Liquid-phase oxidation of naphthalene with H 2O 2 in the presence of ordered mesoporous V- m-Al 2O 3 catalysts

Article abstract of DOI:10.1007/s12039-017-1344-9

Abstract: The ordered mesoporous V- m-Al ₂O ₃ catalysts were successfully synthesized via a facile one-pot evaporation-induced self-assembly (EISA) strategy and applied in the liquid-phase oxidation of naphthalene with hydrogen peroxide in the presence of ascorbic acid as a reductant. The physicochemical properties of the catalysts were investigated using various techniques, like XRD, N ₂ sorption, UV-Vis spectra, Raman spectroscopy, XPS, XRF and TEM. Small-angle XRD, N ₂ sorption and TEM results show that mesoporous V- m-Al ₂O ₃ catalysts possess a highly ordered mesostructure with large surface areas and narrow pore-size distributions. High-angle XRD, UV-Vis spectra and Raman spectroscopy results indicate that VO x species were homogeneously incorporated in the matrix of mesoporous Al ₂O ₃.The catalytic performance in the liquid oxidation of naphthalene with H ₂O ₂ over 8 V- m-Al ₂O ₃ catalyst (naphthalene conversion 45.4% and phthalic anhydride selectivity 61.0%) was higher than other catalysts. The vanadium species incorporated in the 8 V- m-Al ₂O ₃ sample were stable, and its catalytic stability was kept well even after repeated use for 5 times, which indicates a green and economical pathway for naphthalene degradation. Graphical Abstract: SYNOPSIS?In the presence of hydrogen peroxide as oxidant and ascorbic acid as reductant, ordered mesoporous V- m-Al ₂O ₃ catalysts were synthesized via a facile one-pot evaporation-induced self-assembly method and successfully applied to the liquid-phase oxidation of naphthalene.[Figure not available: see fulltext.].

Full text of DOI:10.1007/s12039-017-1344-9

J. Chem. Sci.
© Indian Academy of Sciences
DOI 10.1007/s12039-017-1344-9
REGULAR ARTICLE
Liquid-phase oxidation of naphthalene with H O in the presence
2
2
of ordered mesoporous V-m-Al O catalysts
2
3
a
a
b
a
a
ZHIWEI ZHOU , YANG YU , JUAN QIN , JIAQI ZHANG , FULIN CHENG
a,∗
and WENLIANG WU
a
College of Chemical Engineering, Nanjing Tech University, Nanjing 210009, People’s Republic of China
Technology and Finance Service Center of Jiangsu Province, Productivity Center of Jiangsu Province,
b
Nanjing 210042, People’s Republic of China
E-mail: wwl@njtech.edu.cn
MS received 31 December 2016; revised 21 March 2017; accepted 14 June 2017
Abstract. The ordered mesoporous V-m-Al2O3 catalysts were successfully synthesized via a facile one-pot
evaporation-induced self-assembly (EISA) strategy and applied in the liquid-phase oxidation of naphthalene with
hydrogen peroxide in the presence of ascorbic acid as a reductant. The physicochemical properties of the catalysts
were investigated using various techniques, like XRD, N2 sorption, UV-Vis spectra, Raman spectroscopy, XPS,
XRF and TEM. Small-angle XRD, N2 sorption and TEM results show that mesoporous V-m-Al2O3 catalysts
possess a highly ordered mesostructure with large surface areas and narrow pore-size distributions. High-
angle XRD, UV-Vis spectra and Raman spectroscopy results indicate that VOx species were homogeneously
incorporated in the matrix of mesoporous Al2O3.The catalytic performance in the liquid oxidation of naphthalene
with H2O2 over 8V-m-Al2O3 catalyst (naphthalene conversion 45.4% and phthalic anhydride selectivity 61.0%)
was higher than other catalysts. The vanadium species incorporated in the 8V-m-Al2O3 sample were stable, and
its catalytic stability was kept well even after repeated use for 5 times, which indicates a green and economical
pathway for naphthalene degradation.
Keywords. Ordered mesoporous Al2O3; vanadium; EISA; naphthalene oxidation; phthalic anhydride.
1
. Introduction
However, its poor hydrothermal stability and lack
of catalytic active sites hinder its industrial appli-
10
Naphthalene, a member of polycyclic aromatic hydro-
cation. Liquid-phase oxidation of naphthalene for
the preparation of fine chemicals has been exploited
over mesoporous silica-based materials, such as Fe-
SBA-15, V-MCM-41, Fe-SiO , and Mn(TF PP)-MCM-
1,2
carbons (PAHs), is an environmental pollutant. In
the past decades, many techniques, such as biodegra-
dation, photocatalysis and aerobic catalytic oxidation,
have been exploited for its elimination.3–5 Owing to
lowerefficiencyandhighertimeconsumptionbythefor-
mer two methods, the aerobic catalytic oxidation may be
the most promising approach. However, catalytic oxida-
tion in gas-phase is usually adopted and carbon dioxide
is the final product. This process not only aggravates the
2
5
11–14
4
1.
