Synthesis of MCM-41-supported Mercapto and Vinyl Platinum Complex Catalyst for Hydrosilylation

Article abstract of DOI:10.1080/10426507.2015.1012202

(Chemical Equation Presented). A mesoporous crystalline material (MCM-41)-supported mercapto and vinyl platinum complex [MCM-41-(SH-Pt)-(Vi-Pt)] was prepared and characterized by Fourier Transform-Infrared spectroscopy, thermogravimetry, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The catalytic activity of MCM-41-(SH-Pt)-(Vi-Pt) was evaluated through the hydrosilylation of styrene with methyldiethoxysilane. MCM-41-(SH-Pt)-(Vi-Pt) shows superior activity for hydrosilylation compared with MCM-41-Vi-Pt and MCM-41-SH-Pt respectively, but the selectivity of three catalysts is almost the same. The catalyst MCM-41-(SH-Pt)-(Vi-Pt) could efficiently be recovered by a simple filtration and reused in four consecutive cycles without significant loss of catalytic activity and selectivity.

Full text of DOI:10.1080/10426507.2015.1012202

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Phosphorus, Sulfur, and Silicon and the Related
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Synthesis of MCM-41-supported Mercapto and Vinyl
Platinum Complex Catalyst for Hydrosilylation
ab
a
a
Zhigang Ye , Hongxin Shi & Haimin Shen
a
College of Chemical Engineering Zhejiang University of Technology Hangzhou 310032,
China
b
Institute of Chemistry & Chemical Engineering, Jiujiang University Jiujiang 332005; China.
Accepted author version posted online: 11 Feb 2015.
Click for updates
To cite this article: Zhigang Ye, Hongxin Shi & Haimin Shen (2015): Synthesis of MCM-41-supported Mercapto and
Vinyl Platinum Complex Catalyst for Hydrosilylation, Phosphorus, Sulfur, and Silicon and the Related Elements, DOI:
10.1080/10426507.2015.1012202
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ACCEPTED MANUSCRIPT
Synthesis of MCM-41-supported Mercapto and Vinyl Platinum Complex
Catalyst for Hydrosilylation
a,b
a
a
Zhigang Ye
Hongxin Shi
Haimin Shen
a
College of Chemical Engineering，Zhejiang University of Technology，Hangzhou 310032,
China
b
Institute of Chemistry & Chemical Engineering , Jiujiang University；Jiujiang 332005; China.
E-mail: yzg9988@sohu.com
Abstract
A mesoporous crystalline material (MCM-41) supported mercapto and vinyl platinum
complex [MCM-41-(SH-Pt)-(Vi-Pt)] was prepared and characterized by Fourier Transform
infrared spectroscopy (FT-IR), thermogravimety (TG), transmission electron microscopy (TEM),
X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The catalytic activity of
MCM-41-(SH-Pt)-(Vi-Pt) was evaluated through the hydrosilylation of styrene with
methyldiethoxysilane. MCM-41-(SH-Pt)-(Vi-Pt) shows superior activity for hydrosilylation
compared with MCM-41-Vi-Pt and MCM-41-SH-Pt respectively, but the selectivity of three
catalysts is almost the same. The catalyst MCM-41-(SH-Pt)-(Vi-Pt) could efficiently be
recovered by a simple filtration and reused in four consecutive cycles without significant loss of
the catalytic activity and selectivity.
