Synthesis of acid-base bifunctional mesoporous materials by oxidation and thermolysis

Article abstract of DOI:10.1016/j.materresbull.2011.02.006

A novel and efficient method has been developed for the synthesis of acid-base bifunctional catalyst SO₃H-MCM-41-NH₂. This method was achieved by co-condensation of tetraethylorthosilicate (TEOS), 3-mercaptopropyltrimethoxysilane (MPTMS) and (3-triethoxysilylpropyl) carbamicacid-1-methylcyclohexylester (3TAME) in the presence of cetyltrimethylammonium bromide (CTAB), followed by oxidation and then thermolysis to generate acidic site and basic site. X-ray diffraction (XRD) and transmission electron micrographs (TEM) show that the resultant materials keep mesoporous structure. Thermogravimetric analysis (TGA), X-ray photoelectron spectra (XPS), back titration, solid-state ¹³C CP/MAS NMR and solid-state ²⁹Si MAS NMR confirm that the organosiloxanes were condensed as a part of the silica framework. The bifunctional sample (SO ₃H-MCM-41-NH₂) containing amine and sulfonic acids exhibits excellent acid-basic properties, which make it possess high activity in aldol condensation reaction between acetone and various aldehydes.

Full text of DOI:10.1016/j.materresbull.2011.02.006

Materials Research Bulletin 46 (2011) 951–957
Contents lists available at ScienceDirect
Materials Research Bulletin
journal homepage: www.elsevier.com/locate/matresbu
Synthesis of acid–base bifunctional mesoporous materials by oxidation
and thermolysis
a,
Xiaofang Yu a, Yongcun Zou b, Shujie Wu a, Heng Liu a, Jingqi Guan a, , Qiubin Kan
*
*
a College of Chemistry, Jilin University, Jiefang Road 2519, Changchun 130023, PR China
b State Key Laboratory of Inoranic Synthesis and Preparative Chemistryg, College of Chemistry, Jilin University, Changchun 130012, PR China
A R T I C L E I N F O
A B S T R A C T
Article history:
A novel and efficient method has been developed for the synthesis of acid–base bifunctional catalyst
SO3H–MCM-41–NH2. This method was achieved by co-condensation of tetraethylorthosilicate (TEOS),
3-mercaptopropyltrimethoxysilane (MPTMS) and (3-triethoxysilylpropyl) carbamicacid-1-methylcy-
clohexylester (3TAME) in the presence of cetyltrimethylammonium bromide (CTAB), followed by
oxidation and then thermolysis to generate acidic site and basic site. X-ray diffraction (XRD) and
transmission electron micrographs (TEM) show that the resultant materials keep mesoporous structure.
Thermogravimetric analysis (TGA), X-ray photoelectron spectra (XPS), back titration, solid-state 13C CP/
MAS NMR and solid-state 29Si MAS NMR confirm that the organosiloxanes were condensed as a part of
the silica framework. The bifunctional sample (SO3H–MCM-41–NH2) containing amine and sulfonic
acids exhibits excellent acid-basic properties, which make it possess high activity in aldol condensation
reaction between acetone and various aldehydes.
Received 29 September 2010
Received in revised form 23 December 2010
Accepted 12 February 2011
Available online 18 February 2011
Keywords:
A. Structural materials
B. Chemical synthesis
C. X-ray diffraction
D. Catalytic properties
ß 2011 Elsevier Ltd. All rights reserved.
1. Introduction
Generally, these heterogeneous catalysts are prepared by co-
condensation or post-synthesis grafting [17–20]. In post-synthesis,
Since the discovery of ordered mesoporous silicates M41S was
reported [1,2], surface-modified mesoporous structural materials
have been extensively investigated in recent years for catalysis [3–
5], separation [6,7] and sensor design [8]. Multifunctional catalytic
materials play a pivotal role for achievement of highly efficient
organic synthesis. Particularly nanomaterials with coexisting two
antagonist functions, such as acid and base, are of great interest
owing to their potential novel functions and a wide range of
applications to various catalysis. These functionalities may be used
to perform several steps in a reaction sequence or work in a
cooperative manner to alter the characteristics of a single reaction,
for example, rate, selectivity, and so forth [9–14].
The aldol condensation reaction is recognized as one of the
most fundamental tools for the construction of new carbon–carbon
bonds in the biochemical and purely chemical domains [15,16].
