Synthesis and characterization of a novel hierarchical ZSM-5 zeolite using bi-template method

The main purpose of this project is the synthesis and identification of a novel hierarchicalZSM-5 zeolite by hydrothermal method using soft template. At first, hierarchical ZSM-5sample was made using KIT-6 as the source of silica, and TPAOH (tetrapropylammoniumhydroxide) and CTAB (cetyltrimethylammonium bromide) as microporous and mesoporousdirecting templates. Then, the effect of parameters such as the concentration of CTAB andNaOH on structure formation mechanism were investigated. Another purpose of the project isto expand mesopores, in order to increase the activity and lifetime of the catalyst, which wasdone in the presence of TMB (trimethylbenzene) as an expander molecule. High surface area,high pore volume of mesopores, high acidity, regular morphology and high degree ofcrystallization are the characteristics of the hierarchical zeolite synthesized by this method.After successful synthesis of hierarchical ZSM-5 zeolite, it was used as a catalyst. Undersuitable conditions, Ni metal nanoparticles were applied on its surface and then it was used asan acid-metal bifunctional catalyst to reduce nitro aromatic compounds in water medium atambient temperature. This catalyst showed high efficiency, short reaction time and highlifetime in the reaction. XRD, BET, FE-SEM, TPD, FT-IR and TEM analyzes were used todetermine the physical and chemical properties of the synthesized hierarchical zeolites, and toconfirm the installation of metal nanoparticles on its surface.

کلیدواژه ها:

Hierarchical ZSM-5 ، Bi-template method ، CTAB