Low temperature hydrocracking of paraffinic hydrocarbons over hybrid catalysts

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A hybrid catalyst, which was prepared by physically mixing of a H-ZSM-5 and a Pd/SiO2, showed an excellent activity for the hydrocracking of paraffins at low reaction temperature (503 K). In the n-heptane cracking, the hybrid catalyst gave only isomerized heptane and propane and equimolar amount of i-butane whereas the products on H-ZSM-5 alone distributed from C3 to C9 and C4 products contained all kind of paraffins and olefins. The wide product distribution for H-ZSM-5 system should be attributed to the reaction path comprising oligomerization and cracking of the oligomer. The simple products for the H2-hybrid system should be formed through no other reaction path than the primary cracking reaction on H-ZSM-5, which proceeds through a intermediate containing the protonated dialkylcyclopropane structure, while the hydrocracking reaction over Pd-mordenite hybrid catalyst proceeds via ß-scission of the carbenium ion.

References (10)

  • K. Fujimoto et al.

    Applied Catal.

    (1992)
  • N.Y. Chen et al.

    J. Catal.

    (1978)
  • P.A. Jacobs et al.

    Zeolites

    (1981)
  • J. Weitkamp et al.

    Appl. Catal.

    (1983)
  • B.S. Greensfelder et al.

    Ind. Eng. Chem.

    (1949)
There are more references available in the full text version of this article.

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