Molecular sieve abstract
The present invention relates to new crystalline molecular sieve
SSZ-65 prepared using 1-[1-(4-chlorophenyl)-cyclopropylmethyl]-1-ethyl-pyrrolidi-
nium or 1-ethyl-1-(1-phenyl-cyclopropylmethyl)-pyrrolidinium cation
as a structure-directing agent, methods for synthesizing SSZ-65
and processes employing SSZ-65 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 (1) an oxide of a first tetravalent element to (2) an
oxide of a trivalent element, pentavalent element, second tetravalent
element which is different from said first tetravalent 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
of nitrogen.
3. The process of claim 2 wherein the metal is copper, cobalt or
mixtures thereof.
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
[0001] 1. Field of the Invention
[0002] The present invention relates to new crystalline molecular
sieve SSZ-65 a method for preparing SSZ-65 using a 1-[1-(4-chlorophenyl)-cyclo-
propylmethyl]-1-ethyl-pyrrolidinium or 1-ethyl-1-(1-phenyl-cyclopropylmeth-
yl)-pyrrolidinium cation as a structure directing agent and the
use of SSZ-65 in catalysts for the reduction of oxides of nitrogen
in a gas stream.
[0003] 2. State of the Art
[0004] 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.
[0005] 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
[0006] The present invention is directed to a family of crystalline
molecular sieves with unique properties, referred to herein as "molecular
sieve SSZ-65" or simply "SSZ-65". Preferably, SSZ-65
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 aluminum oxide and silicon
oxide and the term "borosilicate" refers to a molecular
sieve containing oxides of both boron and silicon.
[0007] 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 the process 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.
DETAILED DESCRIPTION OF THE INVENTION
[0008] The present invention comprises a family of crystalline,
large pore molecular sieves designated herein "molecular sieve
SSZ-65" or simply "SSZ-65". 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 7.5 Angstroms.
[0009] In preparing SSZ-65 a 1-[1-(4-chlorophenyl)-cyclopropylmethyl]-1-e-
thyl-pyrrolidinium or 1-ethyl-1-(1-phenyl-cyclopropylmethyl)-pyrrolidinium
cation is used as a structure directing agent ("SDA"),
also known as a crystallization template. The SDA's useful for making
SSZ-65 have the following structures: 1
[0010] 1-[1-(4-Chloro-phenyl)-cyclopropylmethyl]-1-ethyl-pyrrolidinium
2
[0011] 1-Ethyl-1-(1-phenyl-cyclopropylmethyl)-pyrrolidinium
[0012] The SDA cation is associated with an anion (X.sup.-) which
may be any anion that 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.
[0013] In general, SSZ-65 is prepared by contacting an active source
of one or more oxides selected from the group consisting of monovalent
element oxides, divalent element oxides, trivalent element oxides,
tetravalent element oxides and/or pentavalent elements with the
1-[1-(4-chlorophenyl)-cyclopropylmethyl]-1-ethyl-pyrrolidinium or
1-ethyl-1-(1-phenyl-cyclopropylmethyl)-pyrrolidinium cation SDA.
[0014] SSZ-65 is prepared from a reaction mixture having the composition
shown in Table A below.
1 TABLE A Reaction Mixture Typical Preferred YO.sub.2/W.sub.aO.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.2O/YO.sub.2
30-80 35-45
[0015] where Y is silicon, germanium or a mixture thereof; W is
aluminum, gallium, iron, boron, titanium, indium, vanadium or mixtures
thereof; a is 1 or 2; b is 2 when a is 1 (i.e., W is tetravalent);
b is 3 when a is 2 (i.e., W is trivalent); M is an alkali metal
cation, alkaline earth metal cation or mixtures thereof; n is the
valence of M (i.e., 1 or 2); and Q is a 1-[1-(4-chlorophenyl)-cyclopropylmethyl]-1-ethyl-pyrrolidinium
or 1-ethyl-1-(1-phenyl-cyclopropylmethyl)-pyrrolidinium cation.