While aldol condensation has historically been catalyzed with
homogeneous acids and bases, due to environmental and
economic concerns, more current literature has focused on
heterogeneous catalysts. It is demonstrated that heterogeneous
catalysts are able to effectively catalyze condensation reaction
through acid–base cooperative catalysis.
organic functional groups are grafted through a reaction of a silane
coupling agent with the free and geminal silanol groups on the
surface of mesopores. However, the distribution of the functional
groups on the surface of the pore wall is likely not uniform and the
organic groups are grafted mainly on the external surface of the
mesoporous particles or near the pore mouth due to the mass
transfer limitation. Comparatively, the advantage of direct
synthesis is that it produces materials with high loading and
relatively uniform distribution of the functional groups. Davis and
his coworkers reported bifunctional heterogeneous SBA-15 con-
taining primary amine and sulfonic acid, phosphoric acid or
carboxylic acid by co-condensation [12,13]. However, mesoporous
materials functionalized with sulfonic acids and amines were
unable to give rise to higher activities due to mutual destruction of
stronger acids paired with amines in the one-pot synthetic process.
What is more, these acid–base bifunctional mesoporous materials
were prepared under acidic medium so that protonation of amino
groups inevitably occurred. Therefore, interest in exploring some
effective ways to avoid potential mutual destruction of antagonist
functions and protonation of amino groups in the chemical
synthesis process has been growing recently. Site isolation is an
effective method to control the distance between functional
groups. Our group has reported two acid–base bifunctional
mesoporous materials Benzyl-APS-S-SBA-15 and Anthracyl-APS-
S-SBA-15 by controlling steric hindrance [21]. Corriu et al. [22] and
* Corresponding authors. Tel.: +86 431 88499140; fax: +86 431 88499140.
E-mail addresses: guanjq@jlu.edu.cn (J. Guan), qkan@jlu.edu.cn (Q. Kan).
0025-5408/$ – see front matter ß 2011 Elsevier Ltd. All rights reserved.
doi:10.1016/j.materresbull.2011.02.006

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X. Yu et al. / Materials Research Bulletin 46 (2011) 951–957
Lu et al. [23] have also reported on bifunctionalized mesoporous
materials containing an acidic site and a basic site isolated from
one another.
2.2. Chemical synthesis
2.2.1. Synthesis of (3-triethoxysilylpropyl) carbamicacid-1-
methylcyclohexylester (3TAME)
In order to avoid potential mutual destruction of antagonist
functions and protonation of amino groups, in this work, an
alternative chemical synthesis route to the conventional method
to prepare acid–base bifunctional materials was developed
by co-condensation. These alternatives include oxidation of
thiols to obtain the sulfonic acids and then thermolysis of
carbamates to obtain the amines. The catalytic activity of acid–
base bifunctional mesoporous materials has been investigated
in aldol condensation reaction between acetone and various
aldehydes.
(3-Triethoxysilylpropyl) carbamicacid-1-methylcyclohexylester
(3TAME) was prepared according to the modified literature
procedure [24,25]. To a solution of 1-methylcyclohexanol (0.52 g)
in 1,2-dichloroethane (15 mL), triethylamine (0.74 mL) and 3-
(triethoxysilyl) propylisocyanate (1.03 mL) were added. The reac-
tion mixture was stirred under N2 for 24 h at 80 8C. The solvent was
evaporated and the residue was denoted as (3-triethoxysilylpropyl)
carbamicacid-1-methylcyclohexylester (3TAME).
2.2.2. Synthesis of acid–base bifunctional materials
Synthesis of the bifunctional materials is shown in Scheme 1.
Typically, 1.0 g cetyltrimethylammonium bromide (CTAB) was
mixed with 240 g of distilled water and 7 mL 1.0 M NaOH solution.
