Characterization of the extra-large-pore zeolite UTD-1

Article abstract of DOI:10.1021/ja9708528

The molecular sieve UTD-1 is investigated using scanning and transmission electron microscopies (TEM), solid-state NMR spectroscopy, electron (ED) and X-ray diffraction (XRD), adsorption studies, and catalytic test reactions. The results confirm that UTD-1 is the first high-silica zeolite to contain a one;dimensional, extra-large 14-ring pore system. TEM and ED show that UTD-1 is faulted along the (002) planes. Simulations of XRD patterns of faulted structures using DIFFaX indicate that the XRD pattern of a framework containing the so-called double crankshaft chains is in better agreement with the experimental pattern than a framework with the narsarsukite chains previously reported. Thermal/hydrothermal stability studies show that UTD-1 has similar stability to other medium- and large-pore, high-silica zeolites. The ratio of isomerization to disproportionation, and the distribution of trimethylbenzene isomers in the m-xylene isomerization test reaction from UTD-1 are similar to those obtained from other large-pore zeolites (zeolites Y or L). However, UTD-1 shows a p-/o-xylene ratio of products below one.The molecular sieve UTD-1 is investigated using scanning and transmission electron microscopies (TEM), solid-state NMR spectroscopy, electron (ED) and X-ray diffraction (XRD), adsorption studies, and catalytic test reactions. The results confirm that UTD-1 is the first high-silica zeolite to contain a one-dimensional, extra-large 14-ring pore system. TEM and ED show that UTD-1 is faulted along the (002) planes. Simulations of XRD patterns of faulted structures using DIFFaX indicate that the XRD pattern of a framework containing the so-called double crankshaft chains is in better agreement with the experimental pattern than a framework with the narsarsukite chains previously reported. Thermal/hydrothermal stability studies show that UTD-1 has similar stability to other medium-and large-pore, high-silica zeolites. The ratio of isomerization to disproportionation, and the distribution of trimethylbenzene isomers in the m-xylene isomerization test reaction from UTD-1 are similar to those obtained from other large-pore zeolites (zeolites Y or L). However, UTD-1 shows a p-/o-xylene ratio of products below one.

Full text of DOI:10.1021/ja9708528

8474
J. Am. Chem. Soc. 1997, 119, 8474-8484
Characterization of the Extra-Large-Pore Zeolite UTD-1
,
†
‡
§,|
Raul F. Lobo,* Michael Tsapatsis, Clemens C. Freyhardt,
§
§
⊥
¶
Shervin Khodabandeh, Paul Wagner, Cong-Yan Chen, Kenneth J. Balkus Jr.,
Stacey I. Zones, and Mark E. Davis*
⊥
,§
Contribution from the Center for Catalytic Science and Technology, Department of Chemical
Engineering, UniVersity of Delaware, Newark, Delaware 19716, DiVision of Chemistry and
Chemical Engineering, California Institute of Technology, Pasadena, California 91125,
Department of Chemical Engineering, UniVersity of Massachusetts, Amherst, Massachusetts
0
1003, CheVron Research and Technology Co., Richmond, California 94802, and Department of
Chemistry, UniVersity of Texas at Dallas, Richardson, Texas 75083
X
ReceiVed March 17, 1997
Abstract: The molecular sieve UTD-1 is investigated using scanning and transmission electron microscopies (TEM),
solid-state NMR spectroscopy, electron (ED) and X-ray diffraction (XRD), adsorption studies, and catalytic test
reactions. The results confirm that UTD-1 is the first high-silica zeolite to contain a one-dimensional, extra-large
14-ring pore system. TEM and ED show that UTD-1 is faulted along the (002) planes. Simulations of XRD patterns
of faulted structures using DIFFaX indicate that the XRD pattern of a framework containing the so-called double
crankshaft chains is in better agreement with the experimental pattern than a framework with the narsarsukite chains
previously reported. Thermal/hydrothermal stability studies show that UTD-1 has similar stability to other medium-
and large-pore, high-silica zeolites. The ratio of isomerization to disproportionation, and the distribution of
trimethylbenzene isomers in the m-xylene isomerization test reaction from UTD-1 are similar to those obtained from
other large-pore zeolites (zeolites Y or L). However, UTD-1 shows a p-/o-xylene ratio of products below one.
Introduction
poresspores bounded by more than 12-tetrahedral atomsshas
eluded synthetic zeolite science until recently. The synthesis
New zeolitic materials offer opportunities to expand the range
of industrial applications of microporous materials, provided
they contain previously unobserved properties for which novel
catalytic reaction selectivity can be expected.1 Several zeolites
with novel pore architectures have been synthesized during the
last decade, and include materials with cavities containing 10-
and characterization of the zeolite UTD-1 (University of Texas
9-11
at Dallas, number 1) have recently appeared.
Freyhardt et
al. demonstrated that UTD-1 is the first high-silica zeolite with
12
extra-large pores. UTD-1 opens potential avenues to important
catalysts in the fine chemicals and pharmaceutical industry, in
which it is often found that other zeolites cannot be utilized
because the organic reactants cannot diffuse inside the smaller
pores. The large pores of UTD-1 also provide an opportunity
for solid-acid catalysis of large molecular weight hydrocarbons
in the petrochemical industry, e.g., the cracking of heavier
fractions of the feedstocks in the fluid catalytic cracking units.
UTD-1 is a one-dimensional pore zeolite with pores bounded
by 14 tetrahedral (T) atoms (14MR) with an open diameter of
approximately 10 × 7.5 Å. Analyses of the X-ray powder
diffraction data indicate that UTD-1 is an intergrowth of two
or more closely related polymorphs. The structure of UTD-1
can be viewed, in a two dimensional projection, as being formed
and 12-ring windows (NU-87, SSZ-37, SSZ-26, SSZ-33, CIT-
-7
1
, MCM-22, and SSZ-25).2 An example of how each material
type affects the reaction activity, deactivation, and selectivity
for the conversion of m-xylene has been reported.8 One of the
most sought-after characteristics in zeolitic materials, extra-large
*
Correspondence: Raul F. Lobo, Center for Catalytic Science and
Technology, Department of Chemical Engineering, University of Delaware,
Newark, DE. Fax: (302) 831-2085. E mail: lobo@che.udel.edu. Mark E.
Davis, Division of Chemistry and Chemical Engineering, 210-41, California
Institute of Technology, Pasadena, CA 91125.
|
Current address: Solid State Chemistry, Department of Chemistry,
University of Constance, University Street 10, D-78434, Constance,
Germany.
2
1
of layers of two 5-rings connected by 4-rings (5 4 layers parallel
to the ab plane) as indicated in Scheme 1. Consecutive
stackings of these layers create the three-dimensional crystal
structure.
⊥
Chevron Research and Technology.
University of Texas at Dallas.
University of Delaware.
University of Massachusetts.
California Institute of Technology.
Abstract published in AdVance ACS Abstracts, August 15, 1997.
1) Davis, M. E. Chem. Ind. 1992, 137.
¶
†
‡
§
Numerous phosphate-based molecular sieves have been
X
1
3
synthesized with pores larger than 12-T-atom rings (12MR),
(
14
(
2) Shannon, M. D.; Casci, J. L.; Cox, P. A.; Andrews, S. J. Nature
starting with VPI-5 in 1988 (18MR) and shortly after followed
1
991, 353, 417-420.
(
(
3) Nakagawa, Y. Stud. Surf. Sci. Catal. 1994, 84, 323-330.
4) Zones, S. I.; Olmstead, M. M.; Santilli, D. S. J. Am. Chem. Soc.
(9) Balkus, K. J.; Gabrielov, A. G.; Sandler, N. Mater. Res. Soc. Symp.
Proc. 1995, 368, 369-375.
(10) Balkus, K. J.; Khanmamedova, A.; Gabrierlov, A. G.; Zones, S. I.
Stud. Surf. Sci. Catal. 1996, 101, 1341-1348.