[0016] In practice, SSZ-65 is prepared by a process comprising:
[0017] (a) preparing an aqueous solution containing sources of
at least one oxide capable of forming a crystalline molecular sieve
and a 1-[1-(4-chlorophenyl)-cyclopropylmethyl]-1-ethyl-pyrrolidinium
or 1-ethyl-1-(1-phenyl-cyclopropylmethyl)-pyrrolidinium cation having
an anionic counterion which is not detrimental to the formation
of SSZ-65;
[0018] (b) maintaining the aqueous solution under conditions sufficient
to form crystals of SSZ-65; and
[0019] (c) recovering the crystals of SSZ-65.
[0020] Accordingly, SSZ-65 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.
[0021] 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.
[0022] 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.
[0023] 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.
[0024] The reaction mixture is maintained at an elevated temperature
until the crystals of the SSZ-65 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.
[0025] Preferably, the molecular sieve is prepared using mild stirring
or agitation.
[0026] During the hydrothermal crystallization step, the SSZ-65
crystals can be allowed to nucleate spontaneously from the reaction
mixture. The use of SSZ-65 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-65 over any undesired phases. When used as seeds, SSZ-65 crystals
are added in an amount between 0.1 and 10% of the weight of first
tetravalent element oxide, e.g. silica, used in the reaction mixture.
[0027] 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-65 crystals. The
drying step can be performed at atmospheric pressure or under vacuum.
[0028] SSZ-65 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-65 further has a composition, as synthesized
(i.e., prior to removal of the SDA from the SSZ-65) and in the anhydrous
state, in terms of mole ratios, shown in Table B below.
2TABLE B As-Synthesized SSZ-65 YO.sub.2/W.sub.cO.sub.d >15 M.sub.2/n/YO.sub.2
0.01-0.03 Q/YO.sub.2 0.02-0.05
[0029] where Y, W, M, n and Q are as defined above, c is 1 or 2;
and d is 2 when c is 1 or d is 3 or 5when c is 2.
[0030] SSZ-65 can be made with a mole ratio of YO.sub.2/W.sub.cO.sub.d
of .infin., i.e., there is essentially no W.sub.cO.sub.d present
in the SSZ-65. In this case, the SSZ-65 would be an all-silica material
or a germanosilicate. Thus, in a typical case where oxides of silicon
and aluminum are used, SSZ-65 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-65 can be synthesized 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-65 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-65. SSZ-65 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-65.
SSZ-65 can also be prepared directly as an aluminosilicate.
[0031] 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.
[0032] It is believed that SSZ-65 is comprised of a new framework
structure or topology which is characterized by its X-ray diffraction
pattern. SSZ-65 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.
3TABLE I As-Synthesized SSZ-65 2 Theta.sup.(a) d-spacing (Angstroms)
Relative Intensity (%).sup.(b) 6.94 12.74 M 9.18 9.63 M 16.00 5.54
W 17.48 5.07 M 21.02 4.23 VS 21.88 4.06 S 22.20 4.00 M 23.02 3.86
M 26.56 3.36 M 28.00 3.19 M .sup.(a).+-.0.1 .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.
[0033] Table IA below shows the X-ray powder diffraction lines
for as-synthesized SSZ-65 including actual relative intensities.
4TABLE IA 2 Theta.sup.(a) d-spacing (Angstroms) Relative Intensity
(%) 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).+-.0.1
[0034] After calcination, the SSZ-65 molecular sieves have a crystalline
structure whose X-ray powder diffraction pattern include the characteristic
lines shown in Table II:
5TABLE II Calcined SSZ-65 2 Theta.sup.(a) d-spacing (Angstroms)
Relative Intensity (%) 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).+-.0.1
[0035] Table IIA below shows the X-ray powder diffraction lines
for calcined SSZ-65 including actual relative intensities.
6TABLE IIA 2 Theta.sup.(a) d-spacing (Angstroms) Relative Intensity
(%) 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
.sup.(a).+-.0.1
[0036] 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.
[0037] The variation in the scattering angle (two theta) measurements,
due to instrument error and to differences between individual samples,
is estimated at .+-.0.1 degrees.
