A Zeolite Family Nonjointly Built from the 1,3-Stellated Cubic Building Unit

Article abstract of DOI:10.1002/anie.201712885

From a technological point of view, the synthesis of new high-silica zeolites is of prime importance owing to their high potential as industrial catalysts and catalyst supports. Two such materials have been synthesized which are made up of the 1,3-stellated cubic unit (hexahedral ([4²5⁴]) bre unit) as a secondary building unit, with the aid of existing imidazolium-based structure-directing agents under “excess fluoride” conditions. One of them, denoted PST-21, is the first aluminosilicate zeolite consisting of 9-ring apertures solely; it displays exceptional activity towards steering the skeletal isomerization of 1-butene to isobutene and bridges the gap between small- and medium-pore structures. A series of hypothetical structures are also described that are nonjointly built from the bre unit; all of these structures are chemically feasible and will thus be helpful in designing the synthesis of novel zeolites containing 9-ring and/or 10-ring channels.

Full text of DOI:10.1002/anie.201712885

A Journal of the Gesellschaft Deutscher Chemiker
Angewandte
International Edition Chemie
www.angewandte.org
Accepted Article
Title: A Zeolite Family Nonjointly Built from the 1,3-Stellated Cubic
Building Unit
Authors: Donghui Jo, Gi Tae Park, Jiho Shin, and Suk Bong Hong
This manuscript has been accepted after peer review and appears as an
Accepted Article online prior to editing, proofing, and formal publication
of the final Version of Record (VoR). This work is currently citable by
using the Digital Object Identifier (DOI) given below. The VoR will be
published online in Early View as soon as possible and may be different
to this Accepted Article as a result of editing. Readers should obtain
the VoR from the journal website shown below when it is published
to ensure accuracy of information. The authors are responsible for the
content of this Accepted Article.
To be cited as: Angew. Chem. Int. Ed. 10.1002/anie.201712885
Angew. Chem. 10.1002/ange.201712885
Link to VoR: http://dx.doi.org/10.1002/anie.201712885
http://dx.doi.org/10.1002/ange.201712885

Angewandte Chemie International Edition
10.1002/anie.201712885
COMMUNICATION
A Zeolite Family Nonjointly Built from the 1,3-Stellated Cubic
Building Unit
+
+
Donghui Jo , Gi Tae Park , Jiho Shin, and Suk Bong Hong*
Abstract: From a technological point of view, the synthesis of new
high-silica zeolites is of prime importance owing to their high potential
as industrial catalysts and catalyst supports. We report the synthesis
of two such materials made up of the 1,3-stellated cubic unit
TNU-10 (STI) whose syntheses are strongly influenced by the
-
concentrations of OH and Al in the aluminosilicate gel containing
1,4-bis(N-methylpyrrolidinium)butane as an OSDA.[4] While the
-
simultaneous use of high equimolar concentrations of F and
2
4
(
hexahedral ([4 5 ]) bre unit) as a secondary building unit, with the aid
of existing imidazolium-based structure-directing agents under
excess’ fluoride conditions. One of them, denoted PST-21, is the first
OSDA has been quite successful for the discovery of novel zeolite
structures,[ on the other hand, the isomorphous substitution of Si
by Al atoms in the zeolite framework can compete with the
5]
‘
-
aluminosilicate zeolite consisting of 9-ring apertures solely, with
exceptional activity towards skeletal isomerization steering of 1-
butene to isobutene, which bridges the gap between small and
medium pore structures. We also describe a series of hypothetical
structures nonjointly built from the bre unit, all of which are chemically
feasible and will thus be helpful in designing the synthesis of novel
zeolites containing 9-ring and/or 10-ring channels.
encapsulation of F within many different types of small cages of
the crystallized products, as well as within larger void spaces, and
thus change the phase selectivity of the crystallization. Unlike the
case in basic media, however, little attention has been paid to the
-
concentration effect of F as an inorganic synthesis parameter on
the zeolite product.
