Zinc polyoxometalate on activated carbon: An efficient catalyst for selective oxidation of alcohols with hydrogen peroxide

Article abstract of DOI:10.1002/aoc.3332

[PW₁₁ZnO₃₉]^5- was immobilized on activated carbon and characterized using Fourier transform infrared, X-ray diffraction, Brunauer-Emmett-Teller and elemental analysis techniques. Effective oxidation of various alcohols wit

Full text of DOI:10.1002/aoc.3332

Full paper
Received: 21 January 2015
Revised: 12 April 2015
Accepted: 19 April 2015
Published online in Wiley Online Library: 25 May 2015
(wileyonlinelibrary.com) DOI 10.1002/aoc.3332
Zinc polyoxometalate on activated carbon: an
efficient catalyst for selective oxidation of
alcohols with hydrogen peroxide
a
a
b
Elham Assady , Bahram Yadollahi *, Mostafa Riahi Farsani
a
and Majid Moghadam
5ꢀ
[
PW11ZnO39
]
was immobilized on activated carbon and characterized using Fourier transform infrared, X-ray diffraction,
Brunauer–Emmett–Teller and elemental analysis techniques. Effective oxidation of various alcohols with hydrogen peroxide
was performed in the presence of this catalyst. Easy separation of the catalyst from the reaction mixture, cheapness, high activity
and selectivity, stability as well as retained activity in subsequent catalytic cycles make this supported catalyst suitable for small-
scale synthesis. Copyright © 2015 John Wiley & Sons, Ltd.
Additional supporting information may be found in the online version of this article at the publisher’s web site.
Keywords: catalysis; polyoxometalate; activated carbon; alcohol; oxidation; hydrogen peroxide
supporting material for heteropolyanions (HPA) in various redox re-
Introduction
actions. These compounds are low-cost materials with porous
[
33]
Oxidation of alcohols into the corresponding aldehydes or ketones
is one of the most important and simple transformations in organic
synthesis and industrial chemistry.
structures, high surface area and pH stability. ACs can be used
to bind/support acidic HPAs, resulting in an extraordinary
stability/regenerability towards HPA leaching from the AC
[
1,2]
Alcohol oxidation is conven-
[
34]
tionally performed using dichromate and permanganate oxidants.
Unfortunately, these oxidants are usually toxic, expensive and envi-
ronmentally undesirable; and they also produce large amounts of
support. However, limited studies have been carried out using
AC-supported HPAs for oxidative desulfurization. For example,
phosphotungstic acid (HPW)/AC has been reported as an efficient
[3,4]
[35]
wastes.
of hydrogen peroxide as a safe, clean and cheap oxidant has been
With economic and environmental concerns, the use
catalyst for oxidative desulfurization with H O .
2
2
To the authors’ knowledge, few studies have been reported using
transition metal-substituted POMs supported on AC for oxidation of
alcohols. In the work reported here, for the first time, AC was used as
[5]
suggested to realize so-called green oxidation processes.
Polyoxometalates (POMs) are a large family of metal–oxygen
clusters of early transition metals. These compounds have stimu-
lated many current research activities in a broad range of fields
such as catalysis, materials science and medicine. Such a stimula-
tion is because of diverse and highly modifiable sizes, shapes,
charge densities, acidities and reversible redox potentials of
5ꢀ
a support for [PW ZnO ] (PW Zn) and the resulting catalyst was
1
1
39
11
employed in the oxidation of alcohols with hydrogen peroxide.
Experimental
[6,7]
POMs.
of various organic compounds.
different types of POMs such as phosphomolybdate, sandwich-type
They also can act as efficient catalysts in the oxidation
[
8–13]
The catalytic performances of
General and methods
1
4ꢀ
5ꢀ
All materials such as metal salts, alcohols, 30% hydrogen peroxide
and solvents were of analytical grade, commercially available
and used without further purification unless otherwise stated.
POMs, [NaP W O110] , [IMo O ] and other POM catalysts
5
30
6 24
have been demonstrated for oxidation of alcohols, sulfides and al-
kenes using a variety of oxygen sources.
