Molecular sieve abstract
The present invention relates to new molecular sieve SSZ-71 prepared
using a N-benzyl-14-diazabicyclo[2.2.2]octane cation as a structure-directing
agent, methods for synthesizing SSZ-71 and processes employing SSZ-71
in a catalyst.
Molecular sieve claims
1. A process for oxidation of hydrocarbons comprising contacting
said hydrocarbon with an oxidizing agent in the presence of a catalytically
effective amount of a titanium-containing molecular sieve for a
time and at a temperature effective to oxidize said hydrocarbon,
wherein the titanium-containing molecular sieve is a molecular sieve
produced by the method comprising: (1) preparing an as-synthesized
molecular sieve having a composition, as synthesized and in the
anhydrous state, in terms of mole ratios as follows: TABLE-US-00021
YO.sub.2/TiO.sub.2 15-.infin. M.sub.2/n/YO.sub.2 0-0.03 Q/YO.sub.2
0.02-0.05
wherein Y is silicon, germanium or a mixture thereof; 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 N-benzyl-14-diazabicyclo[2.2.2]octane
cation, the as-synthesized molecular sieve having the X-ray diffraction
lines of Table I; and (2) thermally treating the as-synthesized
molecular sieve at a temperature and for a time sufficient to remove
the N-benzyl-14-diazabicyclo[2.2.2]octane cation from the molecular
sieve.
2. A process for epoxidation of an olefin comprising contacting
said olefin with hydrogen peroxide in the presence of a catalytically
effective amount of a titanium-containing molecular sieve for a
time and at a temperature effective to epoxidize said olefin, wherein
the titanium-containing molecular sieve is a molecular sieve produced
by the method comprising: (1) preparing an as-synthesized molecular
sieve having a composition, as synthesized and in the anhydrous
state, in terms of mole ratios as follows: TABLE-US-00022 YO.sub.2/TiO.sub.2
15-.infin. M.sub.2/n/YO.sub.2 0-0.03 Q/YO.sub.2 0.02-0.05
wherein Y is silicon, germanium or a mixture thereof; 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 N-benzyl-14-diazabicyclo[2.2.2]octane
cation, the as-synthesized molecular sieve having the X-ray diffraction
lines of Table I; and (2) thermally treating the as-synthesized
molecular sieve at a temperature and for a time sufficient to remove
the N-benzyl-14-diazabicyclo[2.2.2]octane cation from the molecular
sieve.
3. A process for oxidizing cyclohexane comprising contacting said
cyclohexane with hydrogen peroxide in the presence of a catalytically
effective amount of a titanium-containing molecular sieve for a
time and at a temperature effective to oxidize said cyclohexane,
wherein the titanium-containing molecular sieve is a molecular sieve
produced by the method comprising: (1) preparing an as-synthesized
molecular sieve having a composition, as synthesized and in the
anhydrous state, in terms of mole ratios as follows: TABLE-US-00023
YO.sub.2/TiO.sub.2 15-.infin. M.sub.2/n/YO.sub.2 0-0.03 Q/YO.sub.2
0.02-0.05
wherein Y is silicon, germanium or a mixture thereof; 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 N-benzyl-14-diazabicyclo[2.2.2]octane
cation, the as-synthesized molecular sieve having the X-ray diffraction
lines of Table I; and (2) thermally treating the as-synthesized
molecular sieve at a temperature and for a time sufficient to remove
the N-benzyl-14-diazabicyclo[2.2.2]octane cation from the molecular
sieve.
4. A catalytic oxidation process comprising contacting under oxidation
conditions (1) a reactant which is catalytically oxidizable in the
presence of hydrogen peroxide, (2) aqueous hydrogen peroxide and
(3) a catalytically effective amount of an oxidation catalyst comprising
a molecular sieve produced by the method comprising: (1) preparing
an as-synthesized molecular sieve having a composition, as synthesized
and in the anhydrous state, in terms of mole ratios as follows:
TABLE-US-00024 YO.sub.2/TiO.sub.2 15-.infin. M.sub.2/n/YO.sub.2
0-0.03 Q/YO.sub.2 0.02-0.05
wherein Y is silicon, germanium or a mixture thereof; 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 N-benzyl-14-diazabicyclo[2.2.2]octane
cation, the as-synthesized molecular sieve having the X-ray diffraction
lines of Table I; and (2) thermally treating the as-synthesized
molecular sieve at a temperature and for a time sufficient to remove
the N-benzyl-14-diazabicyclo[2.2.2]octane cation from the molecular
sieve.
5. The process of claim 4 wherein the oxidizable reactant is a
hydrocarbon.
6. A process for the epoxidation of an olefin comprising contacting
said olefin with hydrogen peroxide in the presence of a catalytically
effective amount of a catalyst comprising a molecular sieve produced
by the method comprising: (1) preparing an as-synthesized molecular
sieve having a composition, as synthesized and in the anhydrous
state, in terms of mole ratios as follows: TABLE-US-00025 YO.sub.2/TiO.sub.2
15-.infin. M.sub.2/n/YO.sub.2 0-0.03 Q/YO.sub.2 0.02-0.05
wherein Y is silicon, germanium or a mixture thereof; 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 N-benzyl-14-diazabicyclo[2.2.2]octane
cation, the as-synthesized molecular sieve having the X-ray diffraction
lines of Table I; and (2) thermally treating the as-synthesized
molecular sieve at a temperature and for a time sufficient to remove
the N-benzyl-14-diazabicyclo[2.2.2]octane cation from the molecular
sieve.
Molecular sieve description
[0001] This application claims the benefit under 35 USC 119 of
Provisional Application No. 60/639220 filed Dec. 23 2004.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to new molecular sieve SSZ-71
a method for preparing SSZ-71 using a N-benzyl-14-diazabicyclo[2.2.2]octane
cation as a structure directing agent and the use of SSZ-71 in catalysts
for, e.g., hydrocarbon conversion reactions.