6
The double 4-ring (d4r or [4 ]), which contains 8 T-atoms at its
corners bonded through O bridges along the cube edges, can be
metamorphosed in many ways. One simple modification is the
stellation of a pair of diagonally opposite edges,[6] yielding the 10T
Zeolites and related microporous materials are among the most
important inorganic solids, finding commercial applications in
diverse areas, notably in catalysis and separation.[1] This is largely
due to the continuous discovery of zeolitic materials with
unprecedented framework structures and/or compositions that
has facilitated current process improvements and innovative
technology developments. Zeolites are classified as small,
medium, large, and extra-large pore structures containing rings of
2
4
1,3-stellated cubic unit (Figure 1a). This small cage ([4 5 ]) was
first identified in the natural zeolite brewsterite (BRE) and then
named the bre unit.[7] While there are a total of 45 hypothetical
zeolite structures generated by sharing its corners, edges, or
[8]
faces, only four of them have been found in nature or
[2]
synthesized in the laboratory: the HEU, RRO, and STI structures
are a result of corner-sharing, and the BRE structure of edge-
sharing (Figure S1). However, no zeolite structures consisting of
nonjointly connected bre units solely, i.e., containing this cage as
a secondary building unit (SBU), have so far been proposed or
discovered. Here we report the synthesis of two novel, high-silica
zeolites denoted PST-21 and PST-22, respectively, achieved at a
8, 10, 12, and more than 12 tetrahedral atoms (T-atoms; most
commonly, Si, Al, and P) linked by two-coordinated oxygen atoms,
respectively, and there are today over 230 distinct framework type
codes (FTCs) recognized by the International Zeolite
Association.[ Given the excellent (hydro)thermal stability of
trivalent Al atoms in the silica framework compared to other
heteroatoms, the synthesis of aluminosilicate zeolites with new
framework topologies is in high demand from an application point
of view. In the last decade, however, only a handful of them,
including ERS-18, ITQ-39, and CIT-7,[3] have been reported and
given FTCs, revealing the need to develop a more effective
strategy for synthesizing them.
2]
-
high F concentration (HF/OSDA = 2.0) in the presence of well-
studied imidazolium-based OSDAs.[9] While their structures are
nonjointly made up of bre units, PST-21 is the first aluminosilicate
zeolite containing 9-ring channels only and outperforms any of the
earlier catalysts in selectively isomerizing 1-butene to isobutene.
We also present ten feasible hypothetical zeolite structures
formed of the same SBU, with 8-, 9- and/or 10-ring pores, which
should stimulate the development of synthetic strategies towards
such new zeolites.
We performed the synthesis of zeolites using methyl-
substituted imidazolium cations as an OSDA and synthesis
mixtures with different Si/Al (5-∞) and HF/OSDA (0.5-4.0) ratios
at 175 °C for 14 days. When the HF/OSDA ratio in synthesis
mixtures is fixed to 1.0 or lower, the crystallized products were
always known zeolites, such as ITQ-12 (ITW), ferrierite (FER),
Zeolite synthesis is typically carried out under hydrothermal
conditions (100-200 °C) using a synthesis mixture containing
inorganic structure-directing agents (ISDAs; alkali and/or alkaline
cations, hydroxide or fluoride anions, and heteroatoms other than
Si) and/or organic structure-directing agents (OSDAs; amines or
alkylammonium ions). The crystallization of most zeolites requires
the use of OSDAs. However, its phase selectivity can also be
sensitive to the type and concentration of ISDAs employed. A
good example is medium pore materials TNU-9 (FTC TUN) and
ZSM-5 (MFI), and HPM-1 (STW), the crystallization of which using
OSDAs employed here has already been reported,[
9b,c]
regardless
of their Si/Al ratio and type of OSDA (Table S1). A similar trend
was observed for the synthesis using pure-silica mixtures with
HF/OSDA = 2.0. However, the addition of Al to this mixture led to
changes in the zeolite product: PST-21 and PST-22 were the
phases that crystallized from mixtures with Si/Al = 10 containing
1,2,3-trimethylimidazolium and 1,3,4-trimethyl-imidazolium or
1,2,3,4-tetramethylimidazolium cations as an OSDA, respectively
(Table 1). A further increase of the HF/OSDA ratio in the mixture
[
*]
D. Jo,[+] G. T. Park,[+] Dr. J. Shin, Prof. S. B. Hong
Center for Ordered Nanoporous Materials Synthesis
Division of Environmental Science and Engineering
POSTECH, Pohang 37673 (Korea)
E-mail: sbhong@postech.ac.kr
[+
]
These authors contributed equally to this work.