[
14–24]
Unfortunately, for
[36–38]
K
5
[PW11ZnO39]ꢁ25H
Elemental analyses were performed using inductively coupled
plasma atomic emission spectrometry with a PerkinElmer 7300
2
O was prepared according to the literature.
many of these catalytic systems, the use of toxic solvents or difficult
recovery and reusability of the catalysts have limited their applica-
tions in industrial and laboratorial synthesis. In order to be more ef-
fective in catalytic applications, POMs are usually incorporated on
suitable materials for preparation of heterogeneous catalysts.
Heterogeneous catalytic processes show great advantages in
terms of product separation and catalyst reusability. Therefore, they
*
Correspondence to: Bahram Yadollahi, Department of Chemistry, University of
Isfahan, Isfahan 81746-73441, Iran. E-mail: yadollahi@chem.ui.ac.ir, yadollahi.
b@gmail.com
[3]
are more feasible for industrial applications. Various supports
[25,26]
[27]
[28]
[29]
[30]
a Department of Chemistry, University of Isfahan, Isfahan 81746-73441, Iran
such as silica,
alumina,
carbon,
titania,
zirconia,
[
31]
[32]
MCM-41 and SBA-15 have been used in a range of catalytic
applications. Activated carbon (AC) has been studied as a potential
b Young Researchers and Elite Club, Islamic Azad University, Shahrekord Branch,
Shahrekord, Iran
Appl. Organometal. Chem. 2015, 29, 561–565
Copyright © 2015 John Wiley & Sons, Ltd.

E. Assady et al.
DV elemental analyser. Fourier transform infrared (FT-IR) spectra
were obtained with samples as potassium bromide pellets in the
range 400–4000 cm with a Nicolet Impact 400D instrument. Pow-
der X-ray diffraction (XRD) data were obtained with a Bruker D8 Ad-
vance using Cu Kα radiation (2θ = 5–70°). Brunauer–Emmett–Teller
Results and discussion
ꢀ
1
Characterization of the catalyst
The transition metal-substituted POM K [PW ZnO ]ꢁ25H O and
5
11
39
2
PW Zn@AC were synthesized and characterized using the methods
1
1
(BET) ’apparent’ specific surface area of supported POM was deter-
[36–38]
described elsewhere.
FT-IR spectra, which provide characteristic
mined from nitrogen adsorption measurements at 77K using a
Micromeritics Nanosord sens Iran Ltd Co NS 91 equipment. The
oxidation products were quantitatively analysed using gas chroma-
tography (GC) with a Shimadzu GC-16A instrument with a flame-
fingerprints for POM clusters (P–O, W–O and W–O–W stretch regions)
ꢀ1
in the range 500–1100 cm , were used for structural confirmation.
ꢀ1
For AC, the band at 1500–1600 cm is attributed to the C¼O
stretching vibrations of lactonic, quinonic or carboxylic groups. Also,
1
ionization detector using a silicon DC-200 column. H NMR spectra
ꢀ1
the bands at 900–1300 cm are assigned to C–O–C vibrations or
were obtained in chloroform with a Bruker 400 (296 K) and refer-
enced to tetramethylsilane (0.0 ppm) as external standard.
[39]
C–O stretching of etheric, lactonic, carboxylic or phenolic groups.
In the regions 3037–3124 and 2844–2918 cm , the bands corre-
spond to aromatic and aliphatic groups.
ꢀ1
[40,41]
Figure 1 shows the
FT-IR spectra of K [PW ZnO ]ꢁ25H O, PW Zn@AC and AC. In the
5
11
39
2
11
ꢀ
1
Synthesis of PW11Zn@AC catalyst
FT-IR spectrum of PW Zn@AC, the peaks at 1070 and 960 cm of
11
PW11Zn are overlapped with C–O–C vibrations or C–O stretching of
An aqueous solution of PW Zn was prepared by mixing Na HPO
4
11
2
ether, lactonic, carboxylic or phenolic groups of AC. In addition, a
(
9.1 mmol), Na WO ꢁ2H O (100 mmol) and zinc nitrate (12 mmol)
2
4
2
ꢀ
ꢀ
1
[23–25]
broad intense band centred on 3450 cm
attributed to O–H
2
O bending) indi-
in 200ml of water and adjusting the pH to 4.8.
AC (1g) in
1
stretching and a weak absorption at 1640 cm (H
10 ml of water was added dropwise with stirring for 12 h. The solid
cate the presence of water in PW11Zn@AC and AC. Furthermore, the
was filtered and washed three times with water and then dried in
vacuum at 100 °C for 4 h.