But their catalytic activities were low and
time-consuming catalyst preparation procedure was
required. Compared to the mesoporous silica-based
materials, the non-siliceous mesoporous materials such
as mesoporous metal oxides and heteroatom zeolites
have recently been proposed as potential catalysts in
6,7
15,16
greenhouse effect but also causes wastage of resource.
many catalytic industries.
As a typical metal oxide,
Therefore, it is essential to explore new approaches to
transform naphthalene to some fine chemicals with high
values.
ordered mesoporous alumina has already been applied
in many industrial catalytic reactions, such as petroleum
refinement, oxidation reaction and other fine chemi-
17–19
Since the discovery of mesoporous silica-based mate-
cal industry.
Mesoporous alumina-supported metal
8,9
rials in the 1990s, it has attracted extensive attention.
oxides prepared by the one-pot method can achieve
*
For correspondence
Electronic supplementary material: The online version of this article (doi:10.1007/s12039-017-1344-9) contains supplementary material,
which is available to authorized users.

Zhiwei Zhou et al.
high-quality mesostructures, which can retain homoge- dispersed in ethanol, assisted by an ultrasonic technique. UV-
neous distribution of active sites.20,21 Vanadium con- Vis diffuse reflectance spectra of the samples were measured
in a Lambda 950 spectra analysis instrument in the range
taining catalysts have proved to be the most promising
catalytic systems for oxidation reactions.22 Therefore,
vanadium species incorporated into the matrix of meso-
porous alumina prepared by one-pot method would
show high catalytic performance in the liquid-phase oxi-
dation of naphthalene. Also, it is rarely reported so far.
In this work, the ordered mesoporous V-m-Al O cat-
200–800nm using BaSO as the reference. The absorbance
4
was defined as log (1/T), where T is the transmittance. The
thickness of solid film samples is 0.5mm. The Raman mea-
surements were performed on a LabRAM HR-800 with laser
excitations at 514.5 nm. The surface chemical composition
was analyzed by XPS conducted on the Thermo Scientific
Escalab 250Xi spectrometer with Al K α X-ray source (1486
eV). The weight percent of different component in the cat-
alysts was performed using the Switzerland ARL9800 XRF
2
3
alystswerepreparedbythefacileEISAmethodandtheir
catalytic behavior in the liquid-phase catalytic oxidation
of naphthalene with hydrogen peroxide was investigated techniques.
in this paper. The textural structure and physical proper-
ties of different V-m-Al O catalysts were studied using
2
3
2.3 Catalytic tests
XRD, N sorption, UV-Visspectra, Ramanspectroscopy
2
and TEM technique. The reusability of catalyst was also
investigated.
The catalytic performance of the synthesized catalysts was
carried out in a three-neck flat-bottom flask equipped with a
reflux condenser at atmospheric pressure. In a typical process,
1
g of naphthalene, 0.1g of catalyst and 0.05g of ascorbic acid
were simultaneously added into 20g of acetonitrile as solvent
and the mixture was kept stirring for 10min. Then, 5g of
H2O2 (30 wt.%) was added into the reaction system through
2
. Experimental
2.1 Synthesis of ordered mesoporous V-m-Al O
2
3
◦
a syringe, and the mixture was kept stirring for 6h at 60 C.
catalysts
At the completion of the reaction, the flask was cooled down
to room temperature. The reaction mixture was analyzed on
an SP-6890 gas chromatograph equipped with OV-1701 col-
umn and a flame ionization detector (FID). For the catalyst
recyclability tests, the catalyst was separated by centrifuga-
tion after 6h reaction time and washed with acetonitrile and
The ordered mesoporous V-m-Al2O3 catalysts were prepared
by a modified EISA method according to the reference.20
In a typical synthesis process, 1.0g P123 and stoichiomet-
ric amounts of vanadyl acetylacetonate were dissolved in
20.0mL anhydrous ethanol, followed by the addition of
2.04g aluminum iso-propoxide under vigorous stirring. Then
1.6mL nitric acid (67 wt.%) was dropped into the mixture and
◦
ethanol, then dried at 110 C for 4h before reusing.