(11) Balkus, K. J.; Gabrielov, A. G. Synthesis of novel molecular sieves
using a metal complex as template. U.S., 5,489,424, 1996.
(12) Freyhardt, C. C.; Tsapatsis, M.; Lobo, R. F.; Balkus, K. J.; Davis,
M. E. Nature 1996, 381, 295-298.
(13) Meier, W. M.; Olson, D. H.; Baerlocher, C. Atlas of Zeolite Structure
Types, 4th ed.; Elsevier: London, 1996.
1
992, 114, 4195-4201.
5) Lobo, R. F.; Davis, M. E. J. Am. Chem. Soc. 1995, 117, 3764-
779.
6) (a) Leonowicz, M. E.; Lawton, J. A.; Lawton, S. L.; Rubin, M. K.
(
3
(
Science 1994, 264, 1910-1913. (b) Chan, I. Y.; Labun, P. A.; Pan, M.;
Zones, S. I. Microporous Mater. 1995, 3, 409-418.
(7) Rasband, W., NIH Image, Nat. Inst. Health: Bethesda, MD 1996;
version 1.60.
(
8) Adair, B.; Chen, C. Y.; Wan, K. T.; Davis, M. E. Microporous Mater.
(14) Davis, M. E.; Saldarriaga, C.; Montes, C.; Garces, J.; Crowder, C.
Nature 1988, 331, 698-699.
1
996, 7, 261-270.
S0002-7863(97)00852-4 CCC: $14.00 © 1997 American Chemical Society

Characterization of UTD-1
J. Am. Chem. Soc., Vol. 119, No. 36, 1997 8475
Scheme 1
the methods described in ref 23 and calcined as above. Calcined UTD-1
(2.61 g) was suspended in 175 mL water in a polypropylene bottle. A
total of 3.48 g of aluminum nitrate nonahydrate was dissolved into the
slurry, and the solution was heated for 2.5 days at 90 °C. Upon
removing the plastic bottle from the oven, the solution is pink (dissolved
cobalt in acidic solution) and the solids are white. The solids are
filtered, washed with 100 mL of 0.01 N HCl, and washed with distilled
water. Chemical analyses show a SiO
2
/Al
2
O
3
ratio ∼70. The
aluminum-containing samples of UTD-1 will be denoted Al-UTD-1.
Analytical. Synchrotron X-ray diffraction data were obtained at
the X7A beam line of the Synchrotron Light Source, Brookhaven
National Laboratory. The sample, after calcination and removal of the
cobalt oxide by acid treatment, was dried at 200 °C for 12 h and packed
in a 1 mm glass capillary. The data were collected at room temperature
from 2-65° 2θ with a step scan of 0.01° and a wavelength λ ) 1.2513
Å. Room temperature powder X-ray diffraction (XRD) patterns were
recorded on a Scintag XDS 2000 diffractometer equipped with a liquid
nitrogen-cooled germanium detector, Cu KR radiation λ ) 1.54184 Å
and a Bragg-Brentano geometry.
by AlPO4-8 (14MR), cloverite (20MR), JDF-20 (20MR),17
1
5
16
1
8
19
ULM-5 (16MR), ULM-16 (16MR), and two new vanadium
phosphates with 24MR cages.2
0,21
However, the practical
application of these phosphate-based, extra-large-pore materials
has been hampered by their poor thermal and/or hydrothermal
stability. UTD-1, on the other hand, shows the typical high
The thermal and hydrothermal stability of UTD-1 were investigated
by in situ X-ray powder diffraction. The samples were mounted as
thin films on a platinum-rhodium alloy sample-holder/strip-heater
within an Edmund Buhler high-temperature XRD chamber. The
chamber was evacuated and refilled with the flow gas three times prior
to establishing the steady flow under which the data were collected.
The flow gas for the thermal stability experiments was dry nitrogen.
Nitrogen gas, bubbled through distilled water maintained at room
temperature, was used for the hydrothermal experiments. The gas flow
1
2
thermal and hydrothermal stability of high-silica zeolites.
Because UTD-1 is the first extra-large-pore zeolite, detailed
investigation of its physicochemical properties are merited. Here
we present a detailed characterization of UTD-1 using synchro-
tron X-ray powder diffraction, electron diffraction, high-
resolution transmission electron microscopy, scanning electron
microscopy, solid-state NMR spectroscopy, adsorption studies,
and thermal/hydrothermal stability investigations. The relation-
ship between the geometry of the structure-directing agent (bis-
pentamethylcyclopentadienyl)cobalt(III)), [(Cp*)2Co] , and the
shape and size of the pores is investigated using energy
minimization calculations. The acid-catalyzed properties of
UTD-1 are investigated using the isomerization of xylenes as a
test reaction.
-1
rates were approximately 0.5 L min . The temperature controller was
calibrated to within 10 °C using the melting points of NaCl and KNO
3
as the standards. Samples of calcined and HCl-washed UTD-1 were
mounted on the sample holder in thicknesses varying from ap-
proximately 0.5 mm to 1 mm. The diffraction scans were taken from
+
(
2
-51° 2θ with a 0.04 step size and 5 s count periods. In both thermal
and the hydrothermal experiments, the temperature was ramped at 10
-1
°
C min , and held at the designated temperature for 15 min before
the scan. X-ray diffraction patterns were recorded at room temperature,
00, 400, 500, 600, 800, 900, 1000 °C and finally again at room
2
Experimental Section
temperature.
Scanning electron microscopy (SEM) images were recorded on a
Camscan 2-LV electron microscope operating with an acceleration
voltage of 15 kV. Thermogravimetric analysis (TGA) was carried out
on a Du Pont 951 thermogravimetric analyzer in flowing dry argon
Synthesis. The samples of UTD-1 were synthesized as previously
12,9
reported, using bis(pentamethylcyclopentadienyl)cobalt(III) hydrox-
ide, (Cp*)
2
Co OH, as a structure-directing agent.2
2
To eliminate the organometallic structure-directing agent from the
pores, the as-made UTD-1 (yellow) was heated in a furnace in flowing
nitrogen containing a few percent of air. The solid was heated at 1 °C
-1
using a constant heating rate of 1 K min . Chemical composition
analyses were carried out at Galbraith Laboratories, Knoxville, TN.
The adsorption capacities of UTD-1, SSZ-24, zeolite L, and zeolite
Y were measured at room temperature using a Cahn C-2000 balance
-
1
min to 540 °C and maintained at this temperature for 4 h; the
-
1
temperature was increased again at 0.5 °C min to 600 °C, and held
at this temperature for another 4 h. Finally, the sample was cooled to
room temperature over several hours in the furnace. The product has
a blue color at this point. After the calcination step, the product contains
cobalt oxide occluded in the pores and in the external surface of the
crystals (see below). This oxide is eliminated by an aqueous acid
treatment (12 N HCl and then 7 N HCl) as previously reported.12 The
samples used here for adsorption studies, X-ray powder diffraction,
electron microscopy, and NMR spectroscopy have been treated in this
manner before characterization.
coupled with a computer via an ATI-Cahn digital interface. Several
24
“
plug gauge” molecules with various kinetic diameters are used. The
adsorbate vapors are delivered from the liquid phase and the partial
pressure P/P
0
() 0.15-0.4) of the organic adsorbate was adjusted using
a temperature controlled thermostat. Prior to the adsorption experiment,
-3
the calcined samples are dehydrated at 615 K under a vacuum of 10
Torr for 5 h. The pore volumes are given on the basis of the weight
gains of the adsorbents upon adsorption, and the densities of the liquid
adsorbates at room temperature, i.e., assuming that the adsorbates in
the sample pores have the same density as the liquid state.
For the catalytic tests, the incorporation of aluminum in the samples
was carried out as follows: A sample of UTD-1 was prepared using
Solid-state NMR spectroscopy was performed on a Bruker AM 300
spectrometer equipped with a high power assembly for solids. Samples
2
9
were packed into 4 and 7 mm ZrO
59.63 MHz) single-pulse experiments were performed at spinning rates
of 2.7-3.5 kHz, pulse widths of 4 µs (40° pulse), and recycle delays
2
rotors and spun in air. Si NMR-
(
15) Dessau, R. M.; Schlenker, J. L.; Higgins, J. B. Zeolites 1990, 10,
22-524.