ꢀ
1
absorption peaks at 860–880 and 790–800 cm are characteristic of
Keggin structure and suggest the structure of the POM is preserved
after incorporation on AC.
The XRD patterns of PW11Zn, AC and also PW11Zn@AC were
studied which are shown in Fig. S1. From the results, AC shows an
amorphous structure with a broad band at 2θ about 10° to 30°.
Unfortunately, the characteristic peaks for PW11Zn are located in
the region of the AC broad band. However, in the XRD pattern of
PW11Zn@AC, a small band attributed to PW11Zn is observed. These
results suggest that adsorbed PW11Zn is highly dispersed on the AC
surface, and no crystalline phase is observed after dispersion of
PW11Zn on AC. Similar results have also been reported by Alcañiz-
2 2
Typical procedure for oxidation of alcohols by H O
In a 25ml round-bottomed flask equipped with a reflux condenser,
a mixture of 0.2g of PW11Zn@AC catalyst containing 5 μmol of
PW11Zn, 3 ml of acetonitrile and 1 mmol of alcohol was added. Then
1
2 2
ml of 30% H O was added and the mixture was refluxed for an
appropriate time (25 min to 4 h) with stirring. The progress of the
reaction was monitored using GC with flame ionization detection
and a silica pack column. At the end of the reaction, the catalyst
[
42]
was filtered out and 10 ml of 10% NaHCO
3
was added. The organic
3
Monge et al. where H [PMo12O40] was supported on ACs.
phase was extracted with chloroform and dried. Flash chromatog-
raphy on a short column of silica gel with ethyl acetate–n-hexane
as eluent gave pure products.
The elemental analysis results show that PW11Zn@AC samples
contain 10 wt% of PW11Zn. The molar ratio of P:Zn:W is also esti-
mated to be 1:1:11. These results suggest that the Keggin structure
is well preserved in the supported catalyst. Therefore, the elemental
analysis and FT-IR spectra of PW Zn and PW Zn@AC confirm that
11
11
the structure of PW Zn is unchanged after impregnation of PW Zn
Recycling of the catalyst
11
11
on AC. The BET surface area result for this catalyst shows that the sur-
2
ꢀ1
A typical recycling experiment was carried out as follows. After the
required reaction time, the round-bottom flask was cooled to room
face area is 501 m g . The surface area for AC was previously re-
2
ꢀ1
ported to be 916 m g . So, it is demonstrated that the surface area
of the catalyst after supporting of the POM is lower than that of AC.
The reason is probably due to the presence of modifier species that
are mainly fixed on the micropore entrances and walls, which block
temperature. The PW Zn@AC was separated from the reaction
11
mixture by filtration. The catalyst was then thoroughly washed with
CH CN and acetone followed by drying in vacuum at room temper-
3
[43]
ature. It was then used in further oxidation reaction.
the access of N molecules into the micropores to a certain extent.
2
Catalytic studies
[
37,44,45]
Following our previous studies on oxidative catalysis,
new
heterogeneous catalysts based on transition metal-substituted
POMs on AC were synthesized. The oxidation of benzyl alcohol
with hydrogen peroxide under reflux conditions was chosen as
a model reaction in order to test the catalytic activity of POM@AC
catalysts. The catalytic activity of some other transition metal-
substituted POMs was checked and the results show that
PW11Zn@AC has the best catalytic activity. The oxidation reaction
2 3
in the presence of ZnCl , AC and H PW12O40 as blank catalytic ex-
periments was also performed, resulting in very low conversions
Figure 1. FT-IR spectra of AC, PW11Zn and PW11Zn@AC.
(Table 4, entries 10–12).
wileyonlinelibrary.com/journal/aoc
Copyright © 2015 John Wiley & Sons, Ltd.
