Surfactant-assisted hydrothermal synthesis of core-shell ZSM-5@SSZ-13 zeolite for methanol to olefins reaction

Abstract

Core-shell structured ZSM-5@SSZ-13 (Z@S-1) zeolite composites were successfully synthesized via adding SSZ-13 modified with a surfactant into ZSM-5 synthetic gel under hydrothermal conditions. The presence of surfactant improved the problems of chemical compatibility and charge matching between zeolites with different topological structures. The factors that controlled the formation of Z@S-1 had been studied in detail. The crystalline phase, morphology, aperture properties and acidity of the samples were characterized by XRD, SEM, N2 adsorption-desorption and NH3-TPD, respectively. The Z@S-1 catalyst exhibits good catalytic performance in the methanol-to-olefins (MTO) reaction compared to SSZ-13 and ZSM-5, owing to its hierarchical structure, suitable acidity, as well as the synergistic catalytic effect with ZSM-5 and SSZ-13. In this work, a simple and facile approach was proposed to synthesized core-shell zeolite composite, which had better to improve chemical compatibility issues derived from different topologies.