[0038] The X-ray diffraction pattern of Table I is representative
of "as-synthesized" or "as-made" SSZ-65 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 peak broadening.
[0039] Representative peaks from the X-ray diffraction pattern
of calcined SSZ-65 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.
[0040] Crystalline SSZ-65 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 from acids.
[0041] 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.
[0042] 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 preferred.
[0043] The hydrogen, ammonium, and metal components can be ion-exchanged
into the SSZ-65. The SSZ-65 can also be impregnated with the metals,
or the metals can be physically and intimately admixed with the
SSZ-65 using standard methods known to the art.
[0044] 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.
[0045] 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.
[0046] Regardless of the cations present in the synthesized form
of SSZ-65 the spatial arrangement of the atoms which form the basic
crystal lattice of the molecular sieve remains essentially unchanged.
[0047] SSZ-65 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-65 can be extruded before drying, or, dried or partially
dried and then extruded.
[0048] SSZ-65 can be composited with other materials resistant
to the temperatures and II 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.
[0049] SSZ-65 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-65
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.
[0050] 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.
EXAMPLES
[0051] The following examples demonstrate but do not limit the
present invention.
Example 1
Synthesis of SDA 1-[1-(4-chlorophenyl)-cyclopropylmethyl]-1-ethyl-pyrrolid-
inium Cation
[0052] 3
[0053] 1-[1-(4-Chloro-phenyl)-cyclopropylmethyl]-1-ethyl-pyrrolidinium
[0054] The structure directing agent is synthesized according to
the synthetic scheme shown below (Scheme 1).
[0055] 1-[1-(4-chloro-phenyl)-cyclopropylmethyl]-1-ethyl-pyrrolidinium
iodide is prepared from the reaction of the parent amine 1-[1-(4-chloro-phenyl)-cyclopropylmethyl]-pyrrolidine
with ethyl iodide. A 100 gm (0.42 mole) of the amine, 1-[1-(4-chloro-phenyl)-cyclopropylmeth-
yl]-pyrrolidine, is dissolved in 1000 ml anhydrous methanol in a
3-litre 3-necked reaction flask (equipped with a mechanical stirrer
and a reflux condenser). To this solution, 98 gm (0.62 mole) of
ethyl iodide is added, and the mixture is stirred at room temperature
for 72 hours. Then, 39 gm (0.25 mol.) of ethyl iodide is added and
the mixture is heated at reflux for 3 hours. The reaction mixture
is cooled down and excess ethyl iodide and the solvent are removed
at reduced pressure on a rotary evaporator. The obtained dark tan-colored
solids (162 gm) are further purified by dissolving in acetone (500
ml) followed by precipitation by adding diethyl ether. Filtration
and air-drying the obtained solids gives 153 gm (93% yield) of the
desired 1-[1-(4-chloro-phenyl)-cyclopropylmethyl]-1-et- hyl-pyrrolidinium
iodide as a white powder. The product is pure by .sup.1H and .sup.13C-NMR
analysis.
[0056] The hydroxide form of 1-[1-(4-chloro-phenyl)-cyclopropylmethyl]-1-e-
thyl-pyrrolidinium cation is obtained by an ion exchange treatment
of the iodide salt with Ion-Exchange Resin-OH (BIO RAD.RTM. AH1-X8).
In a 1-liter volume plastic bottle, 100 gm (255 mmol) of 1-[1-(4-chloro-phenyl)-cyclopropylmethyl]-1-ethyl-pyrrolidinium
iodide is dissolved in 300 ml de-ionized water. Then, 320 gm of
the ion exchange resin is added and the solution is allowed to gently
stir overnight. The mixture is then filtered, and the resin cake
is rinsed with minimal amount of de-ionized water. The filtrate
is analyzed for hydroxide concentration by titration analysis on
a small sample of the solution with 0.1N HCl. The reaction yields
96% of (245 mmol) of the desired 1-[1-(4-chloro-phenyl)-cyclopropylmethyl]-1-ethyl-pyrrolidinium
hydroxide (hydroxide concentration of 0.6 M).
