Method for functionalizing synthetic mesoporous crystalline material

F—6246 — 1METHOD OF FUNCTIONALIZING A SYNTHETIC MESOPOROUS CRYSTALLINE MATERIAL

This invention relates to a method of modifying a synthetic mesoporous material by incorporating one or more functional groups into the material.

Porous inorganic solids have found great utility as catalysts and separation media for industrial application. The openness of their microstructure allows molecules access to the relatively large surface area of these materials that enhance their catalytic and sorptive activity. The porous materials in use today can be sorted into three broad categories using the details of th., ir microstructure as a basis for classification. These categories are the amorphous and paracrystalline supports, the crystalline molecular sieves and modified layered materials. The detailed differences in the microstructures of these materials manifest themselves as important differences in the catalytic and sorptive behavior of the materials, as well as in differences in various observable properties used to characterize them, such as their surface area, the sizes of pores and the variability in those sizes, the presence or absence of X-ray diffraction patterns and the details in such patterns, and the appearance of the materials when their microstructure is studied by transmission electron microscopy and electron diffraction methods.

Amorphous and paracrystalline materials represent an important class of porous inorganic solids that have been used for many years in industrial applications. Typical examples of these materials are the amorphous silicas commonly used in catalyst formulations and the paracrystalline transitional aluminas used as solid acid catalysts and petroleum reforming catalyst supports. The term amorphous is used here to indicate a material with no long range order and can be

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-2 — somewhat misleading, since almost all materials are ordered to some degree, at least on the local scale.

An alternate term that has been used to described these materials is x-ray indifferent. The microstructure of ⁵ the silicas consists of 100-250 Angstrom particles of dense amorphous silica (Kirk-Othmer Encyclopedia of Chemical Technology, 3rd Edition, Vol. 20, John Wiley & Sons, New York, p. 766-781, 1982), with the porosity resulting from voids between the particles. Since ¹⁰ there is no long range order in these materials, the pore sizes tend to be distributed over a rather large range. This lack of order also manifests itself in the X-ray diffraction pattern, which is usually featureless.

Paracrystalline materials such as the transitional aluminas also have a wide distribution of pore sizes, but better defined X-ray diffraction patterns usually consisting of a few broad peaks. The microstructure of these materials consists of tiny crystalline regions of 20 condensed alumina phases and the porosity of the materials results from irregular voids between these regions (K. Wefers and Chanakya Misra, Oxides and Hydroxides of Aluminum, Technical Paper No. 19 Revised, Alcoa Research Laboratories, p. 54-59, 1987).

Since, in the case of either material, there is no long range order controlling the sizes of pores in the material, the variability in pore size is typically quite high. The sizes of pores in these materials fall into a regime called the mesoporous range, which, for the purposes of this application, is from 13 to 200 Angstroms.

In sharp contrast to these structurally illdefined solids are materials whose pore size distribution is very narrow because it is controlled by 35 the precisely repeating crystalline nature of the materials' microstructure. These materials are called molecular sieves, the most important examples of

F-6246 — 3“ which are zeolites. The precise crystalline microstructure of most zeolites manifests itself in a well-defined X-ray diffraction pattern that usually contains many sharp maxima and that serves to uniquely define the material. Similarly, the dimensions of pores in these materials are very regular, due to the precise repetition of the crystalline microstructure. All molecular sieves discovered to date have pore sizes in the microporous range, which is usually quoted as 2 to 20 Angstroms, with the largest reported being about 12 Angstroms.

Certain layered materials, which contain layers capable of being spaced apart with a swelling agent, may be pillared to provide materials having a large degree of porosity. Examples of such layered materials include clays. Such clays may be swollen with water, whereby the layers of the clay are spaced apart by water molecules. Other layered materials are not swellable with water, but may be swollen with certain organic swelling agents such as amines and quaternary ammonium compounds. Examples of such non-water swellable layered materials are described in U.S. Patent 4,859,648 and include layered silicates, magadiite, kenyaite, trititanates and perovskites. Another example of a non-water swellable layered material, which can be swollen with certain organic swelling agents, is a vacancy-containing titanometallate material, as described in U.S. Patent 4,831,006.

Once a layered material is swollen, the material may be pillared by interposing a thermally stable substance, such as silica, between the spaced apart layers. The aforementioned U.S. Patents 4,831,006 and 4,859,648 describe methods for pillaring the non-water swellable layered materials described therein. The X-ray diffraction patterns of pillared layered materials can vary considerably, depending on the

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-42089722 degree that swelling and pillaring disrupt the otherwise usually well-ordered layered microstructure. The regularity of the microstructure in some pillared layered materials is so badly disrupted that only one peak in the low angle region of the X-ray diffraction pattern is observed, at a d~spacing corresponding to the interlayer repeat in the pillared material. Less disrupted materials may show several peaks in this region that are generally orders of this fundamental repeat. X-ray reflections from the crystalline structure of the layers are also sometimes observed. The pore size distribution in these pillared layered materials is narrower than that in amorphous and paracrystalline materials but broader than that in zeolitic materials.

In our International Patent Publication No. WO 91/11390, we have described a novel class of inorganic, porous, non-layered, crystalline material which is distinguished from other porous inorganic solids by the regularity of its large open pores, whose size is in the mesoporous range and hence more nearly resembles the pore size of amorphous or paracrystalline materials, but whose regular arrangement and uniformity of size more closely resemble those of crystalline materials such as zeolites. In particular, this novel class of material exhibits, after calcination, an x-ray diffraction pattern with at least one peak at a d-spacing greater then about 18 Angstrom Units and has a benzene adsorption capacity of greater than 15 grams benzene per 100 grams of said material at 50 torr and 25°C.