1
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O
O Si
O
O Si
O
OH
OH
(
EtO) Si(CH ) SH
3 2 3
H O, toluene
2
+
(
EtO) SiCH CH2
reflux
3
O
OH
OH
O Si CH CH CH SH
2
2
2
O
O Si CH CH CH SH
2
2
2
O
MCM-41
MCM-41-SH-Vi
O
O Si
O
Pt
O Si
O
H Pt Cl .6H O , NaHCO , C H OH
2
6
2
3
2 5
K Pt Cl , acetone
2
4
O
O Si CH CH CH SH
2
2
2
O
PtCl2
O Si CH CH CH SH
2
2
2
O
MCM-41-(SH-Pt)-(Vi-Pt)
Keywords: MCM-41; heterogeneous catalyst; hydrosilylation; platinum; alkoxysilane
2
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INTRODUCTION
Hydrosilylation, Eq(1), is a term which describes the addition reaction of organosilicon
compounds having one or more Si-H bonds to unsaturated organic molecules. Hydrosilylation is
1
-5
one of the most important Si-C bond formation reactions in organosilicon chemistry , and
particularly widely used in the silicone industry for preparation of silicon monomers containing
6
,7
functional groups and for cross-linking silicon polymers .
cat
R SiH + CH
CHR'
R SiCH CH R'
(1)
3
2
3
2
2
8
-10
Many transition metal complexes which are immobilized on inorganic substrates
or
11,12
organic polymers
by some functional linkages are known to be catalysts for
1
3
hydrosilylation.
Many types of inorganic and organic solid materials with high surface areas can be used as
support materials including graphite, zeolite, Al , SiO , polyamide and polystyrene. Recently,
2
O
3
2
mesoporous silicate materials such as MCM-41 and SBA-15 which also have large surface areas,
high mechanical strengths, heat and chemical stabilities have been attracting widespread
attention as new materials for catalysts and catalyst supports.
Carrier-supported catalysts are used more and more widely because they possess the
advantages of high activity and selectivity of homogeneous catalysts, but are also easy
recoverability of heterogeneous catalysts.
Recently, Chauhan et al. reported the hydrosilylation of terminal and internal alkynes with
3
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1
4
chlorosilanes, alkylsilanes and alkoxysilanes catalyzed by platinum on carbon. Mao et al.
synthesized a silica-supported Karstedt (Pt)-type catalyst derived from Karstedt’s catalyst and
1
5
applied it to the hydrosilylation of styrene with Me PhSiH. Cai et al. reported the synthesis of a
2
mercapto platinum complex supported on MCM-41 for the hydrosilylation of olefins with
triethoxysilane and found that the complex is an efficient catalyst for hydrosilylation and can be
1
6
reused five times without significant loss of activity. Yang et al. reported the synthesis of a
glass fiber-supported Pt complex catalyst and its catalytic behaviors in the hydrosilylation of
1
7
styrene with triethylsilane.
However, to the best of our knowledge, no hydrosilylation of olefins with
methyldiethoxysilane catalyzed by MCM-41-(SH-Pt)-(Vi-Pt) has been reported so far.
Herein we report the preparation of a heterogeneous catalyst, MCM-41-(SH-Pt)- (Vi-Pt),
which contains two different Pt-based active sites and its performance for the hydrosilylation of
styrene with methyldiethoxysilane. The novel complex could be easily prepared from
commercially available vinyltriethoxysilane and γ-mercapto- propyltriethoxysilane via
immobilization on MCM-41, followed by reaction with chloroplatinic acid and potassium
tetrachloroplatinate. The preparation of the MCM-41-(SH-Pt)-(Vi-Pt) complex is outlined below
(
Scheme 1).
RESULTS AND DISCUSSION
Structure of MCM-41-(SH-Pt)-(Vi-Pt) Complex
4
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-1
The FT-IR spectra of three samples are shown in Figure 1. A broad peak at 3413 cm is
attributed to the O-H stretching vibration derived from the isolated hydroxyl group on the silica
surface (Figure 1a). Obviously, after siloxane modification, the O-H vibration peak decreases
distinctly which provides evidence of the grafting of vinyltriethoxysilane and
γ-mercaptopropyltriethoxysilane (Figure 1, b and c). Meanwhile, the characteristic vibration
-
1
peaks (2925 and 2858 cm ) of the new complex come up, which are attributed to the asymmetric
stretching vibration and symmetric stretching vibration of C—H of -CH - group, respectively
Figure 1, b and c). Weak peaks at 1411 cm is attributed to the C=C—H scissor vibration.
