Molecular sieve abstract
The present invention relates to new crystalline molecular sieve
SSZ-63 prepared using N-cyclodecyl-N-methyl-pyrrolidinium cation
as a structure-directing agent, methods for synthesizing SSZ-63
and processes employing SSZ-63 in a catalyst.
Molecular sieve claims
What is claimed is:
1. In a process for the reduction of oxides of nitrogen contained
in a gas stream in the presence of oxygen wherein said process comprises
contacting the gas stream with a zeolite, the improvement comprising
using as the zeolite a zeolite having a mole ratio greater than
about 15 of an oxide of a first tetravalent element to an oxide
of a second tetravalent element which is different from said first
tetravalent element, trivalent element, pentavalent element or mixture
thereof and having, after calcination, the X-ray diffraction lines
of Table II.
2. The process of claim 1 wherein said zeolite contains a metal
or metal ions capable of catalyzing the reduction of the oxides
3. The process of claim 2 wherein the metal is copper, cobalt or
4. The process of claim 2 wherein the gas stream is the exhaust
stream of an internal combustion engine.
Molecular sieve description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to new crystalline molecular sieve
SSZ-63 a method for preparing SSZ-63 using N-cyclodecyl-N-methyl-pyrrolidinium
cation as a structure directing agent and the use of SSZ-63 in catalysts
for, e.g., hydrocarbon conversion reactions.
2. State of the Art
Because of their unique sieving characteristics, as well as their
catalytic properties, crystalline molecular sieves and zeolites
are especially useful in applications such as hydrocarbon conversion,
gas drying and separation. Although many different crystalline molecular
sieves have been disclosed, there is a continuing need for new zeolites
with desirable properties for gas separation and drying, hydrocarbon
and chemical conversions, and other applications. New zeolites may
contain novel internal pore architectures, providing enhanced selectivities
in these processes.
Crystalline aluminosilicates are usually prepared from aqueous
reaction mixtures containing alkali or alkaline earth metal oxides,
silica, and alumina. Crystalline borosilicates are usually prepared
under similar reaction conditions except that boron is used in place
of aluminum. By varying the synthesis conditions and the composition
of the reaction mixture, different zeolites can often be formed.
SUMMARY OF THE INVENTION
The present invention is directed to a family of crystalline molecular
sieves with unique properties, referred to herein as "molecular
sieve SSZ-63" or simply "SSZ-63". Preferably, SSZ-63
is obtained in its silicate, aluminosilicate, titanosilicate, germanosilicate,
vanadosilicate or borosilicate form. The term "silicate"
refers to a molecular sieve having a high mole ratio of silicon
oxide relative to aluminum oxide, preferably a mole ratio greater
than 100 including molecular sieves comprised entirely of silicon
oxide. As used herein, the term "aluminosilicate" refers
to a molecular sieve containing both alumina and silica and the
term "borosilicate" refers to a molecular sieve containing
oxides of both boron and silicon.
In accordance with this invention, there is provided an improved
process for the reduction of oxides of nitrogen contained in a gas
stream in the presence of oxygen wherein said process comprises
contacting the gas stream with a zeolite, the improvement comprising
using as the zeolite a zeolite having a mole ratio greater than
about 15 of an oxide of a first tetravalent element to an oxide
of a second tetravalent element different from said first tetravalent
element, trivalent element, pentavalent element or mixture thereof
and having, after calcination, the X-ray diffraction lines of Table
II. The zeolite may contain a metal or metal ions (such as cobalt,
copper or mixtures thereof) capable of catalyzing the reduction
of the oxides of nitrogen, and may be conducted in the presence
of a stoichiometric excess of oxygen. In a preferred embodiment,
the gas stream is the exhaust stream of an internal combustion engine.
BRIEF DESCRIPTION OF THE DRAWING
The drawing is a powder X-ray diffraction pattern of calcined SSZ-63.
DETAILED DESCRIPTION OF THE INVENTION
The present invention comprises a family of crystalline, large
pore molecular sieves designated herein "molecular sieve SSZ-63"
or simply "SSZ-63". As used herein, the term "large
pore" means having an average pore size diameter greater than
about 6.0 Angstroms, preferably from about 6.5 Angstroms to about
While not wishing to be bound by any theory, it is believed that
the crystal structure of SSZ-63 consists of two polymorphs of zeolite
beta. Typical zeolite beta (BEA*) has a crystal structure consisting
of about a 50/50 combination of two polymorphs, polymorph A and
polymorph B. It is believed that the crystal structure of SSZ-63
consists of about 60-70% of a beta polymorph referred to herein
as beta-C (Higgins) with the remainder being beta polymorph B. Beta
polymorph C (Higgins) is different from beta polymorph C. The structure
of polymorph C (Higgins) has been postulated in the literature,
but it is believed that polymorph C (Higgins) has heretofore not
been made. A discussion of polymorph C (Higgins) can be found in
Higgins et al, "The framework Topology of Zeolite Beta",
Zeolites, 1988 vol. 8 pp.446-452 with a correction at Higgins
et al., "The Framework Topology of Zeolite Beta--A Correction",
Zeolites, 1989 vol. 9 p. 358.
