area, pore
volume, and pore size were 218.09 m2/g, 0.21 cm3/g and 3.50
nm, respectively.
The pyridine‐IR spectra were employed to evaluate the type
and strength of Brönsted and Lewis acid sites on SFS‐30 [35].
The pyridine‐IR spectra of SFS‐30 (Fig. 5(d)) exhibited bands at
1449 and 1609 cm–1, which demonstrated the existence of
Lewis acid sites in the materials. The bands at 1543 and 1639
cm–1 were those characteristic of the pyridinium ion, which
showed the presence of Brönsted acid sites. The band at 1490
cm–1 was a combination between two separate bands, namely,
those at 1449 and 1543 cm–1, which corresponded to Brönsted
and Lewis acid sites, respectively. These indicated that both
Brönsted and Lewis acid sites existed in the sample. In addition,
the changes of Brönsted acidity and Lewis acidity were ob‐
served from the Fig. 5(d), for desorption temperatures of 150,
250, 350, and 450 °C. Compared with Lewis acidity, the

Qingyan Chu et al. / Chinese Journal of Catalysis 39 (2018) 955–963
959
18000
26000
24000
22000
20000
18000
16000
14000
12000
10000
8000
2p 3/2
Fe 2p
(b)
(a)
SF
16000
SF
SFS-30
706.75
2p 1/2
SFS-30
14000
S 2p
169
12000
10000
8000
13.32
6000
4000
2000
0
158 160 162 164 166 168 170 172 174 176
700
710
720
730
740
Binding energy (eV)
Binding energy (eV)
1449 (LA)
150 oC
250 oC
350 oC
450 oC
(d)
(c)
1609 (LA)
1490 (LA+BA)
1543 (BA)
1639 (BA)
SFS-30
SFS-40
0.0
0.2
0.4
0.6
0.8
1.0
1400
1450
1500
1550
1600
1650
1700
1750
Wavenumber (cm–1)
Relative pressure ( p/p0 )
Fig. 5. Fe 2p (a) and S 2p (b) XPS spectra of SF and SFS‐30; (c) N2 adsorption‐desorption isotherms of SFS‐30 and SFS‐40; (d) The pyridine‐IR spectra
of SFS‐30.
Brönsted acidity was significantly reduced with increasing
temperature.
the active surface area and mesopore volume, which had a sig‐
nificant influence on the properties of the acid, as has been
previously reported [36].
3.2. Influence of loading amounts of Fe2O3 on SBA‐15
3.3. Comparison of catalytic activity
To understand the influence of loading Fe2O3 on the meso‐
porous solid superacid, the catalytic performance of SFS‐x (x =
10, 20, 25, 30, 35, 40, 45) in the alcoholysis was investigated. As
shown in Fig. 6(a), the activity of the catalyst increased as the
enhancement of Fe2O3 loading amount passed through a max‐
imum at x = 30 and then declined. This implied that when x was
below 30, the surface active acid sites increased with the load‐
ing of SF. However, when x was above 30, the excessive SF
probably caused a partial aggregation of catalyst, and hindered
the pore diffusion and decreased the catalytic activity. It indi‐
cated that the increasing loading led to a sustained decrease of
A comparison between the catalytic activity of SF and
SFS‐30 was performed and the results are shown in Fig. 6(b)
and (c). When using 10.0 mg of SF catalyst, it was found that the
optimal molar ratio of styrene oxide to MeOH (93.6 mmol) was
1:7. As shown in Fig. 6(b), the reaction yield of 99.5% at 40 °C
required 45 min for SF. When using the SFS‐30 catalyst, the
reaction easily achieved a yield of 100% after 30 min. Next, we
investigated the alcoholysis of styrene oxide with various other
alcohols with SFS‐30. As illustrated in Fig. 6(c), it is worth men‐
tioning that the alcoholysis yields of the SFS‐30 catalyzed reac‐
tions were 99.7% and 99.6% with EtOH and n‐PrOH, respec‐
tively. However, the yields of the same reactions when cata‐
lyzed by SF were only 95.4% and 69.5%. Furthermore, the cat‐
alytic activity of SFS‐30 was higher than that of SF in the alco‐
holysis of styrene oxide with n‐BuOH, i‐PrOH, i‐BuOH and
s‐BuOH. From these results, we can conclude that the catalytic
activity of SFS‐30 was higher than that of bulk SF, which indi‐
cated that the SF nanoparticles loading on the SBA‐15 not only
enhanced the active surface area of the activity components
(Table 1), but also reduced the amounts of effective compo‐
Table 1
BET surface area, textural data and catalytic activities for bulk SF,
SFS‐30 and SBA‐15.