This new class of molecular sieves has the unique property that a high concentration of hydroxyl groups may be present within the pore openings of the as-synthesized or calcined material. An object of the present invention is to use the hydroxyl groups to react with an organic treatment compound to anchor or

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-5incorporate functional groups into the molecular sieve material. The functional groups can provide unique catalytic sites within the pores or can act as pore size reducing agents so that the pore size can tailored as desired. The functional groups can also serve as precursors to ceramic materials.

Accordingly, the invention resides in a method of modifying an inorganic, porous, non-layered crystalline phase material exhibiting, after calcination, an X-ray diffraction pattern with at least one peak at a d-spacing greater than about 18 Angstrom Units and having a benzene adsorption capacity of greater than 15 grams of benzene per 100 grams of said material at 6.7 kPa (50 torr) and 25^eC, comprising contacting the crystalline material, before or after calcination, with a treatment composition which comprises M'X'Y'n wherein M’ is selected from Groups IIA, IIIA, IVA, VA, VIA, VIIIA, IB, IIB, IIIB, IVB, VB and VIB of the Periodic Table of the Elements; X¹ is selected from halides, hydrides, alkoxides of Cl-6, alkyl of Cl-18, alkenyl of Cl-18 and aryl of C3-8, acetate, aryloxide of C3-18, sulfonates and nitrates; Y* is selected from X, amines, phosphines, sulfides, carbonyls and cyanos; and, n = 1-5.

In a preferred embodiment, the inorganic, porous crystalline phase material has a hexagonal arrangement of uniformly-sized pores at least about 13 Angstroms in diameter and exhibits, after calcination, a hexagonal electron diffraction pattern that can be indexed with a dlOO value greater than 18 Angstrom Units.

Advantageously, the modification can be carried out on the as-synthesized crystalline material without the necessity for removing residual organics. In addition, essentially all internal hydroxyl sites can be functionalized if desired.

The functionalization reaction of the invention may be described according to the formula:

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-6—

Si-O-R’ + M'X'Y'n----> SiOM'Y'n + R'X¹ wherein Si-O-R¹ is a site in the lattice of the crystalline material.

R¹ = H+ or R4N+ which is the organic cation specified in the crystallization methods described hereinbelow.

M' = Elements of Groups IIA, IIIA, IVA, VA, VIA, VIIIA, IB, IIB, IIIB, IVB, VB, or VIB of the Periodic Table of the Elements, (Sargent-Welch Scientific Co. Cat. No. S-18806, 1979). Preferred elements for M* are Groups IVA, VIA, VIIIA, IIIB and IVB, and most preferred elements for M are titanium, chromium, iron, cobalt, nickel, boron, aluminum and silicon.

X' = halides, hydrides, alkoxides of 1-6 carbon atoms, alkyl of 1-18 carbon atoms, aryl of 3-18 carbon atoms, acetates, aryloxides of 3-18 carbon atoms, sulfonates and nitrates. Preferred substituents for X are halides, alkoxides of 1-6 carbon atoms and acetates.

Y¹ can be selected from the substituents described for X¹, or amines, phosphines, sulfides, carbonyls and cyanos. Preferred substituents for Y' are those described for X', amines, sulfides and alkyls with 1-18 carbon atoms. Most preferred substituents for Y’ are those described for X¹, amines and alkyls with 1-18 carbon atoms; n = 1-5.

Non-limiting examples for M'X'Y'n include chromium acetate, chromium nitrate, tetraethylorthosilicate, tetramethylorthosilicate, titanium tetraethoxide, aluminum isopropoxide, aluminum tri-sec butoxide, hexamethyldisilazane, di-sec-butoxyaluminoxytriethoxysilane, diethylphosphatoethyltriethyoxysilane, trimethylborate, chlorodimethylalkylsilane wherein alkyl has 1-18 carbon atoms, ammonia-borane, borane-tetrahydrofuran and dimethylsulfidedibromoborane .

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The ratio of treatment composition to treated composition of matter, duration of treatment and temperature are not critical and may vary within wide limits. The temperature may be, for example, from -70”C to 250°C, with 25^eC to 100°C being preferred; and the time may be from 0.1 to 100 hours, with a time of 0.1 to 30 hours being preferred and a time of 0.1 to 24 hours most preferred.

The treated crystalline material can be used as is or may be further subjected to a thermal treatment or treatment with a reactive gas such as oxygen or carbon monoxide for activation. The treated material may be calcined in a reactive or inert gas such as NH₃, PH₃, air, 02, N2, Ar, H₂, SiH< or B₂H₆.

The treated crystalline material may be described as having functional groups within it according to the formula

I ___SiOM'Y'n

I

These functionalized sites may be, for example:

-SiOP(OMe)₂, -SiOB(OMe)₂, -SiOB(Br)₂.SMe₂, -SiOTi(OEt)₃,

-SiOCr(acetate)₂, -SiOCr(nitrate)₂, -SiOSi(OMe)₃, -SiOAl(s-OPr)₂, -SiOAl(S-OBu)2/ -SiOSi(OEt)₃,

OEt

I o

-SiOSi-CH₂CH₂-P(OEt)₂,

I

OEt

-SiOSi (CH₃)₃, -SiOSi (CH₃) ₂C_sH₁₃, -SiOSi (CH₃) ₂C_ieH₃₇, -SiOSi (CH₃)₂C₆H_s. where Me=CH₃, Et=C₂H_s, Pr=C₃H₇, Bu SC4H9.