In preparing SSZ-63 N-cyclodecyl-N-methyl-pyrrolidinium cation
is used as a structure directing agent ("SDA"), also known
as a crystallization template. In general, SSZ-63 is prepared by
contacting an active source of one or more oxides selected from
the group consisting of monovalent clement oxides, divalent element
oxides, trivalent element oxides, tetravalent element oxides and
pentavalent elements with the N-cyclodecyl-N-methyl-pyrrolidinium
SSZ-63 is prepared from a reaction mixture having the composition
shown in Table A below.
TABLE A Reaction Mixture Typical Preferred YO.sub.2 /W.sub.a O.sub.b
>15 30-70 OH--/YO.sub.2 0.10-0.50 0.20-0.30 Q/YO.sub.2 0.05-0.50
0.10-0.20 M.sub.2/n /YO.sub.2 0.02-0.40 0.10-0.25 H.sub.2 O/YO.sub.2
where Y, W, Q, M and n are as defined above, and a is 1 or 2 and
b is 2 when a is 1 (i.e., W is tetravalent) and b is 3 when a is
2 (i.e., W is trivalent).
In practice, SSZ-63 is prepared by a process comprising:
(a) preparing an aqueous solution containing sources of at least
one oxide capable of forming a crystalline molecular sieve and a
N-cyclodecyl-N-methyl-pyrrolidinium cation having an anionic counterion
which is not detrimental to the formation of SSZ-63;
(b) maintaining the aqueous solution under conditions sufficient
to form crystals of SSZ-63; and
(c) recovering the crystals of SSZ-63.
Accordingly, SSZ-63 may comprise the crystalline material and the
SDA in combination with metallic and non-metallic oxides bonded
in tetrahedral coordination through shared oxygen atoms to form
a cross-linked three dimensional crystal structure. The metallic
and non-metallic oxides comprise one or a combination of oxides
of a first tetravalent element(s), and one or a combination of a
trivalent element(s), pentavalent element(s), second tetravalent
element(s) different from the first tetravalent element(s) or mixture
thereof. The first tetravalent element(s) is preferably selected
from the group consisting of silicon, germanium and combinations
thereof. More preferably, the first tetravalent element is silicon.
The trivalent element, pentavalent element and second tetravalent
element (which is different from the first tetravalent element)
is preferably selected from the group consisting of aluminum, gallium,
iron, boron, titanium, indium, vanadium and combinations thereof.
More preferably, the second trivalent or tetravalent element is
aluminum or boron.
Typical sources of aluminum oxide for the reaction mixture include
aluminates, alumina, aluminum colloids, aluminum oxide coated on
silica sol, hydrated alumina gels such as Al(OH).sub.3 and aluminum
compounds such as AlCl.sub.3 and Al.sub.2 (SO.sub.4).sub.3. Typical
sources of silicon oxide include silicates, silica hydrogel, silicic
acid, fumed silica, colloidal silica, tetra-alkyl orthosilicates,
and silica hydroxides. Boron, as well as gallium, germanium, titanium,
indium, vanadium and iron, can be added in forms corresponding to
their aluminum and silicon counterparts.
A source zeolite reagent may provide a source of aluminum or boron.
In most cases, the source zeolite also provides a source of silica.
The source zeolite in its dealuminated or deboronated form may also
be used as a source of silica, with additional silicon added using,
for example, the conventional sources listed above. Use of a source
zeolite reagent as a source of alumina for the present process is
more completely described in U.S. Pat. No. 5225179 issued Jul.
6 1993 to Nakagawa entitled "Method of Making Molecular Sieves",
the disclosure of which is incorporated herein by reference.
Typically, an alkali metal hydroxide and/or an alkaline earth metal
hydroxide, such as the hydroxide of sodium, potassium, lithium,
cesium, rubidium, calcium, and magnesium, is used in the reaction
mixture; however, this component can be omitted so long as the equivalent
basicity is maintained. The SDA may be used to provide hydroxide
ion. Thus, it may be beneficial to ion exchange, for example, the
halide to hydroxide ion, thereby reducing or eliminating the alkali
metal hydroxide quantity required. The alkali metal cation or alkaline
earth cation may be part of the as-synthesized crystalline oxide
material, in order to balance valence electron charges therein.