stirred for 6 h at room temperature. The sol was subsequently
◦
transferred to a petri dish and dried at 60 C for 48h. The final 3. Results and Discussion
◦
samples were obtained after the gel was calcined at 600 C
for 5h in air and designated as xV-m-Al2O3 (x = 0, 2, 5, 8, 3.1 Catalyst characterization
10 and 12), where x represents the molar ratio of vanadium
species to aluminum species. For comparison, the 8V-Al2O3- Low-angle XRD (LXRD) and wide-angle XRD
c and 8V-Al2O3-i samples were prepared by co-precipitation (WXRD) patterns of different V-m-Al O samples are
2
3
and impregnation methods, respectively.
shown in Figure 1. As can be seen from Figure 1 (A),
◦
a strong diffraction peak centered at around 1.0 and
◦
one weak peak centered at around 1.8 are observed
2.2 Catalysts characterization
for the m-Al O sample, which can be attributed to
2
3
The XRD patterns were obtained on a Rigaku Smartlab instru- p6mm hexagonal symmetry, suggesting it is long-range
1
5
◦
ment with Ni-filtered Cu Kα radiation (λ = 0.154 nm) and
ordered and mesoporous. The peak centered at 1.8
◦
operated at 40kV and 40mA. The scanning step was 0.02 in
disappeared after the incorporation of the vanadium
species, and the intensity of the peak centered at 1.0
◦
◦
◦
the range from 0.5 to 5 (small-angle range) and from 10 to
◦
◦
8
0 (wide-angle range). N2 sorption isotherms were measured
decreased with the vanadium species loading increas-
ing, indicating that its long-range ordered mesostructure
is slightly collapsed. Figure 1 (B) displays the wide-
angle XRD patterns of different V-m-Al O samples. It
can be seen that the amorphous aluminum oxide can be
formed when the molar ratio of vanadium species to alu-
◦
at −196 C using a BELSORP-MINI volumetric adsorption
◦
analyzer. The samples were degassed at 200 C for 2 h under
vacuum before measurement. The surface area was calcu-
lated according to BET method, and the pore size distribution
was determined based on the BJH adsorption model from
the adsorption isotherm branch. TEM image was recorded on
2
3
the JEOL JEM-2010 EX transmission electron microscope minum species is less than 8%. With the further increase
under 200kV. Before TEM measurement, the samples were in vanadium species, three diffraction peaks centered at

Naphthalene oxidation over mesoporous V-m-Al2O3 catalysts
A)
(
(B)
a
a
b
c
b
c
d
e
f
d
e
f
1
2
3
4
5
10 20 30 40 50 60 70 80
2 Theta/Degree
2
Theta/Degree
Figure 1. (A) Low-angle and (B) wide-angle XRD patterns of (a) m-Al2O3, (b)
V-m-Al2O3, (c) 5V-m-Al2O3, (d) 8V-m-Al2O3, (e) 10V-m-Al2O3, (f) 12V-m-Al2O3.
2
(A)
(B)
a
a
b
c
d
e
b
c
d
e
f
f
5
10 15 20 25 30 35 40 45 50
0.0
0.2
0.4
0.6
0.8
1.0
p/p0
d /nm
p
Figure 2. (A) N2 sorption isotherms and (B) pore size distribution curves of (a) m-Al2O3,
(b) 2V-m-Al2O3, (c) 5V-m-Al2O3, (d) 8V-m-Al2O3, (e) 10V-m-Al2O3, (f) 12V-m-Al2O3.
◦
2
θ = 37.6, 45.8 and 67.0 are observed, suggesting that to IUPAC classification and exhibit a H2 hystere-
the crystal γ -Al O (JCPDS Card No. 10-0425) were sis loop, which is typical for mesoporous materials.24
2
3
gained owing to the increasing presence of bulky acety- The hysteresis loop would be distorted and gradually
lacetone ligand, probably.17,23 However, no diffraction shifted to higher pressure with the increase in vanadium
peak of VOx crystalline phase is detected, indicating species loading because of the formation of γ-Al O3
2
that vanadium species is highly dispersed in the frame- phase resulting in its partial destruction of ordered
work of mesoporous Al O . The 8V-Al O -c sample Mesopores, probably, which agreed well with XRD pat-
2
3
2
3
16
prepared by co-precipitation method showed distinct terns. As seen in Table 1, the 8V-m-Al O sample,
crystal γ -Al O phase. Three new peaks centered at 2θ = with BET surface area of 176 m /g and pore volume of
5.7, 27.7 and 28.6 corresponding to diffraction peaks 0.28 cm /g, is optimal over other V-m-Al O samples,
2
3
2
2
3
◦
3
2
2 3
of AlVO (JCPDS Card No. 39-0276) are observed in indicating its potential for high catalytic performance.
