ZEOLITE LZ-133

Abstract: A novel crystalline aluminosilicate composition denomi­ nated "zeolite LZ-133" or simply "LZ-133" and having uniform pore dimensions of approximately 4.3 Angstroms is prepared hydrothermally from a reaction mixture containing as essential reagents, water, alkali or alkaline earth metal oxide, alumina, silica and a quaternary ammonium com­ pound.

Description: ZEOLITE L2-133 The present invention relates in general to aluminosilicate compositions ana to tne methoa for their preparation. More particuiarly the invention relates to novei crystalline aluminosilicates of tne zeolite type prepared hyarothermally from a reaction mixture comprising an alkali or an alkaline earth metal oxide, silica, alumina, water ana methyl quinuclictine ions. In tne synthesis of zeolite species, particularly those which are highly siliceous, from reaction mixtures wnich contain organic nitrogeneous or phosphonium bases, it has been speculated that tnese relatively large ionic species serve, at least in part, as templating agents which influence the topology of the crystalline zeolite product, It is apparent, however, tnat other factors in the synthesis process aiso influence tfle structure of the zeolite product since it is known that the same zeolite species can be producea trom reaction mixtures containing quite different organic bases, ana also tnat gels containing the same organic Dase can produce substantially different zeolite structures. For example, both tetraethylammonium and tetrabutylammonium ions can template the formation of zeolite ZS -ll (U.S.P. 3,709,979), whereas tetraethylammonium ions can also template the formation of zeolite Beta (U.S.P. 3,308,069). Since there are a number of variable parameters in' the synthesis process, it is usually quite aifficult to determine precisely whicn particular value of which particular parameter or parameters are determinative of the structure of the crystallizea product. Frequently, more than one zeolite species is produced in a given synthesis. As reportea in our copending application Serial No. filed contemporaneously with the present application, methylquinuclidine ion is capable of templating the formation of a novel zeolite species, aenominated LZ-132, from a reaction mixture containing same in combination with water, soda, alumina and silica. LZ-132 is topologically related to the mineral levynite and also to the synthetic zeolite species vK-20. We have further found that the same reaction mixture which produces LZ-132 also produces another novel zeolite species, denominated LZ-133, whose crystal structure is as yet unknown, but is likely to be topologically related to LZ-132, ZK-20 and levynite. The X-ray powder ditfraction pattern of LZ-133, however, clearly establishes it as a distinct zeolite species. The mineral zeolite levynite has been known since 1825 and has an idealized chemical composition expressed in terms of mole ratios of oxides as CaO: A1203 : 4 Six, : 6 H20. Levynitek's crystal symmetry is hexagonal with unit cell parameters a0 = 13.32 A and c0 = 22.51 A. The X-ray powder diffraction pattern of levynite is given in "Zeolite Molecular Sieves", D.W. Breck, Wiley (1974) as set rorth in Table I, below. TABLE I d(A) I a(A) I 10.4 35 2.?25 6 8.19 65 2.634 40 7.69 18 2.593 6 6.72 18 2.534 16 5.64 4 2.453 2 5.19 30 2.406 16 4.28 50 2.303 10 4.10 100 2.256 4 3.87 20 2.234 14 3.84 6 2.136 18 3.61 6 3.49 16 2.113 2 3.46 6 2.072 6 3.35 14 2.050 4 3.17 50 3.10 20 1.981 2 2.882 10 1.960 6 2.861 10 1.896 6 2.815 80 ZK-20 is described ana claimea in U.S. Patent 3,459,676 issued August 5, 1969 to G.T. Kerr. ZK-20 is preparea nydrothermaily using an organic cation as a templating agent, namely the l-methyl-1-azonia-4- azabicyclo (2,2,2) octane ion, ana has an as-synthesizea chemical composition, in terms of mole ratios of oxide, of: 0.1-0.02R2O : 0.8-0.9Na20 : Al2O3 4-5 SiO2 : 1-5 H2O. wnerein "R" is the ion used as the templating agent. Its X-ray powoer diffraction is set forth in Table II, below TABLE II a(A) 1 a(A) I 14.2 VW 2.41 M 10.4 M 