<img file="CA2069722C_D0001.tif" />

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In these examples, -Si represents a site in the lattice of the crystalline material. Two additional bonds on the Si are not shown. The invention is not limited to these listed functionalized sites.

In its calcined form, the crystalline material treated by the method of the invention exhibits an X-ray diffraction pattern with at least one peak at a position greater than about 18 Angstrom Units d-spacing (4.909 degrees two-theta for Cu K-alpha radiation). More particularly, the calcined crystalline non-layered material of the invention may be characterized by an X-ray diffraction pattern with at least two peaks at positions greater than about 10 Angstrom Units d-spacing (8.842 degrees two-theta for Cu K-alpha radiation), at least one of which is at a position greater than about IB Angstrom Units d-spacing, and no peaks at positions less than about 10 Angstrom units d-spacing with relative intensity greater than about 20% of the strongest peak. Still more particularly, the X-ray diffraction pattern of the calcined material of this invention will have no peaks at positions less than about 10 Angstrom units d-spacing with relative intensity greater than about 10% of the strongest peak.

X-ray diffraction data were collected on a Scintag PAD X automated diffraction system employing thetatheta geometry, Cu K-alpha radiation, and an energy dispersive X-ray detector. Use of the energy dispersive X-ray detector eliminated the need for incident or diffracted beam monochromators. Both the incident and diffracted X-ray beams were collimated by double slit incident and diffracted collimation systems. The slit sizes used, starting from the X-ray tube source, were 0.5, 1.0, 0.3 and 0.2 mm, respectively. Different slit systems may produce differing intensities for the peaks. The materials of the present invention that have the largest pore sizes may require more highly collimated incident X-ray beams

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92089722 in order to resolve the low angle peak from the transmitted incident X-ray beam.

The diffraction data were recorded by step-scanning at 0.04 degrees of two-theta, where theta is the Bragg angle, and a counting time of 10 seconds for each step. The interplanar spacings, d*s, were calculated in Angstrom units (A), and the relative intensities of the lines, I/lo, where Io is one-hundredth of the intensity of the strongest line, above background, were derived with the use of a profile fitting routine. The intensities were 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 as single lines may consist of multiple overlapping lines which under certain conditions, such as 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 substantial change in 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, thermal and/or hydrothermal history, and peak width/shape variations due to particle size/shape effects, structural disorder or other factors known to those skilled in the art of X-ray diffraction.

The material treated by the method of the invention is further characterised by an equilibrium benzene adsorption capacity of greater than about 15 grams benzene/100 grams crystal at 5.7 kPa (50 torr) and 25°C. The equilibrium benzene adsorption capacity characteristic of this material is measured on the basis of no pore blockage by incidental contaminants.

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-10For instance, the sorption test will be conducted on the crystalline material phase having any pore blockage contaminants and water removed by ordinary methods. Water may be removed by dehydration techniques, e.g.

⁵ thermal treatment. Pore blocking inorganic amorphous materials, e.g. silica, and organics may be removed by contact with acid or base or other chemical agents such that the detrital material will be removed without detrimental effect on the crystal of the invention.

¹⁰ The equilibrium benzene adsorption capacity is determined by contacting the material of the invention, after dehydration or calcination at, for example, 450 to 700°C, typically 540^eC, for at least one hour and other treatment, if necessary, in an attempt to remove ¹⁵ any pore blocking contaminants, at 25°C and 50 torr benzene until equilibrium is reached. The weight of benzene sorbed is then determined as more particularly described hereinafter.

The materials treated by the method of the invention are generally mesoporous, by which is meant they have uniform pores within the size range of 13 to 200 Angstroms, more usually 15 to 100 Angstroms. In a preferred embodiment, the material appears to have a hexagonal arrangement of large channels with open internal diameters from 13 to 200 Angstroms. This structure can be revealed by transmission electron microscopy and electron diffraction. Thus, electron micrographs of properly oriented specimens of the material show a hexagonal arrangement of large channels and the corresponding electron diffraction patterns give an approximately hexagonal arrangement of diffraction maxima. The dlOO spacing of the electron diffraction patterns is the distance between adjacent spots on the hkO projection of the hexagonal lattice and is related to the repeat distance aO between channels observed in the electron micrographs through the formula dlOO = aO 3/2. This d^_Q0 spacing observed

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-11286972?

in the electron diffraction pattern corresponds to the d-spacing of the low angle peak (&gt;18 Angstrom d-spacing) in the X-ray diffraction pattern. The most highly ordered preparations of the material obtained so far have 20-40 distinct spots observable in the electron diffraction patterns. These patterns can be indexed with the hexagonal hkO subset of unique reflections of 100, 110, 200, 210, etc., and their symmetry-related reflections.

As demonstrated hereinafter, the inorganic, nonlayered mesoporous crystalline material used in this invention typically has the following composition: Mn/q(Wa Xb Yc Zd Oh) wherein W is a divalent element, such as a divalent first row transition metal, e.g. manganese, cobalt and iron, and/or magnesium, preferably cobalt; X is a trivalent element, such as aluminum, boron, iron and/or gallium, preferably aluminum; Y is a tetravalent element such as silicon and/or germanium, preferably silicon; Z is a pentavalent element, such as phosphorus; M is one or more ions, such as, for example, ammonium, Group ΙΑ, IIA and VIIB ions, usually hydrogen, sodium and/or fluoride ions; n is the charge of the composition excluding M expressed as oxides; q is the weighted molar average valence of M; n/q is the number of moles or mole fraction of M; a, b, c and d are mole fractions of W, X, Y and Z, respectively; h is a number of from 1 to 2.5; and (a+b+c+d) = 1.

