FP-Co-SiO
2
was used. In the selective oxidation of hydro-
phase and organic groups on the surface. The superhydro-
phobicity of the material has been demonstrated to improve
catalytic performance significantly, which enabled this kind of
material to show highly efficient activity in the selective oxida-
tion of hydrocarbons. Due to the inevitable production of water
molecules in many kinds of organic reaction, this kind of
superhydrophobic material could potentially act as an efficient
catalyst for other reactions due to its superhydrophobicity.
The authors thanks to the financial support by the National
Natural Science Foundation of China (20736010 and
20803074) and the Doctor Startup Foundation of Liaoning
Province.
carbons, alcohol is one of the primary oxidation products,
which can be further oxidized to a ketone. Higher selectivity
for ketones means that superhydrophobic FP-Co-SiO has a
2
stronger oxidation ability, which can also be directly proved
by results of the turnover number (TON) comparison. When
2
FP-Co-SiO was used, the TON reached more than 2000 for
all situations and could reach 5894 in the selective oxidation of
cyclohexene, which is even higher than some homogeneous
1
1
catalytic system. This kind of catalyst can be simply
separated from the reaction solution through centrifugation.
After washing with ethanol and drying, it can be repeatedly
used for at least three times without a decrease in activity.
Based on the above experimental results, we can conclude that
the reported superhydrophobic material is an efficient catalyst
for the selective oxidation of hydrocarbon.
Notes and references
1
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2
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R. G. Bell, Nature, 1999, 398, 227; (d) H. Frei, Science, 2006,
13, 309.
The special surface property of FP-Co-SiO is believed to be
2
the key factor for obtaining such excellent catalytic
3
performance. In the distribution test (Fig. S5 ESIw), it could
be observed that the superhydrophobic FP-Co-SiO could
2
2 P. Stavropoulos, R. Celenligil-Cetin and A. E. Tapper, Acc. Chem.
Res., 2001, 34, 745.
3
J. M. Thomas, R. Raja and D. W. Lewis, Angew. Chem., Int. Ed.,
005, 44, 6456.
remain in a highly distributed state for a much longer time.
The changing trends were monitored through UV-Vis spectro-
scopy kinetic measurements (Fig. S6 ESIw). In addition, a big
difference was found in the adsorbed quantity of hydrophilic
water and hydrophobic benzene for these two materials
2
4
(a) R. Palkovits, M. Antonietti, P. Kuhn, A. Thomas and
F. Schuth, Angew. Chem., Int. Ed., 2009, 48, 6909; (b) L. Liu,
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206; (c) J. Tong, L. Bo, Z. Li, Z. Lei and C. Xia, J. Mol. Catal. A:
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(
Table S1 ESIw). Also, the hydrophobicity index (HI) of
FP-Co-SiO is 18.7 times as high as that of Co-SiO . These
12
2
2
2
results demonstrated that this kind of superhydrophobic
material is more oleophilic than the hydrophilic Co-SiO and
Int. Ed., 2004, 43, 4338; (c) H. Y. Erbil, A. L. Demirel, Y. Avci and
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2
had better proximity to organic molecules. The formation of
water molecules was inevitable during the oxidation reaction
process. To imitate this process, a calculated amount of water
was put in the bottles (Fig. S5f ESIw). After agitation, it was
6
7
D. Quere, Rep. Prog. Phys., 2005, 68, 2495.
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2
observed that, for the hydrophilic Co-SiO , all the materials
were transferred to the water phase. This would consequently
affect the adsorption of the organic substrate onto the material
surface during the reaction process. For the superhydrophobic
9
(a) M. S. Hamdy, A. Ramanathan, T. Maschmeyer, U. Hanefeld
and J. C. Jansen, Chem.–Eur. J., 2006, 12, 1782; (b) W. A.
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FP-Co-SiO , however, the situation was totally different and
2
these particles still remained in the organic phase after the
addition of water. This meant that the produced water
molecules had hardly any effect on the interaction between
the catalytically active sites and the substrate molecules
because of the super-strong water repellent ability of the
material. Accordingly, excellent catalytic performance was
1
997, 18, 408.
10 R. Raja, G. Sankar and J. M. Thomas, J. Am. Chem. Soc., 1999,
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1
1
1 (a) X. L. Tong, J. Xu, H. Miao, G. Y. Yang, H. Ma and
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2
obtained when the superhydrophobic FP-Co-SiO was used
as the catalyst for selective oxidation of hydrocarbons.
In conclusion, a new kind of superhydrophobic nano-
composite material was prepared with metal ions in the bulk
1
1
338 | Chem. Commun., 2011, 47, 1336–1338
This journal is ꢀc The Royal Society of Chemistry 2011