U.S. patent application number 17/323005 was filed with the patent office on 2021-11-25 for molecular sieve ssz-120, its synthesis and use.
The applicant listed for this patent is CHEVRON U.S.A. INC.. Invention is credited to Cong-Yan CHEN, Jesus PASCUAL, Dan XIE, Stacey Ian ZONES.
Application Number | 20210363023 17/323005 |
Document ID | / |
Family ID | 1000005955195 |
Filed Date | 2021-11-25 |
United States Patent
Application |
20210363023 |
Kind Code |
A1 |
ZONES; Stacey Ian ; et
al. |
November 25, 2021 |
MOLECULAR SIEVE SSZ-120, ITS SYNTHESIS AND USE
Abstract
A small crystal size, high surface area aluminogermanosilicate
molecular sieve material, designated SSZ-120, is provided. SSZ-120
can be synthesized using
3,3'-[2,6-naphthalenebis(methylene)]bis[1,2-dimethyl-1H-imidazolium]
dications as a structure directing agent. SSZ-120 may be used in
organic compound conversion reactions and/or sorptive
processes.
Inventors: |
ZONES; Stacey Ian; (San
Francisco, CA) ; PASCUAL; Jesus; (Berkeley, CA)
; XIE; Dan; (Richmond, CA) ; CHEN; Cong-Yan;
(Kensington, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CHEVRON U.S.A. INC. |
San Ramon |
CA |
US |
|
|
Family ID: |
1000005955195 |
Appl. No.: |
17/323005 |
Filed: |
May 18, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
63028642 |
May 22, 2020 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C01P 2002/72 20130101;
C01P 2006/12 20130101; C01B 39/06 20130101; C01B 39/20
20130101 |
International
Class: |
C01B 39/06 20060101
C01B039/06; C01B 39/20 20060101 C01B039/20 |
Claims
1. An aluminogermanosilicate molecular sieve having, in its
calcined form, a powder X-ray diffraction pattern including the
peaks in the following table: TABLE-US-00009 2-Theta d-Spacing
Relative Intensity [.degree.] [nm] [100 .times. I/Io] 6.8 1.30 W
9.5 0.93 W 15.6 0.57 M 21.0 0.42 W 22.2 0.40 VS 25.9 0.34 M 26.9
0.33 M.
2. The aluminogemanosilicate molecular sieve of claim 1, the
molecular sieve comprising crystals having a total surface area of
at least 500 m.sup.2/g, as determined by the t-plot method for
nitrogen physisorption, and/or an external surface area in a range
of at least 100 m.sup.2/g, as determined by determined from the
t-plot method of nitrogen physisorption.
3. The aluminogemanosilicate molecular sieve of claim 2, wherein
the total surface area is in a range of from 500 to 800
m.sup.2/g.
4. The aluminogemanosilicate molecular sieve of claim 2, wherein
the external surface area is in a range of from 100 to 300
m.sup.2/g.
5. The aluminogermanosilicate molecular sieve of claim 1, having a
composition comprising the molar relationship:
Al.sub.2O.sub.3:(n)(SiO.sub.2+GeO.sub.2) wherein n is
.gtoreq.30.
6. An aluminogermanosilicate molecular sieve having, in its
as-synthesized form, a powder X-ray diffraction pattern including
the peaks in the following table: TABLE-US-00010 2-Theta d-Spacing
Relative Intensity [.degree.] [nm] [100 .times. I/Io] 6.8 1.31 W
9.4 0.94 W 15.7 0.57 M 21.0 0.42 M 22.0 0.40 VS 25.9 0.34 M 26.9
0.33 M.
7. The aluminogermanosilicate molecular sieve of claim 6, having a
composition, in terms of molar ratios, as follows: TABLE-US-00011
(SiO.sub.2 + GeO.sub.2)/Al.sub.2O.sub.3 .gtoreq.30 Q/(SiO.sub.2 +
GeO.sub.2) >0 to 0.1
wherein Q comprises
3,3'-[2,6-naphthalenebis(methylene)]bis[1,2-dimethyl-1H-imidazolium]
dications.