16) Estermann, M.; McCusker, L. B.; Baerlocher, C.; Merrouch, A.;
Kessler, H. Nature 1991, 352, 320-323.
17) Jones, R. H.; Thomas, J. M.; Chen, J. S.; Xu, R. R.; Huo, Q. S.; Li,
(
5
(
1
29
1
of 10-100 s. H- Si CPMAS NMR spectra were measured with H
(
1
1
decoupling at spinning rates of 2.5-3 kHz using a 7 ms H pulse ( H
S. G.; Ma, Z. J. Solid State Chem. 1993, 102, 202-208.
9
0°), 29Si contact times of 5-15 ms, and recycle times of 3 s. Si
29
(
(
(
18) Loiseau, T.; Ferey, G. J. Solid State Chem. 1994, 111, 403-415.
19) Loiseau, T.; Ferey, G. J. Mater. Chem. 1996, 6, 1073-1074.
20) Khan, M. I.; Meyer, L. M.; Haushalter, R. C. Chem. Mater. 1996,
NMR chemical shifts are referenced to external standard of tetrakis-
(trimethylsilyl)silane (downfield resonance at -10.05 ppm relative to
1
8
, 43-53.
tetramethylsilane). H NMR (300.15 MHz) spectra were measured at
(21) Schindler, M.; Joswig, W.; Baur, W. H. Z. Anorg. Allg. Chem. 1997,
6
23, 45-54.
(23) Zones, S. I.; Nakagawa, Y. Microporous Mater. 1994, 2, 543-
555.
(
22) Balkus, K. J.; Gabrielov, A. G.; Zones, S. I.; Chan, I. Y. In Synthesis
of Microporous Materials, Zeolites, Clays and Nanocomposites; Kessler,
H., Occelli, M., Eds.; Marcel Dekker: New York, 1996.
(24) Breck, D. W. Zeolite Molecular SieVes: Structure, Chemistry and
Use; Wiley: New York, 1974.

8476 J. Am. Chem. Soc., Vol. 119, No. 36, 1997
Lobo et al.
Figure 2. Solid-state NMR spectra of UTD-1: (a) 29Si MAS NMR
Figure 1. Scanning electron micrograph of a sample of as-synthesized
UTD-1.
29
spectrum of as-made UTD-1; (b) Si MAS NMR spectrum of a calcined
13
1
sample; (c) C CP/MAS of the as-made sample; and (d) H MAS NMR
of as-made UTD-1. An asterisk (*) indicates a spinning side band.
a spinning rate of 11 kHz, pulse lengths of 6.2 µs (70° pulse), and
1
delay times of 5 s. H NMR chemical shifts are referenced to
1
3
adamantane (δ ) 1.74 ppm vs TMS). C NMR (75.47 MHz) spectra
sions of 1 µm by 5 µm. Only one morphology is observed in
the micrograph, an indication that no other phases are present
in the sample besides UTD-1. The SEMs of the calcined and
acid treated UTD-1, i.e., cobalt free, are also indistinguishable
from the as-synthesized material, suggesting that this zeolite is
thermally stable and resistant to the aqueous acid environments
used to eliminate the cobalt oxide formed during calcination.
NMR Spectroscopy. As previously reported, the structure
of UTD-1 is a fully connected framework of tetrahedral TO4/2
1
were measured using cross-polarization with a H 90° pulse of 7 µs
and a contact time of 10 ms at spinning rates of 2.6 kHz, 13C NMR
chemical shifts are referenced to adamantane (downfield resonance at
3
8.4 relative to TMS). Exponential line broadening of 30 Hz was
2
9
13
applied to Si and C NMR data, and spectral fitting was performed
using Bruker LINESIM software and QNMR software.
The samples for transmission electron microscopy (TEM) are
prepared by both direct dispersing and microtomy. For direct disper-
sion, a drop of the zeolite suspension in ethanol is transferred to a
carbon-coated Cu grid. For microtomy, the samples are first embedded
in epoxy (LR white) by vacuum impregnation followed by heating at
1
2
oxide units. The structure is highly faulted and due to the
positive charge of the organometallic complex, in agreement
2
6-31
9
0 °C for 2 h. Sections are prepared using a diamond knife mounted
with reports for other high-silica zeolites,
the presence of
on an ultramicrotome. Thin sections are collected on a carbon-coated
Cu grid. The sample grids are allowed to dry at 110 °C under vacuum
overnight before mounting on the microscope specimen holder.
Electron diffraction, transmission electron microscopy, and high-
resolution electron microscopy (HREM) were performed on a Phillips
31
large numbers of internal silanol groups is observed. The
results from Si NMR and H- Si CP/MAS NMR spectroscopy
of the as-synthesized material show the presence of silicon Q
for the as-made sample (Q stands for X4-nSi[OSi]n, X ) OH
or O ), with a relative population of approximately 10% [Q /
(Q + Q )] (see Figure 2a). The C CP/MAS NMR spectrum
shows two resonances at 7.9 and 96.5 ppm that correspond to
the methyl carbons and the cyclopentadienyl carbons respec-
tively of the structure-directing agent (Figure 2b). Strong
spinning side bands observed for the aromatic resonanaces may
indicate that the ring carbons are held relatively rigidly inside
the zeolite pores (it is not possible to extract or ion exchange
29
1
29
3
n
-
3
4
30 microscope operated at 200 kV. Image processing was carried
3
4
13
7
out using the “Image” software for the MacIntosh.
Molecular dynamics and energy minimization calculations were
2
carried out using CERIUS (v 2.0) of MSI Inc. The UFF force field
2
5
of Rappe et al. was used in all the calculations.
m-Xylene isomerization reactions were carried out in a fixed-bed
reactor at 317 °C (controlled within 1 °C) and ambient pressure. A
total of 53 mg of Al-UTD-1 in its acid form was activated under flowing
He by heating to 350 °C with a temperature ramping rate of 1.2 °C
1
the metal complex). The H NMR spectrum for the as-made
-1
min and maintained at 350 °C for 4 h. After activation of the sample,
the He gas inlet was passed through a saturator filled with m-xylene
material (Figure 2c) shows an intense resonance at 1.5 ppm,
assigned to the protons of the organic structure-directing agent.
(Aldrich 99+%) adsorbed on Chromosorb 102 (Supelco, Bellefonte,
1
The H NMR also shows a small resonance ∼10 ppm probably
Pa) at 10 °C (Pm-xylene ) 3.4 Torr). All inlet/outlet lines were heated
to at least 120 °C to prevent condensation within the lines. The outlet
of the reactor was analyzed by on-line gas chromatrography (HP5890
series II equipped with a 25 m HP-FFAP column and flame ionization
detector).
-
30
due to defect sites of the form SiO ‚‚‚HOSi. This is consistent
with the fact that the cobalt complex in the pore has a net
positive charge that, in the absence of tetrahedral 3+ framework
atoms, i.e., Al or B, is balanced by a defect (siloxy group).30
These results also show that the structure-directing agent is intact
Results and Discussion
(26) (a) Dessau, R. M.; Schmitt, K. D.; Kerr, G. T.; Woolery, G. L.;
Alemany, L. B. J. Catal. 1987, 104, 484-489. (b) Boxhoorn, G., Kortbeek,
As-synthesized UTD-1 is a yellow powder, suggesting that
the organometallic structure-directing agent (also yellow) is
occluded intact inside the void space of the material. UV
diffuse-reflectance spectra of the organometallic complex, alone
and in UTD-1, are identical confirming the previous statement.
SEM of the as-synthesized zeolite (Figure 1) shows that UTD-1
crystallizes in long platelike crystals with approximate dimen-
A. G. T. G., Hays, G. R., Alma, N. C. M. Zeolites 1984, 4, 15-21.
(27) Woolery, G. L.; Alemany, L. B.; Dessau, R. M.; Chester, A. W.
