Preparation and Characterization of Core-Shell Structure Fe/Al2O3-Silicalite-1 Pellets

Abstract: The Silicalite-1 zeolite shell can serve as the stabilizer between materials and environment, or enhance the shape selectivity in catalytic reactions. However, it is difficult to directly grow on the surface of many metal oxides. In this paper, the core-shell structure pellets with Fe/Al2O3 core and Silicalite-1 shell were prepared. The Fe/Al2O3 core was prepared by incipient wetness impregnation of ã-Al2O3 pellet with an aqueous solution of Fe(NO3)3•9H2O. Silicalite-1 membranes were synthesized by the secondary growth of the soaking zeolite seeds from ethanol solution on the Fe/Al2O3 pellet. The seeded layers, the Silicalite-1 membranes and the core-shell structure pellets were characterized by scanning electron microscope (SEM) and energy-diffusive X-ray spectroscopy (EDS). SEM and EDS results showed that continuous and compact silicalite-1 membranes had grown on the Fe/Al2O3 pellet without crack. Keywords: Core-shell structure, Silicalite-1 membrane, Secondary hydrothermal growth