8. The aluminogermanosilicate molecular sieve of claim 6, having a
chemical composition comprising the following molar relationship:
TABLE-US-00012 (SiO.sub.2 + GeO.sub.2)/Al.sub.2O.sub.3 .gtoreq.60
Q/(SiO.sub.2 + GeO.sub.2) >0 to 0.1
wherein Q comprises
3,3'-[2,6-naphthalenebis(methylene)]bis[1,2-dimethyl-1H-imidazolium]
dications.
9. A method of synthesizing an aluminogermanosilicate molecular
sieve, the method comprising: (1) providing a reaction mixture
comprising: (a) a FAU framework type zeolite; (b) a source of
germanium; (c) a structure directing agent (Q) comprising
3,3'-[2,6-naphthalenebis(methylene)]bis[1,2-dimethyl-1H-imidazolium]
dications; (d) a source of fluoride ions; and (e) water; and (2)
subjecting the reaction mixture to crystallization conditions
sufficient to form crystals of the aluminogermanosilicate molecular
sieve.
10. The method of claim 9, wherein the reaction mixture has a
composition, in terms of molar ratios, as follows: TABLE-US-00013
(SiO.sub.2 + GeO.sub.2)/Al.sub.2O.sub.3 30 to 600 Q/(SiO.sub.2 +
GeO.sub.2) 0.10 to 1.00 F/(SiO.sub.2 + GeO.sub.2) 0.10 to 1.00
H.sub.2O/(SiO.sub.2 + GeO.sub.2) .sup. 2 to 10.
11. The method of claim 9, wherein the reaction mixture has a
composition, in terms of molar ratios, as follows: TABLE-US-00014
(SiO.sub.2 + GeO.sub.2)Al.sub.2O.sub.3 60 to 500 Q/(SiO.sub.2 +
GeO.sub.2) 0.20 to 0.70 F/(SiO.sub.2 + GeO.sub.2) 0.20 to 0.70
H.sub.2O/(SiO.sub.2 + GeO.sub.2) 4 to 8.
12. The method of claim 9, wherein the FAU framework type zeolite
is zeolite Y.
13. The method of claim 9, wherein the crystallization conditions
include heating the reaction mixture under autogenous pressure at a
temperature of from 100.degree. C. to 200.degree. C. and for a time
of from 1 day to 14 days.
14. A process for converting a feedstock comprising an organic
compound to a conversion product, the process comprising contacting
the feedstock at organic compound conversion conditions with a
catalyst comprising the aluminogermanosilicate molecular sieve of
claim 1.
15. An organic nitrogen compound comprising a dication having the
following structure: ##STR00003##
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to and the benefit of U.S.
Provisional Application Ser. No. 63/028,642, filed May 22,
2020.
FIELD
[0002] This disclosure relates to a small crystal size, high
surface area aluminogermanosilicate molecular sieve designated
SSZ-120, its synthesis, and its use in organic compound conversion
reactions and sorption processes.
BACKGROUND
[0003] Molecular sieves are a commercially important class of
materials that have distinct crystal structures with defined pore
structures that are shown by distinct X-ray diffraction (XRD)
patterns and have specific chemical compositions. The crystal
structure defines cavities and pores that are characteristic of the
specific type of molecular sieve.
[0004] According to the present disclosure, a small crystal size,
high surface area aluminogermanosilicate molecular sieve,
designated SSZ-120 and having a unique powder X-ray diffraction
pattern, has been synthesized using
3,3'-[2,6-naphthalenebis(methylene)]bis[1,2-dimethyl-1H-imidazolium]
dications as a structure directing agent.
SUMMARY
[0005] In a first aspect, there is provided an
aluminogermanosilicate molecular sieve having, in its calcined
form, a powder X-ray diffraction pattern including the peaks in the
following table:
TABLE-US-00001 2-Theta d-Spacing Relative Intensity [.degree.] [nm]
[100 .times. I/Io] 6.8 1.30 W 9.5 0.93 W 15.6 0.57 M 21.0 0.42 W
22.2 0.40 VS 25.9 0.34 M 26.9 0.33 M.
[0006] The calcined molecular sieve can have a total surface area
(as determined by the t-plot method for nitrogen physisorption) of
at least 500 m.sup.2/g and/or an external surface area (as
determined by the t-plot method for nitrogen physisorption) of at
least 100 m.sup.2/g.