4
8
V-Al O -i sample (Figure S1, Supplementary informa- Compared to 8V-m-Al O and 8V-Al O -i samples,
2
3
2
3
2
3
tion). The results further indicate that the EISA method the 8V-Al O -c sample showed a hysteresis loop at
2
3
is superior to another method in controlling Al O crys- higher pressure and a wider pore diameter distribu-
2
3
tal growth and the dispersion of vanadium species.
tion owing to the stacking mesoporous structure, which
The N sorption isotherms as well as the corre- would result in its lower surface area and pore volume
2
sponding pore size distributions fordifferent V-m-Al O
(Figures S2, S3 and Table S1). In addition, the sur-
2
3
samples are shown in Figure 2 and the detailed textural face area, pore diameter and volume for the 8V-Al O -i
2
3
properties are listed in Table 1. As shown in Fig- sample prepared by impregnation method are much
ure 2 (A), the isotherms for V-m-Al O samples, whose lower than that of 8V-m-Al O sample probably due
2
3
2
3
molar ratio of vanadium species to aluminum species to the partial blocking of mesopores by vanadium
was less than 8%, are type IV isotherms according species.

Zhiwei Zhou et al.
Table 1. Physical properties of mesoporous V-m-Al2O3 catalysts.
Pore size (nm)a SBET (m · g
2
−1 b
)
Pore volume (cm · g
3
−1 c
)
Samples
m-Al2O3
4.8
4.8
4.8
4.9
5.1
7.0
152
159
166
176
149
119
0.24
0.26
0.26
0.28
0.33
0.48
2V-m-Al2O3
5V-m-Al2O3
8V-m-Al2O3
10V-m-Al2O3
12V-m-Al2O3
a
b
c
BJH method; BET specific areas; P/P0 = 0.99.
1
1
1
40
f
950
20
00
e
a
d
c
8
6
4
2
0
0
0
0
b
345
220
560
2
00 300 400 500 600 700 800
Wavelength(nm)
0
2
00
400
600
800
1000
1200
1400
-1
Figure 3. Diffuse reflection UV-Vis spec-
tra of (a) m-Al2O3, (b) 2V-m-Al2O3,
Raman shift (cm )
(
1
c) 5V-m-Al2O3, (d) 8V-m-Al2O3, (e)
0V-m-Al2O3, (f) 12V-m-Al2O3.
Figure 4. Raman spectra of 8V-m-Al2O3 samplewith laser
excitations at 514.5nm.
Figure 3 presents the UV-Vis spectra of different
V-m-Al O samples. Two bands, one centered at 220 can be assigned to the microcrystalline V O species not
2
3
2
5
nm and another centered at 270nm, were observed for detected by XRD patterns.
pure m-Al O sample, which is in good agreement with
Raman spectroscopy is a useful technique provid-
ing information about the various types of vanadium
2
3
2
5
literature. However, compared to the pure m-Al O
2
3
sample, the intensity of absorption band in the region species that are not detected by XRD patterns. The
−1
2
80–290nm increases with the incorporation of vana- Raman lines below 900 cm would be assigned to
dium species. This increase can be attributed to the the vibration of polymeric V-O-V species, and the
26
−1
formation of isolated tetrahedral vanadium species.
Raman lines in the region from 900 to 1000 cm can
At the same time, with the amount of the vanadium be identified with the V=O stretch vibration of poly-
28
species increasing, a red-shifted absorption band in the meric vanadium species. Figure 4 shows the Raman
region from 300 to 330 nm was observed owing to the spectra of 8V-m-Al O sample. It can be seen in Fig-
2
3
−1
polymeric tetrahedral vanadium species. For the sam- ure 4 that a major Raman line at around 950 cm is
ple 10V-m-Al O , a weak absorption band in the region observed accompanied by weak lines at ∼560, ∼345
2
3
−1
4
00–450 nm was observed, which can be attributed to and ∼220 cm . This indicates that the polymeric tetra-
+
5
27
octahedral V species. Similarly, the band increases hedral vanadate, undetectable by the XRD patterns, is
distinctly for 12V-m-Al O sample, which can also be the majorcomponent ofvanadiumspecies afterits incor-
2
3
29,30
attributed to microcrystalline V O species. Compared poration into the structure of m-Al O .
