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US-12623910-B2 - Molecular sieve SSZ-94, catalyst, and methods of use thereof

US12623910B2US 12623910 B2US12623910 B2US 12623910B2US-12623910-B2

Abstract

The present application pertains to family of new crystalline molecular sieves designated SSZ-94. Molecular sieve SSZ-94 is structurally similar to sieves falling within the MTT structure type such as SSZ-32x, SSZ-32, ZSM-23, EU-13, ISI-4, and KZ-1 family of molecular sieves. SSZ-94 is characterized as having magnesium.

Inventors

  • Adeola Florence Ojo

Assignees

  • CHEVRON U.S.A. INC.

Dates

Publication Date
20260512
Application Date
20220324

Claims (15)

  1. 1 . A molecular sieve comprising an MTT framework, a mole ratio of from about 15 to about 100 of silicon oxide to aluminum oxide, a total micropore volume of between 0.02 and 0.05 cc/g, external surface area of between 80 and 120 m 2 /g and magnesium; wherein, the molecular sieve is prepared by the method comprising: (a) preparing a reaction mixture containing: at least one source of silicon, at least one source of aluminum, at least one source of an element selected from Groups 1 and 2 of the Periodic Table, at least one source of magnesium, hydroxide ions, hexamethonium cations, and water; and (b) subjecting the reaction mixture to crystallization conditions sufficient to form crystals of the molecular sieve.
  2. 2 . The molecular sieve of claim 1 , wherein the molecular sieve comprises a magnesium oxide to silicon dioxide ratio of from about 0.005 to about 0.4.
  3. 3 . The molecular sieve of claim 1 , wherein the molecular sieve comprises a magnesium oxide to silicon dioxide ratio of from about 0.01 to about 0.25.
  4. 4 . The molecular sieve of claim 1 , wherein the molecular sieve comprises a magnesium oxide to silicon dioxide ratio of from about 0.04 to about 0.22.
  5. 5 . The molecular sieve of claim 1 , wherein the molecular sieve comprises a magnesium oxide to silicon dioxide ratio of from about 0.05 to about 0.2.
  6. 6 . The molecular sieve of claim 1 , wherein the molecular sieve has a silicon oxide to aluminum oxide mole ratio of 25-50.
  7. 7 . The molecular sieve of claim 1 , wherein the molecular sieve is a product of a reaction mixture comprising a molar ratio of SiO 2 /Al 2 O 3 of from about 15 to about 100, of M/SiO 2 of from about 0.05 to about 0.4, of Q/SiO 2 of from about 0.05 to about 0.5, of OH/SiO 2 of from about 0.1 to about 0.4, of MgO/SiO 2 of from 0.005 to about 0.4, and of H 2 O/SiO 2 of from about 10 to about 300, wherein M is selected from Groups 1 and 2 of the Periodic Table and Q is a hexamethonium cation.
  8. 8 . The molecular sieve of claim 1 , wherein the molecular sieve is a product of a reaction mixture comprising a molar ratio of SiO 2 /Al 2 O 3 of from about 25 to about 50, of M/SiO 2 of from about 0.075 to about 0.3, of Q/SiO 2 of from about 0.1 to about 0.30, of OH/SiO 2 of from about 0.15 to about 0.30, of MgO/SiO 2 of from 0.01 to about 0.25, and of H 2 O/SiO 2 of from about 10 to about 70 wherein M is selected from Groups 1 and 2 of the Periodic Table and Q is a hexamethonium cation.
  9. 9 . The molecular sieve of claim 1 , which further comprises palladium, platinum, or a mixture thereof.
  10. 10 . The molecular sieve of claim 1 , wherein the molecular sieve has an external surface area of between 80 and 110 m 2 /g.