[0007] In a second aspect, there is provided an
aluminogermanosilicate molecular sieve having, in its
as-synthesized form, a powder X-ray diffraction pattern including
the peaks in the following table:
TABLE-US-00002 2-Theta d-Spacing Relative Intensity [.degree.] [nm]
[100 .times. I/Io] 6.8 1.31 W 9.4 0.94 W 15.7 0.57 M 21.0 0.42 M
22.0 0.40 VS 25.9 0.34 M 26.9 0.33 M
[0008] In its as-synthesized and anhydrous form, the
aluminogermanosilicate molecular sieve can have a chemical
composition comprising the following molar relationship:
TABLE-US-00003 Broadest Secondary (SiO.sub.2 +
GeO.sub.2)/Al.sub.2O.sub.3 .gtoreq.30 .gtoreq.60 Q/(SiO.sub.2 +
GeO.sub.2) >0 to 0.1 >0 to 0.1
wherein Q comprises
3,3'-[2,6-naphthalenebis(methylene)]bis[1,2-dimethyl-1H-imidazolium]
dications.
[0009] In a third aspect, there is provided a method of
synthesizing an aluminogermanosilicate molecular sieve, the method
comprising (1) providing a reaction mixture comprising: (a) a FAU
framework type zeolite; (b) a source of germanium; (c) a structure
directing agent (Q) comprising
3,3'-[2,6-naphthalenebis(methylene)]bis[1,2-dimethyl-1H-imidazolium]
dications; (d) a source of fluoride ions; and (e) water; and (2)
subjecting the reaction mixture to crystallization conditions
sufficient to form crystals of the aluminogermanosilicate molecular
sieve.
[0010] In a fourth aspect, there is provided a process of
converting a feedstock comprising an organic compound to a
conversion product which comprises contacting the feedstock at
organic compound conversion conditions with a catalyst comprising
an active form of the aluminogermanosilicate molecular sieve,
described herein.
[0011] In a fifth aspect, there is provided an organic nitrogen
compound comprising a dication having the following structure:
##STR00001##
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 shows the powder X-ray diffraction (XRD) pattern of
the as-synthesized product of Example 2.
[0013] FIGS. 2(A)-2(D) show scanning electron micrograph (SEM)
images of the as-synthesized product of Example 2 at different
magnifications.
[0014] FIG. 3 shows the powder XRD pattern of the calcined product
of Example 3.
[0015] FIG. 4 is a graph illustrating the relationship between
conversion or yield and temperature in the hydroconversion of
n-decane over a Pd/SSZ-120 catalyst.
DETAILED DESCRIPTION
Definitions
[0016] The term "framework type" has the meaning described in the
"Atlas of Zeolite Framework Types", by Ch. Baerlocher and L. B.
McCusker and D. H. Olsen (Sixth Revised Edition, Elsevier,
2007).
[0017] The term "zeolite" refers an aluminosilicate molecular sieve
having a framework constructed of alumina and silica (i.e.,
repeating AlO4 and SiO4 tetrahedral units).
[0018] The term "aluminogermanosilicate" refers to a molecular
sieve having a framework constructed of AlO4, GeO4 and SiO4
tetrahedral units. The alumingermanosilicate may contain only the
named oxides, in which case, it may be described as a "pure
aluminogermanosilicate" or it may contain other additional oxides
as well.
[0019] The term "as-synthesized" is employed herein to refer to a
molecular sieve in its form after crystallization, prior to removal
of the structure directing agent.
[0020] The term "anhydrous" is employed herein to refer to a
molecular sieve substantially devoid of both physically adsorbed
and chemically adsorbed water.
[0021] The term "SiO.sub.2/Al.sub.2O.sub.3 molar ratio" may be
abbreviated as "SAR".
[0022] Synthesis of the Molecular Sieve
[0023] Aluminogermanosilicate molecular sieve SSZ-120 can be
synthesized by: (1) providing a reaction mixture comprising (a) a
FAU framework type zeolite; (b) a source of germanium; (c) a
structure directing agent (Q) comprising
3,3'-[2,6-naphthalenebis(methylene)]bis[1,2-dimethyl-1H-imidazolium]
dications; (d) a source of fluoride ions; and (e) water; and (2)
subjecting the reaction mixture to crystallization conditions
sufficient to form crystals of the aluminogermanosilicate molecular
sieve.