A preferred embodiment of the above crystalline material is when (a+b+c) is greater than d, and h = 2. A further embodiment is when a and d = 0, and h = 2.

In the as-synthesized form, the material employed in this invention typically has a composition, on an anhydrous basis, expressed empirically as follows: rRMn/q(Wa Xb Yc Zd Oh) wherein R is the total organic material not included in M as an ion, and r is the coefficient for R, i.e. the

<img file="CA2069722C_D0002.tif" />

<img file="CA2069722C_D0003.tif" />

<img file="CA2069722C_D0004.tif" />

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12number of moles or mole fraction of R. The M and R components are associated with the material as a result of their presence during crystallization, and are easily removed or, in the case of M, replaced by conventional post-crystallization methods.

Synthesis of the ultra-large pore crystalline material treated by the method of the invention is described in detail in our International Patent

Publication No. WO 91/11390. In particular, materials having the composition defined by the above formula can be prepared from a reaction mixture having a composition in terms of mole ratios of oxides, within the following ranges:

Reactants Useful Preferred

<td>^X2°3^//YO2</td><td> 0</td><td> to</td><td> 0.5</td><td> 0.001</td><td> to</td><td> 0.5</td>

<td> X₂O₃/(YO₂₊Z₂O₅)</td><td> 0.1</td><td> to</td><td> 100</td><td> 0.1</td><td> to</td><td> 20</td>

<td> X₂^O₃/(Y°₂₊W_O+Z₂^O5)</td><td> 0.1</td><td> to</td><td> 100</td><td> 0.1</td><td> to</td><td> 20</td>

<td> Solvent/</td><td></td><td></td><td></td><td></td><td></td><td></td>

<td> (YO₂+WO₊Z₂O₅₊X₂O₃)</td><td> 1</td><td> to :</td><td> 1500</td><td> 5</td><td> to</td><td> 1000</td>

<td> oh”/yo₂</td><td> 0</td><td> to</td><td> 10</td><td> 0</td><td> to</td><td> 5</td>

<td> &lt;^M2/e^O+R2/f^O)/</td><td></td><td></td><td></td><td></td><td></td><td></td>

<td> (YO₂+WO₊Z₂O₅₊X₂O₃)</td><td> 0.01</td><td> . to</td><td> 20</td><td> 0.05</td><td> to</td><td> 5</td>

<td>^M2/e°/</td><td></td><td></td><td></td><td></td><td></td><td></td>

<td> (YO₂₊WO₊Z₂O₅₊X₂O₃)</td><td> 0</td><td> to</td><td> 10</td><td> 0</td><td> to</td><td> 5</td>

<td> R₂/_f0/</td><td></td><td></td><td></td><td></td><td></td><td></td>

<td> (YO₂₊WO₊Z₂O₅₊X₂O₃)</td><td> 0.01</td><td> . to</td><td> 2.0</td><td> 0.03</td><td> to</td><td> 1.0</td>

wherein e and f are the weighted average valences of M and R, respectively, wherein the solvent is a C_ to C_r

Ό alcohol or diol, or, more preferably, water and wherein R comprises an organic directing agent having the formula R^J^R R₄Q wherein Q is nitrogen or phosphorus and wherein at least one of R , R₂ , R₃ and R₄ is aryl or alkyl group having 6 to 36 carbon atoms, e.g.

~^C6^H13' ^-C10^H21 ' ~^C16^H33 ^anà ”^C18^H37' ^{anâ eacil of} the remainder of R^, R^, R^ and R^ is selected from hydrogen and an alkyl group having 1 to 5 carbon atoms.

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-13The compound from which the above ammonium or phosphonium ion is derived may be, for example, the hydroxide, halide, silicate or mixtures thereof.

The particular effectiveness of the above directing agent, when compared with other such agents known to direct synthesis of one or more other crystal structures, is believed due to its ability to function as a template in the nucleation and growth of the desired ultra-large pore materials. Non-limiting examples of these directing agents include cetyltrimethylammonium, cetyltrimethylphosphonium, octadecyltrimethylphosphonium, benzyltrimethylammonium, cetylpyridinium, myristyltriraethylammonium, decyltrimethylammonium, dodecyltrimethy1ammonium and dimethyldidodecylammonium compounds.

Preferably, the total organic, R, present in the reaction mixture comprises an additional organic directing agent in the form of an ammonium or phosphonium ion of the above directing agent formula but wherein each R. , R_, and R. is selected from 12 3 4 hydrogen and an alkyl group of 1 to 5 carbon atoms (2 of the alkyl groups can be interconnected to form a cyclic compound). Examples of the additional organic directing agent include tétraméthylammonium, tetraethylammonium, tetrapropylammonium, tetrabutylammonium and pyrrolidinium compounds. The molar ratio of the first-mentioned organic directing agent to the additional organic directing agent can be in the range 100/1 to 0.01/1. Where the additional organic directing agent is present, the molar ratio R₂y_fO/(YO^+WO+Z^Os+X^O^) in the reaction mixture is preferably 0.1 to 2.0, most preferably 0.12 to 1.0.