Zeolites 1986, 6, 14-16.
(28) Hunger, M.; Karger, J.; Pfeifer, H.; Caro, J.; Zibrowius, B.; Bulow,
M.; Mostowicz, R. J. Chem. Soc., Faraday Trans. I 1987, 83, 3459.
22
(
29) Engelhardt, G.; Michel, D. High-Resolution Solid-State NMR of
Silicates and Zeolites; Wiley: New York, 1987.
(30) Koller, H.; Lobo, R. F.; Burkett, S. L.; Davis, M. E. J. Phys. Chem.
995, 99, 12588-12596.
(31) Lobo, R. F.; Zones, S. I.; Davis, M. E. J. Inclusion Phenom. 1995,
1
(25) Rappe, A. K.; Casewit, C. J.; Colwell, K. S.; Goddard, W. A.; Skiff,
W. M. J. Am. Chem. Soc. 1992, 114, 10024-10035.
21, 47-78.

Characterization of UTD-1
J. Am. Chem. Soc., Vol. 119, No. 36, 1997 8477
Table 1. Adsorption Capacities for UTD-1 and Other Molecular Sieves
adsorption capacity (mL g-1)
adsorbate
n-hexane
,2-dimethyl butane
cyclohexane
,3,5-triisopropyl benzene
kinetic diameter (Å)b
SSZ-24
L
Y
UTD-1a
VPI-5b
4.4
6.2
6.0
∼8.5
0.101
0.128
0.124
0.008
0.152
0.126
0.108
0.109c
0.277
0.251
0.244
0.170d
0.121 (0.106)
0.119 (0.091)
0.111 (0.079)
0.198
0.148f
0.156
0.117
2
e
1
0.111 (0.063)
a
b
Numbers in parentheses are the adsorption capacities of UTD-1 samples after calcination but before treatment with aqueous HCl. From refs
c
d
2
4 and 34. Average of three independent measurements, after 3 h of adsorption time. Zeolite Y adsorbs 1,3,5-triisopropylbenzene very slowly;
e f
this measurement was taken after 5 days of adsorption time at room temperature. Average of two independent measurements. Adsorption capacity
for neopentane.
inside the zeolite pores and that no decomposition products are
occluded in the pores during the crystallization process.
29Si NMR spectra of the calcined and acid-treated samples
tion capacity for 1,3,5-triisopropylbenzene of UTD-1 is in
agreement with the one-dimensional 14MR pore system reported
by Freyhardt et al.
12
(
collected with a recycle delay of 100s) are deconvoluted into
three peaks at -102.9 (3.5%), -111.45 (71%), and -113.2
25.5%) (Figure 2d). The resonance at -102.9 ppm is consistent
with the presence of a small amount of silanol groups remaining
There is a systematic difference in the adsorption capacities
of samples analyzed before or after acid treatment. The
adsorption capacities of calcined Co-containing UTD-1 samples
are lower than the capacities of samples treated with aqueous
HCl, especially for the larger adsorbent molecules. Apparently,
the channels of Co-UTD-1 are partially blocked by occluded
cobalt oxide left inside the sample after calcination. Bright-
field TEM of the cobalt-containing samples (see Supporting
Information) shows cobalt oxide particles both on the crystal
surface and occluded within the 14MR pores. It is also noted
that 1,3,5-triisopropylbenzene adsorbs in Co-containing UTD-1
as rapidly as in Co-free UTD-1. Thus, either the small cobalt
particles occluded in the pores act as a barrier to stop the
diffusion of this large organic molecule beyond certain section
of the pore, and/or only a fraction of the pores contains occluded
cobalt. The cobalt particles do not change significantly the
adsorption of smaller molecules. The rate of adsorption of the
smaller and flexible n-hexane adsorbate is slowed only slightly,
and the nitrogen adsorption data (not shown) also show
approximately similar diffusion rates and total uptake in Co-
containing UTD-1 as in Co-free samples. The adsorption data
suggest as a whole, that indeed Co oxide is occluded in the
pores just after calcination and that the effect of the cobalt must
be taken into account for the evaluation of diffusion/catalytic
properties. Fortunately, the cobalt oxide is completely removed
by the acid treatment (verified by chemical analysis), yielding
complete access to the pores of the material.
(
2
9
after the removal of the structure-directing agent. Also, Si
CP/MAS NMR data from the calcined sample (not shown)
show an enhancement of a resonance at -103 ppm in
agreement with the premise that this resonance is due to a silanol
group. The relative ratios of the two Q resonances is almost
3
4
35
to 1 (various simulations result in relative ratios of 2.8 to
.2). Given the site populations from the structure solution (see
3
below) [Si1(8), Si2(8), Si3(16), Si4(16), Si5(16)] this relative
intensity corresponds to a ratio of 48 to 16. Furthermore, when
shorter recycle delay times are used, the relative intensity of
these two peaks approaches 4, i.e., with shorter delay times the
relative intensity of the resonance at -113.2 ppm diminishes.
It is possible that a fraction of T atoms contributing to the peak
at -113.2 ppm (the less intense resonance), have a longer T1
relaxation time and it is only with longer recycle delays that
this resonance can reach its maximum signal intensity. The
following assignment is consistent with the structural model of
UTD-1: Si1, Si3, Si4, and Si5 are all readily accessible by
oxygen molecules inside the channel and can relax with short
delay times. Si2, however, has no direct access to the channel
system, hence its longer relaxation time. Thus, the assignment
of the two observed bands is that Si3, Si4, and Si5 (total
population 48) comprise the resonance at -111.4 ppm and Si1
and Si2 (total population ) 16) comprise the peak a -113.2
ppm.
The geometrically calculated void volume for the model (see
3
-1
below) is ∼990 Å per unit cell (0.15 mL g ) which is in
agreement with the adsorption capacities reported in Table 1.
The adsorption capacity data are somewhat smaller than the
values expected from the TGA of the as-synthesized UTD-1.
TGA shows a weight-loss event of ∼13.1% between 200 and
Adsorption Studies. Adsorption capacity measurements of
organic molecules in UTD-1 are in agreement with the reported
structure of UTD-1. Table 1 shows the adsorption capacity of
several large-pore zeolites and UTD-1. The adsorption capacity
of UTD-1 is very similar to the adsorption capacity of SSZ-24
8
00 °C. This event has been assigned to the pyrolysis and
combustion of the cobalt complex. Note that an exact com-
parison of the TGA weight loss to the adsorption data is not
possible due to unknown amounts of cobalt oxide in the sample
after heating to 800 °C.
(
AFI), a one-dimensional large pore molecular sieve (7.3 Å in
3
2,33
diameter),
and it is clearly smaller than the adsorption
capacity of a three-dimensional large pore zeolite (FAU) and
1
3
the one-dimensional 18MR VPI-5 (12.1 Å in diameter). The
adsorption capacity of UTD-1, for 2,2-dimethylbutane and
cyclohexane shows that UTD-1 is at least a large-pore material.
Comparison of the adsorption capacity for 1,3,5-triisopropyl-
benzene of zeolite L, zeolite Y, UTD-1 and VPI-5 shows that
the molecule of 1,3,5-triisopropylbenzene (with a kinetic
diameter of ∼8.5 Å) is close to the maximum molecular size
which can pass the 14-rings at this temperature.34 The adsorp-
Characterization of UTD-1 by Diffraction and TEM
Methods
X-ray Diffraction Data. The X-ray powder diffraction
pattern of UTD-1 (see below) can be indexed using an
orthorhombic unit cell with lattice constants of approximately
a ) 18.98 Å, b ) 8.41 Å, and c ) 23.04 Å. The d spacings
and indexing of the experimental pattern are presented in Table
(
32) Bialek, R.; Meier, W. M.; Davis, M. E.; Annen, M. J. Zeolites 1991,
1, 438-442.