[0024] The reaction mixture can have a composition, in terms of
molar ratios, within the ranges set forth in Table 1:
TABLE-US-00004 TABLE 1 Reactants Broadest Secondary (SiO.sub.2 +
GeO.sub.2)/Al.sub.2O.sub.3 30 to 600 60 to 500 Q/(SiO.sub.2 +
GeO.sub.2) 0.10 to 1.00 0.20 to 0.70 F/(SiO.sub.2 + GeO.sub.2) 0.10
to 1.00 0.20 to 0.70 H.sub.2O/(SiO.sub.2 + GeO.sub.2) 2 to 10 4 to
8
wherein Q comprises
3,3'-[2,6-naphthalenebis(methylene)]bis[1,2-dimethyl-1H-imidazolium]
dications.
[0025] In some aspects, the reaction mixture can have a
SiO.sub.2/GeO.sub.2 molar ratio in a range of from 4 to 12 (e.g.,
from 6 to 10).
[0026] The FAU framework type zeolite can be ammonium-form zeolites
or hydrogen-form zeolites (e.g., NH.sub.4-form zeolite Y, H-form
zeolite Y). Examples of the FAU framework type zeolite include
zeolite Y (e.g., CBV720, CBV760, CBV780, HSZ-385HUA, and
HSZ-390HUA). Preferably, the FAU framework type zeolite is zeolite
Y. More preferably, zeolite Y has a SiO.sub.2/Al.sub.2O.sub.3 molar
ratio in a range of about 30 to about 500. The FAU framework type
zeolite can comprise two or more zeolites. Typically, the two or
more zeolites are Y zeolites having different
SiO.sub.2/Al.sub.2O.sub.3 molar ratios. The FAU framework type
zeolite can also be the only silica and aluminum source to form the
aluminogermanosilicate molecular sieve.
[0027] Sources of germanium include germanium oxide and germanium
alkoxides (e.g., germanium ethoxide).
[0028] Sources of fluoride ions include hydrogen fluoride, ammonium
fluoride, and ammonium bifluoride.
[0029] SSZ-120 can be synthesized using a structure directing agent
(Q) comprising
3,3'-[2,6-naphthalenebis(methylene)]bis[1,2-dimethyl-1H-imidazolium]
dications, represented by the following structure (1):
##STR00002##
[0030] Suitable sources of Q are the hydroxides, chlorides,
bromides, and/or other salts of the diquaternary ammonium
compound.
[0031] The reaction mixture can contain seeds of a molecular sieve
material, such as SSZ-120 from a previous synthesis, in an amount
of from 0.01 to 10,000 ppm by weight (e.g., 100 to 5000 ppm by
weight) of the reaction mixture. Seeding can be advantageous to
improve selectivity for SSZ-120 and/or to shorten the
crystallization process.
[0032] It is noted that the reaction mixture components can be
supplied by more than one source. Also, two or more reaction
components can be provided by one source. The reaction mixture can
be prepared either batchwise or continuously.
[0033] Crystallization and Post-Synthesis Treatment
[0034] Crystallization of the molecular sieve from the above
reaction mixture can be carried out under either static, tumbled or
stirred conditions in a suitable reactor vessel, such as
polypropylene jars or Teflon-lined or stainless-steel autoclaves
placed in convection oven maintained at a temperature of from
100.degree. C. to 200.degree. C. for a time sufficient for
crystallization to occur at the temperature used (e.g., 1 day to 14
days). The hydrothermal crystallization process is usually
conducted under autogenous pressure.
[0035] Once the desired molecular sieve crystals have formed, the
solid product is separated from the reaction mixture by standard
separation techniques such as filtration or centrifugation. The
recovered crystals are water-washed and then dried, for several
seconds to a few minutes (e.g., from 5 seconds to 10 minutes for
flash drying) or several hours (e.g., from 4 to 24 hours for oven
drying at 75.degree. C. to 150.degree. C.), to obtain
as-synthesized SSZ-120 crystals having at least a portion of the
structure directing agent within its pores. The drying step can be
performed at atmospheric pressure or under vacuum.
[0036] The as-synthesized molecular sieve may be subjected to
thermal treatment, ozone treatment, or other treatment to remove
part or all of the structure directing agent used in its synthesis.
Removal of the structure directing agent may be carried out by
thermal treatment (i.e., calcination) in which the as-synthesized
molecular sieve is heated in air or inert gas at a temperature
sufficient to remove part or all of the structure directing agent.