Supporting information for this article is given via a link at the end of
the document.
This article is protected by copyright. All rights reserved.

Angewandte Chemie International Edition
10.1002/anie.201712885
COMMUNICATION
No significant changes in the
positions and relative intensities of
most of the X-ray peaks, when
calcined at 600 °C to remove the
occluded OSDAs (Figures S2 and
S3), were observed for PST-21
and PST-22 (Figure S4), revealing
the good stability that is further
supported by 27Al and Si magic
angle spinning (MAS) nuclear
29
magnetic
resonance
(NMR)
spectroscopies (Figures S5 and
S6). More interestingly, although
both novel zeolites were obtained
under excess fluoride conditions
(
HF/OSDA = 2.0), their as-made
form was found to have negligible
F contents as evidenced by 19F
MAS NMR (Figure S7). We are
now
investigating
the
2
4
Figure 1. a) The double 4-ring (left) and its 1,3-stellated unit (right), i.e., the bre ([4 5 ]) unit. The distinct T-atoms in
the latter unit are indicated by red circles. b) The building chain (left) and layer (right) nonjointly comprised of bre
concentration F- effect on their
crystallization using multinuclear
solid-state NMR, and the results
will be given elsewhere.
g
units. Two adjacent building chains (denoted a and a , respectively) are related to each other by a glide symmetry and
connected to form the alternating 4- and 5-rings. The bonds interconnecting each bre unit are represented by red
dotted lines. c) The PST-21 (upper) and PST-22 (bottom) structures viewed along the c axis. Building chains a and ag
are marked in purple and orange, respectively. The building layers in these two structures are stacked in sequences
AAAA… and AA AA … along the a axis, respectively, where the subscript t indicates the simultaneous translation from
the original layer by 0.5b and 0.5c. The PST-21 structure consists of 9-ring channels only, whereas the PST-22
structure comprises of 10-ring channels interconnected by 8-ring apertures. d) Tiling presentation of the PST-21
From
N
2
adsorption
t
t
experiments on their proton form,
or H-PST-21 and H-PST-22, the
(
upper) and PST-22 (bottom) structures. Notice that the 10-ring channels in PST-22 are sinusoidal. Bridging O atoms
micropore volume was calculated
to be 0.18 and 0.16 cm3 g-1,
have been omitted for clarity.
respectively (Figure S8). The
scanning electron micrographs
to 3.0 did not give these two new zeolites or slowed down their
formation. Also, the replacement of Al with the equivalent amount
of B or Ga, under the conditions where their crystallization proved
to be highly reproducible, did not yield them at all (Table S2). It is
worth noting that the Si/Al ratios of as-made PST-21 and PST-22
are always close to 10, regardless of the ratios in their synthesis
show that these two zeolites appear as aggregates of heavily
overlapped thin (< 0.1 μm) plates (Figure S9). Synchrotron
powder X-ray diffraction and Rietveld analyses (Figure S10 and
Tables S3-S7) reveal that both PST-21 and PST-22 structures are
built from the same new building layer containing 4- and 5-rings,
[10]
but not 6-rings, tentatively designated layer pst-21 (Figure 1b).
-
mixtures. Thus, the amount of Al and F in the synthesis mixture
may be critical for directing the crystallization of both zeolites.