33) Richardson, J. W.; Smith, J. V.; Han, S. X. J. Chem. Soc., Faraday
Trans. 1990, 86, 2341.
34) Davis, M. E.; Montes, C.; Hathaway, P. E.; Arhancet, J. P.; Hasha,
D. L.; Garces, G. J. Am. Chem. Soc. 1989, 111, 3919.
2
. The systematic absences are in agreement with a body
1
(
centered unit cell (h + k + l ) 2n), and k ) 2n for all reflections
(
(35) Balkus, K. J.; Biscotto, M.; Gabrielov, A. G. Stud. Surf. Sci. Catal.
1997, 105, 415-423.

8478 J. Am. Chem. Soc., Vol. 119, No. 36, 1997
Lobo et al.
Table 2. d Spacings and Indexing for calcined UTD-1a
XRD data show the absence of such reflections. Streaking is
along a direction perpendicular to the b* reciprocal axis. This
observation suggests also disorder and/or faulting along the b
axis, i.e., along the long axis of the crystals that coincides with
the direction of the 14 T-atom pores. The presence of sharp
h
k
l
d (Å)
I/I
0
1
0
0
0
0
0
0
0
0
0
0
2
2
1
2
0
0
0
0
2
0
2
0
2
0
2
0
2
2
1
2
0
2
0
2
2
2
1
2
0
3
1
4
4
3
5
2
0
1
5)
2
6
1
4
6
1
3
3
0
5
2
2
6
6
4
3)
6
1
3
3
0
2
6
14.66
11.53
9.50
7.13
6.12
5.76
4.93
4.90
4.49
4.40
4.21
4.05
4.05
3.97
3.85
3.74
3.67
3.56
3.46
3.40
3.19
3.16
3.07
3.05
3.03
2.98
2.84
2.76
2.76
2.72
2.69
2.65
2.56
2.53
2.47
2.43
100
38
4.9
0
2
1
3
0
2
3
1
4
0
1
0
0
0
5
4
2
3
5
3
6
1
6
4
4
0
4
6
2
7
5
7
6
6
4
1
0.3
4.4
0.3
1.9
3.5
5.8
1.6
17.9
3.6
3.6
2.6
1.9
0.9
3.7
3.4
0.5
2.0
0.9
2.6
1.2
1.0
0.5
1.5
0.3
1.4
1.4
0.7
0.3
0.7
0.5
1.0
0.5
0.9
spots every second column suggests translations of ( /2b axis.
The intensity of streaking decreases from the [100] (maximum
streaking) to the [101] (some streaking) to [001] (no streaking)
zone axes. Figure 4b and 4c are diffraction patterns from the
[001] zone axis and tilted by few degrees from the [001] axis
respectively. Only sharp spots are observed in Figure 4b with
h+k ) 2n and k ) 2n. However, tilting around the b axis leads
to diffraction patterns as the one shown in Figure 4c where spots
with h + k ) 2n + 1 as well as k ) 2n + 1 appear. The
appearance of these additional spots can be understood by
considering the reciprocal space which is streaked along [001]
due to the faulting/disorder within the (002) planes. Depending
on the tilt, when close to the [001] zone axes, the Ewald sphere
can intercept a streak rather than a sharp Bragg reflection. For
tilts up to (20°, the pattern can maintain the appearance of
high symmetry, where all or some of the forbidden reflections
are observed. However, accurate orientation leads to the pattern
shown in Figure 4b, where the spots are considered to be due
to sharp Bragg reflections. These results are in agreement with
the premise that faulting is within the (002) planes. Moreover,
such disorder and/or faulting will not affect the 14-member ring
channels. This is shown in Figure 3c, which shows no
distortions in the view down the b axis. An electron diffraction
pattern with the electron beam along the b axis ([010] zone
axis) is shown in Figure 4d. The (h0l) reflections are all sharp
and systematic absences are observed for h + l ) 2n + 1,
suggesting a centered unit cell in agreement with the XRD data
that show h + k + l ) 2n. The intensities of the (hkl) spots
with k ) 2n + 1 (along the streaked columns) in Figure 4a are
much less pronounced than the (hkl) spots with k ) 2n. Since
(hkl) spots with k ) 2n + 1 are forbidden in body-centered
cells and allowed in face-centered cells, their presence with small
intensities suggests an intergrowth of body and face-centered
unit cells.
(
(
a
On the basis of the X-ray powder diffraction data only, the
reflections in parentheses cannot be unambigously excluded from the
XRD pattern because of overlap with the previous reflection. However,
the ED data (see text) clearly indicates that these two reflections are
actually not present in the pattern.
except, perhaps, for the two entries indicated in parentheses in
Table 2. The presence or absence of these two reflections in
the XRD pattern cannot be unambiguously confirmed because
of overlap with other reflections. These reflections are,
nonetheless, excluded from the pattern on the basis of ED data
High-Resolution Electron Microscopy. HREM was carried
out along the b-axis direction which gives the diffraction pattern
with the sharp spots shown in Figure 4d. The HREM image
from a microtomed section of UTD-1 is shown Figure 5a (the
original image) while Figure 5b is the FFT-enhanced image.
The resolution of the original image, which was recorded at
near optimum defocus, is about 2 Å as evidenced by optical
diffraction. In addition to the 14-ring, the 5- and 6-rings are
clearly resolved having substantially different intensities. It is
known that for thin zeolite samples and under the Scherzer or
(see below). The absence of all reflections with k ) 2n + 1
suggests the presence of stacking faults and/or disorder along
the b axis. The presence of this type of stacking faults/disorder
is also in agreement with electron diffraction data (Vide infra).
As a consequence of the disorder, the systematic absences
obtained from the analyses of the XRD data cannot be used to
discriminate between different space groups.
optimum focusing condition, the 2D, 3-connected net of the
36-38
structure can be derived from electron micrographs.
It
Electron Diffraction and Transmission Electron Micros-
copy. The transmission electron micrographs shown in Figure
should be noted that the 4-rings do not appear as white dots, as
confirmed by the simulation shown in Figure 5c, but their
presence is suggested from the spacing of the net in the
corresponding positions. The 2D, 3-connected net shown in
Figure 5d can be devised from the HREM image. Attempts to
acquire similar information in directions perpendicular to the
channel length ([100] and [101] zone axes) did not result in
images that can be interpreted in terms of projected potential.
Structure Solution and Disorder in UTD-1. The structure
of UTD-1 was solved by an iterative process of model building,
distance least-square refinement, and comparison of simulated
3
reveal that the UTD-1 particles are aggregates of faceted,
elongated platelets about 5 µm long and 0.1 µm wide. In the
bright field image (Figure 3b) fringes corresponding to the (101)
planes are resolved running down the long axis of the platelets;
i.e., the channels with the 14 T-atom pore opening are running
down the long axis of the crystals.
Characteristic electron diffraction patterns are given in Figure
4
. Figure 4a is a diffraction pattern with the electron beam
perpendicular to the basal plane of the crystals (see Figure 2b),
i.e., the [101] zone axis. This selected-area diffraction pattern
shows alternating rows of sharp and streaking spots. The sharp
spots occur at rows with k ) 2n, and the streaked spots occur
at rows with k ) 2n ( 1 (n ) 0, (1, (2, etc.). Recall that
(
(
(
36) Pan, M. Micron 1996, 27, 219-238.
37) Terasaki, O.; Ohsuna, T. Catal. Today 1995, 23, 201-218.
38) Terasaki, O.; Ohsuna, T.; Sakuma, H.; Watanabe, D.; Nakagawa,
Y.; Medrud, R. Chem. Mater. 1996, 8, 463-468.