2.23 W-M 9.5 W 2.18 VW 8.2 S 2.14 7.7 W 2.07 VW 6.7 M 2.04 W 5.2 S 1.96 W 4.3 S 1.93 W 4.1 VS 1.90 W 3.86 M-S 1.88 VW 3.t2 W 1.86 W 3.48 W 1.80 M 3.34 W 1.69 W 3.18 S 1.68 M 3.10 M 1.60 M 2.87 M 1.555 M 2.81 S-VS 1.545 M 2.64 M 1.435 M 2.59 VW 1.400 M 2.52 W wherein with respect to the intensity values, "I", "VW" represents Very Weak; NW" represents Weak; "M" represents Meaium; "S" represents Strong and "VS" represents Very Strong. These intensity value symDols have the same meaning when usea hereinafter with respect to any X-ray powder dffraction data concerning tnis or other crystalline materials. Zeolite LZ-133, the novel aluminosilicate zeolite species or the present invention, differs substantially in its chemical composition from either of tne atoresaia ZK-20 and levynite materials as well as having a distinguishing X-ray powder aiffraction pattern. LZ-133 has a chemical composition expressed in terms of mole ratios of oxiaes as: X M2/n0 : AL2O3 : y Si : zH2O wherein "M" is at least one cation having the valence "n", "x" nas a vaiue or from zero to 3.5, "y" has a value of from 10 to 80, preferably 15 to 50 and "z" nas a value of from zero to 15, preferably zero to 5, said aluminosilicate having an X-ray powaer diffraction pattern containing at least the 6-spacings of Table III, Table IV or Table V, below. TABLE III 2 theta,degrees 6 (A) 13.5+0.2 6.66-6.46 13.7+0.2 6.56-6.37 14.2+0.2 6.33-6.15 17.3+0.3 5.21-5.04 19.2+0.3 4.70-4.55 19.7+0.2 4.55-4.46 24.3+0.3 3.73-3.62 25.7+0.2 3.49-3.44 27.3+0.2 3.29-3.24 27.9+0.3 3.23-3.16 28.5+0.2 3.15-3.11 29.6+0.2 3.04-3.00 Standard techniques were employea to obtain the data of Table III and all other X-ray data tor LZ-133 appearing hereinafter. The raaiation was the K-alpha doublet of copper, ana a Geiger-counter spectrometer with a strip-chart pen recorder was employea. The peak heights and their positions as a function of 2 times tneta, where theta is tne Bragg angle, were read from the spectrometer chart and the interplanar spacings in Angstroms corresponaing to the recorded lines were determined. As synthesizea, the chemical composition of LZ-133 in terms of mole ratios of oxides is a Q2/nO : b R2O : Al2O3 : c SiO2 : d H2O wherein "a" has a value in the range of 0.1 to 1.5, Q ss an alkali metal or alkaline eartn metal cation having the valence "n", "b" has a value in the range or 0.5 to 2.5, the value of (a + b) is from 0.9 to 3.5, R represents the methylquinuciidine ion, "c" has a value of from 10 to 80 preferably 15 to 50, and "d" has a value of from zero to about 15, aepending upon the degree or dehyaration and the degree to which the intracrystalline pore volume is occupied by the organic or metal cation species. The as-synthesizea form of the zeolite, which can include the dehydratea (activated) form, but not the form which results from ion exchange or calcination at a temperature sufticiently high,i.e.,at least 400 C, but preferably 500 C-650 C., to decompose the organic constituents, has a characteristic X-ray powder diffraction pattern which contains at least the a-spacings set torth in Table IV below: : TABLE IV 2 theta d(A) Relative Intensity 13.5+0.2 6.66-6.46 M 13.7+0.2 b.56-6.37 M t4.2+0.2 6.33-6.15 M 17.3+0.3 5.21-5.04 M 19.2+0.3 4.70-4.55 VS 19.7+0.2 4.55-4.46 M 24.3+0.3 3.71-3.62 S 25.7+0.2 3.49-3.44 M 27.3+0.2 3.29-3.24 M 27.9+0.3 3.23-3.16 M 28.5+0.2 3.15-3.11 M 29.6+0.2 3.04-3.00 M The organic catlons ot tne as-synthesized zeolite are not considered to be ion-exchangeable in the ordinary sense aue to steric considerations of the crystal structure, the organic cations themselves and the positions occupied Dy these cations within the crystal lattice. These large organic cations, moreover, tend to block the pore system ana prevent the normal passage of the smaller metal cation species into ana out of the crystal structure by the conventional ion-exchange mechanism. It is possible, however, to thermally or chemically decompose the organic cation species as well as any occludea organic moieties to molecular or atomic fragments small enough to