CA1192891A - Synthetic crystalline metal silicate and borosilicate compositions and preparation thereof - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

Crystalline metal silicates and metal borosilicate compositions exhibit useful catalytic properties when the reaction mixture from which they are prepared includes a metal whose oxide precipitates at a pH above 7 and an amount of urea or other compound which upon hydrolysis releases ammonia. The precipitated metal hydroxide is incorporated into the crystalline composition as it forms. These compositions exhibit the X-ray pattern of a ZSM-5 zeolite and have an aluminum content of less than 100 wppm and a composition expressed in terms of its oxides as follows:

Description

3~68 1~

- S~NTT-IETIC CRYST~LLINE METAL SILICATE AND BOROSILIC~TE
CO~IPOSITIO~IS A`~D PR~PARATIO~' THERF,OF

The present invention relates to new crystalline r metal silicate and metal borosilicate composition~. ~his invention particularly relates to a method of preparing these compositions and to certain catalytic~conversion processes employing these compositions.
Zeolitic materials, both natural and synthetic, 10 are known to have catalytlc capability for various types of reactions, especially hydrocar~on conversions. The well-Xnown crystalline aluminosilicate æeolites are commonly referred to as "molecular sieves" and are characterized by their highly ordered crystalline structure and uniformly 15 ~;mensioned pores, and are distinguishable from each other ; on the basis of composition, crystal structure, adsorption propertles and the like. The term "molecular sieves" is derived from the ability of the zeolite materials to selectively adsorb molecules on the basis of their size 20 and form.
The processes for producing such crystalline synthetic zeolites are well known in the art. A family of crystalline aluminosilicate ~eolites, designated ZS~-5, is disclosed în U. S. Patent No. 3,702,886, The family of r.~-5 compositions has a characteristic X-ray diffraction pattern and, can also he identified, in terms of mole ra~ios of oxides, as follows:

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o~g+o.2M2/no w2o3:5-looyo2 zH2o wherein M is a cation, n is the valence of said cation, W is selected from the group consisting of aluminum and gallium, Y is selected from the group consisting of silicon and gerrnan-ium, and z is from 0 to 40. In a preferred synthesized form, the zeolite has a formula, in terms of mole ratios of oxides, as follows:
9+0 2M2/nO A12O3 5 lOOSi2 ZH2 and M is selected from the group consisting of a mixture of alkali metal cations, especlally sodium, and tetraalkyl-ammonium cations, the alkyl groups of which preferably contain 2-5 carbon atoms.
UOS. Patent No. 3,9~1,871 relates to novel crystalline metal organosilica-tes which are essentially free of Group IIIA metals, i.e., aluminum and/or gallium. It is noted therein that the amount of alumina present in the known zeolites appears directly related to the acidity characteris-tics of the resultant product and that a low alumina content has been recognized as being advantageous in attaining a low degree of acidity which in many catalytic reacti.ons is translated into low coke making properties and low aging rates. A
typical procedure for making the organosilicates is to react a mixture containing a tetraalkylammonium compound, sodium hydro~ide, an oxide of a metal other -than a metal of Group IIIA, an oxide of silicon, and water until crystals of said metal organosilicates are formed. It is also no-ted in the patent that the family of crystalline metal organo-r '~

~ sillcates have a dcfinite X-ray diffraction pattern which is similar to that for the ZSM-5 zeolites. Minor ~mounts of alumina are contemplated in the patent and are attributable primarily to the presence of aluminum impurities in the reactants and/or equipment employed.
U. S. Patent No. 3,844,835 discloses crystalline silica compositions. The crystalline silica materials may also contain a metal promoter which may be selected from ~roup IIIA, Group VB or Group VIB elements.
U~ S. Patent No~ 4,088,60S is directed to the synthe~sis of a zeolite, such as ZSM-5, which contains an outer shell free from aluminum. The patent states at column 10, line 20 et seqO, that to produce the outer aluminum-free shell it is also essential that the reactive , ,_ , .
'~ aluminum be removed from the reaction mi~.ture. It is there-fore necessary, as noted therein, to process the zeolite and to replace the crystalization medium with an aluminum-free mixture to obtain crystalization of sio2 on the surface of the zeolite which can be accomplished by a total replace~
20 ment of the reaction mixture or by compleY~ing from the original reaction mixture any remaining aluminum ion with reager.ts such as gluconic acid or ethylenediaminetetraacetic acid (EDTA).
Crystalline borosilicate compositiOnS are 25 disclosed in German OffenlegungschriEt 27 46 790~ This application relates speci~ically to borosilicates which are prepared using the usual procedures for making the a'umino-silicate zeoli.es. I~ is noted therein that in instances where a deliberate effort is made to el minate aluminum