Characterization of UTD-1
J. Am. Chem. Soc., Vol. 119, No. 36, 1997 8479
Figure 3. Transmission electron micrographs of UTD-1: Parts a and b are views perpendicular to the 14-MR channels; (c) is a veiw parallel to
the 14-MR channels.
and experimental XRD patterns. The unit cell parameters of
UTD-1 (a ) 18.98 Å, b ) 8.41 Å, and c ) 23.04 Å) suggest
that this material is related to ZSM-48 (orthorhombic, a ) 14.24
diameter and projected potential along the [010] axis, adsorption
capacities, unit cell lattice parameters, and HRTEM micrographs
cannot be used to differentiate between the frameworks as to
which is a better model for UTD-1. To do this, comparison of
experimental and simulated of X-ray powder diffraction patterns
is necessary.
39
Å, b ) 20.14 Å, and c ) 8.40 Å) and SSZ-24 (AFI)
(
hexagonal, a ) b ) 13.65 Å and c ) 8.35 Å).32,33 These two
high-silica zeolites are one-dimensional pore materials formed
by sheets of atoms in an Up-Down combination (denoted Ob).
On the basis of the results from HREM, a framework with the
correct magnitude for a and c can be formed from the σ
expansion of a ferrierite sheet, forming a new “UTD-1” sheet
as indicated in Scheme 2.
One possible framework topology is shown in Figure 6a.
This topology belongs to space group Imma (reported initially
in ref 9 and denoted from now on as polymorph A), has a
cylindrical 6-ring net pore, and contains the so called UDUD
(ObOb) narsarsukite chains along the pore direction (see Figure
7). These chains are also present in the all-silica SSZ-24
If UTD-1 is either body (I) or face-centered (B), as indicated
by the diffraction data, then there are five independent tetra-
hedral atoms in the asymmetric unit. In principle these can be
combined to form 60 (15 for each space group Imma, Immm,
Bmmm, and Bmmb) related structures. The search has been
restricted initially to structures in which the connectivity of the
T atoms that forms the channel surface is formed by a cylindrical
3
2
(AFI).
The simulated XRD pattern of the distance least-
squares refined structure of this model shows many similarities
to the experimental pattern of UTD-1, but also several discrep-
ancies. The discrepancies are all associated with hkl reflections
with index k ) 2n + 1, that are observed in the simulated XRD
pattern but not in the experimental pattern. Faulting/disorder
1
6
-ring net (as it is also reported for ZSM-48 and SSZ-24 and
along ( /2b of the material is one possible explanation for the
32,40
SSZ-31).
This means that there must be a strict alternation
absence of k ) 2n + 1 reflections. Since electron diffraction
of UDUD T atoms (denoted ObOb..., in Figure 6) throughout
the 14MR of the zeolite. In addition, since high-silica zeolites
show only a relatively small number of 4-rings in the structure,
the candidate topologies with small number of 4-rings are
preferred over those with larger number of 4-rings.41 Note that
since all 60 structures have the same framework density, pore
data show conclusively that faulting occurs along the (002)
1
planes and that the faulting involves translations of ( /2b, the
effect of faulting is investigated in detail.
The effect on the XRD pattern of this type of faulting was
investigated using simulations of intergrowth structures with
4
2
1
the program DiFFAX. Periodic faulting of ( /2b within the
02 planes of polymorph A (Imma) forms a new framework
0
(39) Schlenker, J. L.; Rohrbaugh, W. J.; Chu, P.; Valyocsik, E. W.;
with the Bmmm space group (no. 65, nonstandard setting,
Kokotailo, G. T. Zeolites 1985, 5, 355-358.
denoted polymorph B). Note that in Figure 6a, a translation of
(
40) Higgins, J. B. High-Silica Zeolites. In Silica: Physical BehaVior,
1
Geochemistry and Materials Applications; Heaney, P. J., Prewitt, C. T.,
( /2b is equivalent to changing an up T atom for a down T
Gibbs, G. V., Eds.; Mineralogical Society of America: Washington, 1994.
(
41) Lobo, R. F.; Tsapatsis, M.; Freyhardt, C. C.; Chan, I. Y.; Chen, C.
(42) Treacy, M. M. J.; Newsam, J. M.; Deem, M. W. Proc. R. Soc.
London A 1991, 433, 499-520.
Y.; Zones, S. I.; Davis, M. E. J. Am. Chem. Soc. 1997, 119, 3732-3744.

8480 J. Am. Chem. Soc., Vol. 119, No. 36, 1997
Lobo et al.
Figure 4. Electron diffraction patterns of UTD-1. Part a is a diffraction pattern with [101] zone axis (the magnified inset shows the streaking every
other row), and d is a diffraction pattern with [010] zone axis. Parts b and c are diffraction patterns with [001] zone axis and tilted by 10° from the
[001] direction, respectively.
atom and vise versa; and that this faulting breaks the alternating
UDUD sequence allowing 4MRs and 8MRs in the inner surface
A second topology with a cylindrical 6-ring net pore is shown
in Figure 6c. This framework belongs to the Bmmb space group
(no. 63, nonstandard setting, denoted polymorph C) and contains
UUDD chains (double crankshaft chains, see Figure 7). The
atomic coordinates of the distance least-square (DLS-76)44
refined structure are presented in Table 3. As it was the case
with the previous model, the XRD pattern of this polymorph
also shows many similarities to the experimental XRD of UTD-
1
2
of the pores. Effectively, this type of faulting maintains the
2
1
connectivity within the 5 4 layers described in Scheme 1 and
just changes the connectivity between the layers. (See ref 12
for more details about polymorphs A and B.)
The simulations of the XRD patterns of intergrowths of
polymorphs A and B are presented in Figure 8a. Here it is
assumed that the faulting is completely random and that the
disorder can be described only by one parameter p. (For more
details on the use of DIFFaX see refs. 41 and 43 and the manual
of DIFFaX). This parameter is the probability that after any
layer the stacking vector relating two consecutive layers is given
1
1. Periodic faulting of ( /2b within the 002 planes of polymorph
C (Bmmb) forms a new framework with the Immm space group
(no. 71, see Figure 6d and Table 4) denoted polymorph D. This
framework also contains 4MRs and 8MRs in the inner surface
of the pores as polymorph B. Simulations of the XRD patterns
of intergrowths of these two polymorphs are presented in Figure
8b. As before, it is assumed that the intergrowths are completely
random and that the disorder is described by only one parameter
p. The stacking vector to form a layer of polymorph C is R )
1
1
1
by R ) /2a + /2c, i.e., face centering and not by R ) /2a +
1
1
/
2b + /2c, body centering, as would be for polymorph A. A
stacking probability p ) 0% forms the polymorph A and a
stacking probability of 100% forms the polymorph B. A close
match between the calculated and experimental XRD patterns
is obtained for a material with a fault probability of ap-
proximately 20%. This is the proposed structure solution
provided for UTD-1 in ref 12.
1
1
/2a + /2c, face centering, and the stacking vector to form a
1
1
1
layer of polymorph D is R ) /2a + /2b + /2c, body centering.
A very good match between the calculated and experimental
(44) Baerlocher, C.; Hepp, A.; Meier, W. M. DLS-76: A Fortran Program
(
43) Treacy, M. M. J.; Vaughan, D. E. W.; Strohmaier, K. G.; Newsam,
for the Simulation of Crystal Structures by Geometric Refinement; Institut
fuer Kristallographie, ETH: Zurich, 1977.
J. M. Proc. R. Soc. London A 1996, 452, 813-840.

Characterization of UTD-1
J. Am. Chem. Soc., Vol. 119, No. 36, 1997 8481
any known zeolite silicate structure. These structures are
considered unlikely and have not been investigated in detail.
The good agreement between the XRD patterns of the three
proposed intergrowth structures (Figure 9) and the experimental
pattern establish, without ambiguity, that the framework struc-
ture of UTD-1 consists of the “expanded ferrierite” or UTD-1
sheets (parallel to the ac plane). The tetrahedral atoms in each
layer point down or up, and the oxygens are located in the mirror
planes between each UTD-1 sheet. Of the three intergrowths
presented in Figure 9, the intergrowth of the structures with
Bmmb and Immm space groups (polymorphs C and D, see Figure
9
a) shows the closest agreement to the experimental pattern.
