10.1021/acs.chemmater.8b00109.s001
Maria Castro
Maria
Castro
Pit Losch
Pit
Losch
Woojin Park
Woojin
Park
Mohamed Haouas
Mohamed
Haouas
Francis Taulelle
Francis
Taulelle
Claudia Loerbroks
Claudia
Loerbroks
Gert Brabants
Gert
Brabants
Eric Breynaert
Eric
Breynaert
Christine E. A. Kirschhock
Christine
E. A. Kirschhock
Ryong Ryoo
Ryong
Ryoo
Wolfgang Schmidt
Wolfgang
Schmidt
Unraveling Direct Formation of Hierarchical Zeolite
Beta by Dynamic Light Scattering, Small Angle X‑ray Scattering,
and Liquid and Solid-State NMR: Insights at the Supramolecular Level
American Chemical Society
2018
N 6
solution
1 H-DOSY NMR probe
nano-Beta zeolite crystals
Hierarchical Zeolite Beta
formation
mesopore
diphe
Dynamic Light Scattering
spinodal decomposition-type segregation
nm
2018-03-12 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Unraveling_Direct_Formation_of_Hierarchical_Zeolite_Beta_by_Dynamic_Light_Scattering_Small_Angle_X_ray_Scattering_and_Liquid_and_Solid-State_NMR_Insights_at_the_Supramolecular_Level/6116099
A case
study on the understanding of the formation of hierarchical
Beta zeolites using gemini-type piperidine based multiammonium surfactant
(N<sub>6</sub>-diphe) is reported. Complementary techniques were used
to investigate N<sub>6</sub>-diphe’s structure-directing effect
at the molecular level. Combining characterization of the resulting
zeolite materials with the toolboxes herein developed for studying
clear solutions and dense gels discloses self-assembly processes that
govern the growth (and growth inhibition) of nano-Beta zeolite crystals.
In clear solution, small-angle X-ray scattering and liquid-state NMR
provide insights about the formation of nanoparticles and their degree
of order. <sup>14</sup>N and <sup>1</sup>H-DOSY NMR probe the dynamics
and mobility of soluble species. In a dense gel, on the other side, <sup>27</sup>Al- and <sup>29</sup>Si-(MAS) NMR elucidate the varying local
connectivity between initial nano-objects and the final solid products.
It has been found that cylindrical micelles control the transformation
of solubilized silica and alumina during the formation of zeolite
nuclei and guide their crystal growth to nano-Beta rods with bimodal
mesoporosity. The predominant smaller mesopores (6 to 8 nm) originate
from the template’s hydrophobic alkyl chains, while larger
mesopores (10 to 30 nm) are supposed to result from a spinodal decomposition-type
segregation of phases consisting of as-formed hydrophobic zeolite
rods and an aqueous solution.