3 from the borosilicate c-ystal struc~ure hecause of its adverse influence on particular conversion proce.cses~ 'he molar ratios of SiO2~A12O~ can easily exceed 200Q-3000 ar.d -- tilat this r~tio is generally only limited by the availabilit~
o aluminum-free raw materials.
German Offenlegungschrift 28 48 849 relates to crvstalline aluminosiliCateS of the ZSM-5 zeolite series.
Tnese particular zeolites have a silica to alumina mole ratio greater than 20 and are prepared from a reaction mixture containing a source of silica, alumina, a quaternary alkyl ammonium compound and a metal compound including such Group VIII metals as ruthenium, palladium and platinum.
1~ U.S. Patent No. 4,113,658 relates to the precipitation of metal compounds on support materials and discloses the decomposition of urea to form ammonia which in turn causes the formation of precipitates of metal hydro~ides which deposit on solid support materials. ~o suggestion is made of applying this techni~ue to the preparation of crystalline zeolites.
While the art has provided zeolitic catalysts having a wide variety of catalytic and adsorptive properties~ the need still exists for crystalline materials having different and/or enhanced catalytic properties. For example, an important use for a crystalline material is in conversion processes of oxygenated compounds such as the conversion of dimethyl ether and methanol to aliphatic compounds as well as the conversion of synthesis gas or hydrocarbons, such as ethylene, at a significant level of conversion and ~' selectivity.

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- The present invention relates to preparing cry-stalllne ~etal silicate compositions hy ~ a) preparing a first mixture comprising a tetraalkyl ammonium salt, alkali metal hydroxide, silica and water, (b) preparing a second mixture comprising water, a soluble source of a metal whose hydroxide precipitates at a pH
above 7 and an amount of urea or a compound which upon hydrolysis releases ammonia, whe:reby the hydroxide of said metal forms a precipitate.
(c) admlxing an amount of said first mixture and an amount of said second mixture effective to pxovide a reaction mixture having an aluminum content of less than about 100 wppm and having a composition in terms of mole ratios of oxides, falllng within the following range:

OH /SiO2 0.05-3 Q /(Q + A 3 0.01-1 .
H2o/oH 10 -800 SiO2/M2~mO 10 -10, 000 wherein Q+ is tetralkyl a~monium ion, A+ is alkali metal ion, ~ is said metal and m is the valence of said 25 metal, (d) maintaining the reaction mixture at a temperature of about 50 to about 250C until crystals of metal silicate are formed and ~, 1 (e) separating and recovering said crystals.
Corresponding borosilicates are prepare~d by incorp-oratiny a soluble boron compound in the reaction mixture.
The crystalline metal silicates and metal boro-~ silicates prepared by the above method have an X-ray diffraction pattern substantially that of a ZSM-5 zeolite and have a composition in terms of mole ratios of oxides as set forth as follows in Formula A:
(0.2~80)R2: (0.1-20)M20: (0-40) ~23 100 SiO2: (0-200)H20 n m wnerein R is tetraalkyl ammonium cation, ammonium cation, hydrogen cation, alkali metal cation, metal cation or mixtures thereof, n is the valence of R, M is a metal whose hydroxide precipitates at a pH above 7 and m is the valence of said metal, 15 said composition having an aluminum content of less than about 100 wppm.
The catalyst properties of these metal silicates are evidenced in a conversion process which comprises:
contacting an oxygenated compound, such as methanol, dimethyl 20 ether and mixtures thereof with the crystalline metal silicate prepared by the above described method.
These metal silicates are also useful in a process for the polymerization of e~h,rlene which ~omprises contacting ethyl-ene, under conversion conditions, with the crystalline silicate 25 prepared by the above described method.
~ nother conversion process utilizing the metal silicates of this invention involves a method for the conversion of synthesis gas, comprising hydrogen and carbon monoxide, to hydrocarbons and/or oxygenated compounds, said method com-30 prising contacting said synthetic gas, under conversion con-ditions, with the crystalline silicate composition prepared bv the above described method.

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new class of crvstalline metal silicate and metal borosilicate compositions Aas now been discovered. These crystalline compositions are prepared by a process which requires that the amount of aluminum in the reaction mixture 5 be carefully controlled and further that the reaction mixture contain (a) a metal whose hydroxide precipitates at a pH above 7 and ~b) urea or a compound which upon hydrolysis releases ammonia and that the release of ammonia causes the hydroxide of the metal to form in the reaction mixture. The formation lO of the metal h~droxide precipitate is described herein as "urea precipitation." Inan optional embodiment, a source of boron ls included in the reaction mixture so that the crystalline compositions may additionally contain ~23 The silicates of this invention are prepared by 15 heating a reaction mixture comprising tetraalkyl ammonium ion, e.g. tetrapropyl ammonium bromide or hydroxide, alkali metal, i.e. sodium hydroxide, a solubles salt of a metal whose hydroxide is insoluble at a pH above 7, an oxide of silicon, water, and an amount of urea or a compound which 20 upon hydrolysis releases ammonia, said amount being effective to precipitate the hydroxide of the metal, usually having the composition in terms of mole ratios falling within the followiny ranges:
Broad Preferred O~ /SiO2 0.05 ~ 3 0.20 - 0.90 Q /(Q ~-A ) 0.01 - l 0.03 - 0.9 H20/OH lO - 800 20 - 500 3O Si02/M2o lO - lO,000 30 - 4000 r[l ~L