The reaction mixture is maintained at an elevated temperature until
the crystals of the SSZ-63 are formed. The hydrothermal crystallization
is usually conducted under autogenous pressure, at a temperature
between 100.degree. C. and 200.degree. C., preferably between 135.degree.
C. and 160.degree. C. The crystallization period is typically greater
than 1 day and preferably from about 3 days to about 20 days.
Preferably, the molecular sieve is prepared using mild stirring
During the hydrothermal crystallization step, the SSZ-63 crystals
can be allowed to nucleate spontaneously from the reaction mixture.
The use of SSZ-63 crystals as seed material can be advantageous
in decreasing the time necessary for complete crystallization to
occur. In addition, seeding can lead to an increased purity of the
product obtained by promoting the nucleation and/or formation of
SSZ-63 over any undesired phases. When used as seeds, SSZ-63 crystals
are added in an amount between 0.1 and 10% of the weight of silica
used in the reaction mixture.
Once the molecular sieve crystals have formed, the solid product
is separated from the reaction mixture by standard mechanical separation
techniques such as filtration. The crystals are water-washed and
then dried, e.g., at 90.degree. C. to 150.degree. C. for from 8
to 24 hours, to obtain the as-synthesized SSZ-63 crystals. The drying
step can be performed at atmospheric pressure or under vacuum.
SSZ-63 as prepared has a mole ratio of an oxide selected from silicon
oxide, germanium oxide and mixtures thereof to an oxide selected
from aluminum oxide, gallium oxide, iron oxide, boron oxide, titanium
oxide, indium oxide, vanadium oxide and mixtures thereof greater
than about 15; and has, after calcination, the X-ray diffraction
lines of Table II below. SSZ-63 further has a composition, as synthesized
(i.e., prior to removal of the SDA from the SSZ-63) and in the anhydrous
state, in terms of mole ratios, shown in Table B below.
TABLE B As-Synthesized SSZ-63 YO.sub.2 /W.sub.c O.sub.d >15
M.sub.2/n /YO.sub.2 0.01-0.03 Q/YO.sub.2 0.02-0.05
where Y, W, c, d, M, n and Q are as defined above.
SSZ-63 can be made essentially aluminum free, i.e., having a silica
to alumina mole ratio of .infin.. A method of increasing the mole
ratio of silica to alumina is by using standard acid leaching or
chelating treatments. However, essentially aluminum-free SSZ-63
can be synthesized directly using essentially aluminum-free silicon
sources as the main tetrahedral metal oxide component, if boron
is also present. The boron can then be removed, if desired, by treating
the borosilicate SSZ-63 with acetic acid at elevated temperature
(as described in Jones et al., Chem. Mater., 2001 13 1041-1050)
to produce an all-silica version of SSZ-63. SSZ-63 can also be prepared
directly as a borosilicate. If desired, the boron can be removed
as described above and replaced with metal atoms by techniques known
in the art to make, e.g., an aluminosilicate version of SSZ-63.
SSZ-63 can also be prepared directly as an aluminosilicate.
Lower silica to alumina ratios may also be obtained by using methods
which insert aluminum into the crystalline framework. For example,
aluminum insertion may occur by thermal treatment of the zeolite
in combination with an alumina binder or dissolved source of alumina.
Such procedures are described in U.S. Pat. No. 4559315 issued
on Dec. 17 1985 to Chang et al.
It is believed that SSZ-63 is comprised of a new framework structure
or topology which is characterized by its X-ray diffraction pattern.
SSZ-63 as-synthesized, has a crystalline structure whose X-ray
powder diffraction pattern exhibit the characteristic lines shown
in Table I and is thereby distinguished from other molecular sieves.
TABLE I As-Synthesized SSZ-63 d-spacing Relative Intensity 2 Theta
(Angstroms) (%) 7.17 12.32 W 7.46 11.84 W 7.86 11.24 W 8.32 10.62
W 21.42 4.15 M 22.46 3.96 VS 22.85 3.89 W 25.38 3.51 W 27.08 3.29
W 29.62 3.01 W .sup.(a).+-.0.2 .sup.(b) The X-ray patterns provided
are based on a relative intensity scale in which the strongest line
in the X-ray pattern is assigned a value of 100: W (weak) is less
than 20; M (medium) is between 20 and 40; S (strong) is between
40 and 60; VS (very strong) is greater than 60.