Appl. Organometal. Chem. 2015, 29, 561–565

PW Zn@AC-catalysed alcohol oxidation by H O
2 2
11
Table 1. Effect of various solvents in the oxidation of benzyl alcohol
Table 2. Oxidation of various alcohols with hydrogen peroxide
catalysed by PW11Zn@AC
a
a
with H O
2 2
b
Entry
Solvent
CN
Yield (%)
1
2
3
4
5
6
7
8
9
CH
THF
CHCl
n-C
CH
3
100
65
76
5
b
ꢀ1 c
Entry
Alcohol
CH OH
Time (min)
TOF (h
)
3
1
2
3
4
5
6
7
8
9
10
C
6
H
5
2
45
35
267
H
6 14
2-MeC
4-MeC
6
H
H
4
CH
CH
2
OH
OH
343
480
343
480
171
67
3
C(O)OC
2
H
5
54
57
53
56
72
67
6
4
2
25
2
H O
2-MeOC
4-MeOC
3-MeOC
2-O NC
4-O NC
4-BrC
4-FC
4-ClC
2,4-ClC
4-HOC
3-Br-2-HOC
6
H
H
H
4
4
4
CH
CH
CH
2
OH
35
DMF
6
2
OH
OH
25
DMSO
6
2
70
CH
3
OH
OH
10
C
2
H
5
2
6
H
4
CH
CH
CH
CH OH
CH OH
CH OH
CH OH
CH
2
OH
180
240
50
2
6
H
4
2
OH
50
a
2 2
Reaction conditions: benzyl alcohol (1 mmol), catalyst (5 μmol), H O
6
H
4
2
OH
240
480
343
133
240
480
100
171
67
b(1 ml), solvent (3 ml) at reflux in 45 min.
6
H
4
2
25
Yields refer to GC yields.
1
1
2
6
H
4
2
35
1
6
H
3
2
90
In the exploratory experiments, the effect of various solvents was
examined using benzyl alcohol. The results (Table 1) show that the
reaction in acetonitrile gives the highest conversion and selectivity
towards aldehyde. Lower catalytic activities are observed using
other solvents.
13
14
15
16
17
18
19
6
H
4
2
50
H
6 4
2
OH
25
C
C
6
H
11OH
120
70
6
H
5 2
CHCHCH OH
n-C
n-C
CH
7
H15OH
180
180
90
Various amounts of PW11Zn@AC in the oxidation of benzyl al-
cohol were investigated by changing the catalyst amounts from
6
H13OH
67
2
2
CHCH OH
133
0.1 to 0.5g. Results show that the conversion of benzyl alcohol
a
2 2
Reaction conditions: alcohol (1 mmol), catalyst (5 μmol), 30% H O
is increased on increasing the catalyst amount. The maximal con-
version (ca 100%) is achieved when 0.2 g of PW11Zn@AC is used.
Higher amounts of PW11Zn@AC cause a decrease in aldehyde se-
lectivity. The amount of hydrogen peroxide, as one of the factors
influencing the oxidation of benzyl alcohol into benzaldehyde,
was also investigated. The results are shown in Fig. 2. It can be
seen that the conversion of benzyl alcohol is increased on in-
(
1 ml), CH
3
CN (3 ml) at reflux.
b
c
Yields are quantitative and refer to GC yields.
Turnover frequency.
(
Table 2, entries 2–6). Nitrobenzyl alcohols, which have an
creasing the molar ratio of H O to benzyl alcohol. Complete con-
2
2
electron-withdrawing group, are oxidized into the corresponding
aldehydes in longer times compared to other substrates with
electron-donating groups (Table 2, entries 7 and 8). In previous
studies, it was mentioned that electron-rich arenes with electron-
donating substituents show shorter oxidation times whereas times
for electron-withdrawing groups are longer. Halogen-containing
substrates in para position take part in the oxidation reaction giving
high yields (Table 2, entries 9–11). The oxidation of p-hydroxybenzyl
alcohol was also carried out with high selectivity and without oxida-
tion of hydroxyl group. The corresponding aldehyde is the only re-
action product (Table 2, entry 13). In view of the fact that the
oxidation of aliphatic alcohols is much more difficult than that of
benzylic ones, other interesting results are obtained by conversion
of aliphatic alcohols. In this regard, the oxidation of cyclohexanol,
version of benzyl alcohol is obtained using about 10 mmol of
0% H O . Higher amounts of H O decrease the selectivity for
3
2
2
2 2
benzaldehyde.