While sub-atmospheric pressure may be used for the thermal
treatment, atmospheric pressure is desired for reasons of
convenience. The thermal treatment may be performed at a
temperature at least 370.degree. C. for at least a minute and
generally not longer than 20 hours (e.g., from 1 to 12 hours). The
thermal treatment can be performed at a temperature of up to
925.degree. C. For example, the thermal treatment may be conducted
at a temperature of from 400.degree. C. to 600.degree. C. in air
for approximately 1 to 8 hours. The thermally-treated product,
especially in its metal, hydrogen and ammonium forms, is
particularly useful in the catalysis of certain organic (e.g.,
hydrocarbon) conversion reactions.
[0037] Any extra-framework metal cations in the molecular sieve can
be replaced in accordance with techniques well known in the art
(e.g., by ion exchange) with hydrogen, ammonium, or any desired
metal cation.
[0038] Characterization of the Molecular Sieve
[0039] In its as-synthesized and anhydrous form, molecular sieve
SSZ-120 can have a chemical composition comprising the following
molar relationship set forth in Table 2:
TABLE-US-00005 TABLE 2 Broadest Secondary (SiO.sub.2 +
GeO.sub.2)/Al.sub.2O.sub.3 .gtoreq.30 .gtoreq.60 Q/(SiO.sub.2 +
GeO.sub.2) >0 to 0.1 >0 to 0.1
wherein Q comprises
3,3'-[2,6-naphthalenebis(methylene)]bis[1,2-dimethyl-1H-imidazolium]
dications.
[0040] In some aspects, the molecular sieve can have a
SiO.sub.2/GeO.sub.2 molar ratio in a range of from 4 to 12 (e.g., 6
to 10).
[0041] In its calcined form, molecular sieve SSZ-120 can have a
chemical composition comprising the following molar
relationship:
Al.sub.2O.sub.3:(n)(SiO.sub.2+GeO.sub.2)
wherein n is .gtoreq.30 (e.g., 30 to 600, .gtoreq.60, 60 to 500, or
100 to 300).
[0042] Molecular sieve SSZ-120 has a powder X-ray diffraction
pattern which, in its as-synthesized form, includes at least the
peaks set forth in Table 3 below and which, in its calcined form,
includes at least the peaks set forth in Table 4.
TABLE-US-00006 TABLE 3 Characteristic Peaks for As-Synthesized
SSZ-120 2-Theta d-Spacing Relative Intensity [.degree.] [nm] [100
.times. I/Io] 6.8 1.31 W 9.4 0.94 W 15.7 0.57 M 21.0 0.42 M 22.0
0.40 VS 25.9 0.34 M 26.9 0.33 M
TABLE-US-00007 TABLE 4 Characteristic Peaks for Calcined SSZ-120
2-Theta d-Spacing Relative Intensity [.degree.] [nm] [100 .times.
I/Io] 6.8 1.30 W 9.5 0.93 W 15.6 0.57 M 21.0 0.42 W 22.2 0.40 VS
25.9 0.34 M 26.9 0.33 M
[0043] The powder X-ray diffraction patterns presented herein were
collected by standard techniques using copper K-alpha radiation. As
will be understood by those of skill in the art, the determination
of the parameter 2-theta is subject to both human and mechanical
error, which in combination can impose an uncertainty of about
.+-.0.3.degree. on each reported value of 2-theta. This uncertainty
is, of course, also manifested in the reported values of the
d-spacings, which are calculated from the 2-theta values using
Bragg's law. The relative intensities of the lines, I/Io,
represents the ratio of the peak intensity to the intensity of the
strongest line, above background. The intensities are uncorrected
for Lorentz and polarization effects. The relative intensities are
given in terms of the symbols VS=very strong (>60 to 100),
S=strong (>40 to 60), M=medium (>20 to 60), and W=weak (>0
to 20).
[0044] Minor variations in the powder X-ray diffraction pattern
(e.g., experimental variation in peak ratios and peak positions)
can result from variations in the atomic ratios of the framework
atoms due to changes in lattice constants. In addition,
sufficiently small crystals may affect the shape and intensity of
peaks, possibly leading to peak broadening. Calcination can also
cause minor shifts in the powder X-ray diffraction pattern compared
to the pre-calcination powder X-ray diffraction pattern.