Table IA below shows the X-ray powder diffraction lines for as-synthesized
SSZ-63 including actual relative intensities.
TABLE IA d-spacing Relative Intensity 2 Theta.sup.(a) (Angstroms)
(%) 7.17 12.32 5.1 7.46 11.84 13.5 7.86 11.24 10.2 8.32 10.62 4.7
13.38 6.61 1.7 17.20 5.15 1.4 18.21 4.87 2.0 19.29 4.60 1.5 21.42
4.15 15.7 22.46 3.96 100.0 22.85 3.89 6.9 25.38 3.51 6.7 26.02 3.42
1.8 27.08 3.29 12.3 28.80 3.10 3.2 29.62 3.01 8.5 30.50 2.93 2.9
32.88 2.72 1.4 33.48 2.67 5.7 34.76 2.58 1.8 36.29 2.47 1.6 37.46
2.40 1.3 .sup.(a).+-.0.2
After calcination, the SSZ-63 molecular sieves have a crystalline
structure whose X-ray powder diffraction pattern include the characteristic
lines shown in Table II:
TABLE II Calcined SSZ-63 d-spacing Relative Intensity 2 Theta (Angstroms)
(%) 7.19 12.29 M 7.42 11.91 VS 7.82 11.30 VS 8.30 10.64 M 13.40
6.60 M 21.46 4.14 W 22.50 3.95 VS 22.81 3.90 W 27.14 3.28 M 29.70
3.06 W .sup.(a).+-.0.2
Table IIA below shows the X-ray powder diffraction lines for calcined
SSZ-63 including actual relative intensities.
TABLE IIA d-spacing Relative Intensity 2 Theta (Angstroms) (%)
7.19 12.29 27.7 7.42 11.91 68.5 7.82 11.29 67.0 8.30 10.64 40.1
10.46 8.45 3.1 11.31 7.82 6.7 13.40 6.60 25.1 14.38 6.16 5.3 14.60
6.06 6.5 21.46 4.14 11.2 22.50 3.95 100.0 22.81 3.90 13.0 25.42
3.50 9.2 27.14 3.28 19.6 28.80 3.10 8.2 29.70 3.01 11.0 30.48 2.93
3.3 33.56 2.67 3.9 34.86 2.57 3.3 36.29 2.47 3.2 37.64 2.39 2.8
The X-ray powder diffraction patterns were determined by standard
techniques. The radiation was the K-alpha/doublet of copper. The
peak heights and the positions, as a function of 2.theta. where
.theta. is the Bragg angle, were read from the relative intensities
of the peaks, and d, the interplanar spacing in Angstroms corresponding
to the recorded lines, can be calculated.
The variation in the scattering angle (two theta) measurements,
due to instrument error and to differences between individual samples,
is estimated at .+-.0.20 degrees.
The X-ray diffraction pattern of Table I is representative of "as-synthesized"
or "as-made" SSZ-63 molecular sieves. Minor variations
in the diffraction pattern can result from variations in the silica-to-alumina
or silica-to-boron mole ratio of the particular sample due to changes
in lattice constants. In addition, sufficiently small crystals will
affect the shape and intensity of peaks, leading to significant
Representative peaks from the X-ray diffraction pattern of calcined
SSZ-63 are shown in Table II. Calcination can also result in changes
in the intensities of the peaks as compared to patterns of the "as-made"
material, as well as minor shifts in the diffraction pattern. The
molecular sieve produced by exchanging the metal or other cations
present in the molecular sieve with various other cations (such
as H.sup.+ or NH.sub.4.sup.+) yields essentially the same diffraction
pattern, although again, there may be minor shifts in the interplanar
spacing and variations in the relative intensities of the peaks.
Notwithstanding these minor perturbations, the basic crystal lattice
remains unchanged by these treatments.
Crystalline SSZ-63 can be used as-synthesized, but preferably will
be thermally treated (calcined). Usually, it is desirable to remove
the alkali metal cation by ion exchange and replace it with hydrogen,
ammonium, or any desired metal ion. The molecular sieve can be leached
with chelating agents, e.g., EDTA or dilute acid solutions, to increase
the silica to alumina mole ratio. The molecular sieve can also be
steamed; steaming helps stabilize the crystalline lattice to attack
The molecular sieve can be used in intimate combination with hydrogenating
components, such as tungsten, vanadium, molybdenum, rhenium, nickel,
cobalt, chromium, manganese, or a noble metal, such as palladium
or platinum, for those applications in which a hydrogenation-dehydrogenation
function is desired.