Notice that this layer is nonjointly constructed from the bre unit
with five distinct T-sites (Figure 1a). Layer pst-21 can also be
considered as a combination of chains in which the bre unit is
consecutively connected through the T5 atom along the c axis. Its
g
g
building chains are connected in the sequence aa aa …, where
chains a and ag are related by a glide symmetry, to form
alternating 4- and 5-rings between adjacent chains.
Table 1: Aluminosilicate zeolite syntheses using imidazolium-based OSDAs at
different HF concentration.[a]
HF/R
Product[b]
134TMI
On the other hand, the pst-21 layers are stacked one another
along the a axis through the linkage between the T4 atoms in
13DMI
123TMI
1234TMI
12345PMI
t
t
t
sequences AAAA… and AA AA …, where layer A is translated
from layer A by 0.5b and 0.5c, yielding the PST-21 and PST-22
structures, respectively (Figures 1c and S11). We note here that
0
1
2
3
4
.5 FER
.0 A + (U)
.0 FER + A
RTH + ITW FER
RTH + ITW FER + (U)
RTH
RTH + ITW RTH
PST-22 RTH
PST-22 + A RTH + A
RTH
g
chains of the same type (a or a ) are connected within the PST-
PST-21
ITW
D
PST-22
TON + A
D
21 structure in a stacked manner. In contrast, chains of different
types (a and a ) are connected in the PST-22 structure due to the
translation relating the adjacent layers. Such a difference in
interlayer stacking sequence causes discrepancies in their largest
ring size. As shown in Figure 1, PST-21 has a two-dimensional
.0
.0
D
D
g
D
D
[
a] The synthesis mixture composition is 0.5ROH·xHF·1.0SiO
2
2 3
·0.05Al O ·
5
.0H O, where R is OSDA and x is varied between 0.25 ≤ x ≤ 2.0. All
2
syntheses were performed under rotation (60 rpm) at 175 °C for 14 days.
OSDA abbreviations: 13DMI, 1,3-dimethylimidazolium; 123TMI, 1,2,3-
trimethylimidazolium; 134TMI, 1,3,4-trimethylimidazolium; 1234TMI, 1,2,3,4-
tetramethylimidazolium; 12345PMI, 1,2,3,4,5-pentamethylimidazolium. [b] The
product appearing first is the major phase, and the product obtained in a trace
amount is given in parentheses. A, U, and D indicate amorphous, unknown,
and dense phases, respectively.
(
5
2D) pore system consisting of mutually intersecting 9-ring (4.3 ×
.4 Å) channels only. Thus, this zeolite fills the gap between small
(8-ring) and medium (10-ring) pore materials so that it can be
useful in better understanding the fundamentals of shape
selectivity in zeolites. PST-22 is also a 2D zeolite, but contains
sinusoidal 10-ring (5.7 × 5.8 Å) channels interconnected by 8-ring
This article is protected by copyright. All rights reserved.

Angewandte Chemie International Edition
10.1002/anie.201712885
COMMUNICATION
Figure 2. a) 1-Butene conversion and b) selectivity to and c) yield in isobutene
-
1
-1
at 400 °C and 7.5 h WHSV and d) yield in isobutene at 400 °C and 24.0 h
WHSV in the 1-butene skeletal isomerization over H-ferrierite, H-PST-21, and
H-PST-22. The bulk Si/Al ratios of the zeolite catalysts are 8.9, 10, and 11,
respectively.