The premixed TEOS (5.2 mL), MPTMS (0.24 mL) and 3TAME
(0.51 mL) were added into the above mixture after it was stirred
for 30 min at 80 8C. The molar composition of the reaction mixture
was (1–2x) TEOS:x 3TAME:x MPTMS:0.11 CTAB:0.28 NaOH:527
H2O (x = 0.05). The mixture was stirred for 2 h at 80 8C. The
solution was filtered and the precipitate was washed with distilled
water and then ethanol. The CTAB surfactant was extracted by
stirring 1 g of the sample in a solution of 0.5 mL of HCl and 150 mL
of ethanol for 5 h at 50 8C. The resulting mesoporous material was
2. Materials and methods
2.1. Materials
Cetyltrimethylammonium bromide (CTAB) (Aldrich), HCl
(A.R.), H2O2 (30%) (A.R.), tetraethyorthosilicate (Aldrich), 4-
nitrobenzaldehyde (Acros), 4-(trifluoromethyl)benzaldehyde
(Acros), 4-cyanobenzaldehyde (Acros), benzaldehyde (Acros),
1-methylcyclohexanol (Mch) (Acros), 3-(triethoxysilyl) propyli-
socyanate (TCI), 3-mercaptopropyltrimethoxysilane (MPTMS)
(Acros), 3-aminopropyltriethoxysilane (APS) (Acros), and acetone
(A.R.) were commercially available and used as received.
Scheme 1. Synthesis of the bifunctional mesoporous materials of SO3H–MCM-41–NH2.

X. Yu et al. / Materials Research Bulletin 46 (2011) 951–957
953
filtered and washed with copious amount water and ethanol. The
extracted material was then dried and denoted as SH–MCM-41–
NHMch. The thiol groups were oxidized to sulfonic acid groups by
H2O2 in the presence of methanol for 24 h, and then stirred in a
diluted sulfuric acid solution for 2 h [26–28]. The solid was washed
with copious amount of water until a neutral pH, and dried
overnight to obtain a dry white solid denoted as SO3H–MCM-41–
NHMch. The sample was then heated at 185 8C for 6 h under
vacuum to obtain the bifunctional mesoporous silica material
containing aminopropyl groups and sulfonic acid groups, denoted
as SO3H–MCM-41–NH2.
For comparison, mesoporous structural materials MCM-41–
NH2 (only use of 3TAME as organosiloxane), MCM-41–SO3H (only
use of MPTMS as organosiloxane) and HSO3–M-41–NH2 (use of
MPTMS as organosiloxane, and use of APS substituting 3TAME)
were prepared in a similar manner.
2.3. Characterization
Powder X-ray diffraction patterns (XRD) were collected using a
Rigaku D/max-2200 (0.28/min) with Cu K
a radiation (40 kV,
40 mA). Hermogravimetric (TG) analysis was carried out on a
Shimadzu DTA-60 working in a N2 stream. The specific surface
areas were obtained on a Micromeritics ASAP 2020 system at liquid
N2 temperature (À196 8C). Before measurements, the samples
were outgassed at 120 8C for 24 h. The specific surface areas were
calculated by using the Brunauer–Emmett–Teller (BET) method
and the pore size distributions were measured by using Barrett–
Joyner–Halenda (BJH) analysis from the desorption branches of
nitrogen isotherms. Transmission electron microscope (TEM) was
performed on a Hitachi H-8100 electron microscope, operating at
200 kV. 1H NMR experiments were carried out in sealed NMR tubes
on a Varian. The solid state 13C CP/MAS NMR using a Bruker AM-
300 spectrometer with a frequency of 75.48 MHz. The solid state
29Si MAS NMR spectra were measured using a Varian Unity-400
spectrometer with 4 mm zirconia rotors spun at 4 kHz. Elemental
analyses (EA) of N were performed on a VarioEL CHN elemental
analyzer. X-ray photoelectron spectra (XPS) were recorded on a VG
Fig. 1. Powder XRD patterns of (a) SH–MCM-41–NHMch (as-synthesized), (b) SH–
MCM-41–NHMch (extracted), (c) SO3H–MCM-41–NHMch, and (d) SO3H–MCM-
41–NH2.
similar to that of pure siliceous MCM-41, indicating that the
materials contain well-ordered hexagonal arrays. Although the
crystallinity of the materials SO3H–MCM-41–NHMch and SO3H–
MCM-41–NH2 decreases slightly, the similarity of the XRD patterns
to pure siliceous MCM-41 indicates that the framework of SO3H–
MCM-41–NHMch and SO3H–MCM-41–NH2 is still retained during
the oxidation and thermolysis. TEM images of the synthesized
samples are shown in Fig. 2. All the materials show well ordered
and parallel pore structure. These results, together with the XRD
patterns, confirm the formation of the highly ordered mesos-
tructure.