In addition, to vary the pore size of the final crystalline phase material, the total organic, R, in the reaction mixture can include an auxiliary organic in addition to the organic directing agent(s) described above. This auxiliary organic is selected from (1)

<img file="CA2069722C_D0005.tif" />

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-14aromatic hydrocarbons and amines having 5-20 carbon atoms and halogen- and C^-C^ alkyl-substituted derivatives thereof, (2) cyclic and polycyclic aliphatic hydrocarbons and amines of 5 to 20 carbon atoms and halogen- and C^-C ₄ alkyl-substituted derivatives thereof and (3) straight and branched chain aliphatic hydrocarbons and amines having 3-16 carbon atoms and halogen-substituted derivatives thereof.

In the above auxiliary organics, the halogen substituent is preferably bromine. The alkyl substituent may be a linear or branched aliphatic chain, such as, for example, methyl, ethyl, propyl, isopropyl, butyl, pentyl and combinations thereof. Examples of these auxiliary organics include, for example, p-xylene, trimethylbenzene, triethylbenzene and triisopropylbenzene.

With the inclusion of the auxiliary organic in the reaction mixture, the mole ratio of auxiliary organic/YO^ will be from 0.05 to 20, preferably from 0.1 to 10, and the mole ratio of auxiliary organic/organic directing agent(s) will be from 0.02 to 100, preferably from 0.05 to 35.

When a source of silicon is used in the synthesis method, it is preferred to use at least in part an organic silicate, such as, for example, a quaternary ammonium silicate. Non-limiting examples of such a silicate include tétraméthylammonium silicate and tetraethylorthosilicate.

Non-limiting examples of various combinations of W, X, Y and Z contemplated for the above reaction mixture include:

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<td colspan="2"> W</td><td> X</td><td> Y</td><td> z</td>

<td></td><td> —</td><td> Al</td><td> Si</td><td> —</td>

<td></td><td> —</td><td> Al</td><td> —</td><td> P</td>

<td></td><td> —</td><td> Al</td><td> si</td><td> P</td>

<td> 5</td><td> Co</td><td> Al</td><td> —</td><td> P</td>

<td></td><td> Co</td><td> Al</td><td> si</td><td> P</td>

<td></td><td> —</td><td> —</td><td> Si</td><td> —</td>

<td></td><td> including</td><td colspan="2"> the combinations</td><td> of W being Mg, or an element</td>

selected from the divalent first row transition metals, e.g. Mn, Co and Fe; X being B, Ga or Fe; and Y being Ge.

To produce the crystalline material of the invention, the reaction mixture described above is maintained at a temperature of 25 to 250^tfC, preferably 50 to 175°C, and preferably a pH of 9 to 14 for a period of time until the required crystals form, typically 5 minutes to 14 days, more preferably 1 to 300 hours.

When the crystalline material of the invention is an aluminosilicate, the synthesis method conveniently involves the following steps:

(1) Mix the organic (R) directing agent with the solvent or solvent mixture such that the mole ratio of solvent/R₂/_f0 is within the range of 50 to 800, preferably from 50 to 500. This mixture constitutes the primary template for the synthesis method.

(2) To the primary template mixture of step (1) add the silica and alumina such that the ratio of ^R2/f

0/(SiO^+Al^O^) is within the range 0.01 to 2.0.

(3) Agitate the mixture resulting from step (2) at a temperature of 2 0 to 40°C, preferably for 5 minutes to 3 hours.

(4) Allow the mixture to stand with or without agitation, preferably at 20 to 50°C, and preferably for 35 10 minutes to 24 hours.

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2969722 (5) Crystallize the product from step (4) at a temperature of 50 to 150°C, preferably for 1 to 72 hours.

The treatment method of the invention can be used to enhance the activity and/or selectivity of the the present mesoporous crystalline materials for a wide range of catalytic conversion processes. Examples of such processes include cracking and hydrocracking, especially of high molecular weight, high boiling or non-distillable feeds, particularly residual feeds, NOx reduction and oligomerization of olefins, for example to produce high viscosity lubricants. The treated material of the invention can also be used as a sorbent.

In order to more fully illustrate the nature of the invention and the manner of practicing same, the following examples are presented. In the examples, whenever sorption data are set forth for comparison of sorptive capacities for water, cyclohexane, benzene and/or n-hexane, they are equilibrium adsorption values determined as follows:

A weighed sample of the adsorbent, after calcination at about 540°C for at least about 1 hour and other treatment, if necessary, to remove any pore blocking contaminants, is contacted with the desired pure adsorbate vapor in an adsorption chamber. The increase in weight of the adsorbent is calculated as the adsorption capacity of the sample in terms of grams/100 grams adsorbent based on adsorbent weight after calcination at about 540°C. The present composition exhibits an equilibrium benzene adsorption capacity at (6.7 kPa) 50 Torr and 25^DC of greater than about 15 grams/100 grams, particularly greater than about 17.5 grams/100 grams and more particularly greater than about 20 grams/100 grams.

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-17A preferred way to determine equilibrium adsorption values is to contact the desired pure adsorbate vapor in an adsorption chamber evacuated to less than 1 mm at conditions of 1.6 kPa (12 Torr) of water vapor, 5.3 kPa (40 Torr) of n-hexane or cyclohexane vapor, or 6.7 kPa (50 Torr) of benzene vapor, at 25°C. The pressure is kept constant (within about + 0.5 mm) by addition of adsorbate vapor controlled by a manostat during the adsorption period. As adsorbate is adsorbed by the crystalline material, the decrease in pressure causes the manostat to open a valve which admits more adsorbate vapor to the chamber to restore the above control pressures. Sorption is complete when the pressure change is not sufficient to activate the manostat.