Catalytic activityd
Sample
ABET a (m2/g) Vp b (cm3/g) Dc (nm)
yield (%)
reaction time (min)
99.5, 45
Bulk SF
SFS‐30
SBA‐15
6.57
263.78
605.47
0.02
0.38
0.86
11.33
6.95
7.01
100, 30
–
a ABET = BET surface area. b Vp = Pore volume. c D = Pore size.
d Reaction conditions were same to Fig. 6(b).

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Qingyan Chu et al. / Chinese Journal of Catalysis 39 (2018) 955–963
Fig. 6. (a) Influence of load amounts of Fe2O3 on SBA‐15 for alcoholysis of styrene oxide with MeOH, 15 min; (b) Comparison between the catalytic
activity of SF and SFS‐30, catalyst (10.0 mg), styrene oxide (1.60 g, 13.3 mmol), MeOH (3.00 g, 93.6 mmol), 40 °C; (c) SF and SFS‐30 catalyzed alco‐
holysis of styrene oxide with other alcohols, catalyst (10.0 mg), styrene oxide (1.60 g, 13.3 mmol), alcohols (93.6 mmol), 40 °C, 90 min; (d) Catalytic
reusability of SFS‐30, catalyst (50.0 mg), styrene oxide (8.00 g, 66.5 mmol), MeOH (15.00 g, 468 mmol), 40 °C, 30 min.
nents. With the synergistic effect from the nano effect of SF
nanoparticles and the mesostructure of SBA‐15, the reaction
time of catalyzed SFS‐30 was one‐third lower than that re‐
quired when using bulk SF.
and that of other reported catalysts is listed in Table 3. SFS‐30
presented the highest catalytic activity, even with the highest
substrate/catalyst (S/C) ratio of 160:1 and the lowest
MeOH/styrene oxide molar ratio of 7:1. It was also clear that
S2O82–‐Fe2O3 showed a good catalytic performance in the reac‐
tion (Fig. 6(b)). [VIV(TPP)(OTf)2] was the second highest cata‐
lytic activity, but the high activity could only be obtained with
an S/C of 24:1 and a very high MeOH/styrene oxide molar ratio
of 98.8:1. As a result, SFS‐30 with the synergistic effect between
the nano effect of S2O82–‐Fe2O3 nanoparticles and the
mesostructure of SBA‐15 exhibited the more highly efficient
The catalytic performance of SFS‐30 and several different
Brönsted acids for the alcoholysis is compared in Table 2. Simi‐
lar to the non‐catalyzed system, Fe2O3/SBA‐15 did not yield
any products. Obviously, the styrene‐based sulfonic resins pre‐
sented a lower yield with 12.2% conversion and 89% selectivi‐
ty. H2SO4 and p‐toluenesulfonic acid exhibited good catalytic
properties close to those of SFS‐30 with selectivities of 98.9%
and 98.8%, respectively. However, the two acids were dis‐
solved in the reaction mixtures and were difficult to isolate and
reuse: alkaline materials must be used to neutralize the acids to
Table 2
Catalytic performances of SFS‐30 and several different Brönsted acids
for the alcoholysis of styrene oxide with MeOH.
avoid
a
continuous
increase
of
by‐products
Catalyst
Conversion (%)
Selectivity (%)
(1,2‐dimethoxyl‐1‐phenylethane). As a result, large amounts of
salt and wastewater will be produced, which represents an
environmental issue. By contrast, SFS‐30 exhibited an excellent
activity with 100% yield and an ease of separation. However,
Fe2O3/SBA‐15 did not yield any products, which was attributed
to more Lewis acidity sites of SFS‐30, which originated from the
–
0
0
0
0
Fe2O3/SBA‐15
S2O82–‐Fe2O3/SBA‐15 *
H2SO4
p‐toluenesulfonic acid
Styrene‐based sulfonic resins
Reaction conditions: catalyst (10.0 mg), styrene oxide (1.60 g, 13.3
mmol), MeOH (3.00 g, 93.6 mmol), 40 °C, 45 min. * Reaction time was 30
min.
100
99.5
99
100
98.9
98.8
89
12.2
cooperation of S2O8  and Fe2O3 [37].
2
A comparison between the catalytic activity of our SFS‐30

Qingyan Chu et al. / Chinese Journal of Catalysis 39 (2018) 955–963
961
dustrial application.
Table 3
Comparison between the catalytic activity of SFS‐30 and that of other
reported catalysts for the alcoholysis of styrene oxide with MeOH.
