Z. Hasan et al. / Catalysis Communications 26 (2012) 30–33
33
Table 1
Acknowledgements
Elemental composition and BET surface area of S-Dg.
BET surface area (m2/g)
3.9
This study was supported by a grant (B551179-10-03-00) from the
cooperative R&D Program funded by the Korea Research Council Industri-
al Science and Technology, Republic of Korea. This research was also
partly supported by Kyungpook National University Research Fund, 2011.
Elements (wt.%)
C
H
N
0
S
59.51
2.46
1.11a
a
0.35 mmol/g.
Appendix A. Supplementary material
the acid site or sulfur concentration [32]. Moreover, the surface area of
S-Dg (3.9 m2/g) is also lower than that of Amberlyst-15 (45 m2/g). A
low surface area of S-Dg may be another reason for a low kinetic con-
stant because heterogeneous catalysis usually occurs on the surface
rather than in bulk.
Supplementary data to this article can be found online at http://
dx.doi.org/10.1016/j.catcom.2012.05.002.
References
The activation energy is calculated from the Arrhenius equation or
from a plot of lnk vs. 1/T which is shown in Fig. 4(b). The calculated
activation energy of dehydration over S-Dg is 56.7 kJ/mol and some-
what low compared with the energies observed with H-ZSM-5 and
ALO-4 alumina catalysts (95.2 kJ/mol and 83.8 kJ/mol, respectively
[13,34]). Even though further work is needed, the low activation en-
ergy observed in this study may suggest the effectiveness or high ac-
tivity of the S-Dg catalyst per active site, which is in accordance with
acid site densities determined by titrimetric analysis.
[1] Á. Molnár, M. Bartók, Dehydration of Alcohols, in: R.A. Sheldon, H. van Bekkum
(Eds.), Fine Chemicals through Heterogeneous Catalysis, Wiley-VCH, Weinheim,
2001, pp. 295–307.
[2] Y.K. Lee, H.-J. Chae, S.-Y. Jeong, G. Seo, Applied Catalysis A: General 369 (2009)
60–66.
[3] D. Chen, K. Moljord, T. Fuglerud, A. Holmen, Microporous and Mesoporous Mate-
rials 29 (1999) 191–203.
[4] Y.-J. Lee, S.-C. Baek, K.-W. Jun, Applied Catalysis A: General 329 (2007) 130–136.
[5] S. Jiang, Y.K. Hwang, S.H. Jhung, J.-S. Chang, J.-S. Hwang, T. Cai, S.-E. Park, Chemistry
Letters 33 (2004) 1048–1049.
[6] S. Delsarte, P. Grange, Applied Catalysis A: General 259 (2004) 269–279.
[7] E. Medina, R. Bringué, J. Tejero, M. Iborra, C. Fite, Applied Catalysis A: General 374
(2010) 41–47.
The reusability of the catalyst is of great importance for commercial
feasibility; therefore, reusability tests of S-Dg were conducted, and the
results are displayed in Supporting Fig. 1. The PhE conversions over
the S-Dg catalyst in four cycles are all above 93%, representing a good
reusability. The ST selectivity, however, decreases a bit with the number
of recycles. The FTIR spectrum of the used catalyst (Supporting Fig. 2)
shows the intact structure of the sulfonated group, which is the active
site for acid catalysis. Generally, therefore, the S-Dg catalyst can be
regarded as a reusable acid catalyst for ST production from PhE.
Two types of mechanisms for the dehydration of PhE over acidic cata-
lysts have been described by different research groups [13–16,31,35].
Bertero et al. [13,14] and Romanova et al. [35] have suggested that
DPEE can be converted into ST. On the contrary, Lange et al. [16] pro-
posed that DPEE can be obtained from ST. The present study suggests
that ST and DPEE are the primary products and HP is a secondary prod-
uct since the primary and secondary products have non-zero and zero
initial slopes, respectively [14,31]. Again, the concentration of DPEE
shows a maximum and then decreases steadily with the progress of
the reaction, suggesting that DPEE is an intermediate that can be
converted into other products like ST or HP, which is in accordance
with a previous report [31]. Moreover, it is known that olefins can
be obtained from dimethylether in the methanol-to-olefin process
[3,4]. Therefore, the DPEE, produced at the early stage of the reaction,
may be converted into ST. GC-MS analysis shows that the HP is com-
posed of carbon and hydrogen (chemical formula: (C6H5)4(CH)6;
FW: 386). Therefore, HP may be mainly obtained from an oligomer-
ization of ST.
[8] N.A. Khan, D.K. Mishra, J.-S. Hwang, Y.-W. Kwak, S.H. Jhung, Research on Chemical
Intermediates 37 (2011) 1231–1238.
