Synthesis of ZSM-39

A new and useful method for preparing synthetic zeolite ZSM-39 is provided. This new method comprises synthesizing zeolite ZSM-39 in the presence of pyrrolidine as a template rather than the template of a tetraethylammonium cation or n-propylamine.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates generally to a new method of preparing a crystalline 
zeolite material and particularly to a new method of making substantially 
pure zeolite ZSM-39 by utilizing a tetraureacobalt (II) complex and 
pyrrolidine. 
2. Description of the Prior Art 
Zeolitic materials, both natural and synthetic, have been demonstrated in 
the past to have catalytic properties for various types of hydrocarbon 
conversions. Certain zeolitic materials are ordered, porous crystalline 
aluminosilicates having a definite crystalline structure within which 
there are a large number of channels. These cavities and channels are 
precisely uniform in size. Since lthe dimensions of these pores are such 
as to accept for adsorption molecules of certain dimensions while 
rejecting those of larger dimensions, these materials have come to be 
known as "molecular sieves" and are utilized in a variety of ways to take 
advantage of these properties. 
Such molecular sieves, both natural and synthetic, include a wide variety 
of positive ion-containing crystalline aluminosilicates. These 
aluminosilicates can be described as a rigid three-dimensional framework 
of SiO.sub.4 and AlO.sub.4 in which the tetrahedra are cross-linked by 
the sharing of oxygen atoms whereby the ratio of the total aluminum and 
silicon atoms to oxygen is 1:2. The electrovalence of the tetrahedra 
containing aluminum is balanced by the inclusion in the crystal of a 
cation, for example, an alkali metal or an alkaline earth metal cation. 
This can be expressed wherein the ratio of aluminum to the number of 
various cations, such as Ca/2, Sr/2, Na, K or Li is equal to unity. One 
type of cation may be exchanged either entirely or partially by another 
type of cation utilizing ion exchange techniques in a conventional manner. 
By means of such cation exchange, it has been possible to vary the 
properties of a given aluminosilicate by suitable selection of the cation. 
The spaces between the tetrahedra are occupied by molecules of water prior 
to dehydration. 
Prior art techniques have resulted in the formation of a great variety of 
synthetic aluminosilicates. These aluminosilicates have come to be 
designated by letter or other convenient symbols, as illustrated by 
zeolite A (U.S. Pat. No. 2,882,243), zeolite X (U.S. Pat. No. 2,882,244), 
zeolite Y (U.S. Pat. No. 3,130,007), zeolite ZK-5 (U.S. Pat. No. 
3,247,195), zeolite ZK-4 (U.S. Pat. No. 3,314,752) zeolite ZSM-5 (U.S. 
Pat. No. 3,702,886), zeolite ZSM-11 (U.S. Pat. No. 3,709,979) , zeolite 
ZSM-12 (U.S. Pat. No. 3,832,449) and zeolite ZSM-20 (U.S. Pat. No. 
3,972,983), ZSM-23 (U.S. Pat. No. 4,076,842), ZSM-35 (U.S. Pat. No. 
4,016,245), ZSM-38 (U.S. Pat. No. 4,046,859), merely to name a few. The 
preparation of ZSM-5 utilizing a tetraureacobalt (II) complex is described 
in U.S. Pat. No. 4,100,262. 
Zeolite ZSM-39 and its preparation are taught by copending U.S. patent 
application Ser. No. 084,684 filed Oct. 15, 1979, now abandoned. In this 
preparation of ZSM-39, the template employed for the synthesis is 
generally a tetraethylammonium cation or n-propylammine. It has a 
distinctive X-ray diffraction pattern which identifies it from other known 
zeolites. 
SUMMARY OF THE INVENTION 
The present invention relates to an improved method of preparing synthetic 
crystalline zeolite designated as "zeolite ZSM-39" or simply "ZSM-39". The 
porous zeolite composition ZSM-39 can be identified, in terms of moles of 
anhydrous oxides per 100 moles of silica as follows: (0-2.5)M.sub.2 
/nO:(0-2.5)Al.sub.2 O.sub.3 :100 SiO.sub.2 wherein M is at least one 
cation having a valence n, and wherein the zeolite is characterized by the 
distinctive X-ray diffraction pattern as shown in Table I herein. 
In the as synthesized form, the zeolite has a formula, after dehydration, 
in terms of mole ratios of oxides per 100 moles of silica as follows: 
(0-2.5)R.sub.2 O: (0-2.5)M.sub.2 /nO:(0-2.5)Al.sub.2 O.sub.3 :100SiO.sub.2 
wherein R is an aryl ammonium compound and M is an alkali or alkaline 
earth metal cation, especially sodium. 