Figure 3. Tiling presentation of four hypothetical zeolite structures built up of
pst-21 layers in different stacking sequences: a) PST-21_H1, b) PST-21_H2,
c) PST-21_H3, and d) PST-21_H4. They were created by stacking the pst-21
(
2.7 × 6.0 Å) pores (Figure S12). The 9- and 10-ring channels in
these two structures comprise of unprecedented 18-hedral
6
8
4
6
8
2
2
[
2
4 5 9 ] and [4 5 8 10 ] cavities, respectively. By contrast, PST-
1 and PST-22 are characterized by quite similar framework
90°
90°
180°
180°
layers along the a axis in sequences AA AA …, AA AA …,
90°+t
90°+t
180°+t
180°+t
x°
x°+t
AA
AA
…, and AA
AA
…, where layers A and A are obtained
by rotating layer A by x° (x = 90 or 180), without and with the subsequent
translation by 0.5b and 0.5c, respectively.
densities (17.1 and 17.2, respectively; defined as the number of
T-atoms per 1000 Å ).
3
From competitive cracking of n-hexane and 3-methylpentane,
H-PST-21 and H-PST-22 were calculated to have constraint
indices of 6.4 and 11.2, respectively, which fall within the values
for medium pore materials (Figure S13).[11] The skeletal
isomerization of 1-butene to isobutene has long been of both
scientific and technological interest, and the medium pore zeolite
H-ferrierite, whose pore architecture is the same as that of PST-
however, PST-21 may be potentially useful as a novel shape
selective catalyst in the conversion of some slender hydrocarbons,
which could also be the case of PST-22.
The centroids of bre units in layer pst-21 can be considered as
nodes of the (4,4) net topology (Figure S15). When the framework
atoms are included, the resulting tetragonal net is divided into two
types of blocks N and Nm that have a mirror symmetry (m) with
respect to each other, giving it a checkerboard-like array. If so,
the PST-21 structure could be generated by overlapping N and
Nm with themselves along the a axis, respectively. Also, the PST-
2
2, is one of the most widely studied and best catalysts for this
reaction.[
12]
We reacted H-PST-21 (Si/Al = 10) and H-PST-22
Si/Al = 11) with 1-butene at 400 °C and 7.5 h-1 weight hourly
(
space velocity (WHSV) and compared the results with those of H-
ferrierite with a slightly lower Si/Al ratio of 8.9. Interestingly, H-
PST-21 is characterized by a higher 1-butene conversion and a
higher isobutene selectivity over 10 h on stream than H-ferrierite
2
2 structure is obtained when N overlaps with Nm along the same
axis between its adjacent layers, and vice versa. These lines of
m
reasoning led to consider the possibility that blocks N and N with
(
Figure 2), despite its larger amount (12.3 vs 8.1 wt%) of coke
a pseudo-square shape could be linked in a manner different from
that observed for PST-21 or PST-22. We were able to generate
four new hypothetical structures, one of which contains 9-ring
channels only, but smaller than those in PST-21, by selecting the
four-fold rotation as an interlayer symmetry operation, with and
without translation present (Figures 3, S16, and S17 and Tables
S9 and S10). All these structures were calculated to have
deposited. While a similar result was observed for H-PST-22, it is
clear that the desired product (isobutene), as well as the reactant
(
1-butene), can diffuse freely through the 9-ring channels in H-
PST-21.
-1
When WHSV increases to 24.0 h , H-PST-21 showed
considerably higher resistance to deactivation than H-PST-22 and
H-ferrierite (Figure 2d). The acidic properties of H-PST-21 and H-
PST-22 were found to be similar to those of H-ferrierite (Figure
S14). Therefore, the excellent durability of H-PST-21 can be
mainly due to its unique 2D pore structure, because the 8-ring of
-
framework energies relative to α-quartz lower than 30 kJ (mol Si)
1
and to satisfy all local interatomic distances criteria (Tables S9
and S11),[14] revealing their high synthetic accessibility.
.2-5.0 Å.[13] H-PST-21 was not active for aromatic hydrocarbon
We also investigated whether the nonjoint intralayer connection
of bre units different from the connection in PST-21 is possible.
To efficiently create feasible hypothetical layers, we developed a
4
conversions, such as toluene disproportionation and m-xylene
isomerization and disproportionation (Table S8), probably
because of the small 9-ring pore size. As evidenced in Figure 2,
2D-1D deconstruction-reconstruction process (Supporting
Information, text, Figures S18-S21, and Tables S12-S14) that, for
This article is protected by copyright. All rights reserved.