The textural properties of the prepared samples are listed in
Table 1. The total surface area gradually decreased from SO3H–
MCM-41–NH2 to SH–MCM-41–NHMch and SO3H–MCM-41–
NHMch. It is possible that organic groups in the material of
SO3H–MCM-41–NHMch are larger than other two samples. The
pore diameter increases from 2.28 nm for SO3H–MCM-41–NHMch
to 2.38 nm for the sample of SO3H–MCM-41–NH2, and the pore
volume increases from 0.21 cmÀ3 gÀ1 for SO3H–MCM-41–NHMch
to 0.28 cmÀ3 gÀ1 for SO3H–MCM-41–NH2. The results could ascribe
to the decomposition of carbamate groups to amino groups in the
process of thermolysis.
Quantification of the acidic and basic centers on the bifunc-
tional mesoporous materials was performed using elemental
analysis and back titration. The results of N elemental analysis in
Table 1 indicate that there was 0.44 mmol/g of nitrogen for SH–
MCM-41–NHMch, 0.41 mmol/g of nitrogen for SO3H–MCM-41–
NHMch and 0.46 mmol/g of nitrogen for SO3H–MCM-41–NH2. The
results of the back titration are shown in Table 1. It is found that
SO3H–MCM-41–NHMch gives a loading of 0.39 mmol/g of –SO3H
and a small amount of loading of 0.008 mmol/g of –NH2. However,
after the thermolysis, SO3H–MCM-41–NH2 gives a loading of
0.42 mmol/g of –NH2, which are in good agreement with the
loading of –NH2 obtained by elemental analysis results, further
proving that the thermolysis of carbamate groups is an effective
method to generate amines.
ESCA LAB MK-II X-ray electron spectrometer using Al Ka radiation
(1486.6 eV). The measurement error of the spectra was Æ0.2 eV. A
back titration method was used to measure the amount of acidic and
basic centers of the materials according to the modified procedure in
the literature [21,22]. About 0.1 g of the sample was added to a
conical beaker, and then 10 mL 0.01 M HCl (NaOH) solution was
added. The mixture was stirred at room temperature for half an hour;
then, the mixture was filtered and rinsed repeatedly for four times
with 25 mL distilled water. The resulting filtrate was titrated with
0.01 M NaOH (HCl) solution using phenolphthalein as indicator.
2.4. Catalytic tests
The aldol condensation reaction was performed in a flask under
nitrogen [12,13]. First, 4-nitrobenzaldehyde (0.76 mg, 0.5 mmol)
was dissolved in acetone (10 mL). Each catalytic reaction was
carried out over 80 mg catalyst at 50 8C. After the reaction, the
product was filtered with acetone and chloroform to remove the
solid catalyst. The resulting product was obtained and analyzed by
1H NMR in CDCl3.
3. Results and discussion
3.1. Catalyst characterization
Fig. 1 shows the X-ray diffraction patterns of the prepared
samples. All the materials exhibit a prominent peak of (1 0 0) and
two weak peaks of (1 1 0) and (2 0 0) diffraction. The patterns were

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X. Yu et al. / Materials Research Bulletin 46 (2011) 951–957
Fig. 2. TEM images of (a) SH–MCM-41–NHMch, (b) SO3H–MCM-41–NHMch, and (c) SO3H–MCM-41–NH2.
Table 1
The textural properties of the prepared materials.
SBET (m2 gÀ1
)
Dp (nm)
Vp (cmÀ3 gÀ1
)
N contentb
(mmol/g)
Acid amountc
(mmol/g)
Base amountc
(mmol/g)
a
Sample
SH–MCM-41–NHMch
SO3H–MCM-41–NHMch
SO3H–MCM-41–NH2
793.8
734.8
2.37
2.28
2.38
0.22
0.21
0.28
0.44
0.41
0.46
–
–
0.39
0.41
0.008
0.42
1017.9
a
Calculated from desorption branch using the BJH method.
Obtained from CHN elemental analysis.
b
c
Obtained from back titration method.
Fig. 3 exhibits that the TG profiles of the prepared samples.
The oxidation process was monitored by XPS. S2p core-level
spectra of SH–MCM-41–NHMch and SO3H–MCM-41–NHMch are
given in Fig. 4. Samples showed two types of sulfur species: one at
low BE (163.7 eV), corresponding to a SH groups, and another at
higher BE (168.6 eV), associated with sulfonic SO3H groups.