After obtaining the best conditions (0.2 g of PW Zn@AC catalyst,
11
[
51]
1
0 mmol of H O and CH CN as solvent), the reaction of other sub-
2 2 3
strates was also studied (Table 2). The time courses of PW Zn,
11
PW Zn@AC and AC under these reaction conditions are shown
11
in Fig. 3.
Various organic substrates containing electron-donating groups,
such as p-methoxybenzyl alcohol and p-methylbenzyl alcohol, are
converted into the corresponding aldehydes with 99% selectivity
1-hexanol and 1-heptanol into the corresponding ketones takes
place in slightly longer times (Table 2, entries 15, 17 and 18). The ox-
idation of cinnamyl alcohol and 1-propenol gives corresponding
aldehydes without any oxidation of C¼C double bond (Table 2, en-
tries 16 and 19).
It was postulated that the oxidation mechanism for POM
catalysts involves oxo- and peroxometal intermediates by transition
[
52,53]
metal-substituted and addenda atoms.
POMs, it was found that the favoured reaction path is heterolytic
cleavage of O–O bond.
For Zn-substituted
[44]
The stability of the catalyst, very low leaching of the active
component, heterogeneity of the catalyst under reaction condi-
tions and catalyst recyclability are important points that should
be addressed in the oxidation processes over the PW11Zn@AC
Figure 2. Effect of amount of hydrogen peroxide in the oxidation of benzyl
alcohol with PW11Zn@AC.
Appl. Organometal. Chem. 2015, 29, 561–565
Copyright © 2015 John Wiley & Sons, Ltd.
wileyonlinelibrary.com/journal/aoc

E. Assady et al.
catalyst. It is found that PW11Zn@AC does not lose its catalytic
activity/selectivity during at least five catalytic cycles in the oxida-
tion of benzyl alcohol with hydrogen peroxide (Table 3). More-
over, according to the FT-IR data, the structure of PW11Zn in
the supported catalyst is retained during the oxidation reaction
Table 4. Comparison of results for the oxidation of benzyl alcohol by
H O
2 2
in the presence of various POM catalysts
Entry
Catalyst Time (h) Conversion (%) Ref.
[
46]
47]
48]
15]
[49]
44]
50]
45]
1
2
3
4
5
6
7
8
9
Cs1.5
H
1.5PMo12
[SiW11ZnO40]ꢁ12H
[SbW
O
40/SiO
2
5
69.1
100
[
(Fig. 4).
Na
Na
6
2
O
2
[
In order to show the applicability and efficiency of our catalytic
9
9 33
O ]
2
94
84
94
100
93
80
100
13
8
[
system, results are compared with some of the recently reported
methods for the oxidation of benzyl alcohol by hydrogen perox-
ide. As is evident from Table 4, the proposed system yields
H
3
PMo12
[Zn (H O)
[bmim]
HPW-IL-SBA-15/5 m
(TBA) [PW11FeO39]/SiO
PW11Zn@AC
ZnCl
AC
O
40
5
1
]
0ꢀ
4
2
2
(PW
O )
9 34 2
8
[
5
[PW11ZnO39]ꢁ3H
2
O
1.15
6
[
[
4
2
2
0.75
0.75
0.75
0.75
—
—
—
—
10
11
12
2
3
H PW12
O
40
21
superior results in comparison to most of the other methods.
Additionally, our catalytic system has very good reusability for
this reaction.
Conclusions
A novel and efficient procedure for the oxidation of various alcohols
with hydrogen peroxide has been developed using PW Zn@AC as
Figure 3. Conversion–time curves for oxidation of benzyl alcohol with
11
PW11Zn, PW11Zn@AC and AC. Reaction conditions: benzyl alcohol
a cheap, effective and recyclable catalyst. This catalytic system has
been applied for the oxidation of various alcohols into the corre-
sponding carbonyl compounds with good to excellent yields. The
PW11Zn@AC catalyst could be reused for at least five runs with
consistent activity and selectivity.
(
1 mmol), PW11Zn and PW11Zn@AC (5 μmol) or AC (2 g), 30% H
O
2 2
(10 ml)
at reflux in acetonitrile (3 ml).
a
Table 3. Reusability of PW11Zn@AC in the oxidation of benzyl alcohol
b
Acknowledgments
Run
Yield (%)
Support for this research by the University of Isfahan is
acknowledged.