ZSM-39 possesses a definite distinguishing crystalline structure whose 
X-ray diffraction pattern has the following characteristic lines: 
TABLE I 
______________________________________ 
Interplanar Spacing, d(A) 
Relative Intensity 
______________________________________ 
11.2 .+-. 0.2 W 
6.8 .+-. 0.15 M 
5.8 .+-. 0.1 VS 
5.6 .+-. 0.1 VS 
4.8 .+-. 0.1 M 
4.4 .+-. 0.1 M 
3.95 .+-. 0.08 M-S 
3.7 .+-. 0.08 VS 
3.4 .+-. 0.07 M-S 
3.3 .+-. 0.07 VS 
3.2 .+-. 0.07 W 
3.1 .+-. 0.06 W 
3.0 .+-. 0.06 W 
2.3 .+-. 0.05 W 
______________________________________ 
These values were determined by standard technique. The radiation was the 
K-alpha doublet of copper, and a scintillation counter spectrometer with a 
strip chart pen recorder was used. The peak heights, I, and the positions 
as a function of 2 times theta, where theta is the Bragg angle, were read 
from the spectrometer chart. From these, the relative intensities, 100 
I/Io, where Io is the intensity of the strongest line or peak, and d 
(obs.) the interplanar spacing in A, corresponding to the recorded lines, 
were calculated. In Table I the relative intensities are given in terms of 
the symbols W=weak, M=medium, M-S=medium-strong, S=strong and VS=very 
strong. 
It should be understood that this X-ray diffraction pattern is 
characteristic of all the species of ZSM-39 zeolites. Ion exchange of the 
sodium ion with cations reveals substantially the same pattern with some 
minor shifts in interplanar spacing and variation in relative intensity. 
Other minor variations can occur depending on the silicon to aluminum mole 
ratio of the particular sample, as well as if it has been subjected to 
thermal treatment. 
Zeolite ZSM-39 in accord with the invention is prepared from a solution 
containing sources of an alkali metal oxide, preferably sodium oxide, 
pyrrolidine, tetraureacobalt (II) complex, an oxide of silicon, water, and 
with or without an oxide of aluminum. The reaction mixture has the 
following composition expressed in terms of mole ratios of oxides, falling 
within the following ranges: 
______________________________________ 
BROAD PREFERRED 
______________________________________ 
SiO.sub.2 /Al.sub.2 O.sub.3 
5-infinity 40-2000 
H.sub.2 O/SiO.sub.2 
1-3000 10-500 
OH--/SiO.sub.2 
0.001-10 0.005-5 
M/SiO.sub.2 0.01-3 0.01-1 
R/SiO.sub.2 0.01-5 0.01-3 
R'/SiO.sub.2 0.005-2 0.01-1 
______________________________________ 
wherein R is pyrrolidine, R' is tetraureacobalt (II) complex, such as for 
example tetraureacobalt (II) nitrate and M is an alkali metal cation, and 
maintaining the mixture until crystals of the zeolite are formed. 
Thereafter, the crystals are separated from the liquid and recovered. 
Typical reaction conditions consist of heating the foregoing reaction 
mixture to a temperature of from about 25.degree. C. to about 250.degree. 
C. for a period of time of from about 2 days to about 25 days. A more 
preferred temperature range is from about 100.degree. C. to about 
175.degree. C. with the amount of time at a temperature in such range 
being from about 5 days to about 10 days. 
The digestion of the gel particles is carried out until crystals form. The 
solid product is separated from the reaction medium, as by cooling the 
whole to room temperature, filtering and water washing. 
The crystalline product is dried, e.g. at a temperature of about 
120.degree. C. for about 4 hours. Of course, milder conditions may be 
employed if desired, e.g. room temperature under vacuum. 
The composition for the synthesis of synthetic ZSM-39 can be prepared 
utilizing materials which can supply the appropriate oxide. Such materials 
include aluminates, alumina, silicates, silica, hydrosol, silica gel, 
silicic acid, and hydroxides. It will be understood that each oxide 
component utilized in the reaction mixture for preparing ZSM-39 can be 
supplied by one or more essential reactants and they can be mixed together 
in any order. For example, any oxide can be supplied by an aqueous 
solution, sodium hydroxide or by an aqueous solution of a suitable 
silicate; the cation can be supplied by a compound of that cation, such 
as, for example, a salt. The tetraureacobalt (II) complex can be supplied 
by an appropriate compound such as the nitrate, nitrite, sulfate, 
hydroxide, halide or the like, thereof. Crystallization time of the new 
crystal form ZSM-39 will vary with the nature of the reaction mixture 
employed. 