[0004] 2. State of the Art
[0005] 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.
[0006] 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
[0007] The present invention is directed to a family of molecular
sieves with unique properties, referred to herein as "molecular
sieve SSZ-71" or simply "SSZ-71". Preferably, SSZ-71
is in its silicate, zincosilicate, aluminosilicate, titanosilicate,
germanosilicate, vanadosilicate, ferrosilicate 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 "zincosilicate"
refers to a molecular sieve containing both zinc oxide and silicon
oxide. 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.
[0008] In accordance with the present invention, there is provided
a process for oxidation of hydrocarbons comprising contacting said
hydrocarbon with an oxidizing agent in the presence of a catalytically
effective amount of a titanium-containing molecular sieve for a
time and at a temperature effective to oxidize said hydrocarbon,
wherein the titanium-containing molecular sieve is a molecular sieve
produced by the method comprising:
[0009] (1) preparing an as-synthesized molecular sieve having a
composition, as synthesized and in the anhydrous state, in terms
of mole ratios as follows: TABLE-US-00001 YO.sub.2/TiO.sub.2 15-.infin.
M.sub.2/n/YO.sub.2 0-0.03 Q/YO.sub.2 0.02-0.05
[0010] wherein Y is silicon, germanium or a mixture thereof; 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 N-benzyl-14-diazabicyclo[2.2.2]octane
cation, the as-synthesized molecular sieve having the X-ray diffraction
lines of Table I; and [0011] (2) thermally treating the as-synthesized
molecular sieve at a temperature and for a time sufficient to remove
the N-benzyl-14-diazabicyclo[2.2.2]octane cation from the molecular
sieve.
[0012] There is further provided in accordance with this invention
a process for epoxidation of an olefin comprising contacting said
olefin with hydrogen peroxide in the presence of a catalytically
effective amount of a titanium-containing molecular sieve for a
time and at a temperature effective to epoxidize said olefin, wherein
the titanium-containing molecular sieve is a molecular sieve produced
by the method comprising:
[0013] (1) preparing an as-synthesized molecular sieve having a
composition, as synthesized and in the anhydrous state, in terms
of mole ratios as follows: TABLE-US-00002 YO.sub.2/TiO.sub.2 15-.infin.
M.sub.2/n/YO.sub.2 0-0.03 Q/YO.sub.2 0.02-0.05
[0014] wherein Y is silicon, germanium or a mixture thereof; 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 N-benzyl-14-diazabicyclo[2.2.2]octane
cation, the as-synthesized molecular sieve having the X-ray diffraction
lines of Table I; and [0015] (2) thermally treating the as-synthesized
molecular sieve at a temperature and for a time sufficient to remove
the N-benzyl-14-diazabicyclo[2.2.2]octane cation from the molecular
sieve.
[0016] Further provided in accordance with the present invention
is a process for oxidizing cyclohexane comprising contacting said
cyclohexane with hydrogen peroxide in the presence of a catalytically
effective amount of a titanium-containing molecular sieve for a
time and at a temperature effective to oxidize said cyclohexane,
wherein the titanium-containing molecular sieve is a molecular sieve
produced by the method comprising:
[0017] (1) preparing an as-synthesized molecular sieve having a
composition, as synthesized and in the anhydrous state, in terms
of mole ratios as follows: TABLE-US-00003 YO.sub.2/TiO.sub.2 15-.infin.
M.sub.2/n/YO.sub.2 0-0.03 Q/YO.sub.2 0.02-0.05
[0018] wherein Y is silicon, germanium or a mixture thereof; 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 N-benzyl-14-diazabicyclo[2.2.2]octane
cation, the as-synthesized molecular sieve having the X-ray diffraction
lines of Table I; and [0019] (2) thermally treating the as-synthesized
molecular sieve at a temperature and for a time sufficient to remove
the N-benzyl-14-diazabicyclo[2.2.2]octane cation from the molecular
sieve.
[0020] The present invention also provides a catalytic oxidation
process comprising contacting under oxidation conditions (1) a reactant
which is catalytically oxidizable in the presence of hydrogen peroxide,
(2) aqueous hydrogen peroxide and (3) a catalytically effective
amount of an oxidation catalyst comprising a molecular sieve produced
by the method comprising:
[0021] (1) preparing an as-synthesized molecular sieve having a
composition, as synthesized and in the anhydrous state, in terms
of mole ratios as follows: TABLE-US-00004 YO.sub.2/TiO.sub.2 15-.infin.
M.sub.2/n/YO.sub.2 0-0.03 Q/YO.sub.2 0.02-0.05
[0022] wherein Y is silicon, germanium or a mixture thereof; 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 N-benzyl-14-diazabicyclo[2.2.2]octane
cation, the as-synthesized molecular sieve having the X-ray diffraction
lines of Table I; and [0023] (2) thermally treating the as-synthesized
molecular sieve at a temperature and for a time sufficient to remove
the N-benzyl-14-diazabicyclo[2.2.2]octane cation from the molecular
sieve.
[0024] The present invention also provides a process for the epoxidation
of an olefin comprising contacting said olefin with hydrogen peroxide
in the presence of a catalytically effective amount of a catalyst
comprising a molecular sieve produced by the method comprising:
[0025] (1) preparing an as-synthesized molecular sieve having a
composition, as synthesized and in the anhydrous state, in terms
of mole ratios as follows: TABLE-US-00005 YO.sub.2/TiO.sub.2 15-.infin.