2
-1
(
Based on the above results, it is suggested that vinyltriethoxysilane and
γ-mercaptopropyltriethoxysilane are bonded to MCM-41.
[
INSERT
FIGURE 1]
TG was used to confirm the organic content of the MCM-41-(SH-Pt)-(Vi-Pt) complex and
evaluate its thermal stability. TG and DTG curves of three samples are shown in Figure 2. For
MCM-41, there are two weight losses around 100°C and in the 120-550°C range, corresponding
to the losses of physisorbed water (ca.6.5 wt%) and dehydroxylation, respectively.
[
INSERT
FIGURE 2]
For other two samples, TG and DTG curves show three major weight losses. The first
weight loss is due to desorption of water (3 wt%) around 100°C. The second stage in the
1
20-350°C range, corresponding to a weight loss of 12%, is due to the decomposition of the
5
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alkoxysilane. Finally, the weight loss of 3.5% (MCM-41-SH-Vi) and 4%
[
MCM-41-(SH-Pt)-(Vi-Pt)] from 450 to 700 °C are due to dehydroxylation of surface silanol
groups. In addition, It may be coexist that the decompositions of Pt (II) complex and
dehydroxylation above 550°C for the MCM-41-(SH-Pt)-(Vi-Pt). Up to 700°C the total weight
loss of three samples are 11%, 18% and 19%, respectively.
The XRD spectra of three samples are shown in Figure 3, in which three typical peaks of a
hexagonal-ordered array can be indexed as (100), (110) and (200) Bragg reflections, respectively.
But the peak height of MCM-41-(SH-Pt)-(Vi-Pt) is remarkably lower than the peak heights of
other two samples. The reduction in diffraction intensity can be explained by the presence of
alkoxysilanes and platinum complexes covalently grafted inside the pore channels of the
MCM-41 samples, which results in the partial loss of structural integrity. However, the presence
of the peak (100) in MCM-41-(SH-Pt)-(Vi-Pt) catalyst indicates that the mesoporous structure is
preserved in the whole process of catalyst preparation.
[
INSERT
FIGURE 3]
The presence of the mesoporous structure of three samples is also observed by TEM
analysis, in which the typical hexagonal porosity of the MCM-41 matrix can be seen (Figure
4
).TEM of MCM-41 sample shows the regular hexagonal array of uniform channels that is
characteristic of MCM-41. A uniform coating was observed after treated by alkoxysilanes, while
the pore channels are clearly visible. The coating thickness of the MCM-41-(SH-Pt)-(Vi-Pt) is
6
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thicker than that of MCM-41-SH-Vi. Furthermore, TEM images (Figure 4B) reveal that the
formed coating is completely penetrated into mesopores.
[
INSERT
, MCM-41-SH-Vi and MCM-41-SH-Vi-Pt are illustrated in Figure 5.
It clearly shows that the binding energy (BE) of Cl2p of K PtCl is similar to that of
MCM-41-(SH-Pt)-(Vi-Pt), and the binding energies of Si2p and O1S of
INSERT FIGURE 5]
MCM-41-SH-Vi are similar to those of MCM-41-SH-Vi-Pt (Table 1).
Furthermore, the binding energy of Pt4f7/2 in is 0.4eV less than in K
FIGURE 4]
The XPS spectra of K
2
PtCl
4
2
4
[
2
PtCl4, but 1.7eV bigger
than in Pt foil (Table 1). Compared with MCM-41-SH-Vi, the binding energy of S2p in
MCM-41-(SH-Pt)-(Vi-Pt) shifts negatively by 0.5eV toward higher energy (Table 1 ), suggesting
that the S atom donates partial electrons to Pt (II) and a stronger coordination of Pt (II) with the S
atoms on γ-mercaptopropyltriethoxysilane.