2
5
2
3
to8V-m-Al O sample, theabsorptionbandintheregion
Figure 5 shows the TEM images for 8V-m-Al O cat-
2
3
2 3
5+
4
00–450nm corresponding to octahedral V species alyst. The typical long-range ordered mesostructure was
for 8V-Al O -i and 8V-Al O -c samples can also be obviouslyobserved, whichisingoodagreementwiththe
2
3
2
3
observed (Figure S4), which indicate further formation intense XRD peak shown in small-angle XRD patterns.
of extra-framework vanadium species. Furthermore, the The high dispersion of VOx species in the matrix of
band increases distinctly for 8V-Al O -i sample, which m-Al O is shown in the high-resolution TEM image.
2
3
2
3

Naphthalene oxidation over mesoporous V-m-Al2O3 catalysts
Figure 5. TEM images of 8V-m-Al2O3 sample.
the solvent. The major products are phthalic anhydride
and 1,4-napthaquinone. No naphthalene conversion was
5+
V2p3/2
V
observed over pure m-Al O catalyst. Compared to the
2
3
4+
pure m-Al O catalyst, the conversion of naphthalene
V
2
3
could be detected, and it increased with the loading
of vanadium species, increasing from the molar ratio
2
4
to 8, where the naphthalene conversion is as high as
5.4% and the selectivity of phthalic anhydride is max-
a
imum 61.1%; probably, owing to its long-range ordered
mesostructure, high surface area, and appropriate pore
volume and size. With further increase in vanadium
species loading, both the naphthalene conversion and
the selectivity of phthalic anhydride decreased, sug-
gesting that the isolated tetrahedral vanadium species
b
5
20 519 518 517 516 515 514 513
12
Binding Energy (eV)
are the main active sites. In addition, the catalytic
performance in the absence of ascorbic acid was also
investigated, and the naphthalene conversion was 0.3%,
which indicated that the ascorbic acid is essential to
reduce the vanadium species with high valent to lower
valent for the oxidation of naphthalene by hydrogen
Figure 6. XPS spectra for (a) fresh and
b) reduced 8V-m-Al2O3 catalysts.
(
Figure 6 shows XPS spectra for 8V-m-Al O cata-
2
3
33
peroxide. At the same time, naphthalene conversion
for 8V-m-Al O catalyst is much higher than other
lysts in its two states, fresh sample (Figure 6a) and
reduced by ascorbic acid (Figure 6b). A major peak
2
3
5+
two samples, owing to its higher surface area and
appropriate pore size and volume. The results further
indicated that the EISA process is a promising method
to prepare complicated metal oxides with ordered meso-
pores.
centered at 517.3eV corresponding to V species and
another small peak centered at 516.3eV correspond-
4
+
ing to V species for fresh 8V-m-Al O catalyst are
2
3
5+
observed, suggesting that the V species was pre-
dominantly formed.3 However, the peak area of V
1,32
4+
To test the heterogeneity of V-m-Al O catalysts,
species distinctly increased for the reduced catalyst by
ascorbic acid. This indicated that the high valence vana-
dium species are reduced to low valence by ascorbic
acid, which are the active sites for the oxidation of naph-
thalene.
2
3
leaching experiments were carried out according to pre-
13,34
vious reports.
The catalyst was removed at 0.5h
under the optimal reaction condition by centrifugation.
Then, the filtrate was applied for further reaction under
the same reaction condition. The results of leaching
experiment are shown in Figure 7. It can be seen that
the conversion of naphthalene at 0.5h (before catalyst
3
.2 Catalytic performance
Table 2 summarizes the catalyst performance of differ- removal) was 18.2%. With the increasing of reaction
ent V-m-Al O catalysts in the liquid-phase oxidation time, a slight enhancement in naphthalene conversion
2
3
of naphthalene with hydrogen peroxide in the presence was observed, which maybe owing to the little leached
of ascorbic acid as the reductant and acetonitrile as vanadium species dispersed on the support surface

Zhiwei Zhou et al.
Table 2. Catalytic performance of different V-m-Al2O3 catalysts in the liquid-phase oxidation of naphthalene.
Entry Catalysts
Naphthalene conversion (%)
Selectivity (%)
Phthalic anhydride 1,4-naphthoquinone Others
1
2
3
4
5
6
7
8
9
1
m-Al2O3
2V-m-Al2O3
5V-m-Al2O3
8V-m-Al2O3
10V-m-Al2O3
12V-m-Al2O3
Non Catalyst, Non Reductant
8V-m-Al2O3, Non Reductant
8V-Al2O3-c
–
8.0
19.4
45.4
41.1
37.1
–
0.3
18.0
21.2
–
–
–
48.7
51.9
61.0
57.6
54.2
–
11.5
42.3
35.4
33.3
30.2
27.6
28.3
30.3
–
8.9
45.2
49.5
18.0
17.9
11.4
14.1
15.5
–
79.6
12.5
15.1
0
8V-Al2O3-i
Reaction conditions: w(catalyst)/w(naphthalene) = 0.1; w(acetonitrile)/w(naphthalene) = 20; w(ascorbic acid)/w(catalyst)
◦
=
0.5;w(H2O2)/w(naphthalene) = 1.5; reaction time: 6h; reaction temperature: 60 C.
