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Korean Journal of Chemical Engineering

, Volume 12, Issue 4, pp 454–459 | Cite as

TPD study for direct synthesis of methylchlorosilanes

  • Jong Pal Kim
Article

Abstract

Temperature programmed desorption (TPD) was performed to obtain information about the role of silicon, catalyst (copper), and promoters (zinc and tin), and to characterize the active sites for the formation of silanes. Use of infrared spectroscopy allowed rapid analysis of the gas-phase product composition. During TPD where methyl chloride was used as an adsorbate, methyl chloride (MeCl), hydrogen chloride (HC1), methane (CH4) and silanes were produced from contact masses. Although dimethyldichlorosilane (DMDC), methyltrichlorosilane (MTCS), methyltrichlorosilane (MTCS), trimethylchlorosilane (TMCS) and dimethylchlorosilane (DMCS) were produced during the direct reaction, tetrachlorosilane (QCS), trichlorosilane (TCS), methyltrichlorosilane (MTCS), and methyldichlorosilane (MDCS) were the major silanes observed during the TPD. Zinc promotion to silicon-copper contact mass (CuSi mass) increased the production of TCS, while tin promotion decreased the production of silanes having H atom, and increased the production of MTCS. Copromotion of 0.5 wt% zinc and 0.2 wt% tin increased the MTCS production further; however, the copromotion of zinc (0.5 wt%) and tin containing a small amount of tin (0.01 wt%) produced QCS as a major silane product. The silicon sites having two or three surface species such as CH3, Cl and H were proposed as the active sites responsible for the formation of silanes, and the silicon sites of = SiCl2 and =Si(CH3)Cl were the most abundant under the steady state condition.

Key words

Direct Synthesis Metkylchlorosilanes Promoters TPD 

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References

  1. Agarwala, J. P. and Falconer, J. L., “Kinetics of Methylchlorosilanes Formation on Zinc-Promoted Cu3Si”,Int. J. Chem. Kinetics,19, 519 (1987).CrossRefGoogle Scholar
  2. Banholzer, W. F., Lewis, N. and Ward, W., “Active Site Formation in the Direct Process for Methylchlorosilanes”,J. Catal.,101. 405 (1986).CrossRefGoogle Scholar
  3. Fikhtengol’ts, V. S. and Klebansky, A. L., “Synthesis of Organosilicon Compounds”,J. Gen. Chem. USSR,27, 2535(1957).Google Scholar
  4. Frank, T. C. and Falconer, J. L., “Silanes Formation on Silicon: Reaction Kinetics and Surface Analysis”, Langmuir,1, 104 (1985).CrossRefGoogle Scholar
  5. Frank, T. C., Kester, K. B. and Falconer, J. L., “Catalytic Formation of Silanes on Copper-Silicon Alloys”,J. Catal.,91, 44 (1985a).CrossRefGoogle Scholar
  6. Frank, T. C., Kester, K. B. and Falconer, J. L., “Surface Analysis of Methylchlorosilane Formation Catalysts”,J. Catal.,95, 396 (1985b).CrossRefGoogle Scholar
  7. Gasper-Galvin, L. D., Sevenich, D. M., Friedrich, H. B. and Rethwisch, D. G., “Effects of Promoters on the Catalytic Synthesis of Methylchlorosilanes”,J. Catal.,128, 468(1991).CrossRefGoogle Scholar
  8. Kim, J. P., Ph.D. Dissertation, University of Iowa (1990).Google Scholar
  9. Kim, J. P. and Rethwisch, D. G., “Reaction Kinetics for the Direct Synthesis of Methylchlorosilanes”,J. Catal.,134, 168(1992).CrossRefGoogle Scholar
  10. Pauling, L., “The Nature of the Bond”, Cornell University, New York (1960).Google Scholar
  11. Rochow, E.G., “Direct Synthesis of Organosilicon Compounds”,J. Am. Chem. Soc,67, 963(1945).CrossRefGoogle Scholar
  12. Voorhoeve, R. J. H., “+Organohalosilanes, Precursors to Silicones”, Elsevier, New York, 1967.Google Scholar
  13. Voorhoeve, R. J. H. and Vlugter, J. C., “Mechanism and Kinetics of the Metal-Catalyzed Synthesis of Methylchlorosilanes”.J. Catal.,4, 220(1965).CrossRefGoogle Scholar
  14. Ward, W. J. and Carrol, K. M., “Diffusion of Copper in the Copper-Silicon System”,Electrochem. Soc.J., 129(1), 227(1982).CrossRefGoogle Scholar
  15. Ward, W. J., Ritzer, A., Carroll, K. M. and Flock. J. W., “Catalysis of the Rochow Direct Process”,J. Catal.,100. 240(1986).CrossRefGoogle Scholar

Copyright information

© Korean Institute of Chemical Engineering 1995

Authors and Affiliations

  • Jong Pal Kim
    • 1
  1. 1.Department of Chemical EngineeringDong Eui UniversityPusanKorea

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