Metals may also be introduced into the molecular sieve by replacing
some of the cations in the molecular sieve with metal cations via
standard ion exchange techniques (see, for example, U.S. Pat. No.
3140249 issued Jul. 7 1964 to Plank et al.; U.S. Pat. No. 3140251
issued Jul. 7 1964 to Plank et al.; and U.S. Pat. No. 3140253
issued Jul. 7 1964 to Plank et al.). Typical replacing cations
can include metal cations, e.g., rare earth, Group IA, Group IIA
and Group VIII metals, as well as their mixtures. Of the replacing
metallic cations, cations of metals such as rare earth, Mn, Ca,
Mg, Zn, Cd, Pt, Pd, Ni, Co, Ti, Al, Sn, and Fe are particularly
The hydrogen, ammonium, and metal components can be ion-exchanged
into the SSZ-63. The SSZ-63 can also be impregnated with the metals,
or the metals can be physically and intimately admixed with the
SSZ-63 using standard methods known to the art.
Typical ion-exchange techniques involve contacting the synthetic
molecular sieve with a solution containing a salt of the desired
replacing cation or cations. Although a wide variety of salts can
be employed, chlorides and other halides, acetates, nitrates, and
sulfates are particularly preferred. The molecular sieve is usually
calcined prior to the ion-exchange procedure to remove the organic
matter present in the channels and on the surface, since this results
in a more effective ion exchange. Representative ion exchange techniques
are disclosed in a wide variety of patents including U.S. Pat. No.
3140249 issued on Jul. 7 1964 to Plank et al.; U.S. Pat. No.
3140251 issued on Jul. 7 1964 to Plank et al.; and U.S. Pat.
No. 3140253 issued on Jul. 7 1964 to Plank et al.
Following contact with the salt solution of the desired replacing
cation, the molecular sieve is typically washed with water and dried
at temperatures ranging from 65.degree. C. to about 200.degree.
C. After washing, the molecular sieve can be calcined in air or
inert gas at temperatures ranging from about 200.degree. C. to about
800.degree. C. for periods of time ranging from 1 to 48 hours, or
more, to produce a catalytically active product especially useful
in hydrocarbon conversion processes.
Regardless of the cations present in the synthesized form of SSZ-63
the spatial arrangement of the atoms which form the basic crystal
lattice of the molecular sieve remains essentially unchanged.
SSZ-63 can be formed into a wide variety of physical shapes. Generally
speaking, the molecular sieve can be in the form of a powder, a
granule, or a molded product, such as extrudate having a particle
size sufficient to pass through a 2-mesh (Tyler) screen and be retained
on a 400-mesh (Tyler) screen. In cases where the catalyst is molded,
such as by extrusion with an organic binder, the SSZ-63 can be extruded
before drying, or, dried or partially dried and then extruded.
SSZ-63 can be composited with other materials resistant to the
temperatures and other conditions employed in organic conversion
processes. Such matrix materials include active and inactive materials
and synthetic or naturally occurring zeolites as well as inorganic
materials such as clays, silica and metal oxides. Examples of such
materials and the manner in which they can be used are disclosed
in U.S. Pat. No. 4910006 issued May 20 1990 to Zones et al.,
and U.S. Pat. No. 5316753 issued May 31 1994 to Nakagawa, both
of which are incorporated by reference herein in their entirety.
SSZ-63 may be used for the catalytic reduction of the oxides of
nitrogen in a gas stream. Typically, the gas stream also contains
oxygen, often a stoichiometric excess thereof. Also, the SSZ-63
may contain a metal or metal ions within or on it which are capable
of catalyzing the reduction of the nitrogen oxides. Examples of
such metals or metal ions include copper, cobalt and mixtures thereof.
One example of such a process for the catalytic reduction of oxides
of nitrogen in the presence of a zeolite is disclosed in U.S. Pat.
No. 4297328 issued Oct. 27 1981 to Ritscher et al., which is
incorporated by reference herein. There, the catalytic process is
the combustion of carbon monoxide and hydrocarbons and the catalytic
reduction of the oxides of nitrogen contained in a gas stream, such
as the exhaust gas from an internal combustion engine. The zeolite
used is metal ion-exchanged, doped or loaded sufficiently so as
to provide an effective amount of catalytic copper metal or copper
ions within or on the zeolite. In addition, the process is conducted
in an excess of oxidant, e.g., oxygen.