'- where Q is tetraalkyl ammonium ion, A is alkall metal lon, ~1 is said metal and rn lS the valence of said metal and maintaining the mixture at elevated temperature for a time sufficient to form crystals of the product. Typical reaction conditions consist of heating the reaction mixture at elevated temperature, e.g. 50 to about 250C., and even higher, for a period of time of from about 6 hours to as much as 60 days. The preferred temperature is from about 100 to 190C. for time periods of from about 1 to about 16 lO days. The reaction mixture can be heated at elevated pres-sure as in an autoclave, or at normal pressure, e.g. as by refluxing. The preferred method of heating the reaction mixture is at reflu~ temperature.
As is common practice in the production of silicate 15 compositions, when reflux heating of the reaction mixture is employed large amounts of sodium chloride along with some sulfuric acid, are added to the reaction mixture to ensure crystallization of the product. Thus, in reflux preparation, the ratios of OH /SiO2 and like ratios tend to result in 20 values different from the ratios of the autoclave processing.
Of course, in the preparation of the reaction mixture for the heating step, the reaction mixture is maintained subs-tantially free of aluminum, i.e. contains less than 100 wppm.
Optionally, a soluble source of boron may be added to the reaction mixture to permit the preparation of the borosilicate species of the metal silicates of this invention. Where such addition is made the reaction mixture composltion, in terms of mole ratios, will include the 3 following mole ratio falling ~7ithin the following ranges, in addition to those listed above:
Broad Preferred Si~2/B2O3 2-1000 12-500 3~

- Ihe diqes~lon of the gel particles is carried out until crvstals form. The solid product is separate~
from the reaction medium, as by cooling the whole to room temperature, filtering, and water washing.
The foregoing product is dried, e.g., at 110C.
for from about 8 to 25 hours or longer. Of course, milder conditions may be employed if desired, e.g., room temperature under vacuum.
The crystalline silicate compositions prepared 10 in accordance with the above procedure are suhs-tan-tially free of aluminum, i.e., containing less than about 100 wppm ~weight parts per million) and can be identified in terms of the mole ratios of oxides as set forth in Formula A above.
In an optional embodiment, the composition contains B2O3.
15 In preferred embodiments the metal whose hydroxide forms the precipitate is iron, cobalt, bismuth, chromium, molybdenum, nickel, tin, platinum or mixtures thereof.
Members of this family of crystalline metal silicate and metal borosilicate compositions possess a definite 20 crystalline structure which has the x-ray diffraction pattern of a ZSM-5 zeolite.
Although the X-ray diffraction pattern does not distinguish these silicates from a ZSM-5 type zeolite there are significant points of distinction. The compositions 25 are distinct in that the present compositions, in contra-diction to the ZSM-5 zec' tes, are not aluminosilicates and in fact, contain less than 100 ppm of aluminum. The catalytic properties o ZSM-5 type zeolites and the com-positions of this invention also distinguish them. In 30 converting dimethylether, both materials exhibit extremely high yields (above 80%) while the compositions herein prcduce significantly more aliphatic hydrocarbonsand les_ 1 aromatics than does a ZSM-5 tvpe zeollte.
~n important feature of the inventlon is a process for activating the novel crystalline composition of the invention for enhanced use in various conversion processes.
5 In general, the activation procedure comprises: .
(a) Heat treating the dried silicate composition at e.g., about 200 to about 900C., preferably about 400 to about 600C. for about 1 to about 60 hours, preferably about 10 to about 20 hours in a molecular oxygen containing atmosphere.
In a preferred embodiment, the activation procedure comprises:
(1) Heat treating the dried silicate composition at e.g., about 200 to about 900C., preferably about 400 to about 600C. for about 1 to about 60 hours, preferably about 10 to about 20 hours;
(2) Ion exchanging the heat treated silicate composition with a material which upon further heat treating decomposes to provide a composition having a hydrogen cation;
(3) Washing and drying the eYchanged silicate composition;

(4) Heat treating the dried silicate using the procedure of step (1);
It will be appreciated by those skilled in the art that steps (1) - (4), inclusive of the preferred embodiment~, and step (a), above, are well-known and represent methods commonly used to activate zeolite type catalysts.
The composition of the invention may be suitably employed 3 in the form obtained after step 4 or after step a. ~eat treating may be done in any atmosphere as is };nown i~. ~he art and is preferably done in a:ir.