[
INSERT
TABLE 1]
Activity and Selectivity
MCM-41-Vi-Pt and MCM-41-SH-Pt catalysts are synthesized by a tethering procedure as
1
5,16
reported in the literature,
in order to compare the activity and selectivity of MCM-41-Vi-Pt,
MCM-41-SH-Pt and MCM-41-(SH-Pt) -(Vi-Pt) catalysts. The preparation of the carriers and
7
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catalysts was showed in Table 2 and 3. In this work, the activity and selectivity of three catalysts
were compared for the hydrosilylation of styrene with methyldiethoxysilane.
[
INSERT
INSERT
TABLE 2]
TABLE3]
[
Figure 6(A) shows the total yields for the three catalyst series as a function of the reaction
time. It can be observed that the activity of MCM-41-(SH-Pt) - (Vi-Pt) is higher than that of the
other catalysts and without any induction period. The total yield is 99.1% for
o
MCM-41-(SH-Pt)-(Vi-Pt) catalyst at 60 C after 136 min, but only 92.7% for MCM-41-Vi-Pt
o
o
catalyst at 60 C after 386 min and 97.8% for MCM-41-SH-Pt catalyst at 60 C after 197 min.
However, the selectivity (β/α) of three catalysts is almost same, the selectivity (β/α) of
MCM-41-Vi-Pt, MCM-41-SH-Pt and MCM-41-(SH-Pt)-(Vi-Pt) catalysts is 65.9/34.1,62.9/37.1
and 64.2/35.8, respectively.
The effect of the reaction temperature on the hydrosilylation yield catalyzed by
o
MCM-41-(SH-Pt)-(Vi-Pt) was shown in Figure 6(B). The reactions were performed at 40 C,
o
o
o
5
0 C, 60 C and 70 C, respectively. As seen from Figure 6(B), the reaction rate and yields
significantly increase with increases of the reaction temperature. The hydrosilylation yields
o
o
increase from 97.6% to 99.1% as the temperature is raised from 40 C to 70 C. The results show
that yield is enhanced by increasing the reaction temperature due to the increasing conversion.
Furthermore, it was found the selectivity (β/α) improved at higher reaction temperatures.
8
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The influence of MCM-41-(SH-Pt)-(Vi-Pt) dosage on the hydrosilylation yield was then
evaluated, the experimental results were showed in Figure 6(C). The yields increase rapidly with
increasing the catalyst dosage from 0.03g to 0.05g, but the yields are almost same when the
catalyst dosage increase from 0.05g to 0.07g and 0.05g catalyst give the best result with 98.8%
yield after160 min.
[
INSERT
FIGURE 6]
The Recyclability of the MCM-41-(SH-Pt)-(Vi-Pt)
For a heterogeneous transition-metal catalyst, it is very important to examine its ease
separation and good recoverability. To determine the durability and recyclability,
MCM-41-(SH-Pt)-(Vi-Pt) was separated by a centrifuge after each run of hydrosilylation and the
clear liquid is decanted slowly. The catalyst was washed thoroughly with ethanol and diethyl
ether, respectively, followed by vacuum drying at 80°C for 5h. Then, the catalyst can be reused
directly in the next run under the same reaction condition. As observed in Table 4, the yields of
addition products slowly decrease during subsequent runs, but the selectivity (β/α) slowly
increases.
[
INSERT
TABLE 4]
CONCLUSION
In summary, we have described a novel MCM-41-(SH-Pt)-(Vi-Pt) catalyst whose
preparation is simple and convenient. The catalyst has high activity for the hydrosilylation of
9
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styrene with methyldiethoxysilane. In terms of recyclability, the catalyst could has been
efficiently recovered by a simple filtration and reused in four consecutive cycles without
significant loss in the catalytic activity. The high catalytic activity, excellent reusability and the
easy accessibility of the complex make it become a high attractive heterogeneous platinum
catalyst for the hydrosilylation of alkenes and alkynes with alkylsilanes and alkoxysilanes.
