Pure phase titanium-containing zeolite having MEL structure, process for preparing same, and oxidation processes using same as catalyst

Titanium-containing zeolites containing the MEL crystal structure are prepared using an organic templating agent comprising 3,5-dimethylpiperidinium compounds. The zeolites can be made in the pure phase form, and are useful as catalysts for the oxidation of hydrocarbons.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a titanium-containing zeolite having a 
framework structure designated MEL in pure phase form (referred to herein 
as "SSZ-46"), to a process for preparing crystalline titanium-containing 
zeolites having the MEL structure using an organic templating agent 
comprising at least one 3,5-dimethylpiperidinium (3,5-DMP) compound, and 
to oxidation processes using SSZ-46. 
2. State of the Art 
Titanium-containing zeolite ZSM-11 which contains the MEL framework 
structure (commonly referred to as "TS-2") and methods for making it are 
known. For example, Belgian Patent No. 1,001,038, issued Jun. 20, 1989, 
discloses the preparation of TS-2 using tetraalkylammonium cations, such 
as tetrabutylammonium hydroxide ("TBA"), as the organic templating agent. 
It does not, however, disclose the 3,5-DMP compounds of this invention as 
templating agents. Belgian Patent No. 1,001,038 is incorporated herein by 
reference in its entirety. 
It has now been found that titanium-containing zeolites containing the MEL 
framework structure (e.g., TS-2) can be prepared using an organic template 
comprising at least one 3,5-DMP compound, that the zeolite can be made in 
pure phase form, and that this pure phase zeolite (SSZ-46) is useful as a 
catalyst in oxidation reactions. 
SUMMARY OF THE INVENTION 
The present invention provides a titanium-containing crystalline 
composition, as-synthesized and in the anhydrous state, whose general 
formula, in terms of mole ratios, is: 
##EQU1## 
wherein Q is an organic templating agent comprising at least one 
3,5-dimethylpiperidinium compound, and Y is silicon, germanium, or 
mixtures thereof. 
As used herein, the term "titanium-containing" refers to the fact that the 
zeolites of this invention contain titanium atoms in their framework 
structure. 
In accordance with the present invention, there is also provided the 
titanium-containing zeolite SSZ-46 having no intergrowth within its 
crystalline structure of any crystalline structure other than the MEL 
structure. In particular, the SSZ-46 of this invention has no intergrowth 
of ZSM-5 (or its titanium-containing analog, TS-1) crystalline structure. 
The present invention further provides the zeolite SSZ-46 having no 
intergrowth within its crystalline structure of any crystalline structure 
other than the MEL structure and having the X-ray diffraction pattern of 
Table I or Table II below. 
In accordance with the present invention, there is also provided a process 
for preparing titanium-containing zeolites containing the MEL crystal 
structure which comprises: 
(a) preparing an aqueous solution containing (1) sources of titanium oxide; 
(2) sources of an oxide selected from oxides of silicon, germanium or 
mixtures thereof; and (3) an organic templating agent comprising at least 
one 3,5-dimethylpiperidinium compound; 
(b) maintaining the aqueous solution under conditions sufficient to form 
crystals of said titanium-containing zeolite; and 
(c) recovering the crystals of said titanium-containing zeolite. 
The present invention also provides the above-described process for 
preparing titanium-containing zeolites wherein the organic templating 
agent comprises a mixture of a 3,5-dimethylpipperidinium compound and a 
tetraalkylammonium compound. 
Further provided in accordance with this invention are the above-described 
processes for preparing titanium-containing zeolites wherein the zeolite 
so prepared is in pure phase form (i.e., is SSZ-46). 
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 a crystalline, 
titanium-containing molecular sieve for a time and at a temperature 
effective to oxidize said hydrocarbon, wherein the crystalline 
titanium-containing molecular sieve is a zeolite whose general formula is, 
after calcination, 
EQU TiO.sub.2 :wSiO.sub.2 
where w&gt;30, and which has the X-ray diffraction lines of Table II below 
(i.e., the zeolite is SSZ-46). 