The following examples demonstrate but do not limit the present
Synthesis of the Structure-Directing Agent A (N-cyclodecyl-N-methyl-pyrrolidinium
The anion (X.sup.-) associated with the cation may be any anion
which is not detrimental to the formation of the zeolite. Representative
anions include halogen, e.g., fluoride, chloride, bromide and iodide,
hydroxide, acetate, sulfate, tetrafluoroborate, carboxylate, and
the like. Hydroxide is the most preferred anion.
The structure-directing agent (SDA) N-cyclodecyl-N-methyl-pyrrolidinium
cation was synthesized according to the procedure described below
(see Scheme 1). To a solution of cyclodecanone (25 gm; 0.16 mol)
in 320 ml anhydrous hexane in a three-necked round bottom flask
equipped with a reflux condenser and a mechanical stirrer, 34 gm
of pyrrolidine (0.48 mol) and 48 gm (0.4 mol) anhydrous magnesium
sulfate were added. The resulting mixture was stirred while heating
at reflux for five days. The reaction mixture was filtered through
a fritted-glass funnel. The filtrate was concentrated at reduced
pressure on a rotary evaporator to yield 32 gm (96%) of the expected
enamine (1-cyclodec-1-enyl-pyrrolidine) as a reddish oily substance.
.sup.1 H-NMR and .sup.13 C-NMR spectra were acceptable for the desired
product. The enarnine was reduced to the corresponding amine (N-cyclodecyl-pyrrolidine)
in quantitative yield via catalytic hydrogenation in the presence
of 10% Pd on activated carbon at hydrogen pressure of 55 PSI in
Quaternization of N-cyclodecyl-pyrrolidine with methyl iodide (Synthesis
of N-cyclodecyl-N-methyl-pyrrolidinium iodide)
To a solution of 30 gm (0.14 mol.) of N-cyclodecyl-pyrrolidine
in 250 ml anhydrous methanol in a one liter reaction flask, 30 gm
(0.21 mol.) of methyl iodide was added. The reaction mixture was
mechanically stirred for 48 hours at room temperature. Then, a 0.5
mole equivalent of methyl iodide was added and the mixture was heated
to reflux and refluxed for 30 minutes. The reaction mixture was
then cooled down and concentrated under reduced pressure on a rotary
evaporator to give the product as a pale yellow solid material.
The product was purified by dissolving in acetone and then precipitating
by adding diethyl ether. The recrystallization yielded 46 gm (93%)
of the pure N-cyclodecyl-N-methyl-pyrrolidinium iodide. .sup.1 H-NMR
and .sup.13 C-NMR were ideal for the product.
Ion Exchange (Synthesis of N-cyclodecyl-N-methyl-pyrrolidinium
N-cyclodecyl-N-methyl-pyrrolidinium iodide (45 gm; 0.128 mol) was
dissolved in 150 ml water in a 500 ml plastic bottle. To the solution,
160 gm of Ion-Exchange Resin-OH (BIO RAD.RTM. AH1-X8) was added
and the mixture was stirred at room temperature overnight. The mixture
was filtered and the solids were rinsed with an additional 85 ml
of water. The reaction afforded 0.12 mole of the SDA (N-cyclodecyl-N-methyl-pyrrolidinium
hydroxide) as indicated by titration analysis with 0.1N HCl. ##STR2##
Synthesis of Borosilicate SSZ-63
A 23 cc Teflon liner was charged with 4.9 gm of 0.61M aqueous solution
of N-cyclodecyl-N-methyl-pyrrolidinium hydroxide (3 mmol SDA), 1.2
gm of 1M aqueous solution of NaOH (1.2 mmol NaOH) and 5.9 gm of
de-ionized water. To this mixture, 0.06 gm of sodium borate decahydrate
(0.157 mmol of Na.sub.2 B.sub.4 O.sub.7.10H.sub.2 O; .about.0.315
mmol B.sub.2 O.sub.3) was added and stirred until completely dissolved.
To this solution, 0.9 gm of CABO-SIL M-5.RTM. fumed silica (.about.14.7
mmol SiO.sub.2) was added and thoroughly stirred by hand. The resulting
gel was capped off and placed in a Parr steel autoclave and heated
in an oven at about 160.degree. C. while tumbling at about 43 rpm.
The reaction was monitored by periodically monitoring the pH of
the gel, and by looking for crystal growth using scanning electron
microscopy (SEM). Once the crystallization was completed, after
heating for 12 days at the conditions described above, the starting
reaction gel turned into a clear liquid layer and a fine powdery
precipitate. The mixture was filtered through a fritted-glass funnel.
The collected solids were thoroughly washed with water and, then,
rinsed with acetone (.about.20 ml) to remove any organic residues.
