Abstract
Magnesium-aluminium hydrotalcites (MgAl-HTs) with Mg/Al atomic ratio 2,3 and 4 were synthesized bythe coprecipitation method. Vapour phase alkylation of m-cresol with methanol was carried out over these samples calcined at 723K in the temperature range 523–723K at atmospheric pressure. A mixture of O- and C- alkylated products, namely, 3-methyl anisole (3MA), 2,5- and 2,3-dimethylphenols (DMP) and 2,3,6-trimethylphenol (2,3,6-TMP) were obtained. The selectivity of these products depends on the m-cresol/methanol feed ratio, temperature and contact times. The catalytic activity of these catalysts are in the order MgAl 3.0-CHT>MgAl 2.0-CHT>MgAl 4.0-CHT. MgAl 3.0-CHT showed ∼30% selectivity for 2,5-DMP and 40% selectivity for 2,3,6-TMP with ∼40% conversion at 623K or ∼70% conversion at 723K. The alkylation of m-cresol with 2-propanol over MgAl 3.0-CHT at 673K offered nearly 80% selectivity towards thymol with nearly 40% m-cresol conversion.
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H. Fiege, in:, Ullmanns Encyclopedia of Industrial Chemistry, B. Elvers, S. Hawkins, G. Schultz (Eds.) Vol. AI 9, 5th Ed., V.C.H., Weinheim, 1991, p. 313.
R. Dowbenko, in: Kirk-Othmer Encyclopedia of Chemical Technology, J.I. Kroschwit and Mary Houl-Grant (Eds.) 4th Ed., Vol. 2, 1992, p. 106.
E. Santacesaria, D. Grasso, D. Gelosa and S. Carra, Appl. Catal., 61, 89 (1990).
M.C. Samolada, E. Grgoriadou, Z. Kiparissides and I.A. Vasalos, J. Catal., 152, 52 (1995).
S. Sato, K. Koizumi and F. Nozaki, Appl. Catal., 133, L7 (1995).
K. Li, I. Wang and K. Chang, Ind. Eng. Chem. Res., 32, 1007 (1993).
H. Grabowska, J. Jablonski, W. Mista and J. Wrzyszcz, Res. Chem. Intermed., 22, 53 (1996).
L. Garcia, G. Giannetto, M.R. Goldwasser, M. Guisnet and P. Magnoux, Catal. Lett., 37, 121 (1996).
V. Durgakumari, G. Sreekanth and S. Narayanan, Res. Chem. Intermed. 14, 223 (1990).
V. Durgakumari and S. Narayanan, J. Mol. Catal., 65, 385 (1991).
F. Cavani, F. Trifiro and A. Vaccari, Catal. Today, 11, 173 (1991).
J.M.L. Nieto, A. Dejoz and M.I. Vazquez, Appl. Catal., 132, 41 (1995).
S. Narayanan and K. Krishna, Appl. Catal., 147, L25 3 (1996).
J. Shen, B. Guang, M. Tu and Y. Chen, Catal. Today, 30, 77 (1996).
A. Corma, S. Iborra, J. Prima and F. Rey, Appl. Catal., 114, 215 (1994).
M.J. Climent, A. Corrna, S. Iborra and J. Prima, J. Catal., 114, 215 (1994).
H. Tsuji, F. Yagi, H. Hottori and H. Kita, J. Catal., 148, 759 (1994).
D. Tichit, M.H. Lhouty, A. Guida, B.H. Chiche, F. Figaeras, A. Auroux, D. Bartalini and E. Garroone, J. Catal., 151, 50 (1995).
S. Velu and C.S. Swarny, Appl. Catal., 11, 9, 241 (1994).
S. Velu and C.S. Swamy, Catal. Lett., 40, 265 (1996).
S. Velu and C.S. Swamy, Appl. Catal., 145, 141 (1996).
C.P. Bezouhanova and M.A. AI-Zihari, Catal. Lett., 11, 245 (1991).
M. Nitta, K. Aomura and K. Yamaguchi, Bull. Chem. Soc. Jap., 47, 2360 (1974).
T. Yamanaka, Bull. Chem. Soc. Jap., 49, 2669 (1976).
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Velu, S., Sivasanker, S. Alkylation of m-cresol with methanol and 2-propanol over calcined magnesium-aluminium hydrotalcites. Res. on Chem. Intermed. 24, 657–666 (1998). https://doi.org/10.1163/156856798X00555
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DOI: https://doi.org/10.1163/156856798X00555