Isomerization of n-Dodecane for High Selectivity of Multibranched Iso-dodecane over Pt/ZSM-22 – Y Catalyst

In this study, Pt/ZSM-22, Pt/Y, Pt/ZSM-22 + Y (the support is a mechanically blended mixture of ZSM-22 and Y at 1:1 weight ratio), and Pt/ZSM-22 – Y (the support is NaOH + CTAB-treated ZSM-22 + Y) with 0.5 wt % of Pt loading were synthesized and applied as catalysts in the hydroisomerization of n-dodecane. The microstructures and acidic properties of these catalysts were characterized by XRD, TEM, BET, N2 adsorption–desorption isotherms, NH3-TPD, Py-IR, and 27Al-NMR. This study revealed significantly different acidic properties and catalytic performances between the mechanically mixed Pt/ZSM-22 + Y and post-treated Pt/ZSM-22 – Y. In particular, Pt/ZSM-22 – Y not only delivers a high n-dodecane conversion but also significantly enhances the yield and selectivity of multibranched iso-dodecane. This enhanced selectivity of multibranched iso-dodecane may be attributed to the high number of medium-strong acid sites and increased mesopores generated by the post-treatment process.