WO1989008608A1

WO1989008608A1 - Synthetic crystalline molecular sieve and its synthesis

Info

Publication number: WO1989008608A1
Application number: PCT/US1989/000824
Authority: WO
Inventors: Ernest William Valyocsik
Original assignee: Mobil Oil Corporation
Priority date: 1988-03-10
Filing date: 1989-02-27
Publication date: 1989-09-21
Also published as: NZ228228A; KR900700386A; AU3197989A; DK214990D0; EP0437429A1; DK214990A; JPH03503276A

Abstract

A crystalline metalloaluminophosphate molecular sieve has the X-ray diffraction lines, (table I), and is crystallized from a reaction mixture comprising a C5-C7 alkyldiamine as directing agent.

Description

SYNTHETIC CRYSTALLINE MOLECULAR SIEVE

AND ITS SYNTHESIS

This invention relates to a synthetic crystalline molecular sieve and to a method of its synthesis.

Zeolitic materials, both natural and synthetic, have been demonstrated in the past to have catalytic properties for various types of hydrocarbon conversion. Certain zeolitic materials are ordered, porous crystalline aluminosilicates having a definite crystalline structure as determined by X-ray diffraction, within which there are a large number of smaller cavities which may be interconnected by a number of still smaller channels or pores. These cavities and pores are uniform in size within a specific zeolitic material. Since the 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 rigid three-dimensional frameworks of SiO₄ and AlO₄ 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 atoms 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 with 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. Prior art techniques have resulted in the formation of a great variety of synthetic zeolites. The zeolites have come to be designated by letter or other convenient symbols, as illustrated by zeolite A (U.S. Patent 2,882,243), zeolite X (U.S. Patent 2,882,244), zeolite Y (U.S. Patent 3,130,007), zeolite ZK-5 (U.S. Patent 3,247,195), zeolite ZK-4 (U.S. Patent 3,314,752), zeolite ZSM-5 (U.S. Patent 3,702,886), zeolite ZSM-11 (U.S. Patent 3,709,979), zeolite ZSM-12 (U.S. Patent 3,832,449), zeolite ZSM-20 (U.S. Patent 3,972,983), zeolite ZSM-35 (U.S. Patent 4,016,245), and zeolite ZSM-23 (U.S. Patent 4,076,842). Aluminum phosphates are taught in, for example, U.S.

Patents 4,310,440 and 4,385,994. These aluminum phosphate materials have essentially electroneutral lattices. U.S. Patent 3,801,704 teaches an aluminum phosphate treated in a certain way to impart acuity. Microporous aluminum phosphates have a composition typified as:

xR:Al₂O₃: (1.0±0.2)P₂O₅:yH₂O

wherein R is an organic amine or quaternary ammonium salt entrapped within the aluminum phosphate and playing a role as crystallization template, x and y representing the amounts of R and H₂O needed to fill the microporous voids. Because the aluminum/phosphorus atomic ratio of these materials is about unity, they display virtually no ion-exchange properties, the framework positive charge on phosphorus being balanced by corresponding negative charge on aluminum:

AlPO₄=(AlO₂-)(PO₂ ⁺) Silicoaluminophosphates having a variety of structures have also been synthesized, see, for example, Nosa 4,440,871, 4,623,527, 4,639,358, 4,647,442, 4,664,897, 4,639,357 and 4,632,811. Crystalline metalloaluminophosphates are disclosed in U.S. Patent No.4, 713, 227, an antimonophosphoaluminate is disclosed in U.S.

Patent No.4,619, 818 and a titaniumaluminophosphate is disclosed in U.S. Patent No. 4,500,651.

In its broadest aspect, the present invention resides in a synthetic crystalline molecular sieve having the following x-ray diffraction lines:

Interplanar d-Spacing

(A) Relative Intensity (I/I_o)