be removed. tnrough the pore system. Tne organic cations associated with A104 tetrahedra can be converted by this procedure to ammonium or hyarogen cations which are ion-exchangable in the usual manner. Calcination of tne as-synthesized zeolite in air at a temperature of at least 4000C, preferably 5000C to 6500C. for one hour, is sufficient to create the methylqulnuclidine-free decationized form. Lower temperatures and/or shorter calcination periods are requirea to accomplish this result if the calcination is carriea out under vacuum conditions. As will be readily apparent to those skilled in this art, the ratio of the combined organic metallic cations to framework aluminum can appear to be substantially higner in the as-synthesized form ot the zeolite than stoichiometric considerations basea on conventional zeolite chemistry would permit. This phenomenon is not unique to LZ-133, however, and has yenerally been observed in high-silica zeolites synthesized from an organic-containing system. While the exact condition of each organic ana metal cationic moiety of the zeolite are not known, it can be theorized that at least some of the organic species are merely occluded in the structure, and in aadition entrap alkali or alkaline earth species which are not present in association with A104 tetrahedra. In any event there is no doubt that the topology of LZ-133 is essentially zeolitic. It is further notea that upon calcination at temperatures sufficiently high to decompose the organic species present, the X-ray powder diffraction pattern of LL-133 cnanges somewhat. The most notable changes appear in the intensity values for a number of a-spacings. Some snifting in line positions are also notea as well as the appearance or disappearance OI one or more lines attributed to the removal of the organic species. These changes do not, however, indicate a change in the basic topology of the zeolite structure, the X-ray powder ditfraction pattern of which is set forth in Table V below: TABLE V 2 tneta, d(A) Relative Intensity 13.5+0.2 6.66-6.46 S 13.7+0.2 t.56-6.37 S 14.2+0.2 6.33-6.15 S 17.3+0.3 5.21-5.04 W 19.2+0.3 4.70-4.55 S 19.7+0.2 4.55-4.46 M 24.3+0.3 3.71-3.62 MS 25.7+0.2 3.49-3.44 M 27.3+0.2 3.29-3.24 M 27.9+0.3 3.23-3.16 M 28.5+0.2 3.15-3.11 M 29.6+0.2 3.04-3.00 The organic-free form of the zeolite, such as preparea by the calcination ot as-synthesized LL-133 aescribea aDove, either per se or after subsequent ion-exchange, nas tne chemical composition in tne anhydrous state in terms ot mole ratios or oxides x M2/nO : Al2O3 : ySiO2 wnerein "M" is an ammonium, hyarogen or metal cation, "x" has a value of zero to 1.1, "y" has a value of 10 to 80, preferably 15 to 50, said zeoiite having an X-ray powaer aiffraction pattern containing at least the d-spacings set fortn in Table V, supra. As indicated hereinbefore, LZ-133 and LZ-132 are generally produced together as co-crystallization products from the same reaction gel. The proportions of each species proaucea is depenaent upon the value of the various process parameters involved. It appears that the use of silica sols as the silica source in the reaction mixture, lower reaction temperature and longer crystailization times tend to to ravor the proauction of LZ-132, possibly by the reconversion of previously formea LZ-133 which is favored by relatively higher reaction temperatures, shorter crystallization times ana the use of precipitatea amorphous silica as the principal silica source in the reaction gel. Accordingly zeolite LZ-133 can be prepare hydrothermally by crystallization from a gel whose composition expressea in terms of mole ratios of oxides falls within the following ranges: 1.0 Al2O3 : 10-80 SiO2 : 0.3-5.6 R2O 1.0-5.0 Q2/nO : 160-600 H2O wherein "R" represents the methylquinuclidine ion, "W" represents an alkali metal or alkaline earth cation, preteraDly an alkali metal cation such as sodium, potassium or cesium, and "n" is the valence of the saia metal cation. Preferably, the gel composition expresseu in terms or mole ratios of oxiaes shoula fall within tne following ranges. 