Comparison between the spectra of the samples, only a peak
appeared at 163.7 eV due to –SH groups in unoxidized sample SH–
MCM-41–NHMch (Fig. 4a). This peak became weak and a new
strong peak at higher BE (168.6 eV) associated with –SO3H groups
was present after oxidation in Fig. 4b [29,30]. This result reveals
that most of the precursor thiol (–SH) groups were oxidized to the
sulfonic acid (–SO3H) groups by H2O2 at 50 8C.
Weight loss below 100 8C is due to the physically adsorbed
water and ethanol inside the pores. The 4–5% weight loss at
100–200 8C is mainly related to the decomposition of surfactant
template. The weight loss of 10% for MCM-41–NH2, 13% for
SO3H–MCM-41–NH2, 15% for SH–MCM-41–NHMch, and 17% for
SO3H–MCM-41–NHMch in the temperature range from 200 8C to
700 8C was mainly due to the decomposition of organic groups.
Compare with SH–MCM-41–NHMch and SO3H–MCM-41–NH2,
excess weight loss in SO3H–MCM-41–NHMch indicates that
organic groups in the material of SO3H–MCM-41–NHMch are
larger than other two samples.
Fig. 3. TG profiles of (a) MCM-41, (b) MCM-41–NH2, (c) SO3H–MCM-41–NH2, (d)
Fig. 4. S2p core-level spectra of (a) SH–MCM-41–NHMch and (b) SO3H–MCM-41–
SH–MCM-41–NHMch, and (e) SO3H–MCM-41–NHMch.
NHMch.

X. Yu et al. / Materials Research Bulletin 46 (2011) 951–957
955
Fig. 5. Solid-state 13C CP/MAS NMR spectroscopy of (a) SO3H–MCM-41–NHMch and (b) SO3H–MCM-41–NH2.
The successful incorporation of carbamate groups in the
mesoporous materials and transformation of carbamate groups
to the corresponding amino groups were confirmed by solid-state
13C CP/MAS NMR spectroscopy. The 13C CP/MAS NMR spectrum of
SO3H–MCM-41–NHMch is shown in Fig. 5a, the signals at
25.95 ppm (CH3 resonances), 32.25 ppm (CH2 of cyclohexyl) and
159 ppm (carbamate resonances) indicate that the methylcyclo-
hexyl remained intact into the mesoporous MCM-41. The
methylcyclohexyl was released by thermal treatment of SO3H–
MCM-41–NHMch at 185 8C for 6 h under vacuum. It is clearly
reflected in Fig. 5b by the disappearance of resonances associated
with the methylcyclohexyl and the carbamate group (25.95, 32.25
and 159 ppm), while the signals (7.85, 19.91 and 39.82 ppm) of the
propyl spacer were retained [26]. It shows that methylcyclohexyl
was released and carbamate group was successfully transformed
into the corresponding amino groups by thermal treatment. These
results are in good agreement with the conclusion drawn from TG
analysis.
Si(OH)(OSi)3, and Si(OSi)4 silicate species, respectively. In addition,
the resonance peak at À62.5 ppm can be attributed to T3
(Tm = RSi(OSi)3(OH)3Àm, m = 1–3), confirming that the organosi-
loxanes were condensed as a part of the silica framework [31].
3.2. Catalytic properties
The materials were used in the aldol condensation between
acetone and various aldehydes (Table 2). The aldol condensation
was reported to be catalyzed by acid, base and bifunctional acid–
base catalysts. The reaction results show that pure silica MCM-41
almost gave no conversion of 4-nitrobenzaldehyde (entry 1). In the
meanwhile, use of MCM-41 functionalized only with sulfonic acid
groups gave relatively low conversion of 4-nitrobenzaldehyde
(entry 2), while MCM-41 functionalized only with amino groups
gave 85% conversation of 4-nitrobenzaldehyde (entry 3). In
contrast, bifunctional catalyst material SO3H–MCM-41–NH2 gave
conversion to 95% (entry 7), illustrating that the acid–base
cooperation effect should be involved in the catalytic reaction [12].
The superiority of acid–base bifunctional materials SO3H–
MCM-41–NH2 in catalytic behavior is also clearly reflected by the
following results. Before the thermolysis to generate basic site,
SO3H–MCM-41–NHMch only gave conversion to 58% (entry 4).