Angewandte Chemie International Edition
10.1002/anie.201712885
COMMUNICATION
example, allowed us to obtain one 1D building chain type
nonjointly consisting of bre units, tentatively denoted chain bre, by
deconstructing the layer in the BRE structure and then an
unprecedented 2D building layer named layer bre_L1 (Figure
S20). Throughout this strategy, we were able to generate one
more novel hypothetical layer and, eventually, six feasible zeolite
structures built from these two hypothetical layers (Tables S13
and S14). We note that among the known zeolite structures, the
AFR, JSN, OWE, SFO, and ZON and LAU structures can be
[5]
a) M. A. Camblor, L. A. Villaescusa, M. J. Díaz-Cabañas, Top. Catal.
1
999, 9, 59-76; b) M. Moliner, F. Rey, A. Corma, Angew. Chem. Int. Ed.
013, 52, 13880-13889; Angew. Chem. 2013, 125, 14124-14134.
2
[
[
[
6]
7]
8]
J. V. Smith, Chem. Rev. 1988, 88, 149-182.
A. J. Perrotta, J. V. Smith, Acta Cryst. 1964, 17, 857-862.
a) A. Alberti, Am. Miner. 1979, 64, 1188-1198; b) S. Han, J. V. Smith,
Acta Cryst. 1994, A50, 302-307.
[
9]
a) S. I. Zones, Zeolites 1989, 9, 458-467; b) A. Rojas, E. Martínez-
Morales, C. M. Zicovich-Wilson, M. A. Camblor, J. Am. Chem. Soc. 2012,
134, 2255-2263; c) J. E. Schmidt, M. A. Deimund, D. Xie, M. E. Davis,
Chem. Mater. 2015, 27, 3756-3762.
4
1
2 4
nonjointly constructed using the 8T sti ([4 6 ]) and 12T lau ([4 6 ])
units, respectively.[2] Because these two small units are 1-open
[10]
CCDC 1581878 (PST-21) and 1581879 (PST-22) contain the
supplementary crystallographic data for this paper. These data can be
obtained free of charge from The Cambridge Crystallographic Data
Centre via www.ccdc.cam.ac.uk/data_request/cif.
and 1,2,3,4-stellated d4rs, respectively, a number of new
hypothetical structures, which are not present in the current
hypothetical zeolite structure database[15] like those reported here,
can be generated when many d4r-modified building units,
including the undiscovered ones such as the simple 1,5-open d4r
[
11] V. J. Frillette, W. O. Haag, R. M. Lago, J. Catal. 1981, 67, 218-222.
12] a) S. van Donk, J. H. Bitter, K. P. de Jong, Appl. Catal. A 2001, 212, 97-
116; b) S.-H. Lee, C.-H. Lee, S. B. Hong, J. Catal. 2004, 223, 200-211;
c) Y. Lee, M. B. Park, P. S. Kim, A. Vicente, C. Fernandez, I.-S. Nam, S.
B. Hong, ACS Catal. 2013, 3, 617-621.
[
2
2
[6,16]
(
[4 6 ]) unit, are spatially connected in a nonjoint manner.
We
anticipate that our excess fluoride approach will enable the
synthesis of the aluminosilicate version of at least some of these
hypothetical zeolites.
In summary, we have synthesized two novel zeolites, PST-21
and PST-22, made up of bre units as an SBU, in the presence of
methyl-substituted imidazolium and excess fluoride ions. PST-21,
the first aluminosilicate zeolite with two intersecting 9-ring (4.3 ×
[13] a) J.-R. Li, R. J. Kuppler, H.-C. Zhou, Chem. Soc. Rev. 2009, 38, 1477-
1504; b) H. Kim, Y. Jung, J. Phys. Chem. Lett. 2014, 5, 440-446.