1
2
3
4
5
99
99
99
98
98
References
a
Reaction conditions: benzyl alcohol (1 mmol), catalyst (5 μmol), H
b(1 ml), 45 min, CH CN (3 ml) at reflux.
Yields refer to GC yields.
O
2 2
[1] S. Furukawa, A. Tamura, T. Shishido, K. Teramura, T. Tanaka, Appl. Catal.
B 2011, 110, 216.
[2] M. Hudlick, Oxidations in Organic Chemistry, American Chemical
3
Society, Washington, DC, 1990.
[
[
3] X. Wang, G. Wu, N. Guan, L. Li, Appl. Catal. B 2012, 115–116, 7.
4] S. V. Ley, A. Madin, in Comprehensive Organic Synthesis, Vol. 3 (Eds: B. M.
Trost, I. Fleming, S. V. Ley), Pergamon, Oxford, 1991, pp. 251–289.
5] G. Brink, I. W. C. E. Arends, R. A. Sheldon, Science 2000, 287, 1636.
[
[6] I. M. Mbomekalle, B. Keita, L. Nadjo, P. Berthet, K. I. Hardcastle, C. L. Hill,
T. M. Anderson, Inorg. Chem. 2003, 42, 1163.
[
7] K. Sugahara, S. Kuzuya, T. Hirano, K. Kamata, N. Mizuno, Inorg. Chem.
012, 51, 7932.
8] K. Kamata, K. Yonehara, Y. Sumida, K. Yamaguchi, S. Hikichi, N. Mizuno,
Science 2003, 300, 964.
2
[
[9] X. Xue, W. Zhao, B. Ma, Y. Ding, Catal. Commun. 2012, 29, 73.
[
[
[
[
[
10] S. Pathan, A. Patel, Appl. Catal. A 2013, 459, 59.
11] N. Mizuno, K. Yamaguchi, K. Kamata, Coord. Chem. Rev. 2005, 249, 1944.
12] N. Mizuno, M. Misono, Chem. Rev. 1998, 98, 199.
13] M. Misono, Chem. Commun. 2001, 1141.
14] C. Yang, Q. Jin, H. Zhang, J. Liao, J. Zhu, B. Yu, J. Deng, Green Chem.
2
009, 11, 1401.
15] P. Tundo, G. P. Romanelli, P. G. Vazquez, F. Arico, Catal. Commun. 2010,
1, 1181.
[
1
[
[
16] G. Absillis, T. N. Parac-Vogt, Inorg. Chem. 2012, 51, 9902.
17] K. Kamata, K. Yonehara, Y. Nakagawa, K. Uehara, N. Mizuno, Nat. Chem.
2010, 2, 478.
Figure 4. FT-IR spectra of PW11Zn@AC recovered in runs 1, 3 and 5.
wileyonlinelibrary.com/journal/aoc
Copyright © 2015 John Wiley & Sons, Ltd.
Appl. Organometal. Chem. 2015, 29, 561–565

PW Zn@AC-catalysed alcohol oxidation by H O
2 2
11
[
[
18] M. Bonchio, A. Sartorel, P. Mirò, M. Carraro, S. Berardi, O. Bortolini,
A. Bagno, C. Bo, Chem. Eur. J. 2014, 20, 10932.
19] M. Carraro, B. Bassil, A. Sorarù, S. Berardi, A. Suchopar, U. Kortz,
M. Bonchio, Chem. Commun. 2013, 49, 7914.
[39] C. Sepúlveda, R. García, P. Reyes, I. T. Ghampson, J. L. G. Fierro,
D. Laurenti, M. Vrinat, N. Escalon, Appl. Catal. A 2014, 475, 427.
[40] J. Figueiredo, M. Pereira, M. Freitas, J. Orfao, Carbon 1999, 37, 1379.
[41] G. Ramirez, R. Cuevas, Appl. Catal. B 1990, 57, 223.
[42] J. Alcañiz-Monge, G. Trautwein, S. Parres-Esclapez, J. A. Maciá-Agulló,
Micropor. Mesopor. Mater. 2008, 115, 440.
[20] C. L. Hill, C. M. Prosser-McCartha, Coord. Chem. Rev. 1995, 43, 407.
[21] X. Zhang, K. Sasaki, C. L. Hill, J. Am. Chem. Soc. 1996, 118, 4809.