The present invention also provides a process for epoxidation of an olefin 
comprising contacting said olefin with hydrogen peroxide in the presence 
of a catalytically effective amount of a crystalline, titanium-containing 
molecular sieve for a time and at a temperature effective to epoxidize 
said olefin, wherein the crystalline titanium-containing molecular sieve 
is a zeolite whose general formula is, after calcination, 
EQU TiO.sub.2 :wSiO.sub.2 
where w&gt;30, and which has the X-ray diffraction lines of Table II below. 
Further provided in accordance with this invention is a process for 
oxidizing cyclohexane comprising contacting said cyclohexane with hydrogen 
peroxide in the presence of a catalytically effective amount of a 
crystalline, titanium-containing molecular sieve for a time and at a 
temperature effective to oxidize said cyclohexane, wherein the crystalline 
titanium-containing molecular sieve is a zeolite whose general formula is, 
after calcination, 
EQU TiO.sub.2 :wSiO.sub.2 
where w&gt;30, and which has the X-ray diffraction lines of Table II below. 
Among other factors, the present invention is based on the discovery that 
titanium-containing zeolites containing the MEL crystal structure can be 
made using an organic templating agent comprising at least one 
3,5-dimethylpiperidinium compound. It is especially surprising that, by 
using these 3,5-dimethylpiperidinium compounds as the templating agent, 
the titanium-containing zeolite can be prepared in essentially pure phase 
form. Heretofore, it has been difficult to prepare titanium-containing the 
MEL crystal structure (such as TS-2) using conventional templating agents 
without also crystallizing the closely related zeolite ZSM-5. 
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
In one embodiment the present invention comprises: 
(a) preparing an aqueous solution comprising sources of oxides capable of 
forming titanium-containing zeolites containing the MEL crystal structure 
and an organic templating agent comprising at least one 
3,5-dimethylpiperidinium compound; 
(b) maintaining the aqueous solution under conditions sufficient to form 
crystals of said titanium-containing zeolite; and 
(c) recovering the crystals of said titanium-containing zeolite. 
The Templating Agent 
The templating agents useful in the present process are water-soluble 
3,5-dimethylpiperidinium compounds which are capable of acting as a 
templating agent to form titanium-containing zeolites containing the MEL 
crystal structure. 
They have a molecular structure of the general form: 
##STR1## 
wherein R.sup.1 and R.sup.2 independently represent an alkyl group, either 
branched or unbranched, substituted or unsubstituted, containing from 1 to 
about 7 carbon atoms. In addition, R.sup.1 and R.sup.2 together may 
comprise a cyclic alkyl ring system, which, including the positively 
charged nitrogen atom, contains from 4 to 7 atoms, said ring system being 
unsubstituted or substituted with branched or unbranched alkyl groups 
having, e.g., one to three carbon atoms. X.sup.- is an anion which is not 
detrimental to the formation of the titanium-containing zeolite, such as 
those described below. Preferred 3,5-DMP compounds are 
3,5-dimethyl-N,N-diethylpiperdinium compounds; 
3,5-dimethyl-N-methyl-N-ethylpiperidinium compounds; and spiro 
3,5-dimethylpiperidinium compounds such as 
1-azonia-3,5,7-trimethyl-spiro[5.4] decane compounds. 
The anion for the salt may be essentially any anion such as halide or 
hydroxide which is not detrimental to the formation of the zeolite. As 
used herein, "halide" refers to the halogen anions, particularly fluorine, 
chlorine, bromine, iodine, and combinations thereof. Thus, representative 
anions include hydroxide, acetate, sulfate, carboxylate, 
tetrafluoroborate, and halides such as fluoride, chloride, bromide, and 
iodide. Hydroxide and iodide are particularly preferred as anions. 
It has also been found that when the organic templating agent comprises a 
mixture comprising a 3,5-DMP compound and a tetraalkylammonium ("TAA") 
compound, crystallization time is shortened considerably. While not 
wishing to be bound by any theory, it is believed that the TAA facilitates 
nucleation and quickly forms very small crystals (though not necessarily 
of SSZ-46). The 3,5-DMP templating agent then forms the pure phase SSZ-46 
around the nuclei formed by the TAA. Besides speeding crystallization, use 
of the combination of TAA and 3,5-DMP compounds can produce smaller 
crystallites than when either templating agent is used alone under 
corresponding conditions. 