  11. 11 . The molecular sieve of claim 1 , wherein the molecular sieve is prepared from a reaction mixture comprising a molar ratio of SiO 2 /Al 2 O 3 of from about 15 to about 100, of M/SiO 2 of from about 0.05 to about 0.4, of Q/SiO 2 of from about 0.05 to about 0.5, of OH/SiO 2 of from about 0.1 to about 0.4, of MgO/SiO 2 of from 0.005 to about 0.4 and of H 2 O/SiO 2 of from about 10 to about 300 wherein M is selected from Groups 1 and 2 of the Periodic Table and Q is a hexamethonium cation.
  12. 12 . The molecular sieve of claim 1 , wherein the molecular sieve is prepared from a reaction mixture comprising a molar ratio of SiO 2 /Al 2 O 3 of from about 25 to about 50, of M/SiO 2 of from about 0.075 to about 0.3, of Q/SiO 2 of from about 0.1 to about 0.30, of OH/SiO 2 of from about 0.15 to about 0.30, of MgO/SiO 2 of from 0.01 to about 0.25 and of H 2 O/SiO 2 of from about 10 to about 70 wherein M is selected from Groups 1 and 2 of the Periodic Table and Q is a hexamethonium cation.
  13. 13 . The molecular sieve of claim 1 , wherein the molecular sieve is SSZ-94 prepared by the method comprising: (a) preparing a reaction mixture comprising: (i) at least one active source of silicon; (ii) at least one active source of aluminum; (iii) at least one active source of magnesium; (iv) at least one active source of an alkali metal; (v) hydroxide ions; and (vi) an organic templating agent consisting of at least one small, neutral amine capable of forming the zeolite, said amine containing four to about eight carbon atoms and (a) only carbon, nitrogen, and hydrogen atoms, (b) one primary, secondary or tertiary, but not quaternary, amino group, and (c) a tertiary nitrogen atom, or at least one tertiary carbon atom, or a nitrogen atom bonded directly to at least one secondary carbon atom; (b) maintaining the reaction mixture under conditions sufficient to form crystals of the zeolite wherein the zeolite is prepared in the absence of an amine component; and (c) recovering the crystals of the zeolite.
  14. 14 . The molecular sieve of claim 13 , wherein the reaction mixture has a composition in terms of mole ratios falling within the ranges below: SiO 2 /Al 2 O 3 molar ratio 15-100 H 2 O/SiO 2 molar ratio 5-100 OH − /SiO 2 molar ratio 0.07-1.0 M/SiO 2 molar ratio 0.05-0.5 MgO/SiO 2 molar ratio 0.005-0.4 Q/SiO 2 molar ratio 0.02-0.5 wherein: M is an alkali metal cation; and Q is the organic templating agent.
  15. 15 . The molecular sieve of claim 13 , wherein the zeolite has, in the calcined form, an X-ray diffraction pattern substantially as shown in the following Table: 2-Theta (a) d-spacing Relative Absolute (Degrees) (Angstroms) Intensity (%) (b) 8.11 10.888 m 8.80 10.045 w 11.32 7.813 m 14.64 6.046 vw 15.85 5.588 vw 16.32 5.427 vw 18.09 4.899 w 19.67 4.510 vs 20.93 4.241 vs 21.61 4.109 m 22.85 3.890 vs 24.04 3.699 vs 24.64 3.610 vs 25.21 3.530 s 25.96 3.430 s 27.03 3.296 w 28.27 3.155 w 29.38 3.037 vw 29.94 2.983 vw 31.59 2.830 w 33.10 2.704 vw 34.03 2.632 vw 35.49 2.527 s 36.51 2.459 w 37.77 2.380 w 38.52 2.335 w (a) ±0.20 (b) The powder XRD patterns provided are based on a relative intensity scale in which the strongest line in the X-ray pattern is assigned a value of 100: vw = very weak (>0 to <10); w = weak (10 to ≤20); m = medium (>20 to ≤40); s = strong (>40 to ≤60); vs = very strong (>60 to ≤100)