It is postulated that the synthesis of ZSM-39 in accordance with this 
invention may result in the formulation of a new composition for ZSM-39 
with cobalt in the lattice structure. At this point in time, however, it 
would be very difficult to detect the presence of cobalt in the zeolite 
structure. 
DESCRIPTION OF SPECIFIC EMBODIMENTS 
The presently prepared new crystal form ZSM-39 can be utilized as catalytic 
material for a number of hydrocarbon conversion reactions substantially as 
synthesized or the original cations of the as synthesized ZSM-39 can be 
replaced in accordance with techniques well known in the art, at least in 
part, by ion exchange with other cations. When used as synthesized, the 
zeolite is preferably heated to a temperature within the range of from 
65.degree. F. to about 815.degree. F. for a period of time ranging from 
about 1 hour to about 48 hours or more. Preferred replacing cations 
include metal ions, ammonium ions, hydrogen ions and mixtures thereof. 
Particularly preferred cations are those which render the zeolite 
catalytically active especially for hydrocarbon conversion. These include 
hydrogen, rare earth metals, aluminum, metals of Groups IIA, IIIA, IVA, 
VIA, VIII, IB, IIB, IIIB, and IVB. Of the replacing metallic cations, 
particular preference is given to cations of metals such as rare earth, 
Mn, Ca, Mg, Zn, Cd, Pd, Ni, Cu, Ti, Al, Sn, Fe and Co. 
A typical ion exchange technique would be to contact the synthetic ZSM-39 
zeolite with a salt of the desired replacing cation or cations. Although a 
wide variety of salts can be employed, particular preference is given to 
chlorides, nitrates and sulfates. 
Representative ion exchange techniques are disclosed in a wide variety of 
patents including U.S. Pat. Nos. 3,140,249; 3,140,251; and 3,140,253. 
Following contact with the salt solution of the desired replacing cation, 
the zeolite is then preferably washed with water and dried at a 
temperature ranging from 65.degree. F. to about 315.degree. F. and 
thereafter may be calcined in air or other inert gas at temperatures 
ranging from about 480.degree. F. to 650.degree. F. for periods of time 
ranging from 1 to 48 hours or more to produce a catalytically-active 
thermal decomposition product thereof. 
Regardless of the cation replacing the ctions in the synthesized form of 
the ZSM-39 the spatial arrangement of the aluminum, silicon and oxygen 
atoms which generally form the basic crystal lattices of the new crystal 
form ZSM-39 remains essentially unchanged by the described replacement of 
the original cations as determined by taking an X-ray powder diffraction 
pattern of the ion-exchanged material. 
Synthetic ZSM-39 zeolites prepared in accordance hereto can be used either 
in the organic cation or alkali metal form and hydrogen form or another 
univalent of multivalent cationic form. They can also be used in intimate 
combination with a hydrogenating component such as tungsten, vanadium, 
molybdenum, rhenium, nickel, cobalt, chromium, manganese, or a noble metal 
such as platinum or palladium where a hydrogenation-dehydrogenation 
function is to be performed. Such components can be exchanged into the 
composition, impregnated therein or physically intimately admixed 
therewith. Such components can be impregnated in or on to ZSM-39 such as, 
for example, by, in the case of platinum, treating the zeolite with a 
platinum metal-containing ion. thus, suitable platinum compounds for this 
purpose include chloroplatinic acid, platinous chloride and various 
compounds containing the platinum amine complex. Combinations of metals 
and methods for their introduction can also be used. 
ZSM-39 prepared by the instant invention, being composed of very uniformly 
sized crystals, may be formed in a wide variety of particle sizes. 
Generally speaking, the particles can be in the form of a powder, a 
granule, or a molded product, such as extrudate having 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, the aluminosilicate can be extruded before drying or dried 
partially and then extruded. 