EXPERIMENTAL
Materials and Methods
The mesoporous material MCM-41 was obtained from Henan Nanyang Huanyu
Molecular Sieve Co., Ltd. Vinyltriethoxysilane, γ-mercaptopropyltriethoxysilae and
methyldiethoxysilane were obtained from Hubei WD Silicone Co., Ltd. Chloroplatinic acid and
potassium tetrachloroplatinate were purchased from Shanghai Jiuling Fine Chemical Co., Ltd.
1
IR spectra were obtained using a Thermo Nicolet 6700 instrument. H NMR spectra were
recorded on a Bruker AVANCE III (500MHz) spectrometer with TMS as an internal standard in
CDCl
3
as solvent. X-ray photoelectron spectroscopy (XPS) was obtained on a KRATOS AXIS
ULTRA (DLD) spectrometer. Thermogravimetric analysis (TGA) was performed on a
o
-1
PerkinElmer Diamond TG/DTA thermal analyzer system at a heating rate of 10 C min in
nitrogen. Platinum content was determined with inductively coupled plasma atom emission
10
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atomscan16 (ICP-AES,TJA Corporation). Powder XRD patterns were measured on a X'Pert Pro
X-ray diffractometer. The TEM observation was performed at 200 kV using a Tecnai G2 F30
microscope with a LaB6 filament. The hydrosilylation products were analyzed with a GC-14B
gas chromatograph (GC), equipped with a FID detector and a DB-5 capillary column
(
30m×0.25mm). Nitrogen (flow rate, 40 mL/min) was used as the carrier gas. The injector
o
o
temperature and was 250 C and the FID temperature was 300 C.The oven temperature program
o
o
o
was 100 C for 1 min, increased by 10 C/min to 250 C and was maintained for 1 min.
Preparation of MCM-41-SH-Vi
Vinyltriethoxysilane (2.5g, 13.1mmol), γ-mercaptopropyltriethoxysilane (2.5g, 10.5mmol),
MCM-41 (6.0g) and dry toluene (140mL) were placed into a three-necked flask equipped with a
magnetic stirrer, reflux condenser and gas inlet adapter. The mixture was stirred and refluxed for
o
2
4
4h at 80 C. Distilled water (30mL) was added and the mixture was refluxed for an additional
8h. After being cooled to room temperature, the mixture was filtered, then washed with acetone
o
(
3×30mL) and distilled water (3×30mL), followed by dried at 150 C/26pa in vacuum oven for
5h to give 7.63 g yellow MCM-41-SH-Vi.
Preparation of MCM-41-(SH-Pt)-(Vi-Pt)
MCM-41-SH-Vi (3.0g) and sodium hydrogen carbonate (0.075g, 0.9mmol) were added to a
solution of K
2
PtCl
4
(0.15g, 0.36mmol) and H
2
PtCl
6
·6H O (0.15g, 0.29mmol) in a mixture of
2
acetone (70mL) and ethanol (70mL).The mixture was refluxed under a nitrogen atmosphere for
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72h. The solid product was filtered by suction, then washed with acetone (3×30mL), distilled
o
water (3×30mL) and ethanol (3×30mL) successively and dried at 70 C/26pa for 5h to give 3.06g
MCM-41-(SH-Pt)-(Vi-Pt) catalyst.
Hydrosilylation of Styrene with Methyldiethoxysilane
A
mixture of styrene (30.5mmol), methyldiethoxysilane (30.5mmol) and
o
MCM-41-(SH-Pt)-(Vi-Pt) (0.05g) was stirred under nitrogen in an oil bath at 50 C for 4h. The
1
reaction progress was followed by GC and the products were characterized by FT-IR and H
NMR. The hydrosilylation products were found to be α-addition isomer and β-addition isomer,
so the yields were the total yields of the two isomers. The relative molar rations of the
products were determined by the chromatographic peak areas of GC and corresponding
response factors.