Suitable TAA compounds include, but are not limited to, tetrabutylammonium 
and tetrapropylammonium compounds. Preferably, the TAA compound is a 
tetrabutylammonium compound. The anion for the TAA compounds may be 
selected from those described above for the 3,5-DMP) compounds. 
When mixtures of 3,5-DMP and TAA compounds are used, they are generally 
used in a mole ratio of TAA compound(s) to 3,5-DMP compound(s) of from 
about 1:2 to about 1:500. 
Preferably, this mole ratio is from about 1:50 to about 1:200. 
A surprising advantage of using a mixture of 3,5-DMP and TAA compounds as 
the organic templating agent is that crystallization occurs much faster 
than when a 3,5-DMP compound is used alone. Thus, when only a 3,5-DMP 
compound is used as the organic template, crystallization of the 
titanium-containing zeolite typically takes about 30 days. However, when a 
3,5-DMP/TAA mixture is used, crystallization typically takes only about 
ten days. 
The Preparation of Titanium-Containing Zeolites 
The process of the present invention comprises forming a reaction mixture 
containing sources of titanium oxide; sources an oxide of silicon, 
germanium or mixtures thereof (Y); an organic templating agent comprising 
at least one 3,5-DMP compound (Q); and water, said reaction mixture having 
a composition in terms of mole ratios within the following ranges: 
______________________________________ 
Reactants General Preferred 
______________________________________ 
YO.sub.2 /TiO.sub.3 
&gt;25 30-200 
OH/YO.sub.2 0.15-0.40 0.20-0.35 
Q/YO.sub.2 0.15-0.40 0.20-0.35 
H.sub.2 O/YO.sub.2 15-100 25-45 
______________________________________ 
The reaction mixture may be prepared using standard zeolite preparation 
techniques. Typical sources of silicon oxide include silica hydrogel, 
tetraalkyl orthosilicates, and fumed silica. Typical sources of titanium 
include tetraalkylorthotitanates. In addition, coprecipitates comprised of 
both silicon and titanium can be used as a starting reagent. 
Unlike the preparation of aluminosilicate zeolites, the reaction mixture 
for preparing the titanium-containing zeolites of this invention should 
not contain alkali metal hydroxide. The presence of alkali metal cations 
in the reaction mixture can give rise to an undesirable titanium phase in 
the final product. In addition, all of the hydroxide ions needed in the 
reaction mixture are supplied by the organic templating agent. 
The titanium-containing zeolites of this invention should be free of 
aluminum in order to perform optimally as oxidation catalysts. It is, 
however, possible that traces of aluminum may be introduced into the 
zeolite from, e.g., a silica source which contains minor amounts of 
aluminum. If this occurs, the protons associated with the aluminum should 
be replaced with ammonium, alkali metal or alkaline earth cations. 
In preparing the titanium-containing zeolites according to the present 
invention, the reactants and the templating agent are dissolved in water 
and the resulting reaction mixture is maintained at an elevated 
temperature until crystals are formed. The temperatures during the 
hydrothermal crystallization step are typically maintained from about 
100.degree. C. to about 250.degree. C., preferably from about 140.degree. 
C. to about 200.degree. C. The crystallization period is typically greater 
than about five days and generally about six days to about 30 days, 
depending upon whether the templating agent employed is a 3,5-DMP compound 
alone, or a mixture of 3,5-DMP and TAA compounds. Preferably the 
crystallization period is from about five days to about 20 days. 
The hydrothermal crystallization is usually conducted under pressure and 
usually in an autoclave so that the reaction mixture is subject to 
autogenous pressure. The reaction mixture can be stirred during 
crystallization. 
Once the 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 zeolite crystals. The drying step can be performed at 
atmospheric or subatmospheric pressures. 
During the hydrothermal crystallization step, the crystals can be allowed 
to nucleate spontaneously from the reaction mixture. The reaction mixture 
can also be seeded with crystals of titanium-containing zeolites 
containing the MEL crystal structure, or with crystals of ZSM-11 crystals 
(which contain the MEL structure) both to direct, and accelerate the 
crystallization, as well as to minimize the formation of any undesired 
crystalline phases. When seed crystals are used, typically 0.1% to about 
10%. of the weight of silica used in the reaction mixture are added. 
