Molecular sieve SSZ-94, catalyst, and methods of use thereof
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.
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 . 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 . 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 . 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 . 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 . The molecular sieve of claim 1 , wherein the molecular sieve has a silicon oxide to aluminum oxide mole ratio of 25-50.
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 . 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 . The molecular sieve of claim 1 , which further comprises palladium, platinum, or a mixture thereof.
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 . 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 . 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 . 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 . 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 . 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)