2
2
1
1
5
0
5
0
5
0
through the hydrogen bonding rather than incorporated
species in the matrix of mesoporous Al O . The chem-
2
3
ical composition of the fresh and filtered catalysts were
analyzed by XRF techniques. Compared to a fresh cata-
lyst, the vanadium content slightly decreased from 7.42
to 7.34 wt.%, which indicated that the vanadium species
incorporated in the 8V-m-Al O sample was stable and
2
3
thereby resistant to leaching.
Table 3 shows the data on the reusability for 8V-m-
Al O catalyst in the liquid-phase oxidation of naphtha-
2
3
lene. It was observed that the naphthalene conversion
slightly decreased after the reuse for five times. Conver-
sion of naphthalene 39.1% and selectivity of phthalic
anhydride 57.6% was obtained, which suggested that
the 8V-m-Al O catalyst has good reusability implying
0
1
2
3
4
5
6
Reaction time(h)
Figure 7. Leaching experiment of 8V−m−
Al2O3 catalyst in the liquid-phase oxidation
of naphthalene. Reaction conditions: w(cat
alyst)/w(naphthalene) = 0.1; w(acetonitrile)/w(nap
hthalene) = 20; w(ascorbic acid)/w(catalyst) = 0.5;
2
3
its potential industrial application.
Therefore, based on the characterization and catalytic
performance of V-m-Al O catalyst above, a possi-
2
3
w(H2O2)/w(naphthalene) = 1.5; reaction time:
ble mechanism is proposed and shown in Scheme 1.
Accordingly, it is suggested that ascorbic acid will help
◦
6
h; reaction temperature: 60 C.
5
+
to reduce the high valent V species in V-m-Al O cat-
2
3
4
+
alyst to V species. This in turn will activate hydrogen
Table 3. Catalytic reusability of 8V-m-Al2O3 catalyst in the liquid-phase oxi-
dation of naphthalene.
Entry
Naphthalene
Conversion (%)
Selectivity (%)
Phthalic anhydride 1,4-naphthoquinone Others
1
2
3
4
5
45.4
44.2
41.0
42.1
39.1
61.0
58.7
54.9
58.0
57.6
27.6
26.8
27.0
30.9
29.2
11.4
14.5
18.1
11.1
13.2
Reaction conditions: w(catalyst)/w(naphthalene) = 0.1; w(acetonitrile)/
w(naphthalene) = 20; w(H2O2)/w(naphthalene) = 1.5; w(ascorbic acid)/
◦
w(catalyst) = 0.5; reaction time: 6h; reaction temperature: 60 C.

Naphthalene oxidation over mesoporous V-m-Al2O3 catalysts
Beijing Key Laboratory for Enze Biomass and Fine Chem-
icals; Project Funded by the Priority Academic Program
Development of Jiangsu Higher Education Institutions.
References
1
. Clarke T J, Kondrat S A and Taylor S H 2015 Total
oxidation of naphthalene using copper manganese oxide
catalysts Catal. Today 258 610
2
. Aranda A, Puértolas B, Solsona B, Agouram S, Murillo
R, Mastral A M, Taylor S H and Garcia T 2010 Total
Oxidation of Naphthalene Using Mesoporous CeO2
Catalysts Synthesized by Nanocasting from Two Dimen-
sional SBA-15 and Three Dimensional KIT-6 and MCM-
48 Silica Templates Catal. Lett. 134 110
Scheme 1. Possible reaction mechanism for mesoporous
V-m-Al2O3 catalyst in liquid-phase oxidation of naphthalene
with hydrogen peroxide.
3. JouanneauY, MeyerCandDuraffourgN2016Dihydrox-
ylation of four- and five-ring aromatic hydrocarbons by
the naphthalene dioxygenase from Sphingomonas CHY-
1
Appl. Microbiol. Biot. 100 1253
4
. Venkatathri N, Pillai V K, Rajini A, Raju M N and
Reddy I A K 2013 Structural and catalytic properties
of a novel vanadium containing solid core mesoporous
silica shell catalysts for gas phase oxidation reaction J.
