Effects of crystallinity of ZSM-5 zeolite on para-selective tert-butylation of ethylbenzene

doi:10.1016/S1872-2067(11)60482-8

Abstract

Abstract: Highly crystalline ZSM-5 zeolites are important for para-selective alkylation of alkyl aromatics, because they carry few external acid sites for isomerization of p-dialkyl products. Such zeolites (Si/Al = 25, 50, and 75) were synthesized in a fluoride medium between pH 4 and 6. Their crystallinities, crystal sizes, and surface areas were higher than those of a commercial ZSM-5 zeolite. Their para selectivities in alkylation were tested for vapor-phase tert-butylation of ethylbenzene between 200 and 400 °C. As expected, all the catalysts showed more than 90% para selectivity. At 300 °C, ethylbenzene conversion decreased in the order ZSM-5(25, commercial) > ZSM-5(25) > ZSM-5(50) > ZSM-5(75). The catalysts had weak, medium, and strong acid sites, but all the acid sites of ZSM-5(75) were weaker than those of ZSM-5(25) and ZSM-5(50). The high activity of commercial ZSM-5 was caused by its strong acid sites being stronger than those of the synthesized zeolites. Although the activity of the commercial catalyst was higher than those of the present catalysts, the selectivity for 4-t-butylethylbenzene (4-t-BEB) was low. The optimum feed ratio (ethylbenzene:t-butyl alcohol) was 2:1 and the feed rate was 1.65 h⁻¹ for high ethylbenzene conversion and 4-t-BEB selectivity. Time-on-stream studies showed slow catalyst deactivation. Highly crystalline ZSM-5 zeolites are therefore better than a commercial zeolite for para-selective alkylation of alkyl aromatics. They do not require much post-modification for high para selectivity. A fluoride medium is therefore better than an alkaline medium for obtaining highly crystalline para-selective ZSM-5 zeolites.

Key words: ZSM-5, Fluoride medium, p-selectivity, Ethylbenzene, Tert-butylation, Zeolite

PUSHPARAJ Hemalatha, MANI Ganesh, MUTHIAHPILLAI Palanichamy, VELAYUTHAM Murugesan, PARK Yong-Ki, CHOI Won Choon, JANG Hyun Tae. Effects of crystallinity of ZSM-5 zeolite on para-selective tert-butylation of ethylbenzene[J]. Chinese Journal of Catalysis, 2013, 34(2): 294-304.

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References

[1] Ichioka R, Yamakawa S, Okino H, Kato H, Iwayama K, Konta H, Kitamura A. US 6 040 490. 2000
[2] Zuo X, Niu F, Snavely K, Subramaniam B, Busch D H. Green Chem, 2010, 12: 260
[3] Chavan S A, Srinivas D, Ratnasamy P. J Catal, 2001, 204: 409
[4] Chu C C. US 4 496 662. 1985
[5] Burress G T. US 4 565 899. 1986
[6] Kaeding W W, Yannich P J, Klosek J M, Young L B. EP 0 217 492. 1987
[7] Drobny J G. Handbook of Thermoplastic Elastomers. 1st Ed. New York: William Andrew Inc, 2007. 175
[8] Danilina N, Payrer E L, van Bokhoven J A. Chem Commun, 2010, 46: 1509
[9] Wise J J. US 3 251 897. 1966
[10] Haag W O, Lago R M, Weisz P B. Faraday Discuss Chem Soc, 1981, 72: 317
[11] Olson D H, Haag W O. ACS Symp Ser, 1984, 248: 275
[12] Halgeri A B. Bull Catal Soc India, 2003, 2: 184
[13] Kim J H, Namba S, Yashima T. Zeolites, 1991, 11: 59
[14] Kim J H, Namba S, Yashima T. Appl Catal A, 1993, 100: 27
[15] Chen N Y, Garwood W E, Dwyer F G. Shape Selective Catalysis in Industrial Applications. 1st Ed. New York: Dekker, 1989. 26
[16] Guth J L, Kessler H, Higel J M, Lamblin J M, Patarin J, Seive A, Chezeau J M, Wey R. ACS Symp Ser, 1989, 398: 176
[17] Axon S A, Klinowski J. Appl Catal A, 1994, 111: 29
[18] Kessler H, Patarin J, Schott-Darie C. Stud Surf Sci Catal, 1994, 85: 75
[19] Nayak V S, Riekert L. Appl Catal, 1986, 23: 403
[20] Paparatto G, Moretti E, Leofanti G, Gatti F. J Catal, 1987, 105: 227
[21] Arsenova-Härtel N, Bludau H, Schumacher R, Haag W O, Karge H G, Brunner E, Wild U. J Catal, 2000, 191: 326
[22] Umamaheswari V, Palanichamy M, Arabindoo B, Murugesan V. Proc Indian Acad Sci Chem Sci, 2002, 114: 203
[23] Bidart A M F, Borges A P S, Chagas H C, Nogueira L, Lachter E R, Mota C J A. J Braz Chem Soc, 2006, 17: 758
[24] Louis B, Kiwi-Minsker L. Microporous Mesoporous Mater, 2004, 74: 171
[25] Gougeon R D, Brouwer E B, Bodart P R, Delmotte L, Marichal C, Chezeau J M, Harris R K. J Phys Chem B, 2001, 105: 12249
[26] Treacy M M J, Higgins J B. Collection of Simulated XRD Powder Patterns for Zeolites. 4th Ed (Rev). Amsterdam: Elsevier, 2001. 239
[27] Woolery G L, Kuehl G H, Timken H C, Chester A W, Vartuli J C. Zeolites, 1997, 19: 288
[28] Sano T, Wakabayashi S, Oumi Y, Uozumi T. Microporous Mesoporous Mater, 2001, 46: 67
[29] Jeffery G H, Bassett J, Mendham J, Denney R C. Vogel’s Textbook of Quantitative Chemical Analysis. 5th Ed. UK: Longman, 1989. 833
[30] Arichi J, Louis B. Cryst Growth Des, 2008, 8: 3999
[31] Kim J H, Park M J, Kim S J, Joo O S, Jung K D. Appl Catal A, 2004, 264: 37
[32] Vishwanathan V, Jun K W, Kim J W, Roh H S. Appl Catal A, 2004, 276: 251
[33] Kim S D, Baek S C, Lee Y J, Jun K W, Kim M J, Yoo I S. Appl Catal A, 2006, 309: 139
[34] Bortnovsky O, Sazama P, Wichterlova B. Appl Catal A, 2005, 287: 203
[35] Seiler M, Wang W, Hunger M. J Phys Chem B, 2001, 105: 8143
[36] Grieken R V, Sotelo J L, Menéndez J M, Melero J A. Microporous Mesoporous Mater, 2000, 39: 135
[37] Liu Z, Moreau P, Fajula F. Appl Catal A, 1997, 159: 305
[38] Schaefer T, Chan W K, Sebastian R, Schurko R, Hruska F E. Can J Chem, 1994, 72: 1972