Solid state transformation of TEAOH-intercalated kanemite into zeolite beta (BEA)

Abstract

The work reported herein involves the synthesis of zeolite beta by solid state transformation of TEAOH-intercalated kanemite, at 140 °C, under autogenous pressure. A series of TEAOH-intercalated kanemite samples were prepared by intercalation of kanemite with TEAOH at room temperature followed by centrifugation and drying at 35 °C for 24 h. The XRD, TG-DTA and chemical analyses of the TEAOH-intercalated kanemite samples revealed that either the TEAOH molecules were intercalated into the interlayer spaces or strongly adsorbed onto the outer surfaces of kanemite. Zeolite beta samples in high yields (71–97%) were obtained by solid state transformation of TEAOH-intercalated kanemite samples having moderate amounts of TEAOH (TEAOH/SiO₂ = 0.11–0.23). The XRD measurements showed that the zeolite beta samples obtained from the present method were phase-pure and highly crystalline. SEM studies revealed that the zeolite beta samples were composed of agglomerated crystallites. For the zeolite beta samples, surface areas of as high as 586 m² g⁻¹ were observed by the BET method. In addition, the zeolite beta sample (SiO₂/Al₂O₃ = 12) obtained from TEAOH-intercalated kanemite was found to be active for the cracking of n-hexane and its performance was comparable to a standard zeolite beta sample (SiO₂/Al₂O₃ = 20).