Notwithstanding these minor perturbations, the crystal lattice
structure may remain unchanged following calcination.
[0045] The syntheses described herein can produce a molecular sieve
having a small crystal size, such that the total surface area of
the material can be at least 500 m.sup.2/g and the external surface
area can be at least 100 m.sup.2/g. In some aspects, the molecular
sieve described herein can comprise crystals having a total
external surface area of at least 600 m.sup.2/g, at least 625
m.sup.2/g, at least or at least 650 m.sup.2/g, such as from 500 to
800 m.sup.2/g, from 600 to 800 m.sup.2/g, or from 650 to 800
m.sup.2/g. Additionally or alternatively, the molecular sieve
described herein can comprise crystals having an external surface
area of at least 100 m.sup.2/g, at least 110 m.sup.2/g, at least
120 m.sup.2/g, at least 130 m.sup.2/g, or at least 140 m.sup.2/g,
such as from 100 to 300 m.sup.2/g, from 120 to 300 m.sup.2/g, or
from 140 to 300 m.sup.2/g. All surface area values given herein are
determined from nitrogen physisorption using the t-plot method.
Details of this method are described by B. C. Lippens and J. H. de
Boer (J. Catal. 1965, 4, 319-323).
INDUSTRIAL APPLICABILITY
[0046] Molecular sieve SSZ-120 (where part or all of the structure
directing agent is removed) may be used as a sorbent or as a
catalyst to catalyze a wide variety of organic compound conversion
processes including many of present commercial/industrial
importance. Examples of chemical conversion processes which are
effectively catalyzed by SSZ-120, by itself or in combination with
one or more other catalytically active substances including other
crystalline catalysts, include those requiring a catalyst with acid
activity. Examples of organic conversion processes which may be
catalyzed by SSZ-120 include aromatization, cracking,
hydrocracking, disproportionation, alkylation, oligomerization, and
isomerization.
[0047] As in the case of many catalysts, it may be desirable to
incorporate SSZ-120 with another material resistant to the
temperatures and other conditions employed in organic conversion
processes. Such materials include active and inactive materials and
synthetic or naturally occurring zeolites as well as inorganic
materials such as clays, silica and/or metal oxides such as
alumina. The latter may be either naturally occurring, or in the
form of gelatinous precipitates or gels, including mixtures of
silica and metal oxides. Use of a material in conjunction with
SSZ-120 (i.e., combined therewith or present during synthesis of
the new material) which is active, tends to change the conversion
and/or selectivity of the catalyst in certain organic conversion
processes. Inactive materials suitably serve as diluents to control
the amount of conversion in a given process so that products can be
obtained in an economic and orderly manner without employing other
means for controlling the rate of reaction. These materials may be
incorporated into naturally occurring clays (e.g., bentonite and
kaolin) to improve the crush strength of the catalyst under
commercial operating conditions. These materials (i.e., clays,
oxides, etc.) function as binders for the catalyst. It is desirable
to provide a catalyst having good crush strength because in
commercial use it is desirable to prevent the catalyst from
breaking down into powder-like materials. These clay and/or oxide
binders have been employed normally only for the purpose of
improving the crush strength of the catalyst.
[0048] Naturally occurring clays which can be composited with
SSZ-120 include the montmorillonite and kaolin family, which
families include the sub-bentonites, and the kaolins commonly known
as Dixie, McNamee, Georgia and Florida clays or others in which the
main mineral constituent is halloysite, kaolinite, dickite,
nacrite, or anauxite. Such clays can be used in the raw state as
originally mined or initially subjected to calcination, acid
treatment or chemical modification. Binders useful for compositing
with SSZ-120 also include inorganic oxides, such as silica,
zirconia, titania, magnesia, beryllia, alumina, and mixtures
thereof.
[0049] In addition to the foregoing materials, SSZ-120 can be
composited with a porous matrix material such as silica-alumina,
silica-magnesia, silica-zirconia, silica-thoria, silica-beryllia,
silica-titania as well as ternary compositions such as
silica-alumina-thoria, silica-alumina-zirconia
silica-alumina-magnesia and silica-magnesia-zirconia.
[0050] The relative proportions of SSZ-120 and inorganic oxide
matrix may vary widely, with the SSZ-120 content ranging from 1 to
90 wt. % (e.g., 2 to 80 wt. %) of the composite.