Chem. Sci. 125 63
peroxide to produce active oxygen species to oxi-
4
+
dize naphthalene to phthalic anhydride, while V gets
5+
retransformed to V species at the end of the catalytic
cycle.
5
6
7
. Karuppiah J, Reddy E L, Sivachandiran L, Karvembu R
and Subrahmanyam C 2012 Nonthermal plasma assisted
photocatalytic oxidation of dilute benzene J. Chem.
Sci. 124 841
. Bampenrat A, Meeyoo V, Kitiyanan B, Rangsunvigit P
and Rirksomboon T 2008 Catalytic oxidation of naph-
thalene over CeO2-ZrO2 mixed oxide catalysts Catal.
Commun. 9 2349
. Varela-Gandía F J, Ángel Berenguer-Murcia, Lozano-
Castelló D, Cazorla-Amorós D, Sellick D R and Taylor
S H 2013 Total oxidation of naphthalene using palladium
nanoparticles supported on BETA, ZSM-5, SAPO-5 and
alumina powders Appl. Catal. B-Environ. 129 98
4
. Conclusions
ThispaperreportsthesuccessfulsynthesisofV-m-Al O
2
3
by a modified one-pot EISA method. It was applied in
the liquid-phase oxidation of naphthalene with hydro-
gen peroxide in the presence of ascorbic acid as
reductant. Polymeric tetrahedral vanadate was formed
and homogenously incorporated into the framework
of m-Al O , which were the main active sites. The
2
3
8
V-m-Al O catalyst shows higher catalytic perfor-
8. Kresge C T, Leonowicz M E, Roth W J, Vartuli J
C and Beck J S 1992 Ordered mesoporous molecular
sieves synthesized by a liquid-crystal template mecha-
nism Nature 359 710
2
3
mance than other samples owing to its highest surface
area, appropriate pore volume and size, whose naph-
thalene conversion and phthalic anhydride selectivity
are 45.4% and 61.0%, respectively, and it has good
reusability. At the same time, ascorbic acid is essential to
reduce the vanadium species from high valent to lower
valent for the oxidation of naphthalene by hydrogen
peroxide.
9
. Garg S, Soni K, Prasad V V D N, Kumar M, Bhaskar T,
Gupta J K, Dhar G M and Gopinath C S 2014 Effect of
method of preparation on hydrodesulphurization activ-
ity of Co- or Ni-promoted MoS2/SBA − 15 catalysts J.
Chem. Sci. 126 437
1
0. Gómez S, Garces L J, Villegas J, Ghosh R, Giraldo O
and Suib S L 2005 Synthesis and characterization of TM-
MCM-48 (TM = Mn, V, Cr) and their catalytic activity
in the oxidation of styrene J. Catal. 233 60
Supplementary Information (SI)
1
1. Bangó A and Halász J 2009 Oxidation of condensed
cyclic hydrocarbons with H2O2 in the presence of modi-
fied MCM-41 and SBA-15 mesoporous catalysts React.
Kinet. Mech. Cat. 96 413
TheXRD, N2 sorption, UV-visspectracharacterizationforthe
8V-Al2O3-c and 8V-Al2O3-i (Figures S1 to S4, Table S1) are
given in the Supplementary Information, which is available
at www.ias.ac.in/chemsci.
12. Shylesh S and Singh A P 2004 Synthesis, characteri-
zation, and catalytic activity of vanadium-incorporated,
-
grafted, and -immobilized mesoporous MCM-41 in the
Acknowledgements
oxidation of aromatics J. Catal. 228 333
This work was supported by Jiangsu Planned Projects for 13. Andas J, Adam F, Rahman I A and Yun T Y 2014
Post-doctoral Research Funds (1302121C); Open Project of Optimization and mechanistic study of the liquid-phase

Zhiwei Zhou et al.
oxidation of naphthalene over biomass-derived iron cat- 24. Luo H Y, Zhang W, Zhou H W, Huang S Y, Lin P Z, Ding
alyst Chem. Eng. J. 252 382
4. Yang F, Gao S, Xiong C, Wang H, Chen J and Kong Y
Y J and Lin L W 2011 A study of Rh-Sm-V/SiO2 cata-
lysts for the preparation of C2-oxygenates from syngas
Appl. Catal. A-Gen. 214 161
1
2015 Coordination of manganese porphyrins on amino-
functionalized MCM-41 for heterogeneous catalysis of 25. Concepción P, Navarro M T, Blasco T, Nieto J M L,
naphthalene hydroxylation Chin. J. Catal. 36 1035
5. Morris S M, Fulvio P F and Jaroniec M2008 Ordered
Mesoporous Alumina-Supported Metal Oxides J. Am.