14.980 ± 0.1 vs

12.230 ± 0.1 w

7.493 ± 0.1 w

5.930 ± 0.1 w

4.605 ± 0.05 w

It is to be appreciated that all X -tray diffraction data given herein were collected, with a Scintag diffraction system, equipped with a graphite diffracted beam monachromator and scintillation counter, using copper K-alpha radiation. The K-alpha 2 component of the K-alpha 1-K-alpha 2 doublet was removed with a computer stripping program. The effective X-ray wavelength for the tabulated data is therefore the K-alpha 1 value of 1.5405 Angstroms. The diffraction data were recorded by step-scanning at 0.02 degrees of two-theta, where theta is the Bragg angle, and a counting time of 1 second for each step. The interplanar spacings, d's, were calculated in Angstrom units d(A) and the relative intensities of the lines, I/I_o, where I_o is one-hundredth of the intensity of the strongest line, above background, were derived with the use of a profile fitting routine (or second derivative algorithm). The intensities are uncorrected for Lorentz and polarization effects. The relative intensities are given in terms of the symbols vs = very strong (75-100), s = strong (50-74), m = medium (25-49) and w = weak (0-24). It should be understood that diffraction data listed ffor this sample as single lines may consist of multiple overlapping lines which under certain conditions, such as differences in crystallite sizes or very high experimental resolution or crystallographic changes, may appear as resolved or partially resolved lines. Typically, crystallographic changes can include minor changes in unit cell parameters and/or a change in crystal symmetry, without a change in topology of the structure. These minor effects, including changes in relative intensities, can also occur as a result of differences in cation content, framework composition, nature and degree of pore filling, and thermal and/or hydrothermal history.

More specifically, the molecular sieve comprises a three-dimensional framework structure composed of tetrahedral units of MO₂, AlO₂ and PO₂, where M is at least one element other than aluminum or phosphorus, and having the following composition: / ^C

where Q is a cation of valence q, T is an anion of valence t, m is the valence or weighted average valence of the element(s) M, x, y, i and j are numbers satisfying the relationship: z = i-j, and i-j = y-x + (4 + m)(x + y) and z is a number from greater than -1 to less than +1. When z is greater than 0, the metalloaluminophosphate will mostly behave as a cation exchanger with potential use as an acidic catalyst. When z is less than 0, the metalloaluminophosphate will mostly behave as an anion exchanger with potential use as a basic catalyst.

In one preferred embodiment, the element M is silicon alone and the molecular sieve has the following composition:

where 0.01 < x < 1

0.01< y < 1, and x + y < 1 In another embodiment , the element M includes an element other than silicon having an oxidation number of +2 to +6 and an ionic "Radius Ratio" of 0.15 to 0.73 , with the proviso that , when the oxidation number is +2, the Radius Ratio must be 0.52 to 0.62. In some cases , silicon may also be present such that the ratio silicon:non-silicon atoms in the MO₂ component is less than 1, preferably less than 0.5.

The term "Radius Ratio" is defined as the ratio of the crystal ionic radius of the element M to the crystal ionic radius of the oxygen anion, 0^-2.

The crystal ionic radii of elements are listed in the CRC Handbook of Chemistry and Physics, 61st edition, CRC Press, Inc., 1980, pages F-216 and F-217, said listing incorporated herein by reference. In determining the Radius Ratio, it is necessary to use crystal ionic radii of the M atom and oxygen anion (0_-2) which have been measured by the same method.

Non-limiting examples of element M useful herein include:

M Valence Radius Ratio

As +3 0.44

B +3 0.17 Bi +3 0.73

Co +2 0.55

Cu +2 0.54

Fe +2 0.56

Fe +3 0.48

Ge +2 0.55

Ge +4 0.40

In +3 0.61

Mn +2 0.61

Sb +3 0.57

Sn +4 0.54

Ti +3 0.58

Ti +4 0.52

V +3 0.56

V +4 0.48 V +5 0.45

Zn +2 0.56 Non-limiting example of elements not included as M of the present invention include:

Element Valence Radius Ratio B +1 0.26

Ba +1 1.16

Ba +2 1.02

Ce +3 0.78

Cd +1 0.86

Cd +2 0.73

Cr +1 0.61 Cr +2 0.67

Cu +1 0.73

La +1 1.05

Ivfe +1 0.62

Mg +2 0.50

Mo +1 0.70

Sn +2 0.70 Sr +2 0.85

Th +4 0.77

Ti +1 0.73

Ti +2 0.71

Zn +1 0.67

As synthesized , in general, the crystalline composition comprises structural aluminum, phosphorus and element M, and will exhibit an M/(aluminum plus phosphorus) atomic ratio of less than unity and greater than zero, and usually within the range of from 0.001 to 0.99. The phosphorus/aluminum atomic ratio of such materials may be found to vary from 0.01 to 100.0 , as synthesized. It is well recognized that aluminum phosphates exhibit a phosphorus/aluminum atomic ratio of unity, and essentially no element M. Also, the phosphorus-substituted zeolite compositions, sometimes referred to as "aluminosilicophosphate" zeolites, have a silicon/aluminum atomic ratio of usually greater than unity, and generally from 0.66 to 8.0, and a phosphorus/aluminum atomic ratio of less than unity, and usually from 0 to 1. The molecular sieve of the invention is prepared from a reaction mixture hydrogel containing sources of oxides of aluminum , phosphorus and the non-aluminum, non-phosphorus element M, a directing agent R, and water and having a composition , in terms of mole ratios , within the following ranges:

Broad Preferred Most Prfer

P₂O₅/AI₂O₃ 0.01 to 20 0.2 to 5 0.5 to 2

H₂O/AI₂O₃ 2 to 400 5 to 200 10 to 100

H⁺/AI2O3 0.01 to 30 0.5 to 20 1 to 10 R/Al₂O₃ 0.01 to 20 0.1 to 10 0.5 to 5

M/AI₂O₃ 0.01 to 20 0.1 to 10 0.5 to 5

where R is a C₅ - C₇ alkyldiamine, such as , for example, pentanediamine, e .g . 1 ,5-pentanediamine and heptanediamine, e.g . 1 ,7-heptanediamine.

Suitable reaction conditions include a temperature of 80°C to 300°C for a period of time from 5 hours to 20 days. A more preferred temperature range is from 100°C to 200°C with a crystallization time of 24 hours to 10 days. The reaction of the gel particles is carried out until crystals form. The solid product comprising the desired metalloaluminophosphate is then recovered from the reaction medium, such as by cooling the whole to room temperature , filtering and water washing .

The synthesis may be facilitated when the reaction mixture comprises seed crystals , such as those having the structure of the product crystals . The use of at least 0.01%, preferably about 0.10% , and even more preferably about 1% seed crystals (based on total weight) of crystalline material in the reaction mixture will facilitate crystallization in the present method.

The organic directing agent used in the synthesis of the molecular sieve of the invention can be removed to allow access to its internal pore structure by calcining in conventional manner , e.g. at 200 - 550°C for 1 - 48 hours . While the improved crystalline composition of the present invention may be used as a catalyst component in a wide variety of organic compound, e.g. hydrocarbon compound, conversion reactions, it is notably useful in the processes of cracking, hydrocracking, isomerization and reforming. Other conversion processes for which the present composition may be utilized as a catalyst component include, for example, dewaxing.

The crystalline metalloaluminophosphate composition prepared in accordance herewith can be used either in the as-synthesized form, the hydrogen form or another univalent or multivalent cationic form. It 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 the crystalline composition such as, for example, by, in the case of platinum, treating the material with a platinum metal-containing ion. 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. The present composition, when employed either as an adsorbent or as a catalyst in a hydrocarbon conversion process, should be dehydrated at least partially. This can be done by heating to a temperature in the range of 65°C to 315°C in an inert atmosphere, such as air or nitrogen, and at atmospheric or subatmospheric pressures for between 1 and 48 hours. Dehydration can be performed at lower temperature merely by placing the zeolite in a vacuum, but a longer time is required to obtain a particular degree of dehydration. As in the case of many catalysts, it may be desirable to incorporate the hereby prepared metalloaluminophosphate with another material resistant to the temperatures and other conditions employed in certain organic conversion processes. Such matrix materials include active and inactive materials and synthetic or naturally occurring zeolites as well as incorganic materials such as clays, silica and/or metal oxides, e.g. alumina. 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 present metalloaluminophosphate, i.e. combined therewith, which is active, may enhance 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 or reaction. Frequently, crystalline catalytic 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 metalloaluminophosphate include the montmorillonite and kaolin families which include the subbentonites, and the kaolins commonly known as Dixie, McNamee, 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 as originally mined or initially subjected to calcination, acid treatment or chemical modification.

In addition to the foregoing materials, the crystals hereby synthesized can be composited with a porous matrix material such as silica-alumina, silica-magnesia, silica-zirconia, silica-thoria, sϊlica-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 material and matrix vary widely with the crystalline material content ranging from 1 to 90 percent by weight, and more usually in the range of 2 to 50 percent by weight of the composite. Employing a catalyst comprising the composition of this invention containing a hydrogenation component, reforming stocks can be reformed employing a temperature between 450°C and 550°C. The pressure can be between 445 and 3550 kPa (50 and 500 psig), but is preferably between 890 and 2170 kPa (100 and 300 psig). The liquid hourly space velocity is generally between 0.1 and 10 hr^-1, preferably between 1 and 4 hr^-1 and the hydrogen to hydrocarbon mole ratio is generally between 1 and 10, preferably between 3 and 5.