Due to the unpredictability of the factors which control nucleation and 
crystallization in the art of crystalline oxide synthesis, not every 
combination of reagents, reactant ratios, and reaction conditions will 
result in crystalline products. Selecting crystallization conditions which 
are effective for producing crystals may require routine modifications to 
the reaction mixture or to the reaction conditions, such as temperature, 
and/or crystallization time. Making these modifications are well within 
the capabilities of one skilled in the art. 
The titanium-containing zeolite product made by the process of this 
invention has an as-synthesized composition comprising, in terms of mole 
ratios in the anhydrous state, the following: 
##EQU2## 
The titanium-containing zeolite product was identified by its X-ray 
diffraction (XRD) pattern. The X-ray powder diffraction patterns were 
determined by standard techniques. The radiation was the K-alpha/doublet 
of copper. The peak heights I and the positions, as a function of 2.theta. 
where .theta. is the Bragg angle, were read from the relative intensities, 
100.times.I/I.sub.o where I.sub.o is the intensity of the strongest line 
or peak, and d, the interplanar spacing in Angstroms corresponding to the 
recorded lines, can be calculated. 
The X-ray diffraction pattern of Table I is representative of 
as-synthesized SSZ-46 made in accordance with this invention. Minor 
variations in the diffraction pattern can result from variations in the 
silica-to-titania 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. 
TABLE I 
______________________________________ 
As-Synthesized SSZ-46 
d (.ANG.) 
Relative Intensity.sup.a 
______________________________________ 
14.23 W 
11.14 M 
10.04 W 
6.70 W 
5.99 W 
5.57 W 
5.00 W 
4.60 W 
4.36 W 
3.84 VS 
3.71 M 
3.48 W 
3.06 W 
2.98 W 
2.01 W 
______________________________________ 
.sup.(a) The Xray patterns provided are based on a relative intensity 
scale in which the strongest line in the Xray pattern is assigned a value 
of 100: W(weak) is less than 20; M(medium) is between 20 and 40; S(strong 
is between 40 and 60; VS(very strong) is greater than 60. 
Table IA below shows a typical X-ray diffraction pattern for as-synthesized 
SSZ-46 zeolite made in accordance with this invention. In Table IA, the 
intensity (I) of the peaks or lines is expressed as the intensity relative 
to the strongest peak or line in the pattern, i.e., I/I.sub.o .times.100 
where I.sub.o is the intensity of the strongest peak or line. 
TABLE IA 
______________________________________ 
AS-SYNTHESIZED SSZ-46 
d (.ANG.) 
I/I.sub.o .times. 100 
______________________________________ 
14.23 
1.3 
11.14 32.6 
10.04 16.1 
6.70 6.1 
5.99 9.9 
5.57 5.4 
5.00 6.0 
4.60 6.2 
4.36 6.1 
3.84 100.0 
3.71 27.8 
3.48 2.6 
3.06 9.8 
2.98 10.9 
2.01 9.8 
______________________________________ 
The X-ray diffraction pattern of Table II is representative of calcined 
SSZ-46 made in accordance with this invention. 
TABLE II 
______________________________________ 
Calcined SSZ-46 
d (.ANG.) 
Relative Intensity 
______________________________________ 
14.18 
W 
11.14 VS 
10.04 S 
6.71 W 
5.98 M 
5.58 W 
5.01 W 
4.60 W 
4.36 W 
3.84 VS 
3.71 M 
3.49 W 
3.06 W 
2.99 W 
2.01 W 
______________________________________ 
Calcination can also result in changes in the intensities of the peaks as 
well as minor shifts in the diffraction pattern. Notwithstanding these 
minor perturbations, the basic crystal lattice remains unchanged by this 
treatment. 
Table IIA below shows the X-ray diffraction pattern of calcined SSZ-46 made 
in accordance with this invention, including the intensities of the peaks 
or lines. 