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l aromatics thar, does a ZSM-5 type zeollte.
~n important ~eature of the invention is a process for actlvating the novel cr~stalline composition of the inven-tion for enhanced use in various conversion processes.
'5 In general, the activation procedure comprises: .
(a) Heat treating the dried silicate compositior at e.g., about 200 to about 900C., preferably about 400 to about 600C. for about l to about 60 hours, preferably about 10 to about 20 hours in a molecular oxygen containing atmosphere.
In a preferred embodiment,-the activation procedure comprises:
(l) Heat treating the dried silicate composition at e.g., about 200 to about gO~C., preferably about 400 to about 600C. for about l to about 60 hours, preferably about 10 to about 20 hours;
(2) Ion exchanging the heat treated silicate composition with a material which ~pon further heat treating decomposes to provide a composition 2C having a hydrogen cation;
(3) Washing and drying the exchanged silicate composition, (4) ~eat treating the dried silicate using the procedure of step tl);
It will be appreciated by those skilled in the ar' that steps (1) - (4), inclusive of the preferred embodiment, and step (a), above, are well-known and represent methods commonly used to activate zeolite type catalysts.
The composition of the in~ention may be suitably employed 3 in the form obtained after step 4 or after step a. ~eat treating may be done in any atmosphere as is known i~ _he art and is preferably done in air.

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1 r~nere desired, the activation ~rocedure ~ay, optionally, include the Redox Ireatment disclosed in selgian patent no. ~86,090. This treatment includes a heat treatment conducted with a reducing acrent and i5 practiced, following step (a) or steP (4) of -the ahove activation procedures, as follows:
(b) or (5) Treating the heated silicate com~osition with a reduciny agent for about 1 to about 80 hours, preferably about ~ to about 40 hours,at about 200 - to about 900C, preferably about 400 to about 600C., an~
(c) or (6~ Heat treating the reduced silicate using the procedure of step (a) or ~1~, respectively.
Any r~ducing a~ent may be used or a compound which under the treatment conditions forms a reducing agent, 15 such as dimethylether. Dimethylether and hydrogen are p-e~erred because of their demonstrated effectiveness.
The activation procedure disclosed herein which does not include the "RedoY~ Treatment" provides a catalytically active composition which eY.hibits useful levels of conversion 20 and selectivity in the reactions catalyzed by the compos-tions of this invention and is the preferred activation procedure.
Although the inclusion of the "Redox Treatment" is not necessary to provide a useful catalyst, subjecting the com-positions of this invention to Redox Treatment following 25 ox~idative activation may provide some alteration in the selectivity, usually minor in nature. Therefore, where economically justified or where slight alteration in selectivity is required, Redox Treatment may be utilized.

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As noted here.inabove, and as ~.r,own i~ the a-,, t-~ ?roceaure ~or prepa~ing ~eolites, e.g., alu~lnosilicates, is well-known. It is an essential feature of the present invention however, that the crystalline silicate composition

5 be prepared using a reaction mixture containing, based on weight percent silica, less than about 100 wppm aluminum ions, preferably less than about 50 wppm and a hydrolyzable source of ammonia, e.g., urea. Aside from other diEferences wikh prior art crystalline silicate compositions, the 10 silicate and borosilicate compositions formed herein are substantially free of aluminum with the molar ratio of SiO2/A1203 be.ing greater than about 8,000,and even 30,000.
It is not known why the crystalline compositions of this invention provide such unexpected properties as 15 improved selectivity with DME and low hydrocarbon yield and high D~ yield with methanol for the silicates and high C5 + yield with ethylene and synthesis gas for the borosilicates. It is possible that the urea precipitation provides the metal hydroxide in a finely divided form not 20 achieved in other metal containing reaction mixtures and that the metal is located in the crystalline structure in a manner not achieved ln prior art silicates prepared by other methods so that the catalytic properties of the compositions of this invention are different from those of 25 other metal silicates and borosilicates.
The crystalline metal silicates and borosilicates of the present invention are prepared by urea precipitation which causes a metal hydroxide to precipitate in finely ~C divided form. When urea decomposes it releases ammonia 3~

1 wi~lch ill wate^ forms ammonium hvdro~ide. This causes th-p~l of th~ a~ueous mixture to uniformly change. ~ith a s rong base such as caustic there is a highly localized and rapid increase in pH which with diffusion, convection and/cr mlxing graduall~ dissipates to a moderate pI-I increase. ~rea does not function in this fashion, with urea the pH increase lS gradual and uniform throughout the mixture.
Providing the metal hydroxide precipitate in finely divided form by the procedure identified herein as urea precipitate is critical to the process of this invention.
As discussed above, strong bases do not provide the desired precipitation. Urea and other compounds which upon h~droIysis release ammonia are the materials which precipitate the metal hydroxides in the desired fashion in the invention.
Thus, the useful urea precipitation agents include such compounds as urea, acetamide, hydrolyæable derivatives thereof and the like.
The metal from which the compositions of this invention is any metal which is sub]ect to urea precipitation, i.e., any metal whose salt is soluble and whose hydroxide will precipitate in a pH above 7. ~ost metals fall within this definition yet some, such as sodium and potassium, clearly do not. Useful metalsherein include bismuth, cobalt, chromium, iron, mo-1-ybdenum, nickel, 25 ruthenium,tin,tungsten, palladium and platinum. One skilled in the art can, by routine procedures and without an undue amount of experimentation,screen a number of possible candidates by dissolving soluble metal salts in water and adding a source of hydroxide ions until the pH is above 7.
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1 In preparlng the crystalline compositions of the invention it is important that substantially aluminum-free raw materials be employed. The substantially aluminum free silica source can be any of those commonly considered for 5 use in synthesizing zeolites such as powdered sol_d silica, silicic acid, colloidal silica or dissolved silica. A
preferred silica source is Cab O-Sil, sold by Cabot Co.
The substantially aluminum free alkali metal hydroxide is sodium hydroxide, potassium hydroxide or 10 mixtures thereof. Sodium hydroxide is preferred.
The substantially aluminum-free tetraalkyl ammonium compound may be tetrapropyl ammonium hydroxide, chlorid~, bromide and the like.
Similarly, suitable metal salts which are 15 substantially aluminum free and are soluble in the reaction mixture may be employed. Among the various metal salts which may be employed, those which are preferred include:
Group IVA - tin Group VA - bismuth; GrGup VIB - chromium, molybdenum, tungsten; Group VIII - iron, cobalt, nickel, 20 ruthenium, palladium, platinum. The chloride salt is often very useful.
In the optional embodiments, the substantially aluminum-free source of boron may be boron oxide, boric acid, sodium borate and the like.
Where a chelating agent forms part of the reaction mixture, ethylenediaminetetraacetic acid (EDTA), nitrilio-triacetic acid (NTA), 8-hydroxyquinoline-5-sulfonic acid (8HQS) and the like may be employedO
The specific crystalline Compositionsdescribed~
~ when evaluated for catalytic properties without having been calcined, are inactive, possibly because the intracrystal-ine free space is occupied by organic cations from th~