These two models contain the double-crankshaft chains (UUDD)
and are different from the original proposed intergrowth model
for UTD-1 that contains the narsarsukite chains (UDUD). There
is still small disagreement at 2θ > 25, but this may be due to
small errors in the positions of oxygen and silicon atoms within
each layer (only optimized here using DLS-76) and/or an
indication that other intergrowths and/or other up/down se-
quences may be also present in the material in smaller amounts.
In summary, using electron microscopy, solid-state NMR
spectroscopy, adsorption studies, and simulation of X-ray
powder diffraction patterns, we have shown that UTD-1 is a
high-silica zeolite with a one-dimensional 14MR pore archi-
tecture. The structure is heavily faulted with faults parallel to
the (002) planes. The fault planes do not block the pore
apertures. We have also identified a structural model for the
framework topology of the UTD-1. This model is an inter-
growth of what we denote as polymorphs C and D and contains
the so-called double-crankshaft chains running down the pore
axis. Simulation of a random intergrowth of equal amounts of
these polymorphs shows a very good agreement between the
simulated and experimental X-ray powder diffraction patterns.
Figure 5. High-resolution electron-micrograph view down the 14-MR
channels. Part a is the image as recorded while b is the processed image
using FFT filtering. The simulated projection is shown in the inset,
and the derived 2-D net in c.
Scheme 2
Finally, we want to point out the close structural relationships
between UTD-1 and ZSM-48. In both materials, the main
structural unit within the channel walls consists of a double layer
4
1
containing one 6MR surrounded by four 5 MRs (5 6 ). The
up and down sequence of T atoms in polymorph A of UTD-1
is the same as the one proposed by Schlenker et al.39 for the
UUDD-Cmcm polymorph of ZSM-48. Moreover, the up and
down sequence in polymorph C of UTD-1 is the same as the
UDUD-Imma of ZSM-48. Both UTD-1 and ZSM-48 show
disorder in the structure due to the presence of different UD
sequences in the structure.
Thermal and Hydrothermal Stability of UTD-1. The
thermal and hydrothermal stability of UTD-1 is investigated
using in situ X-ray powder diffraction of samples treated at
different temperatures. A dry nitrogen atmosphere is used for
thermal stability studies, and a water/nitrogen atmosphere is used
for hydrothermal stability. Figure 10 shows the XRD patterns
of UTD-1 at selected temperatures in the presence of water vapor
in the nitrogen atmosphere. As it can be observed, little if any,
loss of crystallinity is detected at temperatures up to 1000 °C.
After the high-temperature treatment and decrease of the sample
temperature back to 25 °C, the XRD pattern is almost
indistinguishable from the original XRD pattern. Similar results
are observed for the samples investigated under a dry nitrogen
atmosphere (not shown). These results show conclusively that
UTD-1, despite the large pore apertures, has a thermal/
hydrothermal stability comparable to medium- and large-pore
high-silica zeolites.
XRD patterns is also obtained for a material with a fault
probability of ∼50%.
A third alternative intergrowth structure with cylindrical
6
-ring net pores can also be obtained from combining the up/
2
1
2 1
down 5 4 layers of polymorph A, and the up/down layers 5 4
layers of polymorph C. The disorder in this material could be
also characterized as due to the presence of the narsarsukite
chains and the double-crankshaft chains in different layers. The
main difference between this intergrowth and the previous two
intergrowths is the pores (see Supporting Information). In this
case, the pores are formed only of 6-ring cylindrical nets; no
4MRs or 8MRs are present in the inner surface of the channels.
A good agreement between calculated and experimental XRD
patterns is observed in these simulations for fault probabilities
∼
50% (see Supporting Information).
There are other alternative topologies that could be proposed.
Catalytic Activity of Aluminum-Containing UTD-1. 27Al
MAS NMR spectroscopy of Al-UTD-1 shows the presence of
two peaks at 55 and ∼0 ppm. These two peaks indicate the
However, we have been unable to find any other topology in
which there is either a large number of adjacent 4MR, or there
are secondary building units with no historical precedent in

8482 J. Am. Chem. Soc., Vol. 119, No. 36, 1997
Lobo et al.
Figure 6. Up and down (Ob) configuration of the tetrahedral atoms in different framework topologies of UTD-1: (a) polymorph A, top-left; (b)
polymorph B; (c) polymorph C, top-right; and (d) polymorph D. The dotted lines in a indicate the “layers” used in the simulations of XRD patterns
of faulted materials using DIFFaX.
8
5:15. Chemical analysis also reveals a SiO2/Al2O3 ratio of
almost 70.
We attempted to characterize the samples of Al-UTD-1 using
the isopropylamine desorption method described by Gorte et
4
5
al. to quantify precisely the number density of acid sites in
the sample. We have found that for our experimental conditions,
if the samples contain appreciable amounts of octahedral
aluminum, i.e., Lewis acid sites as in UTD-1, the propene
formed as a result of the amine decomposition oligomerizes.
Thus, the desorption results cannot be used to accurately
4
6
determine the acid site density in Al-UTD-1.
Several aspects of the catalytic activity and selectivity of
zeolite Al-UTD-1 resemble the properties of large-pore zeolites
like zeolite L and mordenite. Recall that zeolite L and
mordenite have a corrugated one-dimensional pore system, and
these corrugations effectively expand the cross section diameters
of the pores. For example, the conversion of m-xylene using
Al-UTD-1 as the catalyst decreased monotonically from 22%
after 120 min of reaction on stream, to ∼5% after 1000 min
(17 h) of reaction time. The relative distribution of trimethyl-
benzenes was 0.71:0.21:0.08 for the 1,3,5-, 1,2,4-, and 1,2,3-
trimethylbenzene isomers, respectively. This distribution is
similar to the distribution observed for other large-pore high-
Figure 7. Narsarsukite (UDUD) and double-crankshaft chains (UUDD)
of tetrahedral atoms connecting successive layers of T-atoms in
polymorphs A and B (narsarsukite) and polymorphs C and D (double-
crankshaft).
47-49,8
silica zeolites,
and it is near the distribution expected from
(
(
45) Farneth, W. E.; Gorte, R. J. Chem. ReV. 1995, 95, 615-635.
presence of tetrahedral aluminum (at 55 ppm) and octahedral
aluminum (∼0 ppm) in the sample, after the treatment with an
aqueous aluminum nitrate solution. On the basis of the relative
areas of these two peaks, it is estimated that the sample contains
tetrahedral and octahedral aluminum in a ratio of approximately
46) Unlike Gorte et al. (see ref 45) we carry out the desorption of the
amine from the zeolite in flowing He gas at 1 bar. Gorte et al. carry out
their desorption experiments in vacuum and this may be the reason for the
polymerization of the propene in the zeolite pores in our experiment.
(
47) Perez-Pariente, J.; Sastre, E.; Fornes, V.; Martens, J. A.; Jacobs, P.
A.; Corma, A. Appl. Catal. 1991, 69, 125-137.

Characterization of UTD-1
J. Am. Chem. Soc., Vol. 119, No. 36, 1997 8483
Table 4. Fractional Atomic Coordinates for Polymorph D (Space
Group Immm No. 71) of UTD-1 [Si64O ]
128
a
atom
multiplicity, Wyckoff letter
x
y
z
Si1
Si2
8l
8l
0.5
0.5
0.6856 0.3812
0.8158 0.2551
Si3
Si4
Si5
16o
16o
16o
4i
8l
16o
4j
16o
8m
16o
16o
8m
16o
8m
8n
0.3579 0.6868 0.2284
0.2682 0.6874 0.3348
0.3568 0.8119 0.4351
O11
O12
O15
O22
O23
O33
O34
O43
O44
O45
O55
O55a
0.5
0.5
0.5
0.3942
0.7140 0.3131
0.4314 0.7644 0.4087
0.5 0.2707
0.4313 0.7743 0.2184
0.3703 0.5 0.2307
0
0.3242 0.7447 0.2878
0.1944 0.7717 0.3231
0.2588 0.5
0.3305
0.2957 0.7332 0.3976
0.3484
0.3517 0.75
0
0.4341
0.5
b
Figure 8. Effect of faulting on the X-ray powder diffraction patterns
of intergrowths of polymorphs A and B (a), and of polymorphs C and
D (b). The instrumental peak broadening was simulated using the
pseudo-Voigt function with u ) 0.2, V ) -0.18, w ) 0.05, and γ )
0
.6 (λ ) 1.2513 Å).