M.sub.2/n/YO.sub.2 0-0.03 Q/YO.sub.2 0.02-0.05
[0026] wherein Y is silicon, germanium or a mixture thereof; 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 N-benzyl-14-diazabicyclo[2.2.2]octane
cation, the as-synthesized molecular sieve having the X-ray diffraction
lines of Table I; [0027] (2) thermally treating the as-synthesized
molecular sieve at a temperature and for a time sufficient to remove
the N-benzyl-14-diazabicyclo[2.2.2]octane cation from the molecular
sieve.
DETAILED DESCRIPTION OF THE INVENTION
[0028] The present invention comprises a family of molecular sieves
designated herein "molecular sieve SSZ-71" or simply "SSZ-71".
In preparing SSZ-71 a N-benzyl-14-diazabicyclo[2.2.2]octane cation
(referred to herein as "benzyl DABCO") is used as a structure
directing agent ("SDA"), also known as a crystallization
template. The SDA useful for making SSZ-71 has the following structure:
[0029] The SDA cation is associated with an anion (X.sup.-) which
may be any anion that is not detrimental to the formation of the
molecular sieve. 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.
[0030] Benzyl DABCO and a method for making it are disclosed in
U.S. Pat. No. 5653956 issued Aug. 5 1997 to Zones.
[0031] SSZ-71 is prepared from a reaction mixture having the composition
shown in Table A below. TABLE-US-00006 TABLE A Reaction Mixture
Typical Preferred YO.sub.2/WO.sub.d >15 >30 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
0-0.40 0.10-0.25 H.sub.2O/YO.sub.2 10-80 15-45
where Y is silicon, germanium or a mixture thereof; W is zinc,
titanium or mixtures thereof; d is 1 or 2 (i.e., d is 1 when W is
divalent or 2 when W is tetravalent); 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 N-benzyl-14-diazabicyclo[2.2.2]octane
cation.
[0032] In practice, SSZ-71 is prepared by a process comprising:
[0033] (a) preparing an aqueous solution containing sources of at
least one oxide capable of forming a molecular sieve and a benzyl
DABCO cation having an anionic counterion which is not detrimental
to the formation of SSZ-71; [0034] (b) maintaining the aqueous solution
under conditions sufficient to form SSZ-71; and [0035] (c) recovering
the SSZ-71.
[0036] SSZ-71 can be prepared as a zincosilicate or titanosilicate.
However, once the SSZ-71 is made, the zinc and/or titanium can be
replaced with other metals by techniques well known in the art.
Accordingly, SSZ-71 may comprise the molecular sieve 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 (1) a first tetravalent
element(s), and (2) one or a combination of a divalent element(s),
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 divalent element, trivalent element, pentavalent element and
second tetravalent element (which is different from the first tetravalent
element) is preferably selected from the group consisting of zinc,
aluminum, gallium, iron, boron, titanium, indium, vanadium and combinations
thereof. More preferably, the divalent or trivalent element or second
tetravalent element is zinc, aluminum, titanium or boron.
[0037] Silicon can be added as silicon oxide or Si(OC.sub.2H.sub.5).sub.4.
Zinc can be added as a zinc salt such as zinc acetate. Titanium
can be added as Ti(OC.sub.2H.sub.5).sub.4.
[0038] A source zeolite reagent may provide a source of metals.
In most cases, the source zeolite also provides a source of silica.
The source zeolite 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 is 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.
[0039] Typically, an alkali metal hydroxide and/or an alkaline
earth metal hydroxide, such as the hydroxide of sodium, potassium,
lithium, cesium, rubidium, calcium, strontium, barium 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 material, in order to balance valence electron
charges therein.
[0040] The reaction mixture is maintained at an elevated temperature
until the crystals of the SSZ-71 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.
[0041] Optionally, the molecular sieve is prepared using mild stirring
or agitation.
[0042] During the hydrothermal crystallization step, the SSZ-71
crystals can be allowed to nucleate spontaneously from the reaction
mixture. The use of SSZ-71 or SSZ-42 (disclosed in U.S. Pat. No.
5653956 issued Aug. 5 1997 to Zones) 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-71 over any undesired phases. When used as seeds,
as-synthesized SSZ-71 or SSZ-42 crystals (containing the SDA) 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.
[0043] 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-71 crystals. The
drying step can be performed at atmospheric pressure or under vacuum.
[0044] SSZ-71 as prepared has a mole ratio of an oxide selected
from silicon oxide, germanium oxide and mixtures thereof to an oxide
selected from zinc oxide, titanium oxide and mixtures thereof greater
than about 15. SSZ-71 further has a composition, as synthesized
(i.e., prior to calcination of the SSZ-71) and in the anhydrous
state, in terms of mole ratios, shown in Table B below. TABLE-US-00007
TABLE B As-Synthesized SSZ-71 YO.sub.2/WO.sub.d >15 M.sub.2/n/YO.sub.2
0-0.03 Q/YO.sub.2 0.02-0.05
where Y, W, d, M, n and Q are as defined above.
[0045] SSZ-71 can be made with a mole ratio of YO.sub.2/WO.sub.d
of .infin., i.e., there is essentially no WO.sub.d present in the
SSZ-71. In this case, the SSZ-71 would be an all-silica material
or a germanosilicate. If SSZ-71 is prepared as a zincosilicate,
the zinc can be removed and replaced with metal atoms by techniques
known in the art. See, for example, U.S. Pat. No. 6117411 issued
Sep. 12 2000 to Takewaki et al. Metals such as aluminum, gallium,
iron, boron, titanium, indium, vanadium and mixtures thereof may
be added in this manner.