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rormlng solution. The~ ma~, nowever, be activated by heat treatment using known technlques such as heatlng in an inert atmosphere or air at 200 - 900C., for 1 to 60 hours. This may be followed by ion exchange with 5 ammonium salts and further heat treatment at 200-- 900C.
if desired.
The crystalline compositions can be used either in the alkali metal form, e.g., the sodium form, the ammonium form, the hydrogen form, or other univalent or lO multivalent cationic form. Preferably, either the ammonium or hydrogen form is employed. They can also be used in intimate combination with hydrogenating components such as tungsten, vanadium, copper, molybdenum, rhenium, iron, nickel, cobalt, chromium, manganese, or a nohle metal 15 such as platinum or palladium where a hydrogenation-dehydrogenation function is to be performed. Such compo-nent can be exchanged intG the composition, impregnated therein or physically intimately admixed therewith. Such component can be impregnated in or on to the present 20 catalyst such as, for example, in the case of platinum, by treating the crystalline composition with a platinum metal-containing ion. Thus, suitable platinum compounds include chloroplatinic acid, platinous chloride and various compounds containing the platinum amine complexes.
The catalyst, when employed either as an adsorbent or as a catalyst in one of the aforementioned processes, may be heat treated as described hereinabove.
~embers of the present family of crystalline compositions can have the original cations associated J therewith replacea by a wide variety of other cations according to techniques well-known in the art. Typical replacing cations wo~lld include hydrogen, ammonium and metal catlons including mixtures of the same. Of the replaciny metallic cations, particular preference is given tO cations of metals such as rare earth metals, manganese ~nd calcium as well as metals of Group II of the Periodic Table, e.g., zinc and Group VlII of the Periodic Table, e.g., nickel. These replacing cations are included within the definition of R in the formula employed herein to deseribe the compositions of this lnvention.
Typieal ion exehange techniques inelude eontaet-ing the members of the family o~ borosilieates with a salt solution of the desired replaeing eation or eations.
Although a wide variety of salts can be employed, partieu-lar preferenee is given to chlorides, nitrates and sulfates.
Representative ion exchange techniques are dis-closed 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 crystalline compositions 2~ are then preferably washed with water and dried at a temperature ranging from 65C. to about 315~C. and there-after heat treated as previously deseribed.
Resardless of the eations replaeing the sodium in the synthesized form of the catalyst, the spatial arrangement of the atoms whieh form the basic crystal lattiees in any given eomposition of this invention remain essentially unehanged by the deseribed replacement o' sodium or other alkali metal as determined by taking an X-ray powder diffraction pattern of the ion--exchanged 3 m~terial. For example, the X-ray diffraction pattern of several ion-exehanged eompositions reveal a pattern sub-stantially the same as that of ZS~q-5 zeolite.

1 Wnen actlvated, these compositions exhibit catalytic properties distinct from comparable silicate and boro-silicate compositions prepared from reaction mixtures which do not contain these same metal ions but which have been ion exchanged 5 to place these same metal ions into the composition. For reasons yet unknown, the compositions of this invention containing the same metal ions, viz~ a Group VIII metal ion, perform differently depending on whether the Group VIII metal ion was formed as part of the crystalline structure at its inception, i.e., by urea 10 precipitation from the reaction mixture or was placed in the structure subsequent to its formation by such means as ion exchanges.
The compositions prepared by the instant.inven-tion are formed in a wide variety of particular sizesD
15 Generally speaking, the particles can be in the ~orm of a powder, a granule, or a molded product, such 2S extrudate having a particle size sufficient to pass through a 2 mesh (qyler) screen a:nd be retained on a 100 mesh ~Tylerl screenO In cases where the catalyst is moldedl such as 20 by e~trusion, the composition can be extruded before drying or dried or pa:rtially dried and then extruded.
In the case of many catalysts, it is desired to incorporate the composition of this invention with another .
material resistant to the temperatures and other conditions 25 employed in organic conversion processes. Such materials include active and inactive materials and synthetic or naturally occurring crystalline compositions as well as inorganic materials such as clays, silica and/or metal oxides. The latter may be either naturally occurring or 3o 3~
.

