RSC Advances
Paper
were reduced due to the excessive doping of Ce, as shown in
Acknowledgements
2
ꢀ
Fig. 6b. In addition, SO4 –Ce0.02/TiO * was prepared by the
2
conventional method and its catalytic activity was also tested. As The authors gratefully acknowledge the nancial supports
shown in Table 2, the corresponding conversion extent of acetic provided by the National Natural Science Foundation of China
2
ꢀ
acid is 75.76% in 45 min, which is higher than that of SO
TiO * (60.08%), indicating the benecial of Ce doped. However, China (863 Program, 2011AA06A108).
it is much lower than that of SO
4
–
(21176161) and the National High Technology R&D Program of
2
2
ꢀ
ꢁ
C
4
–Ce0.02/TiO
2
– 300
(
97.06%), which is prepared by using collagen ber as template.
References
2
ꢀ
2ꢀ
4
Compared with powder SO
TiO – 300 C can be used 6 times without signicant reduction
of catalytic activity. These facts proved that the catalysts of
mesoporous SO4 –Ce /TiO ber prepared using collagen ber
as template have remarkable advantages on the activity and
reusability.
Furthermore, as presented in Table 2, the conversion yield of
acetic acid is rstly increased and then decreased with the
increase of calcination temperature. The maximum activity was
4
–TiO
2
* catalyst, SO
–Ce0.02/
ꢁ
2
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2
ꢀ
x
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–
2
2ꢀ
4
ꢁ
500 C is reduced to 54.64%, which should be caused by the
ꢁ
loss of acid sites under high temperature of 500 C, as shown in
Fig. 6a. Compared with the pure TiO (conversion yield 9.83%),
2
the conversion yield over the sulfated titania was obviously
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In addition, the reusability of the SO4 –Ce /TiO – 300 C
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ꢀ
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2
ꢁ
3
00 C could be reused 6 times without obvious decrease in
11, 3775.
2
ꢀ
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4
–TiO
2
* was 11 P. Yang, D. Zhao, D. I. Margolese, B. F. Chmelka and
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th
greatly reduced to 33.9% at the 6 cycle.
2ꢀ
ꢁ
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4
–Ce0.02/TiO
2
– 300 C can be used as 12 H. Wu, X. Huang, M. Gao, X. Liao and B. Shi, Green Chem.,
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– 300 C is highly effi- 13 S. M. Pradhan, K. S. Katti and D. R. Katti, Biomacromolecules,
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2ꢀ
ꢁ
summarized in Table 3, SO
4
–Ce0.02/TiO
2
4
1
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2
ꢀ
In this study, a series of cerium-doped mesoporous SO
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4
–TiO
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2
ꢀ
was prepared by using CF as the biomass template. SO
TiO
4
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x
/
2
faithfully replicated the natural mesopore structure of 19 K. Arata, Adv. Catal., 1990, 37, 165.
collagen ber during the calcination process without collapse. 20 S. Bingham and W. A. Daoud, J. Mater. Chem., 2011, 21, 2041.
The present investigate reveals that even the presence of S is 21 K. J. A. Raj and B. Viswanathan, ACS Appl. Mater. Interfaces,
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ꢀ
essential important for the activity of SO4 –Ce /TiO , the
2009, 1, 2462.
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x
2
2
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2
ꢀ
acidic strength of SO
4
–Ce
x
/TiO
2
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ꢀ
The as-prepared SO4 –Ce /TiO nanobers can be used as 25 C. Wang, Y. Ao, P. Wang, J. Hou, J. Qian and S. Zhang,
x
2
highly active catalyst for the esterication of carboxylic acids
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4018 | RSC Adv., 2014, 4, 4010–4019
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