The solids were allowed to air-dry over night and, then, dried in
an oven at 120.degree. C. for 1 hour. The reaction afforded 0.85
gram of SSZ-63. The originality of SSZ-63 was determined from its
unique XRD pattern, and by transmission electron microscopy analysis
Conversion of Borosilicate SSZ-63 to Aluminosilicate SSZ-63
Borosilicate SSZ-63 synthesized as described in Example 2 above
and calcined as shown in Example 17 below was suspended in 1M solution
of aluminum nitrate nonahydrate (15 ml of 1M Al(NO.sub.3).sub.3.
9H.sub.2 O soln./1 gm zeolite). The suspension was heated at reflux
for 48 hours. The mixture was then filtered and the collected solids
were thoroughly rinsed with water and air-dried overnight. The solids
were further dried in an oven at 120.degree. C. for 2 hours.
Synthesis of Germanosilicate SSZ-63
A 23 cc Teflon liner was charged with 4.85 gm of 0.61M aqueous
solution of N-cyclodecyl-N-methyl-pyrrolidinium hydroxide (3 mmol
SDA), 1.25 gm of 1M aqueous solution of NaOH (1.25 mmol NaOH) and
5.8 gm of de-ionized water. To this mixture, 0.25 gm of GeO.sub.2
(2.39 mmol) was added and stirred until completely dissolved. To
this solution, 0.7 gm of CAB-O-SIL M-5.RTM. (.about.11.4 mmol SiO.sub.2)
was added and thoroughly stirred by hand. The resulting gel was
capped off and placed in a Parr steel autoclave and heated in an
oven at about 160.degree. C. while tumbling at about 43 rpm. The
reaction was monitored by periodically monitoring the pH of the
gel, and by looking for crystal growth using scanning electron microscopy
(SEM). Once the crystallization was completed, after heating for
six days, the starting reaction gel turned into a clear liquid layer
and a fine powdery precipitate. The mixture was filtered through
a fritted-glass funnel. The collected solids were thoroughly washed
with water and, then, rinsed with acetone (.about.20 ml) to remove
any organic residues. The solids were allowed to air-dry over night
and, then, dried in an oven at 120.degree. C. for one hour. The
reaction afforded 0.73 gram of SSZ-63.
Synthesis of Borosilicate SSZ-63
SSZ-63 was synthesized at varying SiO.sub.2 /B.sub.2 O.sub.3 ratios
in the starting synthesis gel. This was accomplished by using the
synthetic conditions described in Example 2 keeping everything the
same while changing the SiO.sub.2 /B.sub.2 O.sub.3 ratios in the
starting gel. This was done by keeping the amount of CAB-O-SIL M-5.RTM.
(the source of SiO.sub.2) constant while varying the amount of sodium
borate decahydrates added in each run. Consequently, varying the
amount of sodium borate decahydrates led to varying the SiO.sub.2
/Na ratios in the starting gels. The table below shows the SiO.sub.2
/B.sub.2 O.sub.3 and SiO.sub.2 /Na ratios and the observed products
for each run.
Crystallization Example Time No. SiO.sub.2 /B.sub.2 O.sub.3 SiO.sub.2
/Na (days) Products 5 .infin. 14.7 6 BETA (BEA*) 6 280 13.9 12 SSZ-63
7 140 13.3 12 SSZ-63 8 93 12.7 12 SSZ-63 9 70 12.1 12 SSZ-63 10
56 11.6 12 SSZ-63 11 47 11.2 12 SSZ-63 12 40 10.7 12 SSZ-63 13 31
10 12 SSZ-63 14 23 9 12 SSZ-63 15 19 8.2 12 SSZ-63 16 12.6 6.8 12
SSZ-63 SiO.sub.2 /.sup.- OH = 3.7 SiO.sub.2 /R.sup.+ = 4.9 H.sub.2
O/SiO.sub.2 = 44 (R.sup.+ = organic cation (SDA))
Calcination of SSZ-63
The material from Example 3 is calcined in the following manner.
A thin bed of material is heated in a muffle furnace from room temperature
to 120.degree. C. at a rate of 1.degree. C. per minute and held
at 120.degree. C. for three hours. The temperature is then ramped
up to 540.degree. C. at the same rate and held at this temperature
for five hours, after which it is increased to 594.degree. C. and
held there for another five hours. A 50/50 mixture of air and nitrogen
is passed over the SSZ-63 at a rate of 20 standard cubic feet per
minute during heating.