in the form of gela-tinous precipitates or gels including mixtures of silica and metal oxides. Use of a ma-terial in conjunction with the present catalyst tends to improve the conversion and/or selectivlty of the catalyst in certain organic conversion processes. Inactlve materials suitably served as diluents to control the amount of conver-sion in a given process so that products can be obtained economically and in orderly manner without employing other means for controlling the rate of reaction. Normally, ~eolite materials have been incorporated into naturally occurring clays, e.g., bentonite and kaolin, to improve the crush strength of the catalyst under commercial opera-t-ing conditions. These materials, i.e., clays, oxides, etc. function as binders for the catalyst. It is desirable to provide a catalyst having good crush strength, because in a chemical process the catalyst is often subjected to handliny or use which tends to break the catalyst down into powder-like materials which cause problems in processing. These clay binders have been employed for the purpose of improving the crush strength of the catlyst.

In addition to the foregoing materials, the catalyst 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.
The following examples are presented as specific embodiments of the present invention and show some of the unique characteristics of the claimed crystalline composi-tions and are not to be considered as constituting a limitation on the present in~ention.

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1 E~lPL~ 1 This example demonstrates the preparation o~ several members of the ~ovel crystalline silicates of the present invention includirlg the following:
Iron silicate Catalyst I
Iron borosilicate Catalyst II
Cobalt silicate Catalyst IV
Cobalt borosilicate Catalyst V
Iron Silicate Catalyst I
A sodiurn silicate solution tA) containing less than 100 ppm aluminum (based on silica) was prepared by dissolving 80 g of high purity silica (Cab-O-Sil) in a boiling solution of 700 rnl water and 55 g of a 50-52% aqueous NaOH solution. A
second solution (B) containing 85 g NaC1, 33 g of tetrapropyl-15 ammonium bromide (TPA-~r), 23 g of concentrated sulfuric acid, and 300 ml of water was prepared. With both solutions at room temperature, solution B was slowly added -to the sodiurn silicate solution with stirring. The pH was then lowered from 9.04 to 8.50 by adding sulfuric acid.
A solution of 6.3 g FeC13-6H2O, 6.8 g urea, and 150 ml water was prepared at room temperature. No solids were present. The solution was heated to boiling and held at reflux for 20 hours. During heating, some of the urea decomposed evolving ammonia which caused iron to precipitate. The iron 25 containing slurry was then added to the stirred silicate mixture.
The entire mixture was placed in a 2000 ml polypropylene flask which was partially immersed in a hot oil bath at 120C. A
reflux condensor was attached to the flask. After 22 days, the flask was removed frorn the oil bath and cooled. The solid was 3O thoroughly washed with dionized water, collected on a filter and dried at 110C, yielding 92.2 g of final product. The dried material was submitte~ for X-ray analysis and had the same pattern as that published for ZSM-5 type aluminosilicate (zeolite).

, portlo~. (37.!, q) of the drled samle was c~lcinec'.
al 538'' IO' lG hours durina which it lost 12.9~ o~ i,s initia', weight. The calcined sample was mixed with a solution of 60 g ~ Cl in 300 ml of water and refluxed for 4 hours. After washing, the exchange was repeated for 16 hours. The material was filtered, washed, and dried. Before testing, the ammonium ion form was converted to the H-ion form b~7 heating in air at 538C.
Analysis lO ~efore Ion Exchange Fe = 1.29% Al = 74 ppm After Ion Exchange Fe = 1.52% A1 = 77 ppm Iron Borosilicate Catalysts II and III
Two crystalline iron borosili.cate catalysts were prepared by the same general procedure as for catalyst I except 15 rhat 8.9 g of boric acid was dissolved in solution B. Both catalysts exhibited the ZSM-5 type X-ray powder pattern. More information on each catalysts is presented below.
Catalyst II III
Growth time (days) 12 12 20 ~nalysis Before Ion Exchange Fe 1.2% 1.31%
B 0.38% 0.54%
Al 31 ppm 26 ppm 2~After Ion Exchanye Fe 1.4% 1.30%
B 0.28% 0.28%
Al 32 ppm 52 ppm Cobalt Silicate and Cobalt Borosilicate Catalysts IV and V
3C Two catal~stL, were prepared by the same me~nod as catalysts I, II, and III except that 8.5 g Co(NO3)2 6H2O, 12.5 g urea and 175 ml water were used in place of the iron-urea solution.
Further information on each catalyst is presented in the following table.