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to U.S. patent application Ser. No. 17/214,793, filed on Mar. 26, 2021, entitled “MOLECULAR SIEVE SSZ-94, CATALYST, AND METHODS OF USE THEREOF”, the disclosures of which are herein incorporated by reference in their entirety. TECHNICAL FIELD The present disclosure relates to catalysts having an MTT type structure with magnesium oxide referred to as molecular sieve SSZ-94 and methods of use thereof. BACKGROUND AND SUMMARY Because of their unique sieving characteristics, as well as their catalytic properties, crystalline molecular sieves and zeolites are especially useful in applications such as hydrocarbon conversion, gas drying and separation. Although many different crystalline molecular sieves have been disclosed, there is a continuing need for new molecular sieves with desirable properties for gas separation and drying, hydrocarbon and chemical conversions, and other applications. New molecular sieves may contain novel internal pore architectures and acid site properties, providing enhanced selectivities and activities in these processes. Molecular sieves are classified by the Structure Commission of the International Zeolite Association according to the rules of the IUPAC Commission on Zeolite Nomenclature. According to this classification, framework type zeolites and other crystalline microporous molecular sieves, for which a structure has been established, are assigned a three letter code and are described in the “Atlas of Zeolite Framework Types” Sixth Revised Edition, Elsevier (2007) Molecular sieves are periodically ordered in three dimensions. Structurally disordered structures show periodic ordering in dimensions less than three (i.e., in two, one or zero dimensions). This phenomenon is characterized as stacking disorder of structurally invariant Periodic Building Units (PerBuU). Crystal structures built from Periodic Building Units are called end-member structures if periodic ordering is achieved in all three dimensions. Disordered structures are those where the stacking sequence of the Periodic Building Units deviates from periodic ordering up to statistic stacking sequences. Molecular sieves having a MTT-type framework code have a one-dimensional 10-ring pore system. MTT-type molecular sieves have very similar, but not identical, X-ray diffraction patterns. SSZ-32 and its small crystal variant, SSZ-32x, are known MTT-type molecular sieves. SSZ-32 and methods for making it are disclosed in U.S. Pat. Nos. 5,707,600; 5,053,373; 5,300,210; and 5,397,454 which are incorporated herein by reference. It has now been found that by using the manufacturing methods described herein below, a novel molecular sieve designated herein as SSZ-94 is achieved. The present disclosure is directed to a family of crystalline molecular sieves with unique properties and a MTT-type topology, referred to herein as “molecular sieve SSZ-94” or simply “SSZ-94.” Advantageously, the present application pertains in one embodiment to a molecular sieve comprising an MTT-type framework, a mole ratio of from about 15 to about 100 of silicon oxide to aluminum oxide, a total micropore volume of between 0.02 and 0.05 cc/g, an external surface area of between 80 and 120 m2/g; and magnesium. In another embodiment the present application pertains to a process for converting hydrocarbons, comprising contacting a hydrocarbonaceous feed under hydrocarbon converting conditions with a catalyst. The catalyst comprises a molecular sieve comprising an MTT-type framework, a mole ratio of from about 15 to about 100 of silicon oxide to aluminum oxide, a total micropore volume of between 0.02 and 0.05 cc/g, an external surface area of between 80 and 120 m2/g and magnesium. In some embodiments the selectivity is improved over comparable catalysts lacking magnesium. Further features of the disclosed molecular sieve and the advantages offered thereby are explained in greater detail hereinafter with reference to specific example embodiments illustrated in the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 depicts an XRD powder diffraction of an SSZ-94 material of Example 1. FIG. 2 depicts an SEM of an SSZ-94 material of Example 1. FIG. 3 depicts an XRD powder diffraction of an SSZ-32 material of Comparative Example 2. FIG. 4 depicts an SEM of an SSZ-32 material of Comparative Example 2. DETAILED DESCRIPTION Although illustrative embodiments of one or more aspects are provided herein, the disclosed processes may be implemented using any number of techniques. The disclosure is not limited to the illustrative or specific embodiments, drawings, and techniques illustrated herein, including any exemplary designs and embodiments illustrated and described herein, and may be modified within the scope of the appended claims along with their full scope of equivalents. Unless otherwise indicated, the following terms, terminology, and definitions are applicable