[0057] The parent amine 1-[1-(4-chloro-phenyl)-cyclopropylmethyl]-pyrrolid-
ine is obtained from the LiAlH.sub.4-reduction of the precursor
amide [1-(4-chloro-phenyl)-cyclopropyl]-pyrrolidin-1-yl-methanone.
In a 3-neck 3-liter reaction flask equipped with a mechanical stirrer
and reflux condenser, 45.5 gm (1.2 mol.) of LiAlH.sub.4 is suspended
in 750 ml anhydrous tetrahydrofuran (THF). The suspension is cooled
down to 0.degree. C. (ice-bath), and 120 gm (0.48 mole) of [1-(4-chloro-phenyl)-cyclopropyl]-pyrrolidin-1-yl-methanone
dissolved in 250 ml THF is added (to the suspension) drop-wise via
an addition funnel. Once all the amide solution is added, the ice-bath
is replaced with a heating mantle and the reaction mixture is heated
at reflux overnight. Then, the reaction solution is cooled down
to 0.degree. C. (the heating mantle was replaced with an ice-bath),
and the mixture is diluted with 500 ml diethyl ether. The reaction
is worked up by adding 160 ml of 15% wt. of an aqueous NaOH solution
drop-wise (via an addition funnel) with vigorous stirring. The starting
gray reaction solution changes to a colorless liquid with a white
powdery precipitate. The solution mixture is filtered and the filtrate
is dried over anhydrous magnesium sulfate. Filtration and concentration
of the filtrate gives 106 gm (94% yield) of the desired amine 1-[1-(4-chloro-phenyl)-cyclopropylmethyl]-pyrrolidine
as a pale yellow oily substance. The amine is pure as indicated
by the clean .sup.1H and .sup.13C-NMR spectral analysis.
[0058] The parent amide [1-(4-chloro-phenyl)-cyclopropyl]-pyrrolidin-1-yl--
methanone is prepared by reacting pyrrolidine with 1-(4-chloro-phenyl)-cyc-
lopropanecarbonyl chloride. A 2-Liter reaction flask equipped with
a mechanical stirrer is charged with 1000 ml of dry benzene, 53.5
gm (0.75 mol.) of pyrrolidine and 76 gm (0.75 mol.) of triethyl
amine. To this mixture (at 0.degree. C.), 108 1-(4-chloro-phenyl)-cyclopropanecarbonyl
chloride gm (0.502 mol.) of (dissolved 100 ml benzene) is added
drop-wise (via an addition funnel). Once the addition is completed,
the resulting mixture is allowed to stir at room temperature overnight.
The reaction mixture (a biphasic mixture: liquid and tan-colored
precipitate) is concentrated on a rotary evaporator at reduced pressure
to strip off excess pyrrolidine and the solvent (usually hexane
or benzene). The remaining residue is diluted with 750 ml water
and extracted with 750 ml chloroform in a separatory funnel. The
organic layer is washed twice with 500 ml water and once with brine.
Then, the organic layer is dried over anhydrous sodium sulfate,
filtered and concentrated on a rotary evaporator at reduced pressure
to give 122 gm (0.49 mol, 97% yield) of the amide as a tan-colored
solid substance.
[0059] The 1-(4-chloro-phenyl)-cyclopropanecarbonyl chloride used
in the synthesis of the amide is synthesized by treatment of the
parent acid 1-(4-chloro-phenyl)-cyclopropanecarboxylic acid with
thionyl chloride (SOCl.sub.2) as described below. To 200 gms of
thionyl chloride and 200 ml dichloromethane in a 3-necked reaction
flask, equipped with a mechanical stirrer and a reflux condenser,
100 gm (0.51 mol.) of the 1-(4-chloro-phenyl)-cyclopropanecarboxylic
acid is added in small increments (5 gm at a time) over 15 minutes
period. Once all the acid is added, the reaction mixture is then
heated at reflux. The reaction vessel is equipped with a trap (filled
with water) to collect and trap the acidic gaseous byproducts, and
used in monitoring the reaction. The reaction is usually done once
the evolution of the gaseous byproducts is ceased. The reaction
mixture is then cooled down and concentrated on a rotary evaporator
at reduced pressure to remove excess thionyl chloride and dichloromethane.
