Recrystallization on Alkaline Treated Zeolites in
the Presence of Pore-Directing Agents
Eddy Dib
Hussein El Siblani
Shrikant M. Kunjir
Aurelie Vicente
Nicolas Nuttens
Danny Verboekend
Bert F. Sels
Christian Fernandez
10.1021/acs.cgd.7b01416.s001
https://acs.figshare.com/articles/journal_contribution/Recrystallization_on_Alkaline_Treated_Zeolites_in_the_Presence_of_Pore-Directing_Agents/6002072
In
previous works aiming at understanding the mesoporous network
after alkaline treatment in the presence of organic additives, conventional
bulk characterization techniques led to the conclusion that the dissolved
zeolite does not undergo any kind of recrystallization [Verboekend, D., Cryst. Growth. Des. 2013, 13, 5025−5035]. Here for the first time, we demonstrate
using the data obtained from <sup>1</sup>H and <sup>129</sup>Xe NMR
spectroscopy that such recrystallization does occur, which leads to
the formation of a very thin coating of the mesopore walls. This demonstration
is done on a beta (BEA) zeolite treated in the presence of TPA<sup>+</sup> in an alkaline solution. The formation of a small amount
of nanosized crystals or embryonic phases of silicalite-1 (MFI) zeolite
is evidenced, as well as their homogeneous dispersion on the mesoporous
surface of the beta zeolite. We think that these results may explain
why a homogeneous mesopore size distribution is obtained, when organic
pore-directing agents are used in the zeolite hierarchization process
performed in an alkaline medium.
2018-03-14 00:00:00
129 Xe NMR spectroscopy
beta zeolite
BEA
presence
Alkaline Treated Zeolites
nanosized crystals
pore-directing agents
zeolite hierarchization process
recrystallization
mesoporous network
TPA
mesopore walls
1 H
mesopore size distribution
formation
bulk characterization techniques
mesoporous surface
Pore-Directing Agents
MFI