[0046] It is believed that SSZ-71 is comprised of a new framework
structure or topology which is characterized by its X-ray diffraction
pattern. SSZ-71 as-synthesized, has a structure whose X-ray powder
diffraction pattern exhibit the characteristic lines shown in Table
I and Table II and is thereby distinguished from other molecular
sieves. The XRD data shown in Table I and IA was obtained from a
sample of SSZ-71 prepared in the presence of sodium hydroxide. The
XRD data shown in Table II and IIA was obtained from a sample of
SSZ-71 prepared in the presence of strontium hydroxide. TABLE-US-00008
TABLE I As-Synthesized Zn-SSZ-71 Prepared with NaOH 2 Theta.sup.(a)
d-spacing (Angstroms) Relative Intensity.sup.(b) 5.64 15.7 S 8.65
10.2 S 13.65 6.49 M 17.06 5.20 M 20.32 4.37 M 20.64 4.30 VS 23.12
3.85 M 24.08 3.70 VS 26.15 3.41 M 26.57 3.35 M .sup.(a).+-.0.15
.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.
[0047] Table IA below shows the X-ray powder diffraction lines
for as-synthesized Zn-SSZ-71 prepared with NaOH including actual
relative intensities. TABLE-US-00009 TABLE IA 2 Theta.sup.(a) d-spacing
(Angstroms) Relative Intensity (%) 5.64 15.7 60 8.65 10.2 57 11.40
7.8 5 11.95 7.4 7 13.11 6.75 7 13.65 6.49 21 14.34 6.18 5 17.06
5.20 29 17.84 4.97 4 18.23 4.87 10 18.84 4.71 12 19.49 4.55 18 20.32
4.37 37 20.64 4.30 100 21.55 4.12 16 22.03 4.03 16 23.12 3.85 34
24.08 3.70 62 25.29 3.52 20 25.52 3.49 20 26.15 3.41 29 26.57 3.35
33 27.15 3.28 9 28.55 3.13 18 30.00 2.98 8 30.80 2.90 5 31.68 2.82
10 32.45 2.76 5 33.16 2.70 7 34.92 2.57 11 35.61 2.52 14 36.90 2.44
12 38.82 2.32 14 40.26 2.24 12 .sup.(a).+-.0.15
[0048] TABLE-US-00010 TABLE II As-Synthesized Zn-SSZ-71 prepared
with Sr(OH).sub.2 2 Theta.sup.(a) d-spacing (Angstroms) Relative
Intensity.sup.(b) 5.65 15.6 VS 8.69 10.2 VS 16.99 5.22 S 19.52 4.55
M 20.60 4.31 VS 23.13 3.85 M 24.01 3.71 S 24.23 3.67 M 26.14 3.41
M 26.52 3.36 M .sup.(a).+-.0.15 .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.
[0049] Table IIA below shows the X-ray powder diffraction lines
for as-synthesized SSZ-71(Zn-SSZ-71 prepared with Sr(OH).sub.2)
including actual relative intensities. TABLE-US-00011 TABLE IIA
2 Theta.sup.(a) d-spacing (Angstroms) Relative Intensity (%) 5.65
15.6 84 8.69 10.2 67 11.36 7.8 5 11.94 7.4 5 13.17 6.7 7 13.68 6.5
20 14.34 6.18 6 15.31 5.79 2 16.99 5.22 42 18.24 4.86 8 18.79 4.72
17 19.52 4.55 26 20.34 4.37 23 20.60 4.31 100 21.59 4.12 13 22.06
4.03 16 23.13 3.85 37 24.01 3.71 41 24.23 3.67 25 25.25 3.53 20
25.52 3.49 23 26.14 3.41 36 26.52 3.36 30 27.10 3.29 12 28.52 3.13
22 29.85 2.99 6 30.24 2.96 2 30.84 2.90 3 31.64 2.83 11 32.44 2.76
5 33.11 2.71 5 34.86 2.57 6 35.63 2.52 14 36.10 2.49 6 .sup.(a).+-.0.15
[0050] 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.
[0051] The variation in the scattering angle (two theta) measurements,
due to instrument error and to differences between individual samples,
is estimated at .+-.0.15 degrees.
[0052] The X-ray diffraction pattern of Table I is representative
of "as-synthesized" or "as-made" SSZ-71 molecular
sieves. Minor variations in the diffraction pattern can result from
variations in the silica-to-zinc or silica-to-titanium 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.
[0053] 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.
[0054] SSZ-71 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 also
be steamed; steaming helps stabilize the molecular sieve to attack
from acids.
[0055] 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.
[0056] 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.
[0057] The hydrogen, ammonium, and metal components can be ion-exchanged
into the SSZ-71. The SSZ-71 can also be impregnated with the metals,
or the metals can be physically and intimately admixed with the
SSZ-71 using standard methods known to the art.
[0058] 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.
[0059] 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.
[0060] Regardless of the cations present in the synthesized form
of SSZ-71 the spatial arrangement of the atoms which form the basic
crystal lattice of the molecular sieve remains essentially unchanged.
[0061] SSZ-71 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-71 can be extruded before drying, or, dried or partially
dried and then extruded.
[0062] SSZ-71 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.
[0063] The partial oxidation of low value hydrocarbons such as
alkanes and alkenes into high value products such as alcohols and
epoxides is of great commercial interest. These oxidation products
are not only valuable as is, but also as intermediates for specialty
chemicals including pharmaceuticals and pesticides.
[0064] U.S. Pat. No. 4410501 issued Oct. 18 1983 to Esposito
et al., discloses a titanium-containing analogue of the all-silica
ZSM-5 molecular sieve. This material (known as "TS-1")
has been found to be useful in catalyzing a wide range of partial
oxidation chemistries, for example the production of catechol and
hydroquinone from phenol and hydrogen peroxide (H.sub.2O.sub.2)
and the manufacture of propylene oxide and cyclohexanone oxime from
propylene and cyclohexanone, respectively. In addition, TS-1 can
be used to catalyze the reaction of alkanes and aqueous H.sub.2O.sub.2
to form alcohols and ketones. (See Huybrechts, D. R. C. et al.,
Nature 1990 345 240-242 and Tatsumi, T. et al., J.C.S. Chem. Commun.
