Industrial & Engineering Chemistry Research, Vol.50, No.13, 7896-7902, 2011
Sn-Modified ZSM-5 As Support for Platinum Catalyst in Propane Dehydrogenation
Sn modified ZSM-5 was hydrothermally synthesized and this kind of zeolite was used as the support for platinum catalyst in propane dehydrogenation. In this tin-doped material, XRD results established the presence of highly crystalline and the analysis of SEM showed the deterioration in crystal quality. The incorporation of Sn into the framework of ZSM-5 zeolite introduced the strong interactions between Sn species and the support, thus more amounts of tin could exist in oxidized form. Moreover, on the Sn-containing PtNa/Sn-ZSM-5 catalyst, the substitution of Sn changed the interfacial character between Pt and the support, which in consequence promoted the occurrence of spillover hydrogen and facilitated the reduction of Pt species. Compared with the conventional impregnated PtNa/HZSM-5 and PtSnNa/HZSM-5 catalysts, the Sn-modified ZSM-5-based Pt catalyst exhibited higher reaction activity and stability. It showed the lowest deactivation parameter (6.2%) and exhibited a selectivity to propene higher than 98% with the corresponding propane conversion of about 39.0% after the reaction for 9 h.