Figure 9. Comparison of the simulated X-ray powder diffraction
patterns of the three proposed intergrowth structures with the experi-
mental XRD patterns (λ ) 1.2514 Å): (a) intergrowth of polymorphs
C and D with p ) 50%; (b) intergrowth of polymorphs A and C, p )
Table 3. Fractional Atomic Coordinates for Polymorph C, Bmmb
(No. 63, Nonstandard Setting) UTD-1 [Si64
O
128
]
atom
multiplicity, Wyckoff letter
x
y
z
5
0%; and (c) intergrowth of polymorphs A and B, p ) 20%. The
Si1
Si2
Si3
Si4
8f
8f
16h
16h
16h
4c
8f
16h
4c
16h
8g
16h
16h
8g
0.5
0.5
0.3579
0.2682
0.3568
0.5
0.5
0.4314
0.5
0.4313
0.3703
0.3242
0.1944
0.2588
0.2957
0.3484
0.3517
0.4356 0.3812
0.5658 0.2551
0.4368 0.2284
0.4374 0.3348
0.5619 0.4351
0.25
0.4640 0.3131
0.5144 0.4087
0.75
0.5243 0.2184
0.25 0.2307
0.4947 0.2878
0.5217 0.3231
0.25
0.4832 0.3976
instrumental peak broadening was simulated using the pseudo-Voigt
function with u ) 0.1, V ) -0.036, w ) 0.009, and γ ) 0.6.
h). Further details of acidity and catalytic properties of UTD-1
Si5
5
0
will be reported at a later date.
O11
O12
O15
O22
O23
O33
O34
O43
O44
O45
O55
O55a
0.3942
*
+
Packing Arrangement of [(Cp )2 Co] Occluded in the
Micropores. To address the question of the orientation of the
structure-directing agent inside the pores of UTD-1, we have
used energy-minimization calculations. We have followed the
0.2707
5
1
52
procedures reported by Shen and Bell, and Lewis et al. to
carry out the minimizations: (i) the zeolite framework is fixed
during the minimization and only the structure-directing mol-
ecule (1 per unit cell) is allowed to move, and in a second
calculation (ii) the zeolite framework and the organometallic
molecule are allowed to relax. Moreover, no charges are
assigned to the framework and the molecule for the calcula-
0.3305
16h
8g
8e
0.75
0.5
0.4341
0.5
5
2
thermodynamic equilibrium. In addition, the rate of isomer-
ization/disproportionation was lower than 1.8 at all times, similar
to the rates of isomerization of other large pore zeolites
tions.
Two orientations of the organometallic molecule where
investigated in detail: (i) the molecule has its 5-fold axis of
symmetry approximately collinear with the a axis of the crystal
(mordenite, L, and Y). Interestingly, the para/ortho ratio of the
product was 0.8 or lower during the entire reaction period (17
(50) Khodabandeh, S.; Davis, M. E. Manuscript in preparation, 1997.
(
48) Martens, J. A.; Perez-Pariente, J.; Sastre, E.; Corma, A.; Jacobs, P.
A. Appl. Catal. 1988, 45, 85-101.
49) Weitkamp, J.; Ernst, S. Catal. Today 1994, 19, 107-150.
(51) Shen, V.; Bell, A. T. Microporous Mater. 1996, 7, 187-199.
(52) Lewis, D. W.; Freeman, C. M.; Catlow, C. R. A. J. Phys. Chem.
1995, 99, 11194-11202.
(

8484 J. Am. Chem. Soc., Vol. 119, No. 36, 1997
Lobo et al.
distinguish between the two conformations investigated. How-
*
+
ever, Cp 2Co is not spherical, and intuitively we expect the
complex to orient itself. A more comprehensive investigation
will be necessary to address this issue.
Summary
Numerous characterizations of the zeolite UTD-1 confirm that
it contains a one-dimensional, extra-large 14-ring pore system.
TEM and ED show that UTD-1 is faulted along the (002) planes.
It is determinedsusing simulation of XRD patterns of faulted
structuressthat among several possible faulted frameworks
investigated, the XRD pattern of a framework containing double-
crankshaft chains shows the best agreement with the experi-
mental pattern. It is concluded that UTD-1 is an intergrowth
of what we denote as polymorphs C and D. Thermal/
hydrothermal stability studies show that UTD-1 has similar
stability to medium- and large-pore high-silica zeolites. The
ratio of isomerization to disproportionation, and the distribution
of trimethylbenzene isomers in the m-xylene isomerization test
reaction using UTD-1 are similar to those from other large-
pore zeolites (zeolites Y or L). However, UTD-1 reveals a
p-/o-xylene ratio of products below one (unlike zeolites Y and
L). By using energy minimization calculations, it was not
possible to determine relative orientation of the cobalt complex
structure-directing agent inside the pores.
Figure 10. Variable-temperature X-ray powder diffraction patterns of
UTD-1 in a water vapor/nitrogen atmosphere (λ ) 1.5428 Å).
Table 5. Results from Energy Minimization Calculations of
[
(Cp*)
2
Co]+ inside the Pores of UTD-1
total energies (kcal/mol)
framework
fixed) +
framework
(
(flexible) +
+
+
[
(Cp*)
2
Co]
2
[(Cp*) Co]
Acknowledgment. C.C.F., M.E.D., K.B., and R.F.L. are
grateful to Chevron Research and Technology for financial
support. K.B. was partially supported by NSF for this investiga-
tion. R.F.L. is grateful to the University of Delaware Research
Foundation for financial support. M.T. acknowledges support
from the National Center for Electron Microscopy at Lawrence
Berkeley Laboratory through a NCEM/DOE fellowship. We
thank the W.M. Keck Polymer Morphology Laboratory for use
of microscopy facilities. We acknowledge T. Vogt and D. E.
Cox for assistance in collecting the synchrotron data. The XRD
data were collected at X7A beam line, National Synchrotron
Light Source, Brookhaven National Laboratory, which is
supported by the Department of Energy, Division of Materials
Sciences and Division of Chemical Sciences.
5
axis
-fold
5-fold
axis
5-fold
axis
5-fold
axis
framework along a along b along a along b
polymorph C
polymorph D
-301
-298
+1334 +1337 +1035 +1033
+1332 +1340 +1034 +1039
a
All the energies correspond to the total energy of the organometallic
complex + all-silica framework as obtained from the energy minimiza-
b
+
tion. The energy of [(Cp*)
2
Co] calculated in free space is +1399
kcal/mol.
system; and (ii) the 5-fold axis of symmetry is collinear with
the b axis of the crystal. A summary of the results is presented
in Table 5. As it can be observed, the differences in total energy
between the two conformations are very small. These results
are similar for both polymorphs C and D. The only notable
difference between the energy minima is observed for the case
in which the 5-fold axis of the molecule is collinear with a. In
polymorph C, this axis is almost parallel to a, and in contrast,
the 5-fold axis is slanted ∼15° from a in polymorph D.
Qualitatively, the molecule in the latter case reduces its total
energy by aligning the two opposite methyl groups along the
Supporting Information Available: TEM of calcined UTD-
1, illustration of intergrowths of poymorphs A and C, simulation
of XRD patterns of polymorphs A and C, comparison of
experimental and calculated XRD patterns of a 50% intergrowth
of polymorphs C and D and input files for the program DIFFaX
(15 pages). See any current masthead page for ordering and
Internet access instructions.
8
-ring windows formed on the (002) planes as discussed above.
Thus, on the basis of these calculations it is not possible to
JA9708528