Synthesis of ZSM-5 via organotemplate-free and dry gel conversion method: Investigating the effects of experimental parameters

• Published in: Journal of solid state chemistry Vol. 279; p. 120969
• Main Authors: Chen, Yan-Hong, Han, Dong-Min, Cui, Hong-Xia, Zhang, Qiang
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.11.2019
• Subjects: Dry gel conversion method; Influence factors; Template free; ZSM-5 zeolite; ZSM-5 zeolite; Dry gel conversion method; Template free; Influence factors
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1016/j.jssc.2019.120969

ZSM-5 zeolite was successfully synthesized in an organic template-free system by a dry gel conversion (DGC) method. The influence factors, such as crystallization temperature, crystallization time, water content in the autoclave and the SiO2/Al2O3 molar ratio in the dry gel, have been investigated systematically. A series of DGC-ZSM-5 zeolites were characterized by XRD, SEM, XRF, BET and NH3-TPD. The results showed that the high crystallinity of ZSM-5 could be obtained without organic template. The content of water in the autoclave and the SiO2/Al2O3 molar ratio have a significant effect on the crystallinity and purity of DGC-ZSM-5. Furthermore, a possible formation mechanism was proposed based on the investigation of the crystallization process. Compared with the zeolite synthesized by hydrothermal method, the DGC-ZSM-5 zeolite not only exhibits much shorter crystallization time and smaller particle size, but also retains the synthesis gel SiO2/Al2O3 molar ratio in the final materials. The crystallization process of ZSM-5 zeolite by a dry gel conversion method. [Display omitted] •Highly crystalline ZSM-5 was prepared without any organic template by a DGC method.•The prepared ZSM-5 zeolite needs shorter crystallization time.•The prepared ZSM-5 zeolite has higher acidic sites and smaller particle sizes.•External bulk water in the autoclave plays a crucial role in crystallization process.