CH OEt
OEt
OEt
3
MCM-41-(SH-Pt)-(Vi-Pt)
CH CH2
SiH
CH Si CH3
Si CH3
OEt
+ CH3
+
CH2 CH2
OEt
OEt
α-isomer
β-isomer
-
1
α-isomer: FT-IR (cm ): 3061.2, 3025.4, 1600.6, 1492.7, 1451.7 (C
875.4 (-CH -); 2972, 1390.2 (-CH ); 950.4, 1166.1 (Si-OCH CH ); 1106.6, 1081.9 (Si-O);
257.3, 763.5(Si-CH ). 1HNMR δ(CDCl , pm): 7.20(5H,C -), 1.45[3H,C CH(CH )-],
.35[1H,C CH(CH )-], 0.0417(3H,Si-CH ), 3.70(4H, CH CH O-), 1.20(6H, CH O-).
β-isomer: FT-IR (cm ): 3062.7, 3026.8, 1603.2, 1495.2, 1453.1. (C -); 2925.2,
879.9, (-CH -); 2972.4, 1390.2 (-CH ); 952.0, 1166.7 (Si-OCH CH
6
H
5
-); 2926.9,
2
1
2
2
3
2
3
3
3
6
H
5
6
H
5
3
6
H
5
3
3
3
2
3
5
CH
2
-1
6
H
2
2
3
2
3
); 1106.0, 1079.0 (Si-O);
12
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1
1
2
1
257.5, 767.4 (Si-CH
.75(3H,C CH CH -), 1.00(2H, C
.25(6H, CH CH O-).
3
).
H
NMR
δ(CDCl
3
,
ppm): 7.30(5H,C
6
H
5
-),
6
H
5
2
2
6
H
5
CH
2
CH -), 0.145(3H, Si-CH
2
3
), 3.80(4H,CH CH
3
2
O-),
3
2
13
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References
1
. Ojima, I.; Patai, S.; Rappaport, Z. The Chemistry of Organic Silicon Compounds, Vol. 2,
Wiley Interscience, New York, 1989, Chapter 25, pp.1479-1526.
2
. Pukhnarevich, V. B.; Lukevics, E.; Kopylova, L. I.; Voronkov, M. G. Perspectives of
Hydrosilylation, Institute of Organic Synthesis, Riga, 1992.
3
4
. Marciniec, B.; Blazejewska-chadyniak, P.; Kubicki, M. Can. J. Chem. 2003, 81, 1292-1298.
. Chauhan, M.; Hauck, B. J.; Keller, L. P.; Boudjouk, P. J. Organomet. Chem. 2002, 645,
1
-13.
5
6
7
. Tetykh, V. A.; Yanishpolskii, W.; Bereza, L.V.; Pesek, J. J.; Matyska, M. J. Therm. Anal.
Calorim. 2000, 62, 539-544.
. Noll, W. Chemistry and Technology of Silicones, Academic Press, New York, 1968, Chapter
5
, pp.190-245.
. Rich, J.; Cella, J.; Lewis, L.; Rubinsztajn, S.; Stein, J.; singh, N.; Wengrovius, J.
Kirk-Othmer Encyclopedia of Chemical Technology, Wiley, New York, 4th edn., 1996.
8
9
1
1
1
.
Onoe, T.; Iwamoto, S.; Inoue, M. Catal. Commun. 2007, 8, 701-706.
Marciniec, B. Coordin. Chem. Rev. 2005, 249, 2374-2390.
Corma, A.; Garcia, H. Chem. Rev. 2002, 102, 3837-3892.
.
0.