The reaction yields 109 gm (98%) of the desired 1-(4-chloro-phenyl)-cyclopropanecarbonyl
chloride as reddish viscous oil. 4
Example 2
Synthesis of SDA 1-ethyl-1-(1-phenyl-cyclopropylmethyl)-pyrrolidinium
cation
[0060] SDA 1-ethyl-1-(1-phenyl-cyclopropylmethyl)-pyrrolidinium
cation is synthesized using the synthesis procedure of Example 1
except that the synthesis starts from 1-phenyl-cyclopropanecarbonyl
chloride and pyrrolidine.
Example 3
Synthesis of SSZ-65
[0061] A 23 cc Teflon liner is charged with 5.4 gm of 0.6M aqueous
solution of 1-ethyl-1-(1-phenyl-cyclopropylmethyl)-pyrrolidinium
hydroxide (3 mmol SDA), 1.2 gm of 1M aqueous solution of NaOH (1.2
mmol NaOH) and 5.4 gm of de-ionized water. To this mixture, 0.06
gm of sodium borate decahydrate (0.157 mmol of Na.sub.2B.sub.4O.sub.7.10H.sub.2O;
.about.0.315 mmol B.sub.2O.sub.3) is added and stirred until completely
dissolved. Then, 0.9 gm of CAB-O-SIL.RTM. M-5 fumed silica (.about.14.7
mmol SiO.sub.2) is added to the solution and the mixture is thoroughly
stirred. The resulting gel is capped off and placed in a Parr bomb
steel reactor and heated in an oven at 160.degree. C. while rotating
at 43 rpm. The reaction is monitored by checking the gel's pH, and
by looking for crystal formation using Scanning Electron Microscopy
(SEM). The reaction is usually complete after heating 9-12 days
at the conditions described above. Once the crystallization is completed,
the starting reaction gel turns to a mixture comprised of a clear
liquid and powdery precipitate. The mixture is filtered through
a fritted-glass funnel. The collected solids are thoroughly washed
with water and, then, rinsed with acetone (10 ml) to remove any
organic residues. The solids are allowed to air-dry overnight and,
then, dried in an oven at 120.degree. C. for 1 hour. The reaction
affords 0.85 gram of a very fine powder. SEM shows the presence
of only one crystalline phase. The product is determined by powder
XRD data analysis to be SSZ-65.
Example 4
Seeded Synthesis of Borosilicate SSZ-65
[0062] The synthesis of borosilicate SSZ-65 (B-SSZ-65) described
in Example 3 above is repeated with the exception of adding 0.04
gm of SSZ-65 as seeds to speed up the crystallization process. The
reaction conditions are exactly the same as for the previous example.
The crystallization is complete in four days and affords 0.9 gm
of B-SSZ-65.
Example 5
Synthesis of Aluminosilicate SSZ-65
[0063] A 23 cc Teflon liner is charged with 4 gm of 0.6M aqueous
solution of 1-ethyl-1-(1-phenyl-cyclopropylmethyl)-pyrrolidinium
hydroxide (2.25 mmol SDA), 1.5 gm of 1M aqueous solution of NaOH
(1.5 mmol NaOH) and 2 gm of de-ionized water. To this mixture, 0.25
gm of Na--Y zeolite (Union Carbide's LZY-52; SiO.sub.2/Al.sub.2O.sub.3=5)
is added and stirred until completely dissolved. Then, 0.85 gm of
CAB-O-SIL.RTM. M-5 fumed silica (.about.14. mmol SiO.sub.2) is added
to the solution and the mixture is thoroughly stirred. The resulting
gel is capped off and placed in a Parr bomb steel reactor and heated
in an oven at 160.degree. C. while rotating at 43 rpm. The reaction
is monitored by checking the gel's pH (increase in the pH usually
results from condensation of the silicate species during crystallization,
and decrease in pH often indicates decomposition of the SDA), and
by checking for crystal formation by scanning electron microscopy.