TABLE IIA 
______________________________________ 
CALCINED SSZ-46 
______________________________________ 
14.18 
1.4 
11.14 70.0 
10.04 45.0 
6.71 7.8 
5.98 22.4 
5.58 9.7 
5.01 12.5 
4.60 4.7 
4.36 3.8 
3.84 100.0 
3.71 26.6 
3.49 2.8 
3.06 9.7 
2.99 13.9 
2.01 11.9 
______________________________________ 
Pure Phase SSZ-46 
The SSZ-46 of this invention is in pure phase form. As used herein, the 
phrase "pure phase form" refers to the fact that the SSZ-46 of this 
invention is composed of crystals having only the MEL crystal structure, 
i.e., the crystals contain no other crystal structure as an intergrowth 
with the MEL structure. It is believed that, heretofore, although "pure" 
titanium-containing zeolites containing the MEL crystal structure (i.e., 
TS-2) may have been reported as having been prepared, these materials have 
actually contained some amount of an intergrowth of another crystal 
structure, typically ZSM-5. One of the principal advantages of this 
invention is that it provides SSZ-46 without these intergrowths of other 
crystal structures. 
It is believed that the peak in Tables I and II above found at about d=14 
.ANG. demonstrates that the SSZ-46 of this invention is in pure phase 
form. This peak is not found in X-ray diffraction patterns of TS-2 which 
contains ZSM-5 intergrowth, and does appear in Tables I and II where it 
would be expected in a calculated X-ray diffraction pattern for pure phase 
SSZ-46. In addition, the intensities of the peaks in Tables I and II above 
are consistent with the intensities expected for a pure phase SSZ-46. It 
should be noted, however, that as the amount of titanium in the SSZ-46 is 
increased, the peaks in the XRD pattern tend to broaden, with the result 
that the aforementioned peak at d=14 .ANG. may become obscured. 
Oxidation Reactions 
The SSZ-46 prepared by the process of this invention is useful as a 
catalyst in the oxidation of hydrocarbons. Examples of such reactions 
include, but are not limited to, the epoxidation of olefins, oxidation of 
alkanes, and the oxidation of cyclohexane. 
The amount of SSZ-46 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. The optimum quantity of 
catalyst will depend upon a number of factors including reaction 
temperature, the reactivity and concentration of the hydrocarbon 
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 hydrocarbon. 
Typically, the titanium-containing crystalline zeolites of this invention 
are thermally treated (calcined) prior to use as a catalyst. 
The catalyst may be utilized in powder, pellet, microspheric, monolithic, 
extruded, or any other suitable physical form. The use of a binder 
(co-gel) or support in combination with the SSZ-46 may be advantageous. 
Supported or bound catalysts may be prepared by the methods known in the 
art to be effective for zeolite catalysts in general. 
Illustrative binders and supports (which preferably are non-acidic in 
nature) include silica, alumina, silica-alumina, silica-titania, 
silica-thoria, silica-magnesia, silica-zirconia, silica-beryllia, and 
ternary compositions of silica with other refractory oxides. Also useful 
are clays such as montmorillonites, kaolins, bentonites, halloysites, 
dickites, nacrites and anaxites. The proportion of SSZ-46 to binder may 
range from about 99:1 to about 1:99, but preferably is from about 5:95 to 
about 80:20, all expressed on a weight basis. 
The oxidizing agent employed in the oxidation processes of this invention 
is a hydrogen peroxide source such as hydrogen peroxide (H.sub.2 O.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). 
The amount of hydrogen peroxide relative to the amount of hydrocarbon 
substrate is not critical, but must be sufficient to cause oxidation of at 
least some of the hydrocarbon. Typically, the molar ratio of hydrogen 
peroxide to hydrocarbon is from about 100:1 to about 1:100, preferably 
10:1 to about 1:10. When the hydrocarbon 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 small to moderate excess (e.g., 5 
to 50%) of olefin relative to hydrogen peroxide may be advantageous for 
certain substrates. 
If desired, a solvent may additionally be present during the oxidation 
reaction in order to dissolve the reactants other than the SSZ-46, 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 25.degree. C. to about 300.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), nitriles (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. 