1.0 Al2O3 :15-50SiO2: 2.0-4.0 (methylquinuclidine)2O : 1.0-4.5 Na2O : 350-450 H2O In preparing the aqueous reaction mixture the conventional reactants usea in zeolite synthesis are suitably employea. Alumina can be obtained from activatea alumina, alpha alumina, gamma alumina, boehmite, pseuao-boehmite, alumina trihydrate, aluminum hydroxide or soaium aluminate. Silica can be obtainea from precipitated silica, soaium silicates, silica sol, or silica aerogel, preferably precipitated silica. avantageously, the crystallization procedure is carried out at temperatures in the range of from aDout 100 C to 200 C, preferably at 1250C to 150 C, the pressure being autogenous pressure, until the proauct is crystallized. The crystalline product is then fiitered, washed ana driea. The methoa for preparing zeolite LZ-133 is illustrated by the following examples. Example 1 (a) Preparation ot metnylquinucliaine hydroxide (MeQOH). Initially 126.2 grams of quinuciiblne (i-azabicyclo (2,2,2) octane) were dissolved in 126.2 grams or water in a one-liter 3-neck rouna-bottom flask fittea with a condenser, a thermometer ano a mecnanical giass stirring roa with an inert plastic crescent stirring blaae. Using a constant aroppiny funnel, i62.5 grams of methyi iodide (CH3I) were slowly adaea into the quinuclidine solution with vigorous mixing. A temperature rise of 530C was oDservea. After the completion of the aaditon or methyi ioaide solution, the entire solution was mixed vigorously for another 20 hours. A total of about 415 grams of solution proauct was recovered (Calc. 69.5 wt.-% MeQI). The proauct was cnemically analyzea to have 3.6 wt.-% nitrogen ana 26.1 wt.-% carbon (C/N ratio = 8.5; tneoreticai C/N ratio = 8.0) (D) Preparation of LZ-133 To a Deaker were aauea with mixing ana in the order named, 70.5 grams of distilled water, 24.8 grams or a precipitatea amorphous silica containing 84.2 wt.-t Si02, and 27.2 grams of methylquinuclidine oxide. Therearter 3.8 grams ot aistilled water were heated with stirring in a beaker to rorm a not sodium aluminate solution which was then aaaed to the previously prepared silicamethylquinuclidine gel along with 10 grams ot water used to rinse the beaker wherein the sodium aluminate solution was prepared. The resulting final reaction gel was thoroughly mixea and had a molar oxide composition of: 1.0 Al2O3 : 27.3 SiO2 : 3.6 Na2O : 5.6 8B16NI : 420 H2O. The syntnesis yel was then placed in a poiytetrafluoroethylene container which in turn was sealed in a stainless steel pressure vessel and digestea at 2000C for 45 hours. The solid reaction proauct was recoverea by filtration, wasnea with water and aries at ambient temperature. The proauct was identified by X-ray aiffraction as zeolite LZ-133. The chemical composition of tne proauct from a repeatea synthesis is as tollows: 5.3 wt.% A1203, 74.6 wt.% SiO2, 1.2 wt.% Na2O, 10.5 wt.% C, 1.7 wt.% N, and 16.8 wt.% loss on ignition at 1000 C. The anhyarous chemical composition expressea in terms of oxiae mole ratios was as follows: 1.0 A1203:23.9 SiO2: 0.37 Na2O: 1.05(C8H16N+)2O The as-synthesizea LZ-133 exhibited the following X-ray powder aiffraction pattern. This pattern is essentially the same as tne patterns of all other uncalcined zeolite LZ-133 compositions which are in tne mixea soalum ana methylquinuclidine cation form. 20 a, (A} 7.7 11.5 6 9.8 9.03 9 12.1 7.31 9 13.5 6.56 31 13.8 6.42 26 14.2 6.24 14.6 6.07 10 16.2 5.47 11 17.2 5.16 32 17.8 4.98 6 18.1 4.90 8 18.5 4.80 18 19.3 4.60 100 19.8 4.48 34 20.9 4.25 9(sh) 20.6 4.31 9 21.4 4.15 20 2z.8 a.90 24 23.4 3.80 13 24.3 3.66 62 24.9 3.58 11 25.8 3.45 28 27.2 3.28 23 27.8 3.21 29 28.4 .14 26 28.6 3.12 27 29.6 3.02 27 30.3 2.905 6 31.0 2.885 2 32.2 2.780 4 32.9 2.722 3 33.8 2.652 8 34.9 2.571 2 35.8 2.321 11 (c) A portion of the crystalline LZ-133 obtainea in part (b) of this Example 1 was calcined in air at 6000C. tor 2 hours. The calcined product had an X-ray powaer aifrraction pattern characterized by the following data. This pattern is essentially the same as the