The reaction is usually complete after heating for 12 days at the
conditions described above. Once the crystallization is completed,
the starting reaction gel turns to a mixture comprised of a liquid
and powdery precipitate. The mixture is filtered through a fritted-glass
funnel. The collected solids are thoroughly washed with water and,
then, rinsed with acetone (10 ml) to remove any organic residues.
The solids are allowed to air-dry overnight and, then, dried in
an oven at 120.degree. C. for 1 hour. The reaction affords 0.8 gram
of SSZ-65.
Examples 6-15
Syntheses of SSZ-65 at Varying SiO.sub.2/B.sub.2O.sub.3 Ratios
[0064] SSZ-65 is synthesized at varying SiO.sub.2/B.sub.2O.sub.3
mole ratios in the starting synthesis gel. This is accomplished
using the synthetic conditions described in Example 3 keeping everything
the same while changing the SiO.sub.2/B.sub.2O.sub.3 mole ratios
in the starting gel. This is done by keeping the amount of CAB-O-SIL.RTM.
M-5 (98% SiO.sub.2 and 2% H.sub.2O) the same while varying the amount
of sodium borate in each synthesis. Consequently, varying the amount
of sodium borate leads to varying the SiO.sub.2/Na mole ratios in
the starting gels. Table 1 below shows the results of a number of
syntheses with varying SiO.sub.2/B.sub.2O.sub.3 in the starting
synthesis gel.
7TABLE 1 Crystallization Example No. SiO.sub.2/B.sub.2O.sub.3 SiO.sub.2/Na
Time(days) Products 6 140 13.3 15 SSZ-65 7 93 12.7 12 SSZ-65 8 70
12.1 12 SSZ-65 9 56 11.6 12 SSZ-65 10 47 11.2 12 SSZ-65 11 40 10.7
12 SSZ-65 12 31 10 12 SSZ-65 13 23 9 12 SSZ-65 14 19 8.2 6 SSZ-65
15 14 7.1 6 SSZ-65 .sup.-OH/SiO.sub.2 = 0.28 R.sup.+/SiO.sub.2
= 0.2 H.sub.2O/SiO.sub.2 = 44 (R.sup.+ = organic cation (SDA))
Example 16
Calcination of SSZ-65
[0065] SSZ-65 as synthesized in Example 3 is calcined to remove
the structure directing agent (SDA) as described below. A thin bed
of SSZ-65 in a calcination dish is heated in a muffle furnace from
room temperature to 120.degree. C. at a rate of 1.degree. C./minute
and held for 2 hours. Then, the temperature is ramped up to 540.degree.
C. at a rate of 1.degree. C./minute and held for 5 hours. The temperature
is ramped up again at 1.degree. C./minute to 595.degree. C. and
held there for 5 hours. A 50/50 mixture of air and nitrogen passes
through the muffle furnace at a rate of 20 standard cubic feet (0.57
standard cubic meters) per minute during the calcination process.
Example 17
Conversion of Borosilicate-SSZ-65 to Aluminosilicate SSZ-65
[0066] The calcined version of borosilicate SSZ-65 (as synthesized
in Example 3 and calcined in Example 16) is easily converted to
the aluminosilicate SSZ-65 version by suspending borosilicate SSZ-65
in 1M solution of aluminum nitrate nonahydrate (15 ml of 1M Al(NO.sub.3).sub.3.9H.sub.2O
soln./1 gm SSZ-65). The suspension is heated at reflux overnight.
The resulting mixture is then filtered and the collected solids
are thoroughly rinsed with de-ionized water and air-dried overnight.
The solids are further dried in an oven at 120.degree. C. for 2
hours.