A catalyst comprising the present composition can also be used for hydroisomerization of normal parrffins, when provided with a hydrogenation component, e.g. platinum. Hydroisomerization is carried out at a temperature between 250°C to 450°C, preferably 300°C to 425°C, with a liquid hourly space velocity between 0.1 and 10 hr^-1, preferably between 0.5 and 4 hr^-1, employing hydrogen such that the hydrogen to hydrocarbon mole ratio is between 1 and 10. Additionally, the catalyst can be used for olefin or aromatics isomerization employing temperatures between 0°C and 550°C.

A catalyst comprising the metalloaluminophosphate of this invention can also be used for reducing the pour point of gas oils. This process is carried out at a liquid hourly space velocity between 0.1 and 5 hr^-1 and a temperature between 300°C and 425°C.

Other reactions which can be accomplished employing a catalyst comprising the composition of this invention containing a metal, e.g. platinum, include hydrogenation-dehydrogenation reactions and desulfurization reactions , olefin polymerization (oligomerization) , and other organic compound conversions such as the conversion of alcohols (e.g . methanol ) to hydrocarbons . In order to more fully illustrate the nature of the invention and the manner of practicing same , the following examples are presented .

Example 1 A 22.71 g quantity of 86 % H₃PO₄ was diluted with 29.3 g H₂O, followed by the mixing of 10.2 g alpha-alumina monohydrate (i .e. Catapal SB) into the dilute phosphoric acid solution . This slurry was mixed , with stirring , at 25 °C for 10 minutes . To the resulting homogeneous suspension was added 16.3 g of 1 ,7-heptanediamine as directing agent .

The mixture was transferred to a 300 ml stainless steel autoclave. A 10.42 g quantity of tetraethylorthosilicate was then poured into the autoclave before sealing.

The reaction mixture prepared had the following composition, in mole ratios:

P₂O₅/Al₂O₃ = 1 .0

H₂O/AI ₂O₃ = 20

H⁺/AI₂O₃ = 8.0

R/Al₂O₃ = 0.5

SiO₂/Al₂O₃ = 0.5

with R being the 1 ,7-heptanediamine .

The sealed autoclave was heated for 19 hours at 146°C, then for 4 days at 180°C with stirring at 800 rpm.

The crystalline product composition was separated from the final liquids by filtration , water washed , and then dried at 110°C. The dried product composition was analyzed by X-ray diffraction , proving it to contain the present silicoaluminophosphate composition comprising crystals having large pore windows . Table 1 lists the X-ray diffraction pattern of the dried , as-synthes ized , product composition of this example. Table 1

Interplanar Observed Relative d-Spacings (A) 2xTheta Intensities (I/I_o)

16.261 5.435 35.4

15.016 5.885 100.0

14.248 6.203 8.3

12.704 6.958 0.9

8.152 10.852 1.9

7.503 11.794 12.9

5.306 16.707 3.9

4.830 18.366 4.9

4.598 19.300 5.2

3.459 25.749 1.1

2.751 32.544 2.7

2.743 32.643 2.9

2.649 33.831 1.4

Example 2

A 23.1 g quantity of 86% H₃PO₄ was diluted with 70.74 g H₂O, followed by the mixing of 10.1 g alpha-alumina monohydrate (i .e. Kaiser) into the dilute phosphoric acid solution. This slurry was mixed , with stirring , at 25°C for 10 minutes. To the resulting homogeneous suspension was added 13.02 g of 1 ,7-heptanediamine as directing agent.

The mixture was transferred to a 300 ml stainless steel autoclave. A 10.41 g quantity of tetraethylorthosilicate was then poured into the autoclave before sealing.

The reaction mixture prepared had the following composition, in mole ratios:

P₂O₅/AI₂O₃ = 1.0

H₂O/AI₂O₃ = 40 H⁺/Al₂O₃ = 4.1

R/AI₂O₃ = 1.0

SiO₂/Al₂O₃ = 0.5 with R being the 1,7-heptanediamine. The sealed autoclave was heated to 200°C and stirred (800 rpm) at this temperature and autogenous pressure for 3 days .