The reaction temperature is not critical, but should be sufficient to 
accomplish substantial conversion of the substrate hydrocarbon 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, hydrocarbon 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 hydrocarbon 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 hydrocarbon substrate should 
preferably be present in the liquid phase. 
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. 
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 
One of the oxidation reactions for which SSZ-46 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 30 carbon atoms. 
The use of light (low-boiling) C.sub.2 to C.sub.10 mono-olefins is 
especially advantageous. 
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 cyclohexene, for 
example). 
Other examples of suitable substrates include unsaturated fatty acids or 
fatty acid derivatives such as esters or glycerides, and oligomeric or 
polymeric unsaturated compounds such as polybutadiene. Benzylic and 
styrenic olefins may also be epoxidized, although the epoxides of certain 
styrenic olefins such as styrene may further react or isomerize under the 
conditions utilized in the present invention to form aldehydes and the 
like. 
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. 
Exemplary olefins suitable for use in the process of this invention include 
ethylene, propylene, the butenes (i.e., 1,2-butene, 2,3-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, styrene (and other 
vinyl aromatic substrates), polybutadienes, polyisoprene, cyclopentene, 
cyclohexene, cycloheptene, cyclooctene, cyclooctadiene, cyclododecene, 
cyclododecatriene, 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, unsaturated 
triglycerides such as soybean oil, 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. 
Olefins which are especially useful for epoxidation are the C.sub.2 
-C.sub.30 olefins having the general structure 
EQU R.sup.3 R.sup.4 C.dbd.CR.sup.5 R.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.20 
alkyl. 
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.

The following examples demonstrate but do not limit the present invention. 
EXAMPLES 
There are numerous variations on the embodiments of the present invention 
illustrated in the Examples which are possible in light of the teachings 
supporting the present invention. It is therefore understood that within 
the scope of the following claims, the invention may be practiced 
otherwise than as specifically described or exemplified. 
Example 1 
Preparation of 3,5-dimethyl-N,N-diethylpiperidinium hydroxide templating 
agent (Template A) 
200 Grams of 3,5-dimethylpiperidine, 255 grams of potassium bicarbonate and 
1700 ml of methanol were added to a 3-liter 3-necked flask which was 
equipped with a mechanical stirrer, addition funnel and reflux condenser. 
794 Grams of ethyl iodide was added to the resulting reaction mixture and, 
once addition was complete, the mixture was heated for three days at 
reflux. After cooling, the reaction mixture was concentrated and the 
desired solids isolated. The product, 3,5-dimethyl-N,N-diethylpiperidinium 
iodide, was recrystallized from hot acetone/methanol. 
Ion exchange to the corresponding hydroxide was achieved using Bio-Rad 
AG1-X8 anion exchange resin. The hydroxide ion concentration was 
determined by titration of the resulting solution using phenolphthalein as 
the indicator. 
Example 2 
Synthesis of SSZ-46 
9.22 Grams of a 15.46 weight percent 3,5-dimethyl-N,N-diethylpiperidinium 
hydroxide (Template A) solution were added to a beaker equipped with a 
stir bar. 0.0628 Gram of tetraethylorthotitanate (TEOT) was then added to 
the beaker under rigorous stirring. To the resulting clear solution was 
added 3.63 grams of water. Finally, 1.53 grams of fumed, amorphous silica 
(CabOSil M-5) was added slowly under stirring and blended until a 
homogeneous mixture was obtained. A small amount of seed crystals (0.007 
gram of pure phase ZSM-11 made with Template A) was added to speed 
crystallization. All reactants should be free from inorganic alkali. The 
resulting gel had a molar ratio as follows: 
EQU Si:Ti:Template A:H.sub.2 O=1:0.01:0.3:25 
The gel was charged into a 20 ml capacity Teflon-lined autoclave and 
tumbled (43 RPM) at 175.degree. C. under autogenous pressure for two 
weeks. The resulting crystalline product was recovered by filtration, and 
readied for catalysis by calcination in air at 595.degree. C. for five 
hours. 