1. Corma, A.; Garcia, H.; Leyva, A. J. Catal. 2006, 240, 87-99.
2. Drake, R.; Sherrington, D.C.; Thomson, S. J. React. Funct. Polym. 2004, 60, 65-79.
14
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1
1
3. Tanabe, M.; Ito, D.; Osakada, K. Organometallics 2007, 26, 459-462.
4. Chauhan, M.; Hauck, B.J.; Keller, L.P.; Boudjouk, P. J. Organomet. Chem. 2002, 645,
1
-13.
1
1
1
5. Miao, Q.J.; Fang, Z. P.; Cai, G. P. Catal. Commun. 2003, 4, 637-639.
6. Hu, R.; Zha, L. F.; Cai, M. Catal. Commun. 2010, 11, 563-566.
7. Yang, H.T.; Fang, Z. P.; Fu, X.Y. Catal. Commun. 2008, 9, 1092-1095.
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Table 1
XPS data for Pt foil, K
2
PtCl , MCM-41-SH-Vi, MCM-41-(SH-Pt)-(Vi-Pt)
4
a
(
in eV)
a
The binding energies are referenced to C1s(284.6eV) and the energy differences were
determined with an accuracy of ±0.2eV.
Sample
Pt4f7/2
S
2p
Si2p
O
1s
Cl2p
K
1
2
PtCl
98.6
4
73.3
MCM-41-SH-Vi
MCM-41-SH-Vi-Pt
163.7
164.2
103.4
103.5
532.6
532.5
72.9
71.2
198.5
Pt foil
16
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Table 2
Preparation of MCM-41-SH, MCM-41-Vi and MCM-41-SH-Vi
reactant / g
Entry
carrier / g
1
MCM-41 (6.0)
(EtO)
3
SiCH=CH (5.0)
2
MCM-41-Vi (7.58)
2
MCM-41
(6.0)
(EtO)
3
Si(CH
2
)
3
SH
(5.0)
MCM-41-SH (8.00)
3
MCM-41 (6.0)
(EtO)
3
Si(CH
2
)
3
SH (2.5) (EtO)
3
SiCH=CH (2.5)
2
MCM-41-SH-Vi (7.63)
17
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Table 3 Preparation of MCM-41-SH-Pt, MCM-41-Vi-Pt and MCM-41-(SH-Pt)-(Vi-Pt)
catalysts.
Entry
Reactant / g
Catalyst / g
Pt load / mg / g
1
5
2
1
3
1
MCM-41-Vi (3.0)
H
2
2
PtCl
6
(0.30)
(0.30)
MCM-41-Vi-Pt (3.02)
MCM-41-SH-Pt (3.04)
MCM-41-(SH-Pt)-
(Vi-Pt) (3.06)
.887*
2.205
8.331
MCM-41-SH (3.0)
MCM-41-(SH-Pt)-
K
PtCl
4
H
2
PtCl
6
(0.15)
(0.15)
(
Vi-Pt) (3.0)
K
2
PtCl
4
*The formation of platinum black was observed during the preparation of MCM-41-Vi-Pt
catalyst.