Example 18
Ammonium-Ion Exchange of SSZ-65
[0067] The Na.sup.+ form of SSZ-65 (prepared as in Example 3 or
as in Example 5 and calcined as in Example 16) is converted to NH.sub.4.sup.+-SSZ-65
form by heating the material in an aqueous solution of NH.sub.4NO.sub.3
(typically 1 gm NH.sub.4NO.sub.3/1 gm SSZ-65 in 20 ml H.sub.2O)
at 90.degree. C. for 2-3 hours. The mixture is then filtered and
the obtained NH.sub.4-exchanged-product is washed with de-ionized
water and dried. The NH.sub.4.sup.+ form of SSZ-65 can be converted
to the H.sup.+ form by calcination (as described in Example 16)
to 540.degree. C.
Example 19
Argon Adsorption Analysis
[0068] SSZ-65 has a micropore volume of 0.16 cc/gm based on argon
adsorption isotherm at 87.5.degree. K (-186.degree. C.) recorded
on ASAP 2010 equipment from Micromerities. The sample is first degassed
at 400.degree. C. for 16 hours prior to argon adsorption. The low-pressure
dose is 6.00 cm.sup.3/g (STP). A maximum of one hour equilibration
time per dose is used and the total run time is 35 hours. The argon
adsorption isotherm is 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).
Example 20
Constraint Index
[0069] The hydrogen form of SSZ-65 of Example 3 (after treatment
according to Examples 16 17 and 18) is pelletized at 3 KPSI, crushed
and granulated to 20-40 mesh. A 0.6 gram sample of the granulated
material is calcined in air at 540.degree. C. for 4 hours and cooled
in a desiccator to ensure dryness. Then, 0.5 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 feed of n-hexane and 3-methylpentane is introduced
into the reactor at a rate of 8 .mu.l/min. The feed is delivered
by a Brownlee pump. Direct sampling into a GC begins after 10 minutes
of feed introduction. The Constraint Index (CI) value is calculated
from the GC data using methods known in the art. SSZ-65 has a CI
of 0.67 and a conversion of 92% after 20 minutes on stream. The
material fouls rapidly and at 218 minutes the CI is 0.3 and the
conversion is 15.7%. The data suggests a large pore zeolite with
perhaps large cavities.
Example 21
Hydrocracking of n-Hexadecane
[0070] A 1 gm sample of SSZ-65 (prepared as in Example 3 and treated
as in Examples 16 17 and 18) is suspended in 10 gm de-ionized water.
To this suspension, 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 is added. The pH
of the solution is adjusted to pH of .about.9 by a drop-wise addition
of dilute ammonium hydroxide solution. The mixture is then heated
in an oven at 75.degree. C. for 48 hours. The mixture is then filtered
through a glass frit, washed with de-ionized water, and air-dried.
The collected Pd-SSZ-65 sample is slowly calcined up to 482.degree.
C. in air and held there for three hours.
[0071] The calcined Pd/SSZ-65 catalyst is pelletized in a Carver
Press and granulated to yield particles with a 20/40 mesh size.
Sized catalyst (0.5 g) is 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.
[0072] After the catalyst is tested with n-hexadecane, it is titrated
using a solution of butylamine in hexane. The temperature is increased
and the conversion and product data evaluated again under titrated
conditions. The results shown in the table below show that SSZ-65
is effective as a hydrocracking catalyst.
8 Temperature 260.degree. C. (550.degree. F.) Time-on-Stream (hrs.)
342.4-343.4 WHSV 1.55 PSIG 1200 Titrated? Yes n-16 % Conversion
96.9 Hydrocracking Conv. 47.9 Isomerization Selectivity, % 50.5
Cracking Selectivity, % 49.5 C.sub.4-, % 2.7 C.sub.5/C.sub.4 16.9
C.sub.5+C.sub.6/C.sub.5 % 16.74 DMB/MP 0.06 C.sub.4-C.sub.13 i/n
3.83 C.sub.7-C.sub.13 yield 38.35
Example 22
Synthesis of SSZ-65
[0073] SSZ-65 is synthesized in a manner similar to that of Example
3 using a 1-[1-(4-chlorophenyl)-cyclopropylmethyl]-1-ethyl-pyrrolidinium
cation as the SDA. |