[
14] a) M. D. Foster, A. Simperler, R. G. Bell, O. D. Friedrichs. F. A. A. Paz,
J. Klinowski, Nat. Mater. 2004, 3, 234-238; b) Y. Li, J. Yu, R. Xu, Angew.
Chem. Int. Ed. 2013, 52, 1673-1677; Angew. Chem. 2013, 125, 1717-
1721.
[15] M. D. Foster, M. M. J. Treacy, A Database of Hypothetical Zeolite
Structures: http://www.hypotheticalzeolites.net/ (accessed Nov 9, 2017).
5.4 Å) channels, exhibits exceptional performance in the 1-butene
[
16] a) K. J. Andries, J. V. Smith, Proc. R. Soc. Lond. A 1994, 444, 217-238;
b) C. M. Draznieks, J. M. Newsam, A. M. Gorman, C. M. Freeman, G.
Férey, Angew. Chem. Int. Ed. 2000, 39, 2270-2275; Angew. Chem. 2000,
skeletal isomerization. The structure of PST-22 is also a 2D pore
system, but consists of sinusoidal 10-ring (5.7 × 5.8 Å) channels
interconnected by 8-ring (2.7 × 6.0 Å) windows. We have also
generated a total of ten hypothetical structures nonjointly built
from the bre unit that are chemically feasible and thus
synthesizable.
112, 2358-2363.
Acknowledgements
We acknowledge financial support from the National Creative
Research Initiative Program (2012R1A3A-2048833) through the
National Research Foundation of Korea and from the National
Research Council of Science & Technology Grant (CRC-14-1-
KRICT) by the Korea government (MSIP). We thank S. Seo, K.
Lee, and S. H. Cha at POSTECH for their help in structure
refinements and catalytic experiments and PAL (Pohang, Korea)
for synchrotron diffraction beam time. PAL is supported by MSIP
and POSTECH.
Keywords: aluminosilicates • 1-butene skeletal isomerization •
excess fluoride approach • novel 9-ring structure • zeolites
[
[
1]
2]
M. E. Davis, Nature 2002, 417, 813-821.
Ch. Baerlocher, L. B. McCusker, Database of Zeolite Structures:
http://www.iza-structure.org/databases/ (accessed Nov 9, 2017).
a) S. Zanardi, R. Millini, F. Frigerio, A. Belloni, G. Cruciani, G. Bellussi,
A. Carati, C. Rizzo, E. Montanari, Microporous Mesoporous Mat. 2011,
[
3]
1
43, 6-13; b) T. Willhammar, J. Sun, W. Wan, P. Oleynikov, D. Zhang, X.
Zou, M. Moliner, J. Gonzalez, C. Martínez, F. Rey, A. Corma, Nat. Chem.
012, 4, 188-194; c) J. E. Schmidt, D. Xie, T. Rea, M. E. Davis, Chem.
2
Sci. 2015, 6, 1728-1734.
[
4]
a) S. B. Hong, E. G. Lear, P. A. Wright, W. Zhou, P. A. Cox, C.-H. Shin,
J.-H. Park, I.-S. Nam, J. Am. Chem. Soc. 2004, 126, 5817-5826; b) S. B.
Hong, H.-K. Min, C.-H. Shin, P. A. Cox, S. J. Warrender, P. A. Wright, J.
Am. Chem. Soc. 2007, 129, 10870-10885.
This article is protected by copyright. All rights reserved.

Angewandte Chemie International Edition
10.1002/anie.201712885
COMMUNICATION
COMMUNICATION
Novel zeolite structures: PST-21,
the first aluminosilicate zeolite
containing 9-ring channels only, as
well as PST-22 with both 10- and 8-
ring apertures, has been synthesized
using methyl-substituted imidazolium
cations under excess fluoride
conditions.
D. Jo, G. T. Park, J. Shin, S. B. Hong*
Page No. – Page No.
A Zeolite Family Nonjointly Built
from the 1,3-Stellated Cubic
Building Unit
This article is protected by copyright. All rights reserved.