The crystalline product composition was separated from the final liquids by filtration , water washed , and then dried at 110°C. The dried product crystals were analyzed by X-ray diffraction, proving it to be the present silicoaluminophosphate composition comprising crystals having large pore windows . Table 2 l ists the X-ray diffraction pattern of the dried, as-synthesized , product of this example. Table 2

Interplanar Observed Relative d-Spacings (A) 2xTheta Intensities (I/I_o)

29.635 2.982 0.5

14.970 5.903 100

12.223 7.232 3

9.843 8.984 1

9.312 9.497 1

8.717 10.146 0.5

7.484 11 .824 5

6.691 13.232 1

5.927 14.946 1

5 .551 15 .963 0.5

5.377 16.485 0.5

4.967 17.854 0.5

4.828 18.374 1

4.601 19.290 1

4.421 20.081 1

4.313 20.588 1

4.178 21.261 0.5

4.023 22.093 0.5

3.970 22.393 0.5

3.792 23.454 0.5

3.732 23.840 0.5

3.508 25.384 0.5

3.446 25.854 0.5

3.354 26.576 1

3.025 29.521 0.5

2.991 29.864 0.5

2.945 30.344 0.5

2.920 30.608 0.5

2.792 32.046 0 .5

2.746 32.598 0.5

2.632 34.062 0.5 A quantity of the as-synthesized composition of this example was calcined at 300°C in air for 3 hours and also analyzed by X-ray diffraction. The results of this analysis proved the product hereof to be structurally stable to thermal treatment.

Example 3 To further exemplify the present invention, another preparation of the present silicoaluminophosphate was conducted by repeating Example 2, except the directing agent is 1 ,5-pentanediamine. The reaction mixture prepared had the composition, in mole ratios:

P₂O₅/Al₂O₃ = 1.0

H₂O/Al₂O₃ = 40 H⁺/Al₂O₃ = 4.1

R/Al₂O₃ = 1.0

SiO₂/Al₂O₃ = 0.5 with R being the 1 ,5-pentanediamine.

Crystallization, separation and drying of product was completed as in Example 2. The dried product crystals , analyzed by

X-ray diffraction, proved to be the present silicoaluminophosphate composition comprising crystals having large pore windows . Table 3 lists the X-ray diffraction pattern of the dried, as-synthesized product of this example.

Table 3

Interplanar Observed Relative d-Spacings (A) 2xTheta Intensities (I/I_o)

14.980 5 .90 100

12. 230 7.23 3

9.860 8.97 1

9.316 9.49 1

8.706 10.16 1

7.493 11.81 5

6.695 13.22 1

5.930 14.94 2

5.597 15 .83 1

5.385 16.46 1

4.981 17.81 1

4.828 18.38 1

4.605 19.27 1

4.425 20.06 1

4.317 20.57 1

4.180 21.25 1

4.029 22.06 1

3.973 22.38 1

3.767 23.62 1

3.731 23.85 1

3.512 25.36 1

3.446 25 .86 1

3.400 26.21 1

3.356 26.56 1

3.028 29.50 1

Example 4

A 23.1 g quantity of 86 % H₃PO₄ was diluted with 40 , 74 g H₂O, followed by the mixing of 10.1 g alpha-alumina monohydrat e (i .e. Catapal SB), and 6.0 g indium nitrate dissolved in 30.0 g H₂O, into the dilute phosphoric acid solution. This slurry was mixed, with stirring, at 25°C for 10 minutes .

To the resulting homogeneous suspension was added 13.0 g of 1 ,7-heptanediamine as directing agent . The mixture was then transferred to a 300 ml stainless steel autoclave. The reaction mixture prepared had the following composition , in mole ratios :

P₂O₅/AI₂O₃ = 1 .0 H₂O/AI ₂O₃ = 40

H⁺/AI₂O₃ = 4

R/AI₂O₃ = 1.0

M/Al₂O₃ = 0.2 with R comprising the 1 ,7-heptanediamine and M comprising indium.

The sealed autoclave was heated for 19 hours at 146°C, then for 4 days at 180°C with stirring at 400 rpm.