In the case of many catalysts, it is desired to incorporate the ZSM-39 
hereby prepared with another material 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 s well as inorganic materials such as clays, silica 
and/or metal oxides. The latter may be either naturally occurring or in 
the form of gelatinous precipitates, sols or gels including mixtures of 
silica and metal oxides. Use of a material in conjunction with the ZSM-39 
i.e. combined therewith, which is active, tends to improve the conversion 
and/or selectivity of the catalyst in certain organic conversion 
processes. Inactive materials suitably serve as diluents to control the 
amount of conversion in a given process so that products can be obtained 
economically and orderly without employing other means for controlling the 
rate of reaction. Frequently, zeolite materials have been incorporated 
into naturally occurring clays, e.g., bentonite and kaolin. These 
materials, i.e., clays, oxides, etc., function, in part, as binders for 
the catalyst. It is desirable to provide a catalyst having good crush 
strength, because in a petroleum refinery the catalyst is often subjected 
to rough handling, which tends to break the catalyst down into powder-like 
materials which cause problems in processing. 
Naturally occurring clays which can be composited with the hereby 
synthesized ZSM-39 catalyst include the montmorillonite and kaolin family, 
which families include the sub-bentonites, and the kaolins commonly known 
as Dixie, McNammee, Georgia and Florida clays or others in which the main 
mineral constituent is halloysite, kaolinite, dickite, nacrite, or 
anauxite. Such clays can be used in the raw state or initially subjected 
to calcination, acid treatment or chemical modification. 
In addition to the foregoing materials, the ZSM-39 catalyst hereby 
synthesized can be composited with a porous matrix material such as 
silica-alumina, silica-magnesia, silica-zirconia, silica-thoria, 
silica-beryllia, silica-titania as well as ternary compositions such as 
silica-alumina-thoria, silica-alumina-zirconia, silica-alumina-magnesia 
and silica-magnesia-zirconia. The matrix can be in the form of a cogel. A 
mixture of these components could also be used. The relative proportions 
of finely divided crystalline aluminosilicate ZSM-39 and inorganic oxide 
gel matrix vary widely with the crystalline aluminosilicate content 
ranging from about 1 to about 90 percent by weight and more usually in the 
range of about 2 to about 50 percent by weight of the composite.

In order to more fully illustrate the nature of the invention and the 
manner of practicing same, the following examples are presented. These 
examples are not to be considered limiting, as would be realized by one of 
ordinary skill in the art. 
EXAMPLE 1 
A solution was prepared containing 10.0 grams of tetraureacobalt (II) 
nitrate, 160 grams of Mc/B Colloidal Silica (30% SiO.sub.2), manufactured 
by Matheson, Coleman and Bell, 1.7 grams of NaAl.sub.2 O.sub.3 (40% 
Al.sub.2 O.sub.3, 33% Na.sub.2 O, 27% H.sub.2 O), 17.1 grams of 
pyrrolidine and 52 grams of water. All the above ingredients, except for 
the silica, were combined and heated to about 50.degree. C. with stirring, 
then mixed with the silica. The resulting gel was placed in a stirred 
autoclave and heated for over four hours at 160.degree. C. This 
temperature was maintained for nine days at 90 RPM. The temperature was 
the elevated to 210.degree. C. for 5 days at 90 RPM. 
The product of this example, weighting 53.3 grams, was filtered, washed and 
dried. It was then calcined in helium at 540.degree. F., overnight. The 
product was then air calcined at 540.degree. F. An exchange with 4 M 
NH.sub.4 Cl was attempted twice at reflux conditions. The synthesis 
product was identified as ZSM-39 whose elemental analysis was: 
Al.sub.2 O.sub.3 =0.88% 
SiO.sub.2 =91.35% 
Na=0.02% 
SiO.sub.2 /Al.sub.2 O.sub.3 =176.5 
The X-ray diffraction pattern in Table I was derived from the zeolite 
produced in this example. 
EXAMPLE 2 
The product of Example 1 was contacted with n-hexane at 60 mm at 20.degree. 
C. The sorption of n-hexane at these conditions was 0.4%. 
EXAMPLE 3 
The same gel formulation of Example 1, except that 7.0 grams of NaCl was 
added, was used in this example. This formulation was run at 160.degree. 
C. for 3 days in a stirred autoclave at 90 RPM. The resulting product was 
identified by its X-ray diffraction pattern as being ZSM-39, and is shown 
in Table I herein. 
EXAMPLE 4 
The product of Example 3 was contacted with n-hexane at 60 mm and 
20.degree. C. The sorption of n-hexane at these conditions was 0.8%. 
EXAMPLE 5 
The same formulation as Example 3 was run at 160.degree. C. for 7 days at 
90 RPM. The resultant product was ZSM-39. 
EXAMPLE 6 
The product of Example 3 was calcined at 1100.degree. `C. for about 1 hour. 
The zeolite lost only about 35% of its crystallinity after this 
calcination, thus demonstrating its extremely high thermal stability.