Indexed by:期刊论文

Date of Publication:2019-01-29

Journal:RSC ADVANCES

Included Journals:SCIE、Scopus

Volume:9

Issue:7

Page Number:3653-3660

ISSN No.:2046-2069

Key Words:Aluminum compounds; Pore structure; Silica; Sodium compounds; Zeolites, Acidic properties; Hierarchical pores; Hydrothermal methods; Internal defects; Nano aggregates; Possible mechanisms; SiO2/Al2O3 ratio; Species distributions, Fluorine compounds

Abstract:An aerosol-assisted hydrothermal method has been applied to synthesizing hierarchical beta zeolites with SiO2/Al2O3 ratios ranging from 44 to 392 in NaF media. Two different morphologies, including nano-aggregates with interparticle mesopores and plate-like zeolites with intracrystalline mesopores, can be formed depending on the SiO2/Al2O3 ratios of the synthesis gels. A possible mechanism for the formation of the beta zeolites has been proposed. The obtained beta zeolites show hierarchical pores, good Al species distribution and less internal defect sites. Evaluation, by the cracking of 1,3,5-triisopropylbenzene (1,3,-TIPB), is consistent with the acidic properties and the pore structure of beta zeolites with different ratios of SiO2/Al2O3.