Synthesis of mesoporous zeolites in fluoride media with structure directing multiammonium surfactants

Mesoporous zeolite beta in pure -silica form and its analogues, including aluminosilicate, stannosilicate, and titanosilicate, were synthesized at near -neutral pH in the presence of fluoride ion as a mineralizer and piperidinium-functionalized multiammonium surfactant as a zeolite structure -directing agent (SDA). During hydrothermal synthesis, the surfactant headgroup generated zeolite beta frameworks with a thickness of 9 nm while numerous surfactant molecules were self -organized to form a nanosponge-like mesostructure in a disordered manner. The mesopores generated after calcination to remove the surfactant were highly uniform and further. tailored with diameters in the range of 3.2-4.5 nm according to the surfactant tail lengths. MFI zeolite was also synthesized with a nanosheet morphology using C16H33-N+(CH3)(2)-C6H12-N+(CH3)(2)-C6H13 as the SDA in fluoride media. The zeolite samples obtained in this manner exhibited remarkably enhanced thermal stability, Bronsted acid strength, and hydrophobic nature compared to those synthesized at a high pH using OH as the mineralizer due to the reduced defect sites, as confirmed by Si-29 MAS NMR and FT-IR measurements. Due to these advantages, the mesoporous zeolite beta obtained in the fluoride media exhibited high catalytic activity in esterification of oleic acid with methanol. (C) 2016 Elsevier Inc. All rights reserved.
Publisher
ELSEVIER SCIENCE BV
Issue Date
2017-02
Language
English
Keywords

HIGH-SILICA ZEOLITES; BETA-ZEOLITE; CATALYST; NANOSHEETS; WATER; NANOPARTICLES; DESILICATION; DEFECTS; ACIDITY; LEWIS

Citation

MICROPOROUS AND MESOPOROUS MATERIALS, v.239, pp.19 - 27

ISSN
1387-1811
DOI
10.1016/j.micromeso.2016.09.037
URI
http://hdl.handle.net/10203/219595
Appears in Collection
CH-Journal Papers(저널논문)
Files in This Item
There are no files associated with this item.
  • Hit : 260
  • Download : 0
  • Cited 0 times in thomson ci
This item is cited by other documents in WoS
⊙ Detail Information in WoSⓡClick to seewebofscience_button
⊙ Cited 3 items in WoSClick to see citing articles inrecords_button

qr_code

  • mendeley

    citeulike


rss_1.0 rss_2.0 atom_1.0