[9] J.A. Maciá-Agulló, D. Cazorla-Amorós, A. Linares-Solano, U. Wild, D.S. Su, R.
Schlögl, Catalysis Today 102–103 (2005) 248–253.
[10] F. Cavani, F. Trifiró, Applied Catalysis A: General 133 (1995) 219–239.
[11] J.-S. Chang, D.-Y. Hong, V.P. Vislovskiy, S.-E. Park, Catalysis Surveys from Asia 11
(2007) 59–69.
[12] M. Ji, G. Chen, J. Wang, X. Wang, T. Zhang, Catalysis Today 158 (2010) 464–469.
[13] N.M. Bertero, C.R. Apesteguía, A.J. Marchi, Catalysis Communications 10 (2009)
1339–1344.
[14] N.M. Bertero, C.R. Apesteguía, A.J. Marchi, Catalysis Communications 10 (2008)
261–265.
[15] J.-P. Lange, V. Otten, Industrial and Engineering Chemistry Research 46 (2007)
6899–6903.
[16] J.-P. Lange, V. Otten, Journal of Catalysis 238 (2006) 6–12.
[17] M.-H. Zong, Z.-Q. Duan, W.-Y. Lou, T.J. Smith, H. Wu, Green Chemistry 9 (2007)
434–437.
[18] J.M. Campelo, M. Jaraba, D. Luna, R. Luque, J.M. Marinas, A.A. Romero, Chemistry
of Materials 15 (2003) 3352–3364.
[19] M.A. Harmer, W.E. Farneth, Q. Sun, Advanced Materials 10 (1998) 1255–1257.
[20] N. Lucas, A. Bordoloi, A.P. Amrute, P. Kasinathan, A. Vinu, W. Bohringer, J.C.Q.
Fletcher, S.B. Halligudi, Applied Catalysis A: General 352 (2009) 74–80.
[21] S.M. Kumbar, S.B. Halligudi, Catalysis Communications 8 (2007) 800–806.
[22] J.S. Lee, J.W. Yoon, S.B. Halligudi, J.-S. Chang, S.H. Jhung, Applied Catalysis A: General
366 (2009) 299–303.
[23] R.J. White, V. Budarin, R. Luque, J.H. Clark, D.J. Macquarrie, Chemical Society Re-
views 38 (2009) 3401–3418.
[24] R.A. Arancon, H.R. Barros Jr., A.M. Balu, C. Vargasc, R. Luque, Green Chemistry 13
(2011) 3162–3167.
[25] R. Luque, J.H. Clark, ChemCatChem 3 (2011) 594–597.
[26] R. Luque, V. Budarin, J.H. Clark, P. Shuttleworth, R.J. White, Catalysis Communica-
tions 12 (2011) 1471–1476.
[27] V.L. Budarin, J.H. Clark, R. Luque, D.J. Macquarrie, Chemical Communications
(2007) 634–636.
[28] R. Xing, N. Liu, Y. Liu, H. Wu, Y. Jiang, L. Chen, M. He, P. Wu, Advanced Functional
Materials 17 (2007) 2455–2461.
[29] B. Zhang, J. Ren, X. Liu, Y. Guo, Y. Guo, G. Lu, Y. Wang, Catalysis Communications
11 (2010) 629–632.
4. Conclusion
[30] J. Wang, W. Xu, J. Ren, X. Liu, G. Lu, Y. Wang, Green Chemistry 13 (2011)
2678–2681.
[31] N.A. Khan, J.-S. Hwang, S.H. Jhung, Bulletin of the Korean Chemical Society 32
(2011) 1327–1330.
[32] J.T. Yu, A.M. Dehkhoda, N. Ellis, Energy & Fuels 25 (2011) 337–344.
[33] X.-Y. Liu, M. Huang, H.-L. Ma, Z.-Q. Zhang, J.-M. Gao, Y.-L. Zhu, X.-J. Han, X.-Y. Guo,
Molecules 15 (2010) 7188–7196.
[34] T. Takahashi, T. Kai, M. Tashiro, Canadian Journal of Chemical Engineering 66
(1988) 433–437.
Liquid phase dehydration of PhE to ST was carried out using
carbon-based solid acid catalysts prepared form renewable resources
like D-glucose for the first time. The catalysts were obtained facilely in
one-step or carbonization and sulfonation were done simultaneously
in one-pot synthesis. The S-Dg catalyst shows higher ST selectivity
and lower activation energy than other solid acid catalysts that have
been used so far, suggesting carbon-based catalysts are very effective
in producing styrene.
[35] R.G. Romanova, A.A. Lamberov, I.G. Shmelev, Kinetics and Catalysis 45 (2004)
422–428.