[22] S. J. Zhang, S. Gao, Z. W. Xi, J. Xu, Catal. Commun. 2007, 8, 531.
[23] A. Khenkin, R. Neumann, Adv. Synth. Catal. 2002, 344, 1017.
[24] N. M. Okun, T. M. Anderson, C. L. Hill, J. Am. Chem. Soc. 2003, 125, 3194.
[25] W. Kuang, A. Rives, M. Fournier, R. Hubaut, Appl. Catal. A 2003, 250, 221.
[26] X. M. Yan, G. S. Su, L. Xiong, J. Fuel, Chem. Technol. 2009, 37, 318.
[27] A. Griboval, P. Blanchard, E. Payen, M. Fournier, I. L. Dubois, J. R. Bernard,
Appl. Catal. A 2001, 217, 173.
[43] X.-L. Lio, J.-X. Guo, Y.-H. Chu, D.-M. Luo, H.-Q. Yin, M.-C. Sun, R. Yavuz,
Fuel 2014, 123, 93.
[44] Z. Nadealian, V. Mirkhani, B. Yadollahi, M. Moghadam, S. Tangestaninejad,
I. Mohammadpoor-Baltork, J. Coord. Chem. 2012, 65, 1071.
[45] M. R. Farsani, B. Yadollahi, J. Mol. Catal. A 2014, 392, 8.
[46] G. Peng, Y. Wang, C. Hu, E. Wang, S. Feng, Y. Zhou, H. Ding, Y. Liu, Appl.
Catal. A 2001, 218, 91.
[
[
[
28] I. V. Kozhevnikov, Catal. Lett. 1994, 27, 187.
29] S. Damyanova, J. L. G. Fierro, Chem. Mater. 1998, 10, 871.
30] S. Damyanova, L. M. Gómez, M. A. Bañares, J. L. G. Fierro, Chem. Mater.
[47] J. Wang, L. Yan, G. Li, X. Wang, Y. Ding, J. Suo, Tetrahedron Lett. 2005, 46,
7023.
[48] R. H. Ingle, N. K. Kala Raj, P. Manikandan, J. Mol. Catal. A 2007, 262, 52.
[49] Y. Ding, W. Zhao, B. Ma, W. Qiu, Can. J. Chem. 2011, 89, 13.
[50] H. Zhao, L. Zeng, Y. Li, C. Liu, B. Hou, D. Wu, N. Feng, A. Zheng, X. Xie,
S. Su, N. Yu, Micropor. Mesopor. Mater. 2013, 172, 67.
[51] K. P. Peterson, R. C. Larock, J. Org. Chem. 1998, 63, 3185.
[52] N. K. Kala Raj, A. V. Ramaswamy, P. Manikandan, J. Mol. Catal. A 2005,
227, 37.
2
000, 12, 501.
[
[
[
31] P. A. Jalil, M. A. Al-Daous, A. R. A. Al-Arfaj, A. M. Al-Amer, J. Beltramini,
S. A. I. Barri, Appl. Catal. A 2001, 207, 159.
32] F. Marme, G. Coudurier, J. C. Védrine, Micropor. Mesopor. Mater. 1998,
22, 151.
33] S. Sumimoto, C. Tanaka, S. T. Yamaguchi, Y. Ichihashi, S. Nishiyama,
S. Tsuruya, Ind. Eng. Chem. Res. 2006, 45, 7444.
[53] Y. Liu, K. Murata, M. Inaba, Catal. Commun. 2005, 6, 679.
[34] I. V. Kozhevnikov, Chem. Rev. 1998, 98, 171.
[35] J. Xiao, L. Wu, Y. Wu, B. Liu, L. Dai, Z. Li, Q. Xia, H. Xi, Appl. Energy 2014,
1
13, 78.
36] H. Hamidi, E. Shams, B. Yadollahi, F. K. Esfahani, Electrochim. Acta 2009,
4, 3495.
Supporting information
[
5
Additional supporting information may be found in the online ver-
sion of this article at the publisher’s web site.
[
[
37] H. Danafar, B. Yadollahi, Catal. Commun. 2009, 10, 842.
38] B. J. S. Johnson, A. Stein, Inorg. Chem. 2001, 40, 801.
Appl. Organometal. Chem. 2015, 29, 561–565
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