Solid-state 29Si MAS NMR spectroscopy has been proven to be
the most useful technique for providing chemical information
regarding the condensation of organosiloxane. As shown in Fig. 6,
the peaks with chemical shift at À91.5, À101.0, and À110.3 ppm
were attributed to the Q2, Q3, and Q4 bands of Si(OH)2(OSi)2,

956
X. Yu et al. / Materials Research Bulletin 46 (2011) 951–957
Fig. 6. Solid state 29Si MAS NMR spectroscopy of SO3H–MCM-41–NH2.
Table 2
Test of catalysts
.
Entry
R
Catalysta
A %
B %
Total conversionb
TOFd (hÀ1
)
1
2
NO2
NO2
NO2
NO2
NO2
NO2
NO2
CF3
CN
MCM-41
0
12
78
53
36
50
80
79
78
20
0
6
0
18
85
58
38
54
95
93
86
23
–
MCM-41–SO3H
–
3
MCM-41–NH2
7
–
4
SO3H–MCM-41–NHMch
SO3H–M-41–NH2
MCM-41-A/MCM-41-Bc
SO3H–MCM-41–NH2
SO3H–MCM-41–NH2
SO3H–MCM-41–NH2
SO3H–MCM-41–NH2
5
–
5
2
0.14
–
6
4
7
15
14
8
0.36
0.35
0.32
0.09
8
9
10
H
3
a
0.5 mmol aldehyde in 10 mL acetone stirred at 50 8C for 20 h.
Total conversion determined through 1H NMR spectroscopic analysis with THF as the internal standard.
b
c
1:1 mixture of sulfonic acid functionalized MCM-41(MCM-41–SO3H) and amine-functionalized MCM-41 (MCM-41–NH2).
TOF is based on mmol of aldehyde converted per mmol of active site.
d
However, when using bifunctional material SO3H–MCM-41–NH2
as catalyst (entry 7), a significant improvement in conversion (to
95%) was observed. Meanwhile, a physical mixture of MCM-41–
the rate of per site was enhanced by the SO3H–MCM-41–NH2.
The catalytic properties of synthetic materials have also been
tested in aldol condensation reaction between acetone and other
aldehydes with electron-withdrawing group (entries 8 and 9),
and SO3H–MCM-41–NH2 still exhibited higher conversion and
TOF value. In addition, when without electron-withdrawing
group is at position 4 (entry 10), poor conversion to the aldol
product and TOF value is observed.
NH2 and MCM-41–SO3H, showed
a conversion that was
obviously lower than SO3H–MCM-41–NH2 (entries 6 and 7).
These results further proved the bifunctional properties and the
co-presence of acidic and basic active sites of SO3H–MCM-41–
NH2. The performance of SO3H–MCM-41–NH2 was not as good
as SO3H–MCM-41–NH2, and it only gave 38% conversion of
4-nitrobenzaldehyde (entry 5), implying that a part of amino-
propyl was oxidated by H2O2 during the oxidation. The results
confirm that thermolysis of carbamates to obtain the amino
groups is an effective method to avoid oxidation of the amino
groups. The thermolysis of carbamates to generate amino groups
avoids either potential mutual destruction of acid–base groups
or the protonation of the amino groups. Furthermore, the
methylcyclohexyl can provide more steric hindrance to turn the
acid–base distance. All these could be critical factors that make
bifunctional material possess high activity for aldol condensa-
tion reaction. Also, the highest turnover frequency (TOF),
expressed per mmol of aldehyde converted per mmol of active
site, was achieved on the SO3H–MCM-41–NH2. It indicates that
4. Conclusion
In conclusion, a method for successful cohabitation of organic
acids and organic amines on high-surface-area MCM-41 through
oxidation and thermolysis is described. The novel method to obtain
bifunctional material can reduce mutual destruction between
sulfonic acids and amines and protonation of amino group.
Furthermore, the methylcyclohexyl group can provide more steric
hindrance to turn the acid–base distance. All these could be critical
factors that make bifunctional material possess high activity for
aldol condensation reaction. We also expect that the bifunctional
materials can serve as novel selective catalysts for other important
carbon–carbon bond forming reactions.

X. Yu et al. / Materials Research Bulletin 46 (2011) 951–957
[12] R.K. Zeidan, M.E. Davis, J. Catal. 247 (2007) 379–382.
957
Acknowledgments
[13] R.K. Zeidan, S.J. Hwang, M.E. Davis, Angew. Chem., Int. Ed. 45 (2006) 6332–
6335.
The authors greatly appreciate the support of the National
Natural Science Foundation of China (20673046) and Jilin Province
(20090591).