Another method for benzene adsorption data is on a suitable thermogravimetric analysis system, such as a

TM computer-controlled 990/951 duPont TGA system. The adsorbent sample is dehydrated (physically sorbed water removed) by heating at, for example, about 350°C or 500*C to constant weight in flowing helium. If the sample is in as-synthesized form, e.g. containing organic directing agents, it is calcined at about 540°C in air and held to constant weight instead of the previously described 350^eC or 500^eC treatment. Benzene adsorption isotherms are measured at 25^eC by blending a benzene saturated helium gas stream with a pure helium gas stream in the proper proportions to obtain the desired benzene partial pressure. The value of the adsorption at 6.7 kPa (50 Torr) of benzene is taken from a plot of adsorption isotherm.

In the examples, percentages are by weight unless otherwise indicated.

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-18EXAMPLE 1

A solution of 2,7 grains of NaA10₂ (43.5% A1₂O₃, 30% Na₂0) in 146.9 grains of water was mixed with 34.5 grains of NaOH, 189.1 grams of cetyltrimethylairnnonium hydroxide solution prepared by contacting a 29 wt % ⁵ N,N_rN-trimethyl-l-hexadecanaminium chloride solution with an excess of hydroxide for halide resin, and 110.7

TM grams of Ultrasil (92% SiO₂) . After stirring overnight it was loaded into a 600 cc autoclave and reacted at 150^eC with 400 rpm stirring for 72 hours. The mixture had the following relative molar composition:

<td> 0.25</td><td> moles</td><td> A1₂O₃</td>

<td> 10</td><td> moles</td><td> Na₂0</td>

<td> 36</td><td> moles</td><td> SiO₂</td>

<td> 2.5</td><td> moles</td><td> (CTMA)2O</td>

<td> 362.5</td><td> moles</td><td> H₂O</td>

Following filtration of the mixture, the solid product which precipitated from the filtrate was recovered by filtration, washed with water, then calcined at 550“C for 10 hours in air.

The calcined product proved to have a surface area of 1193 m2/g and the following equilibrium adsorption capacities in grams/100 grams anhydrous sorbent:

<td> H2O</td><td> 10.2</td>

<td> Cyclohexane</td><td> &gt; 50</td>

<td> n-Hexane</td><td> 48.9</td>

<td> Benzene</td><td> 68.1</td>

The X-ray diffraction pattern of the calcined product of this example may be characterized as including a very strong relative intensity line at 50.7 30 +_ 3.0 Angstroms d-spacing and a weak line at 30.7 +_

1.0 Angstroms.

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<img file="CA2069722C_D0006.tif" />

EXAMPLE 2

A 0.50 gram portion of a calcined product prepared as in Example 1 was added to a rapidly stirred solution of 10 grains chlorotrimethylsilane in 15 grams hexamethyldisiloxane. The mixture was refluxed under N2 overnight, cooled, the reagents removed on a rotary evaporator, the product washed with two 10 mL portions of acetone and air dried to yield 0.53 grams of product.

A solid state magic angle spinning NMR spectrum of this product was obtained using 90 degree pulses at 1200 s intervals with proton decoupling. This spectrum showed peaks at 15 and -108 ppm. The peak at 15 ppm has been assigned to trimethylsilyl groups (T. Yanagisawa, et al., Reactivity of Solids, Vol. 5, 167 (1988)) and shows that the product has reacted. Integration of the two peaks showed that 17.9% of the silicons in the original product had been converted.

The internal pore volume of the trimethylsilylated product was compared to that of the starting material by both benzene sorption and argon physisorption. The total reduction in pore volume was measured as 48% by benzene and 34% by argon. The diameter of the TMS group was measured to be about 0.4-0.5 nm from CPK molecular models. An onion skin coating of TMS groups on the inside of the pore should, therefore, cause a decrease of 0.8-1.0 nm in pore diameter. The Horvath-Kowazoe transform of the argon isotherm shows the pore diameter to have decreased from 3.94 to 3.04 nm (0.90 nm) in agreement with what was predicted from the models.

Water sorption was measured before and after the chlorotrimethylsilane treatment. The calcined product of Example 1 sorbed 10.0 weight percent water at 30°C and 12.5 torr while the treated material sorbed 3.3 weight percent water. This demonstrates that

CA 02069722 2001-11-21 trichloromethylsilane treatment increases the hydrophobic character of the novel crystalline material.

EXAMPLE 3

A 0.50 gram portion of a product prepared as in Example 1 was added to a rapidly stirred solution of 15 mL hexamethyldisilazane in 15 grams hexamethyldisiloxane. The mixture was refluxed under N₂overnight, cooled, the reagents removed on a rotary evaporator, the product washed with two 10 mL portions of acetone and air dried to yield 0.52 grams of product.

A solid state magic angle spinning NMR spectrum of this product obtained using 90 degree pulses at 1200 s intervals with proton decoupling. This spectrum showed peaks at 15 and -108 ppm. The peak 15 ppm has been assigned to trimethylsilyl groups (Id.) and shows that the product has reacted. Integration of the two peaks showed that 16.8% of the silicons in the original product had been converted. Within the experimental error of the Si-nmr experiment, the conversion by chlorotrimethylsilane and hexamethyldisilazane was the same.

Examples 2 and 3 show pore size reduction using the treatment method of the invention.