patterns of all other zeolite LZ-133 compositions which have been calcined at above 5000C. tor a surficient time to be tree of organic cations ana whose metal cations consist of sodium cations 20 a, I/IO 7.7 11.5 20 8.1 10.9 18 9.8 Y.03 33 12.1 7.31 28 13.7 6.46 100 13.9 6.37 14.2 6.24 t7 14.7 6.03 10 16.2 5.47 7 17.3 5.13 14 17.9 4.96 18.1 4.90 9 18.6 4.77 19.4 4.58 91 9.9 4.46 37 20.7 4.29 8 21.5 4.13 16 23.0 3.87 20 23.7 3.75 11 24.5 3.63 65 24.9 3.58 25.9 3.44 30 27.4 3.26 27 28.1 3.18 33 28.5 3.13 29 28.7 3.11 30 29.7 3.01 3b 30.4 2.940 7 31.0 2.885 5 32.3 2.772 6 32.8 2.730 6 33.6 2.667 SH 34.0 2.637 11 35.0 2.564 6 36.0 2.495 32 (SH = shoulder) (a) Aasorption capacities were measurea on the calcined product using a standard McBain-Bakr gravimetric absorption apparatus. The following data were obtained on samples activate at 3500C unaer vacuum for 16 hours. Kinetic Pressure Temp( C) Wt.% Diameter (A) (torr) ¯¯¯¯¯¯¯¯¯ Adsorbea 02 .46 97.0 -183 12.0 02 3.46 502 -183 i4.4 n-hexane 4.3 99.0 23 4.8 n-butane 4.3 760 23 1.42* iso-butane 5.0 504 23 0.67 H20 2.65 4.6 23 10.8 H20 2.65 19.0 23 19.4 *After 6.5 hours The pore size of the calcined proauct is 4.3 A as shown by adsorption of n-hexane (kinetic diameter of 4.3 A) and nil adsorption of iso-butane (kinetic aiameter of 5.0 A). Examples 2-4 Using synthesis proceaures similar to those aetailed in Example 1, supra, three additional preparations or LZ-j3j were maue using tne reagents ana conaitions set forth in tabular form below. In ali preparations, the proauct was LZ-133 along with a small amount of zeolite LZ-132 as an impurity component. LZ-132 is described in detail in copendng application Serial No. ¯¯¯¯¯¯¯¯¯¯ filed contemporaneously witn tne present application. TABLE VI Synthesis Gel Composition LZ-133 Product Composition, Oxide Mole Ratio Oxide Mole Ratio EXAMPLE Al2O3 SiO2 Na2O H2O MeQI Temp., C Time (hrs) Al2O3 SiO2 Na2O R2O 2 1.0 40.0 4.5 420 5.6 200 24 1.0 30.7 0.35 1.3 3 1.0 50.0 5.0 500 8.0 200 47.5 1.0 45.1 0.44 1.5 4 1.0 27.3 2.64* 420 5.6 200 48 1.0 23.2 0.09** 0.99 *Plus 1.3 Cs2O **Plus 0.42 Cs2O Example 5 In order to demonstrate tne catalytic activity of zeolite Ls-133, a sample was employed as the catalyst in the catalytic cracking of n-butane. The sample selected was the product of Example 2, above, which had been washed with soaium hydroxide solution followea by washing with hydrochloric acid and subsequent calcination at 600 C. ADout 5 grams of the sample (20-40 U.S. Standara mesh) was placed in a 1/2-inch O.D. quartz tube reactor and activated in situ for 60 minutes 3 at 5000C in a flowing (200 cm /min.) stream of dry helium. Thereafter a feedstock consiEting of a mixture of 2 mole-% n-butane in helium was passed over the catalyst sample at the rate of 50cm3/min. for a period of 40 minutes. Tne product stream was analyzed at 10minute intervals. The pseudo first-oraer reaction rate constant (ka) was then calculated to determine the catalytic activity of the zeolite LZ-133. The k a value for the calcined LZ-133 sample was found to be 3.8 as compared to a K value of 1.1 for NH4-Y zeolite. Tne hydropnobic surface characteristics of LZ-133 are very similar to those of LZ-132. The characteristics of the latter zeolite, in this regard, were demonstrated using an ethanol-water shake test. A one gram sample of a stepwise-calcined sample of Example l(b) was added to a small serum bottle. The stepwise calcination procedure consisted of raising the sample temperature to 1000C., followed by a heat-up rate of l000C/hr., with an intermittent holding time of one hour when the temperature reached 200 , 3000, 4000 ana 5000C, until the final temperature reached 5900C. During the heat-up time, the sample was under a nitrogen purge. When the temperature reached 5900C, 5.0 vol.-% of C2H5 OB in H 20 solution was introduced. The bottle was sealed ana shaken tnroughly. The liquid was anaiyzea by gas chromatography and the result indicatea a total of 14.9% ethanol removal. For comparison, acia-washea silicalite removed 23% ethanol from the same solution.