1990 476-477.)
[0065] TS-1 has many salient features, other than its catalytic
abilities, which make it attractive as a commercial catalyst. Most
importantly, it is a solid. This allows for easy separation from
the reactants and products (typically liquids) by simple, inexpensive
filtration. Moreover, this solid has high thermal stability and
a very long lifetime. Calcination in air at moderate temperatures
(550.degree. C.) restores the material to its original catalytic
ability. TS-1 performs best at mild temperatures (<100.degree.
C.) and pressures (1 atm). The oxidant used for reactions catalyzed
by TS-1 is aqueous H.sub.2O.sub.2 which is important because aqueous
H.sub.2O.sub.2 is relatively inexpensive and its by-product is water.
Hence, the choice of oxidant is favorable from both a commercial
and environmental point of view.
[0066] While a catalyst system based on TS-1 has many useful features,
it has one serious drawback. The zeolite structure of TS-1 includes
a regular system of pores which are formed by nearly circular rings
of ten silicon atoms (called 10-membered rings, or simply "10
rings") creating pore diameters of approximately 5.5 .ANG..
This small size results in the exclusion of molecules larger than
5.5 .ANG.. Because the catalytically active sites are located within
the pores of the zeolite, any exclusion of molecules from the pores
results in poor catalytic activity.
[0067] SSZ-71 containing titanium oxide (Ti-SSZ-71) is useful as
a catalyst in oxidation reactions, particularly in the oxidation
of hydrocarbons. Examples of such reactions include, but are not
limited to, the epoxidation of olefins, the oxidation of alkanes,
and the oxidation of sulfur-containing, nitrogen-containing or phosphorus-containing
compounds.
[0068] The amount of Ti-SSZ-71 catalyst employed is not critical,
but should be sufficient so as to substantially accomplish the desired
oxidation reaction in a practicably short period of time (i.e.,
a catalytically effective amount). The optimum quantity of catalyst
will depend upon a number of factors including reaction temperature,
the reactivity and concentration of the substrate, hydrogen peroxide
concentration, type and concentration of organic solvent, as well
as the activity of the catalyst. Typically, however, the amount
of catalyst will be from about 0.001 to 10 grams per mole of substrate.
[0069] Typically, the Ti-SSZ-71 is thermally treated (calcined)
prior to use as a catalyst.
[0070] The oxidizing agent employed in the oxidation processes
of this invention is a hydrogen peroxide source such as hydrogen
peroxide (H.sub.2O.sub.2) or a hydrogen peroxide precursor (i.e.,
a compound which under the oxidation reaction conditions is capable
of generating or liberating hydrogen peroxide).
[0071] The amount of hydrogen peroxide relative to the amount of
substrate is not critical, but must be sufficient to cause oxidation
of at least some of the substrate. Typically, the molar ratio of
hydrogen peroxide to substrate is from about 100:1 to about 1:100
preferably 10:1 to about 1:10. When the substrate is an olefin containing
more than one carbon-carbon double bond, additional hydrogen peroxide
may be required. Theoretically, one equivalent of hydrogen peroxide
is required to oxidize one equivalent of a mono-unsaturated substrate,
but it may be desirable to employ an excess of one reactant to optimize
selectivity to the epoxide. In particular, the use of a moderate
to large excess (e.g., 50 to 200%) of olefin relative to hydrogen
peroxide may be advantageous for certain substrates.
[0072] If desired, a solvent may additionally be present during
the oxidation reaction in order to dissolve the reactants other
than the Ti-SSZ-71 to provide better temperature control, or to
favorably influence the oxidation rates and selectivities. The solvent,
if present, may comprise from 1 to 99 weight percent of the total
oxidation reaction mixture and is preferably selected such that
it is a liquid at the oxidation reaction temperature. Organic compounds
having boiling points at atmospheric pressure of from about 50.degree.
C. to about 150.degree. C. are generally preferred for use. Excess
hydrocarbon may serve as a solvent or diluent. Illustrative examples
of other suitable solvents include, but are not limited to, ketones
(e.g., acetone, methyl ethyl ketone, acetophenone), ethers (e.g.,
tetrahydrofuran, butyl ether), nitrites (e.g., acetonitrile), aliphatic
and aromatic hydrocarbons, halogenated hydrocarbons, and alcohols
(e.g., methanol, ethanol, isopropyl alcohol, t-butyl alcohol, alpha-methyl
benzyl alcohol, cyclohexanol). More than one type of solvent may
be utilized. Water may also be employed as a solvent or diluent.
[0073] The reaction temperature is not critical, but should be
sufficient to accomplish substantial conversion of the substrate
within a reasonably short period of time. It is generally advantageous
to carry out the reaction to achieve as high a hydrogen peroxide
conversion as possible, preferably at least about 50%, more preferably
at least about 90%, most preferably at least about 95%, consistent
with reasonable selectivities. The optimum reaction temperature
will be influenced by catalyst activity, substrate reactivity, reactant
concentrations, and type of solvent employed, among other factors,
but typically will be in a range of from about 0.degree. C. to about
150.degree. C. (more preferably from about 25.degree. C. to about
120.degree. C.). Reaction or residence times from about one minute
to about 48 hours (more desirably from about ten minutes to about
eight hours) will typically be appropriate, depending upon the above-identified
variables. Although subatmospheric pressures can be employed, the
reaction is preferably performed at atmospheric or at elevated pressure
(typically, between one and 100 atmospheres), especially when the
boiling point of the substrate is below the oxidation reaction temperature.