The crystalline product of this reaction was determined by X-ray 
diffraction (XRD) to be a titanium-containing zeolite having the MEL 
crystal structure in pure phase form, i.e., SSZ-46, having the following 
characteristic X-ray diffraction lines: 
TABLE III 
______________________________________ 
d (.ANG.) 
I/I.sub.o .times. 100 
______________________________________ 
14.17 
1.0 
11.13 27.7 
10.03 19.7 
7.45 10.2 
6.69 5.5 
5.98 9.8 
5.57 5.0 
5.01 4.9 
4.60 5.3 
4.35 5.8 
3.84 100.0 
3.71 28.1 
3.48 3.2 
3.06 9.5 
2.98 11.4 
2.01 9.2 
______________________________________ 
Example 3 
Synthesis of SSZ-46 
6.6 Grams of a 11.36 weight percent solution of Template A was combined 
with 5.68 grams of water and stirred until homogeneous. The final reactant 
mixture was prepared by adding 0.96 gram of a silica-titania coprecipitate 
(Si/Ti mole ratio=54), such as W. R. Grace Si-Ti. Type III/2. The 
resulting mixture had a molar ratio as follows: 
EQU Si:Ti:Template A:H.sub.2 O=1:19:0.25:40 
After adding 0.01 gram of pure phase ZSM-11 crystals (made with Template A) 
as seed crystals, the entire mixture was placed in a 20 ml capacity 
Teflon-lined autoclave and tumbled (43 RPM) at 175.degree. C. under 
autogenous pressure for two weeks. The resulting crystalline product was 
recovered by filtration and readied for catalysis by calcination in air at 
595.degree. for five hours. 
The crystalline product was analyzed by XRD and found to be SSZ-46 having 
the following characteristic X-ray diffraction lines: 
TABLE IV 
______________________________________ 
d (.ANG.) 
I/I.sub.o .times. 100 
______________________________________ 
11.16 
44.6 
10.06 21.2 
7.46 14.0 
6.70 8.8 
6.00 11.4 
5.57 7.3 
5.02 4.8 
4.61 6.9 
4.36 9.4 
3.85 100.0 
3.71 38.8 
3.48 3.1 
3.06 8.8 
2.98 12.2 
2.01 9.0 
______________________________________ 
Example 4 
Synthesis of SSZ-46 
25 Grams of tetraorthosilicate (TEOS) was placed in a round bottom flask 
fitted with a stir bar, and 0.865 gram of TEOT was added thereto followed 
by dropwise addition of 69.1 grams of a 11.37 weight percent solution of 
Template A. The mixture was kept in an ice bath during the addition of the 
Template A. After all of the Template A had been added, the ice bath was 
removed and the mixture allowed to stir at room temperature for five 
hours. The flask was then heated to 60.degree. C. under vacuum to 
accelerate hydrolysis and evaporate the ethyl alcohol which is released. 
After all the alcohol had been removed, water was added so that the final 
gel composition had the following molar ratio: 
EQU Si:Ti:Template A:H.sub.2 O=1:0.03:0.35:28 
A small amount of seed crystals (0.04 gram of pure phase ZSM-11 made with 
Template A) was added to the resulting clear colorless solution, which was 
then transferred into Teflon-lined autoclaves and tumbled at 160.degree. 
C. under autogenous pressure for four weeks. The resulting crystalline 
product was recovered by centrifugation and readied for catalysis by 
calcination in air at 595.degree. C. for five hours. 
The crystalline product was determined by XRD to be SSZ-46 having the 
following characteristic X-ray diffraction lines: 
TABLE V 
______________________________________ 
d (.ANG.) 
I/I.sub.o .times. 100 
______________________________________ 
11.15 
46.8 
10.05 24.0 
7.45 11.5 
6.69 6.9 
6.00 10.7 
5.57 5.9 
5.01 4.2 
4.60 6.7 
4.36 8.9 
3.84 100.0 
3.71 36.1 
3.06 7.1 
2.98 10.7 
2.01 8.1 
______________________________________ 
Example 5 
Synthesis of SSZ-46 
The procedure described in Example 3 was used, except that the reaction 
mixture contained 13.19 grams TEOS, 0.15 gram TEOT, and 25.53 grams of an 
11.36 wt % aqueous solution of Template A. This resulted in the following 
molar composition: 
EQU Si:Ti:Template A: H.sub.2 O=1:0.01:0.25:40 
The resulting clear, colorless solution was placed in Teflon-lined 
autoclaves and a small amount of seed crystals (0.075 gram of a pure phase 
ZSM-11 made using Template A) was added to speed crystallization. The 
autoclaves were tumbled at 175.degree. C. under autogenous pressure for 12 
days. The resulting crystalline product was recovered by filtration and 
readied for catalysis by calcination in air at 595.degree. C. for 5 hours. 
