Self-assembly of fibrous ZSM-5 zeolites in the presence of sodium alginate--颗粒学报PARTICUOLOGY

Jiang, J., Ji, S., Duanmu, C., Pan, Y., Wu, J., Wu, M., & Chen, J. (2017). Self-assembly of fibrous ZSM-5 zeolites in the presence of sodium alginate. Particuology, 33, 55-62. https://doi.org/10.1016/j.partic.2017.01.002

Self-assembly of fibrous ZSM-5 zeolites in the presence of sodium alginate

Jinlong Jiang ^{a b c}*, Shoupeng Ji ^a, Chuansong Duanmu ^b, Yichang Pan ^c, Jie Wu ^a, Mei Wu ^a, Jing Chen ^a

a Faculty of Chemical Engineering, Key Laboratory for Palygorskite Science and Applied Technology of Jiangsu Province, Huaiyin Institute of Technology, Huaian 223003, China
b Jiangsu Provincial Engineering Laboratory for Advanced Materials of Salt Chemical Industry, Huaiyin Institute of Technology, Huaian 223003, China
c State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 210009, China

10.1016/j.partic.2017.01.002

Volume 33, August 2017, Pages 55-62

Received 5 August 2016, Revised 30 December 2016, Accepted 2 January 2017, Available online 2 May 2017, Version of Record 13 June 2017.

E-mail: jiangjinlong75@163.com

Highlights

• Fibrous ZSM-5 (F-ZSM-5) zeolites were synthesized in the presence of sodium alginate (SA).

• F-ZSM-5 crystals were composed of nano-sized crystals along the crystallographic b direction.

• The carboxyl and hydroxyl groups of SA synergistically induced the formation of F-ZSM-5.

• The Si/Al molar ratio of F-ZSM-5 zeolites could be adjusted by controlling NaAlO₂ amount.

Abstract

ZSM-5 zeolites with a fibrous morphology were successfully self-assembled in the presence of sodium alginate. The effect of the sodium alginate concentration, Si/Al molar ratio in the synthesis gel, crystallization temperature and time, and the addition order of the sodium alginate on the morphology of the ZSM-5 zeolites was investigated. The possible formation mechanism of fibrous ZSM-5 zeolite crystals was also proposed. The results indicated that the carboxyl and hydroxyl groups of sodium alginate synergistically induced the self-stacking of ZSM-5 nanocrystals and thus the formation of the fibrous ZSM-5 zeolites. The Si/Al molar ratio of the fibrous ZSM-5 zeolites could be adjusted by controlling the amount of the NaAlO₂ additive; however, high Si/Al molar ratios also hindered the self-stacking of ZSM-5 nanocrystals. A high crystallization temperature (180 °C), a moderate sodium alginate concentration (8.33 g/L), and the addition of sodium alginate prior to tetraethoxysilane were necessary for the formation of fibrous ZSM-5 zeolites.

Graphical abstract

Keywords

Fibrous morphology; Self-assembly; Sodium alginate; ZSM-5 zeolite

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