화학공학소재연구정보센터
HWAHAK KONGHAK, Vol.31, No.4, 369-377, August, 1993
Cs-Modified Zeolite X촉매상에서의 톨루엔의 측쇄알킬화 반응
Side Chain Alkylation of Toluene with Methanol over Cs-Modified Zeolite X Catalysts
초록
Cs-modified zeolite X촉매상에서 스타이렌을 얻기 위하여 메탄올에 의한 톨루엔의 측쇄알킬화 반응을 행하였다. 세슘 양이온이 교환된 촉매는 Linde 13X(Union Carbide Co.)촉매를 여러 가지 농도의 cesium acetate와 cesium nitrate용액으로 이온 교환하였으며, 붕소(boron)가 첨가된 촉매는 cesium acetate와 cesium nitrate용액에 일정량의 boric acid를 첨가한 용액으로 이온 교환하였다. 반응 생성물로 스타이렌, 에틸벤젠 및 소량의 자일렌 이성체가 생성되며, 이온 교환 용액의 농도가 증가함에 따라 촉매의 산도 및 세기는 감소하고 염기도 및 세기는 조금씩 증가하는 경향을 나타내었다. Boron의 첨가는 촉매의 산도 및 세기를 크게 감소시키는 반면 염기도 및 세기는 약간 증가시키는 경향을 나타내며, boron이 첨가된 촉매상에서의 알킬화 반응시 스타이렌의 수율이 상당히 증가하였다. 따라서 첨가되는 boron은 촉매의 염기특성보다는 산특성에 큰 영향을 미치는 것으로 생각되며, boron의 이러한 산특성 및 염기특성의 조절 효과에 의하여 스타이렌의 생성에 알맞는 분위기가 촉매내에 제공되어 지는 것으로 생각되었다.
Side-chain alkylation of toluene with methanol was studied over cesium-modified zeolite X to produce styrene. Cesium-cation exchanged catalysts were prepared from the parent NaX(commercial Linde 13X) by ion-exchange method with various cesium acetate and nitrate solutions. And boron-added catalysts were modified with boron-added cesium acetate and nitrate solutions. Reaction products were styrene, ethylbenzene and small amount of xylene isomers. And yield and selectivity of styrene were enhanced in proportion to the concentration of the exchanged cesium solution. Acidity and acid strength of a catalyst were decreased, while basicity and base strength of a catalyst were increased slightly as the concentration of ion-exchange solutions was higher. Boron-addition resulted in great increment of styrene yield and selectivity because of considerable decrease of acidity and acid strength and a little increase of basicity and base strength. It was suggested that the increase of styrene yield requires suitable ratio of the acidity and acid strength to the basicity and base strength into the catalyst.
  1. Yashima T, Sato K, Hayasaka T, Hara W, J. Catal., 26, 303 (1972) 
  2. Tanabe K, Takahashi O, Hatorri H, React. Kinet. Catal. Lett., 7, 347 (1977) 
  3. Itoh H,Miyamoto A, Murakami Y, J. Catal., 64, 284 (1988) 
  4. Unland ML, Barker GE, "Catalysts of Organic Reactions," (Moser, W.R., ed), p. 51, Dekker, New York (1981)
  5. Itoh H, Hatorri T, Suzuki K, Murakami Y, J. Catal., 79, 21 (1983) 
  6. Yamaguchi N, Kobayashi A, Sodesawa T, Nozaki F, React. Kinet. Catal. Lett., 25(1-2), 11 (1984) 
  7. Moon SK, Kang SC, Seo KT, Chang YW, HWAHAK KONGHAK, 24(1), 9 (1986)
  8. Engelhardt J, Szanyi J, Valyon J, J. Catal., 107, 296 (1987) 
  9. King ST, Garces JM, J. Catal., 104, 59 (1987) 
  10. Garces JM, Vrieland GE, Bates SI, Scheidt FM, "Catalysis by Acids and Bases," (Imelik, B., Et al. eds.), Elsevier, Amsterdam, Vol. 20, p. 67 (1985)
  11. Zheng S, Cai J, Liu D, "Catalysts: Theory to Practice: Proceeding of the 9th International Congress on Catalysis, Calgary, Canada," (Philips, M.J. and Ternan, M) (1988)
  12. Freeman JJ, Unland ML, J. Catal., 54, 183 (1978) 
  13. Moon SK, Kim HJ, Seo KT, Paek SW, HWAHAK KONGHAK, 25(6), 601 (1987)
  14. Moon SK, Kim HJ, Seo KT, HWAHAK KONGHAK, 27(4), 422 (1989)
  15. Hathaway PE, Davis ME, J. Catal., 119, 497 (1989) 
  16. Unland ML, J. Phys. Chem., 82, 580 (1978) 
  17. Barthomeuf D, J. Phys. Chem., 88, 42 (1984) 
  18. Jacobs PA, Uytterhoeven JB, J. Catal., 50, 109 (1977) 
  19. Hathaway PE, Davis ME, J. Catal., 116, 263 (1989) 
  20. Hathaway PE, Davis ME, J. Catal., 116, 279 (1989) 
  21. Unland ML, Barker GE, U.S. Patent, 4,115,424 (1978)
  22. Unland ML, Freeman JJ, J. Phys. Chem., 82, 1036 (1978) 
  23. Sidorenko YN, Galich PN, Ukt. Khim. Zh., 36, 1234 (1970)
  24. Scokart PO, Rouxhet PG, J. Chem. Soc.-Faraday Trans., 76, 1476 (1980)