Seed-induced synthesis of hierarchical architectures of ZSM-5 nanocrystalline aggregates by the solid state crystallization

• Published in: Advanced powder technology : the international journal of the Society of Powder Technology, Japan Vol. 33; no. 8; p. 103666
• Main Authors: Chen, Yan-Hong, Han, Dong-Min, Zhang, Qiang
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.08.2022
• Subjects: Crystallization kinetics; Solid state conversion method; Zeolite seed solution; Zeolite ZSM-5 aggregates; Zeolite seed solution; Zeolite ZSM-5 aggregates; Solid state conversion method; Crystallization kinetics
• ISSN: 0921-8831; 1568-5527
• DOI: 10.1016/j.apt.2022.103666

[Display omitted] •ZSM-5 nanocrystalline aggregates were prepared by seed-induced method.•Zeolite seed solution leads to samples with enhanced textural properties.•No mesoporogen was introduced for the synthesis of hierarchical ZSM-5 zeolite.•The aluminum content and alkalinity are crucial for the morphology of samples.•The synthetic method will be feasible in the economy and environmental protection. A seed-induced rapid synthesis of hierarchical ZSM-5 aggregates was achieved by the solid state conversion method in an inorganic system. No secondary mesoporogen was introduced to construct supplementary pore. The physical and chemical properties of the products were characterized by using XRD, SEM, TEM, XRF and N2 adsorption–desorption techniques. The results revealed that the synthesized samples typically exhibit the uniform spherical zeolite ZSM-5 aggregates composed of loosely packed nanocrystals. It was clearly found that the morphology, mesoporosity and particle size of synthesized samples were directly affected by the type of the seed and synthesis conditions. The well-dispersed hierarchical ZSM-5 aggregates were synthesized at NaOH/SiO2 = 0.15, 20 ≤ SiO2/Al2O3 ≤ 40 with the acid of zeolite seed solution in guiding the structure. In addition, the crystal growth of zeolite samples synthesized with zeolite seed solution was studied at 433, 453, and 473 K. The results suggested that the activation energies for the induction, transition and crystallization stages were 91.44, 104.37 and 77.68 kJ∙mol−1, respectively. The method provides a cost-effective and industrially applicable route to synthesize hierarchical ZSM-5 aggregates.