EXAMPLE 4

Four hundred grams of cetyltrimethylammonium (CTMA) hydroxide solution, prepared by contacting a 29 wt% N,N,N-trimethyl-l-hexadecanaminium chloride solution with an excess of hydroxide-for-halide resin, was combined with two hundred grams of tétraméthylammonium (TMA) silicate solution (10% by wt. silica, l:l,TMA:Si) with stirring. Fifty grams of

TM

HiSil, a precipitated hydrated silica containing about wt% free water and about 4.5 wt% bound water of hydration and having an ultimate particle size of about

CA 02069722 2001-11-21

-210.02 micron, was added. The resulting mixture was placed in a polypropylene bottle and put into a steam box (about 100°C) for 48 hours. The mixture had a composition in terms of moles per mole of AI2O3:

<td> 391.4</td><td> moles</td><td> of</td><td> SiO₂</td>

<td> 71.4</td><td> moles</td><td> of</td><td> (CTMA)20</td>

<td> 61.6</td><td> moles</td><td> of</td><td> (TMA)2O</td>

<td> 9144</td><td> moles</td><td> of</td><td> h₂o</td>

The resulting solid product was recovered by filtration and dried in air at ambient temperature. The chemical analyses of the as-synthesized product were:

<td> SiO₂</td><td> 23.7</td><td> wt%</td>

<td> AI2O3</td><td> 0.2</td><td> wt%</td>

<td> N</td><td> 2.3</td><td> wt%</td>

<td> C</td><td> 33.9</td><td> wt%</td>

<td> Ash, 1000^eC</td><td> 22.1</td><td> wt%</td>

EXAMPLE 5

A portion of the product from Example 4 was then calcined at 540^eC for one hour in nitrogen, followed by six hours in air. The benzene sorption for this material was 39.5 wt%.

EXAMPLE 6

One gram of the air dried product of Example 4 was mixed with one gram titanium tetraethoxide at room temperature for overnight. The mixture was then reacted with 5 grams of water for one hour. The product was calcined in nitrogen at 538 ^eC for one hour then air for 6 hours at 538°C. The benzene sorption at 30’C was 25.0 wt%.

EXAMPLE 7

One gram of the air dried product of Example 4 was mixed with one gram aluminum tri-sec-butoxide at room temperature for overnight. The mixture was then

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<img file="CA2069722C_D0007.tif" />

reacted with 5 grains of water for one hour. The product was calcined in nitrogen at 538 °C for one hour then air for 6 hours at 538^DC. The benzene sorption at 30°C was 37.5 wt%.

EXAMPLE 8

Ten grams of the air-dried product from Example 4 was combined with Di-s-butoxyaluminoxytriethyoxylsilane (DBALS), on a 1/1 gram for gram basis, and fifty grams of absolute ethanol and allowed to mix overnight. This mixture was then combined with one hundred grams of water and stirred for one hour. The resulting solid product was recovered by filtration and dried in air at temperature. The functionalized product was then calcined at 54 0 °C for one hour in nitrogen, followed by six hours in air.

EXAMPLE 9

Ten grams of the air-dried product from Example 4 was combined with Di-s-butoxyaluminoxytriethyoxylsilane (DBALS), on a 1/1 gram for gram basis, and fifty grams of hexamethyldisiloxane and allowed to mix overnight. This mixture was combined with one hundred grams of water and stirred for one hour. The resulting solid product was recovered by filtration and dried in air at ambient temperature. The functionalized product was then calcined at 540^eC for one hour in nitrogen, followed by six hours in air.

EXAMPLE 10

Ten grams of the air-dried product from Example 4 was combined with Diethylphosphatoethyltriethoxysilane, on a 1/1 gram for gram basis, and fifty grams of absolute ethanol and allowed to mix overnight. This mixture was then combined with one hundred grams of water and stirred for one hour. The resulting solid product was recovered by filtration and dried in air at

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-232059722 ambient temperature. The functionalized product was then calcined at 540°C for one hour in nitrogen, followed by six hours in air.

EXAMPLE 11

Ten grams of the air-dried product from Example 4 was combined with Trimethylborate, on a 2/1 gram for gram basis, and fifty grams of absolute ethanol and allowed to mix overnight. This mixture was then combined with one hundred grams of water and stirred for one hour. The resulting solid product was recovered by filtration and dried in air at ambient temperature. The functionalized product was then calcined at 540^DC for one hour in nitrogen, followed by six hours in air.

EXAMPLE 12

Ten grams of the air-dried product from Example 4 was combined with 7.5 grams of aluminum isopropoxide and fifty grains of absolute ethanol and allowed to mix overnight. This mixture was then combined with one hundred grams of water and stirred for one hour. The resulting solid product was recovered by filtration and dried in air at ambient temperature. The functionalized product was then calcined at 540°C for one hour in nitrogen, followed by six hours in air.

Elemental Analysis of the product of untreated Example 4 is compared with the treated products of Example 8-12 in Table 1 below.

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-24TABLE 1

ELEMENTAL ANALYSES OF SYNTHESIS PRODUCTS

ASH

<td></td><td> C</td><td> N</td><td> Si</td><td> Al</td><td> P</td><td> B (1000C)</td>

<td> EX. 4</td><td> 33.0</td><td> 2.32</td><td> 10.9</td><td> 0.052</td><td> -</td><td> 22.1</td>

<td> Ex. 8</td><td> -</td><td> -</td><td> 25.9</td><td> 11.2</td><td> -</td><td> 77.0</td>

<td> Ex. 9</td><td> -</td><td> -</td><td> 32.3</td><td> 5.2</td><td> -</td><td> 84.5</td>

<td> Ex. 10</td><td> -</td><td> -</td><td> 32.9</td><td> -</td><td> 4.7</td><td> 74.3</td>

<td> Ex. 11</td><td> -</td><td> -</td><td> 32.1</td><td> -</td><td> -</td><td> 2.6 76.3</td>

<td> Ex. 12</td><td> -</td><td> -</td><td> 16.2</td><td> 17.7</td><td> —</td><td> 80.8</td>

Examples 6-12 illustrate other types of functional groups which can be incorporated into the crystalline material using the method of the invention.