Catalyst IV V
Boric Acid Added No Yes Growth Time 13 13 Analysis Before Ion Exchange CO 1.63~ 1.65~
Al 19 ppm 25 ppm B - 0.44 After Ion Exchange Co 1.28% 0.83~
Al 30 ppm 35 ppm B - 0.33%
E~ample II
The iron silicate and iron borosilicate of Example I (Catalysts I, II and III) were evaluated for their catalytic properties and compared to catalysts designated A, B and C
which had been prepared by other methods~

Catalyst A was an iron silicate prepared without a chelating agent. The catalyst is similar to the catalyst disclosed in Example 6 of British patent 1,555,928 (German Offenlegungschrift 27 55 770).

Catalyst B was an iron silicate prepared with a chelating agent.

Catalyst C was an iron borosilicate prepared with a chelating agent.

Catalyst C was prepared as follows 80.0 g of fumed silica (Cab-O-Sil) was dissolved in 55.0 g of 50~ NaOH and 800 ml water. The solution was poured into a 2000 ml polypropylene flask which was placed in an oil bath at 120 & for 24 hours. A reflu~ condenser was attached to the flask.

A second solution was prepared containing 85.0 g NaCl, 33.0 g tetrapropylammonium bromide, 8.9 g boric acid, 19.0 g of concentrates sulfuric acid and 350 ml water.
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th both SOlUtlOlls at room temr~erature, the second solutio~ was slowl,- added to the SOdlUm sllicate solutlon ~ith m~ ng.
A third solution containing 8.5 g of 50gO NaO~ .0 a of 8 hydro~yquinoline-5-sulfonic acid (8XQS), 300 ml t/G_er and 6.0 g of FeC13.6H2O was prepared and added to the a~o~re.
The pH was 9.1 ~nd was adjusted to 8.5 with H2SO
Total weight of mixture = 1791.3 g.
The slurry was placed in a 2000 ml polypropylene 10 flask (reflux condenser attached) and partially i~mersed in an oil bath at 120C for 15 days, after which the flask was removed and cooled. The pH = 10.1 and the weight loss due to evaporation was 25 g. The solid was collected on a filter, washed and dried at 120C for 24 hours yielding 86~6 g of the Na form of the 15 iron borosilicate.
Ee = 1.2% B = .27%
Catalyst A was prepared as Catalyst C except no boron compound and no 8HQS were used.
Catalyst B was prepared as Catalyst C except no boron 20 compound was used.
The iron silicate catalysts were e~aluated as follows:
1. Dimethyl Ether (DME) Test Data A11 catalysts were tested in the H form with 1.5 g ; DME/g cat/hr at 6 psig.
25 Catalvst I A
Svn. Method Urea PPT. "Prior Art Type" 8 HQS
Temp. C 420 500 420 500 420 500 HC Yield(C)89 82 99 99 100 100 % HC Sel.(C) 3,~ Cl 5 4 3 5 7 7 C4 18 13 22 19 2~ 26 C5~ 50 55 40 14 54 2 Ar 5 9 15 38 7 2 3~L
, , ~ ne test data shows the urea ~re~ci~itatio~ methou yields a catalyst that is superior to catalysts prepareu b~
other methods for the production of aliphatic hydrocarbons.
The differences in hydrocarbon selectivity are ma,~imi~ed at 500C.
2. Ethylene Test Data Not available.
3. ~ethanol Tes-t Data The catalysts were tested in the H form with 1.5 g C2H4/g cat/hr and a N2 cofeed (molar CH3OH/N2~r~1) at 6 psig.
Catalyst I A B
Syn. Method Urea PPT. "Prior Art Type" 8 HQS
Temp. C 420 500 420 500 420 500 % HC Yield(C)15 2 98 99 92 98 % HC Sel.(C) Cl 0100 1 7 1 9 C~ 45 0 4 42 51 17 C5+ 43 88 16 39 23 Ar. 0 0 3 22 2 29 % Oxy Yield(C) 36 51 0 1 0 g~ Oxy Sel.(C) Test data shows the product selectivities obtained from ca-talyst I are quite different than those obtained with catal st A and B. Compared to A and B~ catalyst I gives high yields of DME and relatively low hydrocarbon yields.
4. Synthesis Gas Test Data Mot available.
The iron borosilicateswere evaluated as follows.
Comparative data for iron borosilicates prepared without chelate have not been included since the compositions are usually amorphorous.

9~

1 1 D~lE q~est Dat-Catalysts were tested in the H rorm with l.
DME/g cat/hr. at 6 psig.
Catal~st II III C
r; Sy~. Method Urea PPT. ~rea PPT.~ 8 HQS
TemP. C 420 500 420 500 420 500 % HC Yield(C)100 100 100 100 100 99 % HC Sel.(C) C:L 3 3 4 8 5 9 c3 23 ll 20 16 8 10 C5 ~ 53 38 48 36 54 38 Ar 2 5 3 12 9 12 15 Catalyts II andIII show the reproducibility of synthesis and testing. The hydrocarbon selectivities of these catalysts are very similar to those obtained with C.
2~ Ethylene Test Data Catalysts were tested in the H form with 1. 5 g C2H4/g 20 cat~hr. at 420C and 6 psig.
Catal~7st II III C
Syn. MethodUrea PPT.Urea PPT. 8 HQS
HC Yield(C) 0 7 9 ~ HC Sel.(C) Cl ~ 0 o C2~6 ~ 14 C3 ~ 2 o C4 ~ 34 86 C5f ~ 6 4 o 3 Ar - 0 0 A difference in catalytic properties is observed depending on the method of preparation. Ca~alyst III ga~7e predominantly C5+ hydrocarbons, whlle C gave mostly C4 hydro-carbons.