Chem. Soc. 130 15210
Panzacchi B and Rey F 2004 Vanadium oxide supported
on mesoporous Al2O3: Preparation, characterization and
reactivity Catal. Today 96 179
1
1
26. Blasco T, Galli A, Nieto J M L and Trifiró F 1997
Oxidative Dehydrogenation of Ethane and n-Butane on
VOx/Al2O3 Catalysts J. Catal. 169 203
6. Cai W, Yu J, Anand C, Vinu A and Jaroniec M
2011 Facile Synthesis of Ordered Mesoporous Alumina
and Alumina-Supported Metal Oxides with Tailored 27. Eon J G, Olier R and Volta J C 1994 Oxidative Dehydro-
Adsorption and Framework Properties Chem. Mater. 23
genation of Propane on γ −Al2O3 Supported Vanadium
1147
Oxides J. Catal. 145 318
1
1
1
2
2
7. Liu Q, Gao J, Gu F, Lu X, Liu Y, Li H, Zhong Z, Liu 28. Florea M, Marin R S, P a˘ l a˘ s¸ anu F M, Nea ¸t u F and
B, Xu G and Su F 2015 One-pot synthesis of ordered
mesoporous Ni-V-Al catalysts for CO methanation J.
Catal. 326 127
Pârvulescu V I 2015 Mesostructured vanadia-alumina
catalystsforthesynthesisofvitaminK3 Catal. Today 254
29
8. Gholampour N, Yusubov M and Verpoort F 2016 Inves- 29. Makgwane P R and Ray S S 2015 Development of a high-
tigation of the preparation and catalytic activity of
supported Mo, W, and Re oxides as heterogeneous cata-
lysts in olefin metathesis Catal. Rev. 58 113
performance nanostructured V2O /SnO2 catalyst for
efficient benzene hydroxylation Appl. Catal. A-Gen. 492
10
5
9. Hosseinzadeh R, Tajbakhsh M, Mohadjerani M and 30. Mannepalli L K, Dupati V, Vallabha S J and Manorama S
Mohammad A 2010 Copper-catalysed N-arylation of
arylsulfonamides with aryl bromides and aryl iodides
using KF/Al2O J. Chem. Sci. 122 143
V 2013 Synthesis of substituted guanidines using Zn-Al
hydrotalcite catalyst J. Chem. Sci. 125 1339
31. Bukallah S B, Bumajdad A, Khalil K M and Zaki M
I 2010 Characterization of mesoporous VOx/MCM-41
composite materials obtained via post-synthesis impreg-
nation Appl. Surf. Sci. 256 6179
32. Carja G, Nakamura R, Aida T and Niiyama H 2003
Mg-V-Al mixed oxides with mesoporous properties
using layered double hydroxides as precursors: catalytic
behavior for the process of ethylbenzene dehydrogena-
tion to styrene under a carbon dioxide flow J. Catal. 218
104
0. Yuan Q, Yin A X, Luo C, Sun L D, Zhang Y W, Duan
W T, Liu H C and Yan C H 2008 Facile synthesis for
ordered mesoporous gamma-aluminas with high thermal
stability J. Am. Chem. Soc. 130 3465
1. Ham H, Kim J, Cho S J, Choi J H, Dong J M and Bae J
W 2016 Enhanced Stability of Spatially Confined Cop-
per Nanoparticles in an Ordered Mesoporous Alumina
for Dimethyl Ether Synthesis from Syngas ACS Catal. 6
5629
2
2. Li X H, Li W Y and Xie K C 2005 Supported Vana- 33. Long Z, Zhou Y, Chen G, Zhao P and Wang J 2014 4,4’-
dia Catalysts for Dehydrogenation of Ethylbenzene with
CO2 Catal. Lett. 105 223
Bipyridine-modified molybdovanadophosphoric acid: A
reusable heterogeneous catalyst for direct hydroxylation
of benzene with O2 Chem. Eng. J. 239 19
23. Yuan H, Zhang C, Huo W, Ning C, Tang Y, Zhang Y,
CongD, ZhangW, LuoJ, LiSandWangZ2014Selective 34. Reddy J S, Liu P and Sayari A 1996 Vanadium contain-
hydrogenation of maleic anhydride over Pd/Al2O3 cat-
alysts prepared via colloid deposition J. Chem. Sci. 126
ing crystalline mesoporousmolecular sieves Leaching
of vanadium in liquid phase reactions Appl. Catal. A-
Gen. 148 7
141