The crystalline product was determined by XRD to be SSZ-46. 
Example 6 
Synthesis of SSZ-46 
13.9 Grams of TEOS was placed in a round bottom flask fitted with a stir 
bar, and 0.232 gram of TEOT was added followed by dropwise addition of 
26.3 grams of an 11.36 wt % solution of Template A. The mixture was kept 
in an ice bath during the addition of the TEOT. After all of the TEOT had 
been added, the ice bath was removed and the mixture allowed to stir at 
room temperature for 5 hours. Then, 0.16 gram of an aqueous solution of 
tetrabutylammonium hydroxide (55%) was added to the flask. The flask was 
then heated to 60.degree. C. under vacuum to accelerate hydrolysis and 
evaporate the ethyl alcohol which was released. After all of the alcohol 
had been removed, water was added so that the final gel composition, on a 
molar basis, was as follows: 
EQU Si:Ti:Template A:H.sub.2 O=1:0.015:0.245:0.005:40 
The resulting clear, colorless solution was then transferred into 
Teflon-lined autoclaves and tumbled at 175.degree. C. under autogenous 
pressure for 8 days. The resulting crystalline product was recovered by 
filtration and readied for catalysis by calcination in air at 595.degree. 
C. for 5 hours. 
The crystalline product was determined by XRD to be SSZ-46. 
Example 7 
Epoxidation of 1-Octene 
Fifty mg of each in turn of the powdered catalysts indicated in Table A 
below, 6 ml of acetone, 10 millimoles of 1-octene, 0.1 gram of mesitylene 
(as internal standard), and 3.3 millimoles of aqueous H.sub.2 O.sub.2 
(31.1% w/w) were loaded into a glass autoclave equipped with a magnetic 
stir bar. The autoclave was then immersed into a constant temperature oil 
bath maintained at 60.degree. C. The reactants were allowed to stir 
vigorously for 3 hours at this temperature. 
After this time, the solution was allowed to return to ambient temperature 
and the residual amount of H.sub.2 O.sub.2 was determined by cerimetric 
titration. The reaction product was analyzed by quantitative gas 
chromatography to determine the conversion of 1-octene. The results are 
indicated in Table A below. 
TABLE A 
______________________________________ 
Catalyst 1-Octene Conversion (%) 
H.sub.2 O.sub.2 Effciency (%) 
______________________________________ 
TS-2 9.62 73.9 
Ex. 2 9.27 86.3 
Ex. 3 6.38 97.2 
Ex. 6 8.47 85.0 
______________________________________ 
Example 8 
Oxidation of n-Octane 
Fifty mg of each in turn of the powdered catalysts indicated in Table B 
below, 6 ml of acetone, 30 millimoles of n-octane, 0.3 gram of mesitylene 
(as internal standard), and 10 millimoles of aqueous H.sub.2 O.sub.2 
(31.1% w/w) were loaded into a glass autoclave equipped with a magnetic 
stir bar. The autoclave was then immersed into a constant temperature oil 
bath maintained at 100.degree. C. The reactants were allowed to stir 
vigorously for 4 hours at this temperature. 
After this time, the solution was allowed to return to ambient temperature 
and the residual amount of H.sub.2 O.sub.2 was determined by cerimetric 
titration. The reaction product was analyzed by quantitative gas 
chromatography to determine the conversion of n-octane. The results are 
indicated in Table B below. 
TABLE B 
______________________________________ 
Catalyst n-Octane Conversion (%) 
______________________________________ 
Ex. 2 21.7 
Ex. 6 16.0 
______________________________________