2~

.
3. Me-thanol Tes-t Da-ta Both catalysts were tested in the H form with 1O5 g CH30H/g cat/hr and a N2 cofeed (molar CH30H/N2rV1) at 6 psig.
Catalys-t III C
Method Urea PPT. 8 HQS
Temp~ C 420 500 420 500 % HC Yield(C) 86 94 94 88 % HC Sel.(C) C3 0 0 ~ 22 C5t 82 89 60 12 Ar 1 2 3 19 The hydrocarbon selectivities above show that catalyst III gave an exceptionally high C5+ fraction, particularly a-t 500C, relative to catalyst C.

4. Synthesis Gas Test Data Not available.

EXAMPLE III
The cobalt silicate and cobalt borosilicate of Example I (Catalysts IV and V) were evaluated for their catalytic properties in a series of tests. The results are as follows:
1. DME Test Data Both catalysts were tested in the H form with 1.5 g DME/g cat/hr at 6 psig.
30 Catalyst IV V
Composition SiO2/Co2O3 SiO2/B2O3/co2o3 Temp. C 420 420 500 ~ HC Yield(C) 4 6 12 ~;r ~r~91 , , ., .

~ 6~
~26-Catalyst IV ~7 C Sel.(C) Cl 5 44 30 C~ 0 4 5 C5+ 3 8 15 Ar 0 0 0 2. Ethylene Test Data 10 Both IV and V were inacti.ve at 420C.
3. Methanol Test Data Not available.
4. Synthesis Gas Test Data Not available.

Claims (9)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A method of preparing a crystalline silicate composition which comprises:
a) preparing a first mixture comprising a tetraalkyl ammonium salt, alkali metal hydroxide, cilica and water, b) preparing a second mixture comprising water, a soluble source of a metal whose hydroxide precipitates at a pH above 7 and an amount of urea or a compound which upon hydrolysis releases ammonia, said amount effective to pre-cipitate the hydroxide of said metal, whereby the hydroxide of said metal forms a precipitate, c) admixing an amount of said first mixture and an amount of said second mixture effective to provide a reaction mixture having an aluminum content of less than about 100 wppm (based on silica) and having a composition in terms of mole ratios of oxides, falling within the following ranges:
OH-/SiO2 0.05 - 3 Q+/(Q+ + A+) 0.01 - 1 SiO2/M2/m0 10 - 10,000 wherein Q+ is tetralkyl ammonium ion, A+ is alkali metal ion, M is said metal and m is the valence of said metal, d) maintaining the reaction mixture at a temp-erature of about 50 to about 250°C until crystals of metal silicate are formed and e) separating and recovering said crystals.

2. A method according to Claim 1 wherein a soluble boron compound is admixed with said first mixture and wherein the mole ratios of oxides in said reaction mixture has an additional mole ratio range of SiO/B2O3 2 - 1000

3. A method according to claim 1 wherein the metal is iron, cobalt, bismuth, chromium, molybdenum, nickel, tin, platinum or mixtures thereof.

4. A method according to claim 1, 2, or 3 wherein said crystalline silicate composition is activated by a process comprising heating said composition in a molecu-lar oxygen containing atmosphere.

5. A method according to claim 1 wherein the first mixture of step (a) additionally comprises sulfuric acid and sodium chloride and steps (b) and (d) are conducted under refluxing conditions.

6. A crystalline silicate composition prepared according to the method of claim 1 and having a composition in terms of mole ratios of oxides as follows:

: : (0-40) B2O3: 100 SiO2:

(0-200)H2O wherein R is tetralkyl ammonium cation, ammonium cation, hydrogen cation, alkali metal cation, metal cation or mixtures thereof, n is the valence of R, M is a metal whose hydroxide percipitates at a pH of above 7 and m is the valence of said metal, said composition having an aluminum content of less than about 100 wppm, based on silica.

7. Process for converting oxygenated compounds of the methanol and dimethyl ether type to hydrocarbons compris-ing contacting the oxygenated compound under conversion condi-tions with the crystalline silicate composition of claim 6.

8. Process for the polymerization of ethylene com-prising contacting ethylene under conversion conditions with the crystalline silicate composition of claim 6.

9. Process for the conversion of synthesis gas, comprising hydrogen and carbon monoxide, to hydrocarbons and/or oxygenated compounds by contacting the synthesis gas under conversion conditions with the crystalline silicate composition of claim 6.