EXAMPLE 13

In this example, 1.65 grams of NaA10₂ was added to 80 grams of cetyltrimethylammonium hydroxide (CTMAOH) solution, prepared by contacting a 29 wt.% N,N,N-trimethyl-l-hexadecanaminium chloride solution with a hydroxide-for-halide exchange resin. The mixture was stirred until the NaA10₂ was completely dissolved. To this solution was added 40.0 grams of tétraméthylammonium silicate solution (10 wt.% SiO2), 10.0 grams of HiSil (90 wt.% SiO₂) , and 6.01 grams of

1,3,5-trimethylbenzene. The resulting mixture was stirred at room temperature for several minutes. The gel was then loaded into a 300 ml autoclave and heated to 105^eC while stirring at 150 RPM. After about 4 hours of heating, the reaction was quenched with cold water, and the contents removed. The product was filtered and washed several times with warm (60-70°C) distilled water and with acetone. The final product was calcined at 538*C in a N₂/air mixture for 8 hours. The gel reaction mixture had a composition in terms of moles per mole A1₂O₃ as follows:

CA 02069722 2001-11-21

<td> 1.25</td><td> moles</td><td> Na₂0</td>

<td> 27.8</td><td> moles</td><td> SiO₂</td>

<td> 5.1</td><td> moles</td><td> (CTMA)2O</td>

<td> 2.24</td><td> moles</td><td> (TMA)2O</td>

<td> 650</td><td> moles</td><td> H₂0</td>

<td> 6.91</td><td> moles</td><td> 1,3,5-trimethylbenzene</td>

The calcined product of this example proved to have a surface area of 948.6 m²/g and a benzene adsorption capacity of 64.0 wt.%.

EXAMPLE 14

One gram of the product of Example 13 was mixed with one gram tetr^ethylorthosilicate at room temperature for overnight. The mixture was then reacted with 5 grams of water for one hour. The product was calcined in nitrogen at 538 ”C for one hour then air for 6 hours at 538*C. The benzene sorption at 25’C was 40.0 wt%. Since the crystalline material had an initial benzene sorption of 64.0 wt%, the pore volume was reduced by 37% suggesting that the pore diameter was reduced by 8 Angstroms.

EXAMPLE 15

To 18.7 gm of N-clear (Na-silicate) dissolved in 30.0 gm of distilled water was added 1.2 gm of sulfuric acid dissolved in 10 gm of water. After allowing the resulting mixture to stir for ten minutes, 16.77 gm cetyltrimethylammonium bromide in 50.2 gm H₂0 was added and the resulting gel was allowed to stir for 0.5 h. At this point 20 gm of water was added to the reaction. The gel was then crystallized under static, autogenous conditions in a polypropylene bottle (100C). The resulting product was washed thoroughly with distilled water, dried and calcined to 538C. The X-ray diffraction pattern of the calcined product of this example included a very strong relative intensity line at 33.2 + 2.0 Angstroms d-spacing and weak lines at

CA 02069722 2001-11-21

19.8 + 1.0 Angstroms and 17.5 + 1.0 Angstroms. The benzene sorption for this material was 50%.

EXAMPLE 16

0.5 gm of the product of Example 15 was combined with 10 mL of (CH3)₂S:BH₃ in 20 mL of toluene. After stirring for ca. 5 minutes the solid was isolated by vacuum filtration_t washed with n-hexanes and then washed with acetone. The dried product was then calcined in air to 538°C.

The X-ray diffraction pattern of the product of this example included a very strong relative intensity line at 32.4 + 2.0 Angstroms d-spacing and weak lines at 19.5 + 1.0 and 17.2 + 1.0 Angstroms. The benzene sorption was 41 wt.%. Since the crystalline material of Example 15 had a benzene sorption value of 50%, the pore volume of the material of the present example appears to have been reduced.

EXAMPLE 17

Three grams of calcined crystalline material prepared as described in Example 4 were added to a solution of 0.14 grams chromium acetate monohydrate in 10 grams water. This mixture was reacted overnight at room temperature. Excess moisture was removed under vacuum. The catalyst was dried in nitrogen at 250°C for 5 hours then air at 600^eC for 9 hours. The temperature was lowered to 350^eC and the sample reduced in carbon monoxide for 30 minutes.

EXAMPLE 18

The product of Example 17 was contacted at 120°C with 1-decene at 1.91 LHSV. An oligomerization product was isolated and had a viscosity of 2419 centistokes (cS) at 40^eC and 238 cS at 100^eC. The calculated viscosity index was 237.

CA 02069722 2001-11-21

-27EXAMPLE 19

An oligomerization of 1-decene was carried out as in Example 18 except that the reaction temperature was increased to 182°C at 1.95 LHSV. The product was isolated by distillation and its viscosity was 197 cS at 40°C and 27.6 cS at 100^eC. The viscosity index was 178.

The products of the oligomerization of Examples 18 and 19 over a crystalline material treated according to the invention, have much higher viscosities than expected using prior art Cr/SiO₂ catalysts.