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Qingyan Chu et al. / Chinese Journal of Catalysis 39 (2018) 955–963
Graphical Abstract
Chin. J. Catal., 2018, 39: 955–963 doi: 10.1016/S1872‐2067(17)63007‐9
Enhancement of catalytic activity by homo‐dispersing S2O82–‐Fe2O3 nanoparticles on SBA‐15 through ultrasonic adsorption
Qingyan Chu, Jing Chen,Wenhua Hou *, Haoxuan Yu, Ping Wang,Rui Liu, Guangliang Song,Hongjun Zhu *, Pingping Zhao
Nanjing Tech University; Research institute of QILU petrochemical company, SINOPEC; Nanjing University;
Shandong University of Technology
Mesoporous superacids S2O82–‐Fe2O3/SBA‐15 with active nanoparticles are prepared by ultrasonic adsorption. TEM images show
S2O82–‐Fe2O3 nanoparticles of approximately 6 × 8 nm are uniformly distributed in the inner mesoporous channels of SBA‐15.
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2
超声吸附制备均匀分散在SBA-15的S2O8 -Fe2O3纳米粒子:
2–
增强S2O8 -Fe2O3本体催化活性
a,b
a
c,*
d
a,d
a
a
a,
＃
d
楚庆岩 , 陈 静 , 侯文华 , 余昊轩 , 王 平 , 刘 睿 , 宋广亮 , 朱红军 , 赵萍萍
a南京工业大学化学与分子工程学院, 江苏南京211816
b中国石化齐鲁分公司研究院, 山东淄博255400
c南京大学化学化工学院介观化学教育部重点实验室, 江苏南京210023
d山东理工大学化工学院, 山东淄博255049
摘要: 酸催化剂在化学反应和化工生产中具有重要的作用. 传统无机酸, 如H2SO4, H3PO4和对甲苯磺酸等具有较高的催化
活性, 但是存在污染大、设备腐蚀严重以及催化剂不能重复使用等问题. 固体酸具有酸性强、易分离、环境友好以及稳定
性和重复使用性好等特点因而近年来越来越引起人们的关注. 其中, SO42-MxOy固体超强酸(如SO42-ZrO2, SO42-TiO2和
SO42-SnO2等)因具有很好的催化性能而备受关注. 相比SO42-MxOy, S2O82-MxOy具有更强的酸性和稳定性而成为研究的重
点. 如何克服固体超强酸本体的低比表面积和孔容, 增加其比表面积和催化活性是固体超强酸研究的热点. 超声吸附法可
保证所制介孔固体酸活性组分均匀分散, 以及大的比表面积和更多的酸性位点. 因此采用超声吸附法制备了一种新型介
孔固体酸S2O82-Fe2O3/SBA-15. 相比S2O82-Fe2O3本体、B酸和文献报道催化剂, 负载30%Fe2O3的S2O82-Fe2O3/SBA-15在环
氧苯乙烷甲醇醇解的探针反应中显示出很高的催化活性, 反应收率为100%. S2O82-Fe2O3纳米粒子的纳米效应和SBA-15介
孔结构的协同作用使S2O82-Fe2O3/SBA-15具有高催化活性.
相比S2O82-Fe2O3本体, 采用超声分散技术制备的S2O82-Fe2O3/SBA-15固体超强酸具有典型的介孔结构、大的比表面积

Qingyan Chu et al. / Chinese Journal of Catalysis 39 (2018) 955–963
963
和孔容, 并且表面富含酸性位点. 并且吡啶红外分析S2O82-Fe2O3/SBA-15表面富含L酸和B酸. 环氧苯乙烷甲醇醇解探针反
应表明, Fe2O3负载量为30%时, S2O82-Fe2O3/SBA-15的催化活性最高, 优于S2O82-Fe2O3本体和已报道的布朗酸和路易斯酸
等催化剂, 将醇底物拓展(ROHs, R = C2H5-C4H9), S2O82-Fe2O3/SBA-15的催化活性也优于S2O82-Fe2O3 本体. 同时,
S2O82-Fe2O3/SBA-15具有很好的重复使用性能, 连续使用七次, 反应收率在84.1%以上. 总之, 具有高催化活性、好的稳定性
和经济性的S2O82-Fe2O3/SBA-15具有广阔的应用前景.
关键词: 介孔固体酸; 纳米粒子; 纳米效应; S2O82-Fe2O3/SBA-15; 酸性位; 超声分散; 醇解
收稿日期: 2017-11-23. 接受日期: 2017-12-29. 出版日期: 2018-05-05.
*通讯联系人. 电话/传真: (025)58137480; 电子信箱: whou@nju.edu.cn
#通讯联系人. 电子信箱: zhuhj@njtech.edu.cn
基金来源: 国家重点研究发展计划项目(2016YFB0301703); 江苏省产学研前瞻性联合研究项目(BY2016005-06); 国家自然科学
基金(21506118).
本文的电子版全文由Elsevier出版社在ScienceDirect上出版(http://www.sciencedirect.com/science/journal/18722067).