[14] R.K. Zeidan, V. Dufaud, M.E. Davis, J. Catal. 239 (2006) 299–306.
[15] C. Palomo, M. Oiarbide, J.M. Garcı´a, Chem. Soc. Rev. 33 (2004) 65–75.
[16] R.W. Snell, E. Combs, B.H. Shanks, Top. Catal. 53 (2010) 1248–1253.
[17] S. Huh, H.T. Chen, J.W. Wiench, M. Pruski, V.S.Y. Lin, J. Am. Chem. Soc. 126 (2004)
11010–11011.
References
[18] L. Beaudet, K.Z. Hossain, L. Mercier, Chem. Mater. 15 (2003) 327–334.
[19] A. Walcarius, C. Delacote, Chem. Mater. 15 (2003) 4181–4192.
[20] D.J. Macquarrie, D.B. Jackso, Chem. Commun. 18 (1997) 1781–1782.
[21] Y.Q. Shao, J.Q. Guan, S.J. Wu, H. Liu, B. Liu, Q.B. Kan, Micropor. Mesopor. Mater. 128
(2010) 120–125.
[22] J. Alauzun, A. Mehdi, C. Rey, R.J.P. Corriu, J. Am. Chem. Soc. 128 (2006) 8718–8719.
[23] H. Li, S.T. Xu, W.P. Zhang, X.B. Lu, Chin. Chem. Lett. 20 (2009) 1051–1054.
[24] E.G. Doyagu¨ez, F. Caldero´n, F. Sa´nchez, A. Ferna´ndez-Mayoralas, J. Org. Chem. 72
(2007) 9353–9356.
[1] C.T. Kresge, M.E. Leonowicz, W.J. Roth, J.C. Vartuli, J.S. Beck, Nature 359 (1992)
710–712.
[2] T. Yanagisawa, T. Shimizu, K. Kuroda, C. Kato, Bull. Chem. Soc. Jpn. 63 (1990) 988–
992.
[3] I. Rodriguez, S. Iborra, A. Corma, F. Rey, J.L. Jorda´, Chem. Commun. 7 (1999) 593–
594.
[4] I.K. Mbaraka, D.R. Radu, V.S.Y. Lin, B.H. Shanks, J. Catal. 219 (2003) 329–336.
[5] S.H. Shen, L.J. Guo, Mater. Res. Bull. 43 (2008) 437–446.
[6] S. Dai, M.C. Burleigh, Y. Shin, C.C. Morrow, C.E. Barnes, Z. Xue, Angew. Chem., Int.
Ed. 38 (1999) 1235–1239.
[25] J.D. Bass, A. Katz, Chem. Mater. 15 (2003) 2757–2763.
´
[26] B. Rac, A. Molnr, P. Forgo, M. Mohai, I. Bertti, J. Mol. Catal. A: Chem. 244 (2006) 46–
57.
[27] E. Cano-Serrano, J.M. Campos-Martin, J.L.G. Fierro, Chem. Commun. 2 (2003) 246–
247.
[28] Q.Z. Wu, J.F. Liao, Q. Yin, Y.G. Li, Mater. Res. Bull. 43 (2008) 1209–1217.
[29] R. Guo, X.C. Ma, C.L. Hu, Z.Y. Jiang, Polymer 48 (2007) 2939–2945.
[30] E. Cano-Serrano, G. Blanco-Brieva, J.M. Campos-Martin, J.L.G. Fierro, Langmuir 19
(2003) 7621–7627.
[7] H. Yoshitake, T. Yokoi, T. Tatsumi, Chem. Mater. 15 (2003) 1713–1721.
[8] V.S.Y. Lin, C.Y. Lai, J. Huang, S.A. Song, S.J. Xu, J. Am. Chem. Soc. 123 (2001) 11510–
11511.
[9] J.D. Bass, A. Solovyov, A.J. Pascall, A. Katz, J. Am. Chem. Soc. 128 (2006) 3737–3747.
[10] F. Gelman, J. Blum, D. Avnir, Angew. Chem., Int. Ed. 40 (2001) 3647–3649.
[11] S. Shylesh, A. Wagner, A. Seifert, S. Ernst, W.R. Thiel, Chem. Eur. J. 15 (2009)
7052–7062.
[31] X.S. Zhao, G.Q. Lu, J. Phys. Chem. B 102 (1998) 1556–1561.