EXAMPLES
[0051] The following illustrative examples are intended to be
non-limiting.
Example 1
Synthesis of
3,3'-[2,6-naphthalenebis(methylene)]bis[1,2-dimethyl-1H-imidazolium]
dihydroxide
[0052] A 250 mL round bottom flask equipped with a magnetic stir
bar was charged with 5 g of 2,6-bis(bromomethyl)naphthalene, 3.83 g
of 1,2-dimethylimidazole and 100 mL of methanol. A reflux condenser
was then attached, and the mixture heated at 65.degree. C. for 3
days. After cooling, methanol was removed on a rotary evaporator to
provide white solids. The initially recovered solids from rotary
evaporation were further purified by recrystallization from cold
ethanol. The recrystallized dibromide salt was pure by .sup.1H- and
.sup.13C-NMR spectroscopy.
[0053] The dibromide salt was exchanged to the corresponding
dihydroxide salt by stirring it with hydroxide exchange resin in
deionized water overnight. The solution was filtered, and the
filtrate was analyzed for hydroxide concentration by titration of a
small sample with a standardized solution of 0.1 N HCl.
Example 2
Synthesis of SSZ-120
[0054] Into a tared 23 mL Parr reactor was added 0.27 g of Tosoh
HSZ-390HUA Y-zeolite (SAR=500), 0.05 g of GeO.sub.2 and 2.5 mmol of
an aqueous
3,3'-[2,6-naphthalenebis(methylene)]bis[1,2-dimethyl-1H-imidazoli-
um] dihydroxide solution. The reactor was then placed in a vented
hood and water was allowed to evaporate to bring the
H.sub.2O/(SiO.sub.2+GeO.sub.2) molar ratio to 7 (as determined by
the total mass of the suspension). Then, 2.5 mmol of HF was added
and the reactor was heated to 160.degree. C. with tumbling at 43
rpm for about 7 days. The solid products were recovered by
centrifugation, washed with deionized water and dried at 95.degree.
C.
[0055] Powder XRD of the as-synthesized product gave the pattern
indicated in FIG. 1 and showed the product to be a pure form of a
new phase, SSZ-120. Significantly decreased crystal size is
inferred from the peak broadening in the powder XRD pattern.
[0056] FIGS. 2(A)-2(D) show illustrative SEM images of the
as-synthesized product at various magnifications.
[0057] The product had a SiO.sub.2/GeO.sub.2 molar ratio of 8, as
determined by Inductively Coupled Plasma-Atomic Emission
Spectroscopy (ICP-AES).
Example 3
Calcination of SSZ-120
[0058] The as-synthesized molecular sieve of Example 1 was calcined
inside a muffle furnace under a flow of air heated to 550.degree.
C. at a rate of 1.degree. C./minute and held at 550.degree. C. for
5 hours, cooled and then analyzed by powder XRD.
[0059] The powder XRD pattern of the calcined material is shown in
FIG. 3 and indicates that the material remains stable after
calcination to remove the structure directing agent.
Example 4
[0060] Example 2 was repeated using Zeolyst CBV780 Y-zeolite
(SAR=80) as the FAU source. Powder XRD showed the product to be
SSZ-120.
Example 5
[0061] Example 2 was repeated using Zeolyst CBV760 Y-zeolite
(SAR=60) as the FAU source. Powder XRD showed the product to be
SSZ-120.
[0062] The product was calcined as described in Example 2. The
surface area of the sample was then measured using nitrogen
physisorption and the data were analyzed with the t-plot method.
The determined total surface area was 693 m.sup.2/g and the
external surface area was 144 m.sup.2/g. The micropore volume was
0.2666 cm.sup.3/g.
Example 6
[0063] Example 2 was repeated using Zeolyst CBV720 Y-zeolite
(SAR=30) as the FAU source. Powder XRD showed the product to be
SSZ-120.