Ion exchange of calcined SSZ-63 material (as prepared in Example
2 and calcined as in Example 17) is performed using NH.sub.4 NO.sub.3
to convert the SSZ-63 from its Na.sup.+ form to the NE.sub.4.sup.+
form, and, ultimately, the H.sup.+ form. Typically, the same mass
of NH.sub.4 NO.sub.3 as SSZ-63 is slurried in water at a ratio of
25-50:1 water to SSZ-63. The exchange solution is heated at 95.degree.
C. for two hours and then filtered. This procedure can be repeated
up to three times. Following the final exchange, the SSZ-63 is washed
several times with water and dried. This NH.sub.4.sup.+ form of
SSZ-63 can then be converted to the H.sup.+ form by calcination
(as described in Example 17) to 540.degree. C.
Constraint Index Determination
The hydrogen form of the SSZ-63 of Example 2 (after treatment according
to Examples 17 3 and 18) is pelletized at 2-3 KPSI, crushed and
meshed to 20-40 and then >0.50 gram is calcined at about 540.degree.
C. in air for four hours and cooled in a desiccator. 0.50 Gram is
packed into a 3/8 inch stainless steel tube with alundum on both
sides of the molecular sieve bed. A Lindburg furnace is used to
heat the reactor tube. Helium is introduced into the reactor tube
at 10 cc/min. and at atmospheric pressure. The reactor is heated
to about 315.degree. C., and a 50/50 (w/w) feed of n-hexane and
3-methylpentane is introduced into the reactor at a rate of 8 .mu.l/min.
Feed delivery is made via a Brownlee pump. Direct sampling into
a gas chromatograph begins after ten minutes of feed introduction.
The Constraint Index value is calculated from the gas chromatographic
data using methods known in the art. SSZ-63 has a Constraint Index
of 1.1 after 10 minutes at 315.degree. C. with 87.7% feed conversion.
The Constraint Index dropped with time on stream (0.6 at 100 minutes)
suggesting that SSZ-63 is a large pore molecular sieve.
Hydrocracking of n-Hexadecane
A sample of SSZ-63 as prepared in Example 2 was treated as in Examples
17 3 and 18. Then a sample was slurried in water and the pH of
the slurry was adjusted to a pH of .about.10 with dilute ammonium
hydroxide. To the slurry was added a solution of Pd(NH.sub.3).sub.4
(NO.sub.3).sub.2 at a concentration which would provide 0.5 wt.
% Pd with respect to the dry weight of the molecular sieve sample.
This slurry was stirred for 48 hours at 100.degree. C. After cooling,
the slurry was filtered through a glass frit, washed with de-ionizcd
water, and dried at 100.degree. C. The catalyst was then calcined
slowly up to 482.degree. C. in air and held there for three hours.
The calcined catalyst was pelletized in a Carver Press and crushed
to yield particles with a 20/40 mesh size range. Sized catalyst
(0.5 g) was packed into a 1/4 inch OD tubing reactor in a micro
unit for n-hexadecane hydroconversion. The table below gives the
run conditions and the products data for the hydrocracking test
on n-hexadecane. After the catalyst was tested with n-hexadecane,
it was titrated using a solution of butyl amine in hexane. The temperature
was increased and the conversion and product data evaluated again
under titrated conditions. The results shown in the table below
show that SSZ-63 is effective as a hydrocracking catalyst.
Temperature 500.degree. F. 560.degree. F. (260.degree. C.) (293.degree.
C.) Time-on-Stream (hrs.) 6.1-7.1 47.6-50.1 WHSV 1.55 1.55 PSIG
1200 1200 Titrated? No Yes n-16 % Conversion 100 96.5 Hydrocracking
Conv. 93.4 34.95 Isomerization Selectivity, % 6.6 63.8 Cracking
Selectivity, % 93.4 36.2 C4-, % 8.8 31.85 C5/C4 9.6 12.85 C5 + C6/C5
% 23.34 18.1 DMB/MP 0.12 0.07 C4 - C13 i/n yield 6.98 4.88 C7 -
C13 yield 64.84 26.6
Argon Adsorption Analysis
SSZ-63 has a micropore volume of 0.22 cc/gm based on argon adsorption
isotherm at 87.6 K recorded on ASAP 2010 equipment from Micrometers.
The low-pressure dose was 3.00 cm.sup.3 /g (STP) with 15-s equilibration
interval. The argon adsorption isotherm was analyzed using the density
function theory (DFT) formalism and parameters developed for activated
carbon slits by Olivier (Porous Mater., 1995 2 9) using the Saito
Foley adaptation of the Horvarth-Kawazoe formalism (Microporous
Materials, 1995 3 531) and the conventional t-plot method (J.
Catalysis, 1965 4 319). Analogous measurements were made with
nitrogen using the Digisorb system.