Isomerization of endo-tetrahydrodicyclopentadiene over Y zeolite catalysts

Synthesis of exo-tetrahydrodicyclopentadiene (exo-THDCPD) through the isomerization of endo-tetrahydrodicyclopentadiene (endo-THDCPD) was investigated over HY zeolite catalysts. Conversion of endo-THDCPD increased with the increase of Si/Al₂ ratio of HY zeolite catalysts, which can be attributed to increase of acid strength with increase of Si/Al₂ ratio. Yield of exo-THDCPD, however, was the highest over HY with Si/Al₂ ratio of 30, because the production of cyclopentadiene and oligomers was minimized. The optimal reaction temperature was 180°c because the higher reaction temperature increased the production of by-products. The yield of exo-THDCPD also increased with the amount of the catalyst in feed. In the isomerization reaction of endo-THDCPD using the HY zeolite catalysts, it was confirmed that the internal diffusion resistance in the pore of catalysts would have more significant effects on the reaction activity than that of the external diffusion resistance of catalysts.