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Table 4
The recyclability of the MCM-41-(SH-Pt)-(Vi-Pt) catalyst
a
The relative molar rations of the products are measured by the area normalization method. X
i
=
f
i
A
i
/∑f ,Yield = X + X
i
A
i
α
β
Conditions: styrene 30.5 mmol, methyldiethoxysilane 30.5 mmol, MCM-41-(SH-Pt)-(Vi-Pt)
a
Cycle
t / h
3
Yield / %
98.6
Selectivity (β/α)
59.7/40.3
1
2
3
4
3
98.7
61.9/38.1
5
96.0
62.6/37.4
9
91.4
64.9/35.1
a
The relative molar rations of the products are measured by the area normalization method. X =
i
f
i
A
i
/∑f
i
A
i
,
Yield = X
α
+ X
β
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a
b
3413
1411
2925
c
1458
2858
Si-CH2-
1087
4
000
3000
2000
1000
-1
Wavenumber cm
Figure 1
FTIR spectra of (a) MCM-41, (b) MCM-41-SH-Vi and
c) MCM-41-(SH-Pt)-(Vi-Pt)
(
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DTG(MCM-41)
MCM-41
MCM-41-SH-Vi
MCM-41-SH-Vi-Pt
DTG(MCM-41-SH-Vi)
DTG(MCM-41-SH-Vi-Pt)
c
1.4
1.2
1.0
0.8
0.6
0.4
100
b
95
(A)
(B)
90
a
85
0.2
a
0
.0
b
c
80
-0.2
0
200
400
600
800
0
200
400
600
800
o
o
T ( C)
T ( C)
Figure 2
(A)TG and (B)DTG profile in N
2
of (a) MCM-41, (b) MCM-41-SH-Vi and (c)
MCM-41-(SH-Pt)-(Vi-Pt)
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(100)
4000
3000
2000
1000
0
a
b
(110)
c
(200)
2
3
4
5
6
2θ (degree)
Figure 3
XRD patterns of (a) MCM-41, (b) MCM-41-SH-Vi and
c) MCM-41-(SH-Pt)-(Vi-Pt)
(
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A
B
C
Figure 4
TEM micrographs of (A) MCM-41, (B) MCM-41-SH-Vi and
C) MCM-41-(SH-Pt)-(Vi-Pt)
(
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S2p
Pt 4f7/2
1600
1200
Pt 4f5/2
1
200
8
00
00
0
c
8
00
4
a
d
b
400
80
78
76
74
72
70
174
172
170
168
166
164
162
160
Binding Energy / eV
Binding Energy /eV
Figure 5
(
XPS spectra of (a) MCM-41-(SH-Pt)-(Vi-Pt), (b) K
2
PtCl ,
4
c) MCM-41-(SH-Pt)-(Vi-Pt) and (d) MCM-41-SH-Vi.
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1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
a
b
c
0
50
100
150
200
t (min)
250
300
350
400
(
A)
Figure 6 (A)
MCM-41-SH-Pt and (c) MCM-41- Vi-Pt Conditions: styrene 30.5 mmol, methyldiethoxysilane
0.5 mmol, catalyst 0.05g.
The activity and Selectivity of the catalyst (a) MCM-41- (SH-Pt)-(Vi-Pt), (b)
3
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100
70°C
95
90
85
80
60°C
50°C
40°C
0
50
100
150
200
250
300
t (min)
(
B)
Figure 6 (B)
Effect of reaction temperature on the yield. Conditions: styrene 30.5 mmol,
methyldiethoxysilane 30.5 mmol, MCM-41-(SH-Pt)-(Vi-Pt) 0.05g
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100
80
60
40
20
0
0
0
.03g
.05g
0.07g
0
50
100
150
200
t (min)
(
C)
Figure 6 (C)
Effect of the amount of the catalyst on the yield. Conditions: styrene 30.5 mmol,
o
methyldiethoxysilane 30.5 mmol, MCM-41-(SH-Pt)-(Vi-Pt) 0.05g, temperature 50 C.
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O
O Si
O
O Si
O
OH
OH
(
EtO) Si(CH ) SH
3 2 3
H O, toluene
2
+
(
EtO) SiCH CH2
reflux
3
O
OH
OH
O Si CH CH CH SH
2
2
2
O
O Si CH CH CH SH
2
2
2
O
MCM-41
MCM-41-SH-Vi
O
O Si
O
Pt
O Si
O
H Pt Cl .6H O , NaHCO , C H OH
2
6
2
3
2 5
K Pt Cl , acetone
2
4
O
O Si CH CH CH SH
2
2
2
O
PtCl2
O Si CH CH CH SH
2
2
2
O
MCM-41-(SH-Pt)-(Vi-Pt)
Scheme 1 Preparation of MCM-41-(SH-Pt)-(Vi-Pt)
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