The crystalline product composition was then separated from the final liquids by filtration, water washed, and then dried at

110°C. Samples of the dried product crystals and calcined (500°C in air for 3 hours) crystals, were analyzed by X-ray diffraction, and found to be the present metalloaluminophosphate composition comprising crystals having large pore windows. A quantity of the as-synthesized composition of this example, analyzed for chemical composition, had the following components :

Component Wt .%

C 13.44

N 4.27

Al 13.07

P 14.62

M+Si 9.99

Ash 71.42

Example 5

A 23.1 g quantity of 86% H₃PO₄ was diluted with 40.74 g

H₂O, followed by the mixing of 10.1 g alpha-alumina monohydrate

(i.e. Kaiser), and 4.29 g tin sulfate dissolved in 30.0 g H₂O, into the dilute phosphoric acid solution (Sn being +4 valence in this solution under these conditions). This slurry was mixed, with stirring, at 25°C for 10 minutes.

To the resulting homogeneous suspension was added 25.5 g of 1,5-pentanediamine as directing agent.

The mixture was then transferred to a 300 ml stainless steel autoclave. The reaction mixture prepared had the following composition, in mole ratios:

P₂O₅/Al₂O₃ = 1.0

H₂O/AI₂O₃ = 40

H⁺/AI₂O₃ = 4

R/AI₂O₃ = 1.0

M/Al₂O₃ = 0.2 wi th R comprising the 1 ,5-pentanediamine and M compris ing tin.

The sealed autoclave was heated' to 200°C and stirred (800 rpm) at this temperature and autogenous pressure for 3 days .

The crystalline product composition , separated from the final liquids by filtration, water washing , and drying at 110°C, produced an X-ray diffraction pattern proving it to be the present metalloaluminophosphate composition comprising crystals having large pore windows .

A quantity of the composition of this example, calcined at 300°C in air for 3 hours , was also analyzed by X-ray diffraction .

The results of this analysis proved the product to be structurally stable to thermal treatment .

Claims

CLAIMS:

1. A synthetic crystalline molecular sieve haying the following X-ray diffraction lines:

Interplanar d-Spacing

(A) Relative Intensity (I/I_n)

14.980 ± 0.1 vs

12.230 ± 0.1 w

7.493 ± 0.1 w

5.930 ± 0.1 w

4.605 ± 0.05 w

2. The molecular sieve of claim 1 and comprising a threedimensional framework structure composed of tetrahedral units of MO₂, AlO₂ and PO₂, where M is at least one element other than aluminum or phosphorus, and having the following composition:

where Q is a cation of valence q, T is an anion of valence t, m is the valence or weighted average valence of the element(s) M, x, y, i and j are numbers satisfying the relationship: i-j = y-x + (4 + m)(x + y).

3. The molecular sieve of claim 2 wherein M is silicon alone and the molecular sieve has the following composition:

where 0.01 < x < 1

0.01 < y < 1, and x + y < 1

4. The molecular seive of claim 2 wherein M includes an element other than silicon having an oxidation number +2 and an ionic radius ratio of 0.52 to 0.62 or an oxidation number of +3 to +6 and an ionic radius ratio of 0.15 to 0.73.

5. A molecular sieve of claim 4 wherein M includes In³⁺, Sb³⁺, Sn⁴⁺, Ti³⁺ or Ti⁴⁺.

6. The molecular sieve of claim 4, wherein M also includes silicon such that the ratio of siliconmon-silicon atoms in the MO₂ component is less than 1.

7. A method for synthesizing the molecular sieve of claim 2 comprising the steps of preparing a reaction mixture comprising sources of Al₂O3, P₂O₅, an oxide of M, water and an organic directing agent R having a composition within the following ranges:

P₂O₅/Al₂O₃ 0.01 to 20

H₂O/AI₂O₃ 2 to 400

H⁺/AI₂O₃ 0.01 to 30

R/AI₂O₃ 0.01 to 20

M/AI₂O₃ 0.01 to 20

wherein R is a C₅-C₇ alkyldiamine, (ii) maintaining said mixture under sufficient conditions until crystals of said molecular sieve are formed and (iii) recovering said crystalline molecular sieve from step (ii).

8. The method of claim 7 wherein said mixture has the following composition ranges:

P₂O₅/AI₂O₃ 0.2 to 5

H₂O/AI₂O₃ 5 to 200

H⁺/AI₂O₃ 0.5 to 20

R/AI₂O₃ 0.1 to 10

M/AI₂O₃ 0.1 to 10

9. The method of claim 7 wherein said directing agent R is 1,7-heptanediamine or 1,5-pentanediamine.

10. The method of claim 7 wherein said conditions include a temperature of 80-300°C for 5 hours to 20 days.