Claims: CLAIMS i. Crystalline aluminosilicate zeolite composition having a chemical composition in terms of mole ratios of oxides x M2/nO : A1203 : y Si02 : z H2O wherein "M" is at least one cation having the valence "n", "x" has a value of from zero to 3.5, "y" has a value of from 10 to 80 and "x" has a value from zero to 15, said aluminosilicate having an X-ray powder diffraction pattern containing at least the d-spacings set forth in Table III, Table IV or Table V. 2. Crystalline aluminosilicate zeolite composition according to claim i wherein "y n has a value of from 15 to 50. 3. Crystalline aluminosilicate zeolite composition according to claim I which has an X-ray powder aiffraction pattern containing at least the d-spacings set fortn in Table IV. 4. Crystalline aluminosilicate zeolite composition according to claim 1 which has an X-ray powder diffraction pattern containing at least the d-spacings set forth in Table V. 5. Crystalline aluminosilicate zeolite composition having an as-synthesized chemical composition in terms of mole ratios of oxides: a Q2/nO : bR2O : A1203 : cSiO2 : dH2O wherein "a" has a value in the range ot 0.1 to 1.5, Q is an alkali metal or alkaline earth metal cation having the valence of NnN, N has a value in the range of 0.5 to 2.5, the value of (a + b) is from 0.9 to 3.5, "R" represents the methylquinuclidine ion, "c" has a value of from 10 to 80, "d" has a value of from zero to 15,saia zeolite composition having an X-ray powder diffraction pattern which contains at least the d-spacings set forth in Table IV. 6. Crystalline aluminosilicate zeolite composition according to claim 5 wherein "c" has a value of from 15 to 50. 7. Crystalline aluminosilicate composition according to claim 4 wherein "x" has a value of zero to 1.1 and wM" is a cation selected from the group consisting of ammonium, hydrogen or metal. 8. Crystalline aluminosilicate composition resulting from the calcination of the composition of claim 5 at a temperature of at least 4000C up to the crystal destruction temperature thereof. 9. Process ror separating the less polar molecular species from admixture with at least one other molecular species having a greater polarity, said less polar species and at least one of said greater polar species having kinetic aiameters of not greater than 4.3 A which comprises contactingsaid mixture with a crystalline zeolitic molecular sieve of claim 1 or claim 5 which is at least partially activated. 10. Process according to claim 9 wnerein tne molecular species of greater polarity is water. il. Process for the catalytic conversion of hydrocarbns which comprises contacting said hyarocarbon under hydrocarbon conversion conditions with a catalyst composition comprising a zeolite of claim I or claim 5 whicn nas been at least partially activated.

Inventors: BRENT, MEI-TAK LOK, CANNAN, THOMAS RICHARD, FLANIGEN, EDITH MARIE
Applicants: UNION CARBIDE CORPORATION
Application year: 1983
Main classification: C01B33
IPC codes: B01J20, C01B39, C07B61, C07C9, C07C67, C07C1, C07C4, C07C7, B01J29