Generally, it is desirable to pressurize the reaction vessel sufficiently
to maintain the reaction components as a liquid phase mixture. Most
(over 50%) of the substrate should preferably be present in the
liquid phase.
[0074] The oxidation process of this invention may be carried out
in a batch, continuous, or semi-continuous manner using any appropriate
type of reaction vessel or apparatus such as a fixed bed, transport
bed, fluidized bed, stirred slurry, or CSTR reactor. The reactants
may be combined all at once or sequentially. For example, the hydrogen
peroxide or hydrogen peroxide precursor may be added incrementally
to the reaction zone. The hydrogen peroxide could also be generated
in situ within the same reactor zone where oxidation is taking place.
[0075] Once the oxidation has been carried out to the desired degree
of conversion, the oxidized product may be separated and recovered
from the reaction mixture using any appropriate technique such as
fractional distillation, extractive distillation, liquid-liquid
extraction, crystallization, or the like.
Olefin Epoxidation
[0076] One of the oxidation reactions for which Ti-SSZ-71 is useful
as a catalyst is the epoxidation of olefins. The olefin substrate
epoxidized in the process of this invention may be any organic compound
having at least one ethylenically unsaturated functional group (i.e.,
a carbon-carbon double bond) and may be a cyclic, branched or straight-chain
olefin. The olefin may contain aryl groups (e.g., phenyl, naphthyl).
Preferably, the olefin is aliphatic in character and contains from
2 to about 20 carbon atoms. The use of light (low-boiling) C.sub.2
to C.sub.10 mono-olefins is especially advantageous.
[0077] More than one carbon-carbon double bond may be present in
the olefin, i.e., dienes, trienes and other polyunsaturated substrates
may be used. The double bond may be in a terminal or internal position
in the olefin or may alternatively form part of a cyclic structure
(as in cyclooctene, for example).
[0078] Other examples of suitable substrates include unsaturated
fatty acids or fatty acid derivatives such as esters.
[0079] The olefin may contain substituents other than hydrocarbon
substituents such as halide, carboxylic acid, ether, hydroxy, thiol,
nitro, cyano, ketone, acyl, ester, anhydride, amino, and the like.
[0080] Exemplary olefins suitable for use in the process of this
invention include ethylene, propylene, the butenes (i.e., 12-butene,
23-butene, isobutylene), butadiene, the pentenes, isoprene, 1-hexene,
3-hexene, 1-heptene, 1-octene, diisobutylene, 1-nonene, 1-tetradecene,
pentamyrcene, camphene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene,
1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene,
1-eicosene, the trimers and tetramers of propylene, cyclopentene,
cyclohexene, cycloheptene, cyclooctene, cyclooctadiene, dicyclopentadiene,
methylenecyclopropane, methylenecyclopentane, methylenecyclohexane,
vinyl cyclohexane, vinyl cyclohexene, methallyl ketone, allyl chloride,
the dichlorobutenes, allyl alcohol, allyl carbonate, allyl acetate,
alkyl acrylates and methacrylates, diallyl maleate, diallyl phthalate,
and unsaturated fatty acids, such as oleic acid, linolenic acid,
linoleic acid, erucic acid, palmitoleic acid, and ricinoleic acid
and their esters (including mono-, di-, and triglyceride esters)
and the like.
[0081] Olefins which are especially useful for epoxidation are
the C.sub.2-C.sub.20 olefins having the general structure R.sup.3R.sup.4C.dbd.CR.sup.5R.sup.6
wherein R.sup.3 R.sup.4 R.sup.5 and R.sup.6 are the same or different
and are selected from the group consisting of hydrogen and C.sub.1-C.sub.18
alkyl.
[0082] Mixtures of olefins may be epoxidized and the resulting
mixtures of epoxides either employed in the mixed form or separated
into the different component epoxides.
[0083] The present invention further provides a process for oxidation
of hydrocarbons comprising contacting said hydrocarbon with hydrogen
peroxide in the presence of a catalytically effective amount of
Ti-SSZ-71 for a time and at a temperature effective to oxidize said
hydrocarbon.
EXAMPLES
[0084] The following examples demonstrate but do not limit the
present invention.
Examples 1A-1H
Synthesis of Zincosilicate SSZ-71 (Zn-SSZ-71)
[0085] Zn-SSZ-71 is synthesized by preparing the gels, i.e., reaction
mixtures, having the compositions, in terms of mole ratios, shown
in the table below. 9.06 g of benzyl DABCO hydroxide (0.815 mmol/g)
solution are mixed with 13.8 g of deionized water. Then, respectively,
an appropriate amount of ammonium hydroxide or alkali hydroxide
or alkaline earth hydroxide is added. Subsequently, 0.18 g of Zn(CH.sub.3COO).sub.2
are added and stirred at room temperature overnight. Finally, 1.63
g of Cab-O-Sil M-5 are mixed and stirred at room temperature for
1 hour. The resulting gel is placed in a Parr bomb reactor and heated
in an oven at 150.degree. C. while rotating at 43 rpm. The reaction
is held under these conditions for 17 and 29 days, respectively,
of run time. TABLE-US-00012 Ex. No. Gel Composition Remark 1A 0.018(NH.sub.4).sub.2:0.15R.sub.2O:0.03Zn(CH.sub.3COO).sub.2:SiO.sub.2:-
43H.sub.2O with NH.sub.4OH only without AlkOH or AlkE(OH).sub.2
1B-1F 0.018Alk.sub.2O:0.15R.sub.2O:0.03Zn(CH.sub.3COO).sub.2:SiO.sub.2:43H-
.sub.2O Alk = Li, Na, K, Rb or Cs (all in hydroxide form) 1G-1H
0.018AlkEO:0.15R.sub.2O:0.03Zn(CH.sub.3COO).sub.2:SiO.sub.2:43H.sub.-
2O AlkE = Sr or Ba (all in hydroxide form) R is benzyl DABCO in
hydroxide form. Alk is alkali metal. AlkE is alkaline earth metal.