Example 7
Bronsted Acidity
[0064] Bronsted acidity of the molecular sieve of Example 5 in its
calcined form was determined by n-propylamine
temperature-programmed desorption (TPD) adapted from the published
descriptions by T. J. Gricus Kofke et al. (J. Catal. 1988, 114,
34-45); T. J. Gricus Kofke et al. (J. Catal. 1989, 115, 265-272);
and J. G. Tittensor et al. (J. Catal. 1992, 138, 714-720). A sample
was pre-treated at 400.degree. C.-500.degree. C. for 1 hour in
flowing dry H.sub.2. The dehydrated sample was then cooled down to
120.degree. C. in flowing dry helium and held at 120.degree. C. for
30 minutes in a flowing helium saturated with n-propylamine for
adsorption. The n-propylamine-saturated sample was then heated up
to 500.degree. C. at a rate of 10.degree. C./minute in flowing dry
helium. The Bronsted acidity was calculated based on the weight
loss vs. temperature by thermogravimetric analysis (TGA) and
effluent NH.sub.3 and propene by mass spectrometry. The sample had
a Bronsted acidity of 250 .mu.mol/g, indicating that aluminum sites
are incorporated into the framework of the molecular sieve.
Example 8
Constraint Index Testing
[0065] Constraint Index is a test to determine shape-selective
catalytic behavior in molecular sieves. It compares the reaction
rates for the cracking of n-hexane (n-C6) and its isomer
3-methylpentane (3-MP) under competitive conditions (see V. J.
Frillette et al., J. Catal. 1981, 67, 218-222).
[0066] The hydrogen form of the molecular sieve prepared per
Example 5 was pelletized at 4 kpsi, crushed and granulated to 20-40
mesh. A 0.6 g sample of the granulated material was calcined in air
at 540.degree. C. for 4 hours and cooled in a desiccator to ensure
dryness. Then, 0.47 g of material was packed into a 1/4 inch
stainless steel tube with alundum on both sides of the molecular
sieve bed. A furnace (Applied Test Systems, Inc.) was used to heat
the reactor tube. Nitrogen was introduced into the reactor tube at
9.4 mL/minute and at atmospheric pressure. The reactor was heated
to about 700.degree. F. (371.degree. C.), and a 50/50 feed of
n-hexane and 3-methylpentane was introduced into the reactor at a
rate of 8 .mu.L/minute. The feed was delivered by an ISCO pump.
Direct sampling into a GC began after 15 minutes of feed
introduction. Test data results after 15 minutes on stream
(700.degree. F.) are presented in Table 5.
TABLE-US-00008 TABLE 5 Constraint Index Test n-Hexane Conversion, %
64.8 3-Methylpentane Conversion, % 93.3 Feed Conversion, % 79.1
Constraint Index (excluding 2MP) 0.39 Constraint Index (including
2MP) 0.39
Example 9
Hydroconversion of n-Decane
[0067] Material from Example 5 was calcined in air at 595.degree.
C. for 5 hours. After calcination, the material was loaded with
palladium by mixing for three days at room temperature 4.5 g of a
0.148 N NH.sub.4OH solution with 5.5 g of deionized water and then
a (NH.sub.3).sub.4Pd(NO.sub.3).sub.2 solution (buffered at pH 9.5)
such that 1 g of this solution mixed in with 1 g of molecular sieve
provided a 0.5 wt. % Pd loading. The recovered Pd/SSZ-120 material
was washed with deionized water, dried at 95.degree. C., and then
calcined to 300.degree. C. for 3 hours. The calcined Pd/SSZ-120
catalyst was then pelletized, crushed, and sieved to 20-40
mesh.
[0068] 0.5 g of the Pd/SSZ-120 catalyst was loaded in the center of
a 23 inch-long.times.1/4 inch outside diameter stainless steel
reactor tube with alundum loaded upstream of the catalyst for
preheating the feed (a total pressure of 1200 psig; a down-flow
hydrogen rate of 160 mL/minute when measured at 1 atmosphere
pressure and 25.degree. C.; and a down-flow liquid feed rate of 1
mL/hour). All materials were first reduced in flowing hydrogen at
about 315.degree. C. for 1 hour. Products were analyzed by on-line
capillary GC once every 60 minutes. Raw data from the GC was
collected by an automated data collection/processing system and
hydrocarbon conversions were calculated from the raw data.
Conversion is defined as the amount n-decane reacted to produce
other products (including iso-C10). Yields are expressed as mole
percent of products other than n-decane and include iso-C10 isomers
as a yield product. The results are shown in FIG. 4 and indicate
that the catalyst is quite active and not particularly selective
for isomerization, making considerable cracked product from
n-decane.
* * * * *