Akademik Veri Yönetim Sistemi
JOURNAL OF THE FACULTY OF ENGINEERING AND ARCHITECTURE OF GAZI UNIVERSITY, cilt.24, sa.2, ss.369-377, 2009 (SCI-Expanded)
In the content of this study, silica supported Fe-MCM-48 catalysts were produced using direct hydrothermal synthesis (Fe-MCM-48-1) and wet-impregnation (Fe-MCM-48-2) methods and an unsupported Fe-Mo-O catalyst was produced using a co-precipitation method. AAS, XRD and BET results showed that with the hydrothermal synthesis method, high amounts of iron (Fe/Si(in solid) = 0.56) could be incorporated into the catalyst, however, the MCM-48 structure was deteriorated, formation of significant amounts of Fe2O3 phase was observed and BET surface area (214 m(2)/g) was low. When iron was incorporated into the MCM-48 structure by the wet-impregnation method, AAS, XRD and BET results showed that less iron could be incorporated (Fe/Si(in solid) = 0.12) with respect to hydrothermal synthesis, however, cubic porous structure of MCM-48 was preserved and BET surface area (982 m(2)/g) was very high. Characterization results for the Fe-Mo-O catalyst showed that the catalyst had regular crystalline structure and possessed the Fe-2(Mo4O)(3) and MoO3 phases, however, its BET surface area was very low (12 m(2)/g) compared to the silica based catalysts. It was also seen that the Fe-MCM-48-1 and Fe-Mo-O catalysts had non-homogeneous pore size distributions and the Fe-MCM-48-2 catalyst had homogeneous mesoporous size distribution centered around 2.8 nm.