[0086] The products are analyzed by X-ray diffraction and determined
to be Zn-SSZ-71.
Examples 2A-2D
Synthesis of Zincosilicate SSZ-71 (Zn-SSZ-71)
[0087] Zn-SSZ-71 is synthesized using the procedure of Examples
1A-1H except that EDTA (ethylenediaminetetraacetic acid) is added
together with NaOH to the benzyl DABCO hydroxide solution. The reaction
is run at 150.degree. C. under rotation at 43 rpm. The gel composition
is given below. TABLE-US-00013 Ex. Synthesis Time, No. Gel Composition
days 2A 0.018Na.sub.2O:0.15R.sub.2O:0.03EDTA:0.03Zn(CH.sub.3COO).sub.2:SiO.sub.-
2:43H.sub.2O 7 2B 0.018Na.sub.2O:0.15R.sub.2O:0.03EDTA:0.03Zn(CH.sub.3COO).sub.2:SiO.sub.-
2:43H.sub.2O 15 2C 0.018Na.sub.2O:0.15R.sub.2O:0.03EDTA:0.03Zn(CH.sub.3COO).sub.2:SiO.sub.-
2:43H.sub.2O 22 2D 0.018Na.sub.2O:0.15R.sub.2O:0.03EDTA:0.03Zn(CH.sub.3COO).sub.2:SiO.sub.-
2:43H.sub.2O 29 R is benzyl DABCO in hydroxide form.
[0088] The products are analyzed by X-ray diffraction and determined
to be Zn-SSZ-71.
Examples 3A-3B
Synthesis of All-Silica SSZ-71 (Si-SSZ-71) Using Boron-SSZ-42 as
Seeds
[0089] Si-SSZ-71 is synthesized using the procedure of Example
1A-1H except that (1) no Zn(CH.sub.3COO).sub.2 is added, (2) 2 wt.
% as-made B-SSZ-42 (on the SiO.sub.2 base) is used as seeds and
(3) the reaction is run under static conditions. The gel compositions
(excluding the seeds) are given below. The reaction is held under
these conditions for 14 days of run time. TABLE-US-00014 Ex. No.
Gel Composition 3A 0.018(NH.sub.4).sub.2O:0.15R.sub.2O:SiO.sub.2:43H.sub.2O
3B 0.018K.sub.2O:0.15R.sub.2O:SiO.sub.2:43H.sub.2O R is benzyl DABCO
in hydroxide form.
[0090] The products are analyzed by XRD and found to be Si-SSZ-71.
Examples 4A-4C
Synthesis of All-Silica SSZ-71 (Si-SSZ-71) Using Si-SSZ-71 as Seeds
[0091] Si-SSZ-71 is synthesized using the procedure of Examples
3A-3B under static conditions except that 2 wt. % as-made Si-SSZ-71
(on the SiO.sub.2 base) is used as seeds and no ammonium hydroxide
or alkali hydroxide such as KOH is used. The gel composition (excluding
the seeds) is given below. TABLE-US-00015 Ex. No. Gel Composition
Synthesis Time, days 4A 0.15R.sub.2O:SiO.sub.2:43H.sub.2O 2.6 4B
0.15R.sub.2O:SiO.sub.2:43H.sub.2O 28 4C 0.15R.sub.2O:SiO.sub.2:43H.sub.2O
38 R is benzyl DABCO in hydroxide form.
[0092] The products are analyzed by XRD and found to be Si-SSZ-71
(the product of Example 4A contained SSZ-42 as an impurity).
Examples 5A-5C
Synthesis of Si-SSZ-71
[0093] Si-SSZ-71 is synthesized as described in Examples 4A-4C
under the following conditions: [0094] (1) with varying amount of
water but otherwise identical gel composition, [0095] (2) without
NH.sub.4OH or other alkali or alkaline earth hydroxide (e.g., KOH,
etc.), [0096] (3) without seeds, [0097] (4) under tumbling at 43
rpm, [0098] (5) at 150.degree. C., [0099] (6) with two different
synthesis time: 15 and 30 days.
[0100] The gel compositions and conditions are given below: TABLE-US-00016
Tumbled at 43 rpm Ex. No. Gel Composition 150.degree. C. 5A (1)
0.15R.sub.2O:SiO.sub.2:43H.sub.2O 15 d 30 d 5B (2) 0.15R.sub.2O:SiO.sub.2:29H.sub.2O
15 d 30 d 5C (3) 0.15R.sub.2O:SiO.sub.2:15H.sub.2O 15 d 30 d R is
benzyl DABCO in hydroxide form.
[0101] The products are analyzed by XRD and found to be Si-SSZ-71
with the exception of Example 5C at 15 days, which remained a gel.
Examples 6A-6F
Synthesis of Titanosilicate SSZ-71 (Ti-SSZ-71)
[0102] Ti-SSZ-71 is synthesized by preparing the gels, i.e., reaction
mixtures, having the composition, in terms of mole ratios, shown
in the table below. Ti(OC.sub.2H.sub.5).sub.4 and Cab-O-Sil M-5
are used as titanium and silicon source, respectively. 126.2 g of
benzyl DABCO hydroxide (0.614 mmol/g) solution are mixed with 7.3
g of deionized water. Then, 0.61 g of Ti(OC.sub.2H.sub.5).sub.4
are added under vigorous stirring and then further stirred at room
temperature overnight. Subsequently, an appropriate amount of water
is added to reach the water content given in the gel composition
below because some water is evaporated when stirred overnight. Finally,
18.14 g of Cab-O-Sil M-5 are mixed and stirred at room temperature
for 1 hour. The resulting gel is placed in a Parr bomb reactor and
heated in an oven at 150 or 160.degree. C. while rotating at 43
rpm. TABLE-US-00017 Ex. Time, No. Gel Composition Temp, .degree.
C. days 6A 0.15R.sub.2O:0.01Ti(OC.sub.2H.sub.5).sub.4:SiO.sub.2:25H.sub.2O
150 7 6B 0.15R.sub.2O:0.01Ti(OC.sub.2H.sub.5).sub.4:SiO.sub.2:25H.sub.2O
150 14 6C 0.15R.sub.2O:0.01Ti(OC.sub.2H.sub.5).sub.4:SiO.sub.2:25H.sub.2O
150 21 6D 0.15R.sub.2O:0.01Ti(OC.sub.2H.sub.5).sub.4:SiO.sub.2:25H.sub.2O
160 7 6E 0.15R.sub.2O:0.01Ti(OC.sub.2H.sub.5).sub.4:SiO.sub.2:25H.sub.2O
160 14 6F 0.15R.sub.2O:0.01Ti(OC.sub.2H.sub.5).sub.4:SiO.sub.2:25H.sub.2O
160 21 R is benzyl DABCO in hydroxide form.
[0103] The products are analyzed by X-ray diffraction and determined
to be Ti-SSZ-71.
Examples 7A-7F
Synthesis of Titanosilicate SSZ-71 (Ti-SSZ-71)
[0104] Ti-SSZ-71 is synthesized by preparing the gels, i.e., reaction
mixtures, having the composition, in terms of mole ratios, shown
in the table below. Ti(OC.sub.2H.sub.5).sub.4 and Si(OC.sub.2H.sub.5).sub.4
are used as titanium and silicon source, respectively. 39.13 g of
Si(OC.sub.2H.sub.5).sub.4 are placed in a plastic beaker. 1.30 g
of Ti(OC.sub.2H.sub.5).sub.4 are then quickly added to Si(OC.sub.2H.sub.5).sub.4
under stirring. The mixture of Ti(OC.sub.2H.sub.5).sub.4 and Si(OC.sub.2H.sub.5).sub.4
is placed in an ice bath. 107.0 g of benzyl DABCO hydroxide (0.614
mmol/g) solution are added to this mixture under vigorous stirring
and then further stirred at room temperature overnight. Subsequently,
an appropriate amount of water is added to reach the water content
given in the gel composition below because some water is evaporated
when stirred overnight. The resulting gel is placed in a Parr bomb
reactor and heated in an oven at 150 or 160.degree. C. while rotating
at 43 rpm. TABLE-US-00018 Ex. Time, No. Gel Composition Temp, .degree.
C. days 7A 0.175R.sub.2O:0.03Ti(OC.sub.2H.sub.5).sub.4:SiO.sub.2:28H.sub.2O
160 7 7B 0.175R.sub.2O:0.03Ti(OC.sub.2H.sub.5).sub.4:SiO.sub.2:28H.sub.2O
160 14 7C 0.175R.sub.2O:0.03Ti(OC.sub.2H.sub.5).sub.4:SiO.sub.2:28H.sub.2O
160 21 7D 0.175R.sub.2O:0.03Ti(OC.sub.2H.sub.5).sub.4:SiO.sub.2:28H.sub.2O
150 7 7E 0.175R.sub.2O:0.03Ti(OC.sub.2H.sub.5).sub.4:SiO.sub.2:28H.sub.2O
150 14 7F 0.175R.sub.2O:0.03Ti(OC.sub.2H.sub.5).sub.4:SiO.sub.2:28H.sub.2O
150 21 R is benzyl DABCO in hydroxide form.
[0105] The products are analyzed by X-ray diffraction and determined
to be Ti-SSZ-71.
Examples 8A-8C
Synthesis of Titanosilicate SSZ-71 (Ti-SSZ-71)
[0106] Si-SSZ-71 is synthesized as described in Examples 7A-7F
except that 2 wt. % as-made Si-SSZ-71 (on the SiO.sub.2 base) is
used as seeds. The gel composition (excluding the seeds) is given
below. Ti(OC.sub.2H.sub.5).sub.4 and Si(OC.sub.2H.sub.5).sub.4 are
used as titanium and silicon source, respectively. The resulting
gel is placed in a Parr bomb reactor and heated in an oven at 150.degree.
C. while rotating at 43 rpm. TABLE-US-00019 Ex. Time, No. Gel Composition
Temp, .degree. C. days 8A 0.175R.sub.2O:0.01Ti(OC.sub.2H.sub.5).sub.4:SiO.sub.2:28H.sub.2O
150 6 8B 0.175R.sub.2O:0.01Ti(OC.sub.2H.sub.5).sub.4:SiO.sub.2:28H.sub.2O
150 18 8C 0.175R.sub.2O:0.01Ti(OC.sub.2H.sub.5).sub.4:SiO.sub.2:28H.sub.2O
150 24 R is benzyl DABCO in hydroxide form.
[0107] The products are analyzed by X-ray diffraction and determined
to be Ti-SSZ-71.
Example 9
Calcination of Zn-SSZ-71
[0108] Na/Zn-SSZ-71 as synthesized in Example IC with NaOH is calcined
to remove the structure directing agent (SDA) as described below.
A thin bed of Na/Zn-SSZ-71 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 10
Conversion of calcined Zn-SSZ-71 to Al-SSZ-71
[0109] The calcined Na/Zn-SSZ-71 (5 g) prepared in Example 9 is
with combined with 500 grams of 1 M aqueous Al(NO.sub.3).sub.3 solution
and treated under reflux for 100 hours. The resulting Al-SSZ-71
product is then washed with 1 liter of water, filtered and air-dried
at room temperature in vacuum filter. |