Synthesis of aluminum-containing molecular sieve SSZ-60
View Patent ↗A method for preparing an aluminosilicate molecular sieve having the SSY framework structure is described. The method includes (1) a step of preparing a reaction mixture containing an aluminosilicate zeolite having an FAU framework type; N-ethyl-N-(3,3,5-trimethylcyclohexyl)pyrrolidinium cations and/or N-ethyl-N-(2,4,4-trimethylcyclopentyl)pyrrolidinium cations; an alkali metal; hydroxide ions; seed crystals; and water; and (2) a step of subjecting the reaction mixture to crystallization conditions sufficient to form crystals of the aluminosilicate molecular sieve. The resulting molecular sieves are useful as catalysts, particularly when used in combination with exchanged transition metal(s).
1. A method of synthesizing an aluminosilicate molecular sieve having an SSY framework, the method comprising:
(1) preparing a reaction mixture consisting essentially of:
(a) a source of aluminum and silicon, where the source of both aluminum and silicon is an aluminosilicate zeolite having an FAU framework;
(b) a structure directing agent [Q] selected from the group consisting of N-ethyl-N-(3,3,5-trimethylcyclohexyl) pyrrolidinium cations, N-ethyl-N-(2,4,4-trimethylcyclopentyl) pyrrolidinium cations, and a combination thereof;
(c) a source of an alkali metal [M];
(d) a source of hydroxide ions;
(e) seed crystals; and
(f) water; and
(2) heating the reaction mixture to obtain the aluminosilicate molecular sieve having an SSY framework.
2. The method of claim 1 , wherein the reaction mixture has a composition, in terms of molar ratios, as follows:
SiO 2 /Al 2 O 3
20 to 200
Q/SiO 2
0.05 to 0.50
M/SiO 2
0.10 to 0.80
OH/SiO 2
0.10 to 1.00
H 2 O/SiO 2
10 to 80.
3. The method of claim 1 , wherein the reaction mixture has a composition, in terms of molar ratios, as follows:
SiO 2 /Al 2 O 3
30 to 100
Q/SiO 2
0.15 to 0.40
M/SiO 2
0.20 to 0.50
OH/SiO 2
0.20 to 0.80
H 2 O/SiO 2
15 to 50.
4. The method of claim 1 , wherein the aluminosilicate zeolite having the FAU framework is zeolite Y.
5. The method of claim 1 , wherein the alkali metal comprises sodium, potassium, or a mixture of sodium and potassium.
6. The method of claim 1 , wherein the seed crystals comprise a crystalline molecular sieve having an SSY framework.
7. The method of claim 1 , wherein, in the reaction mixture, a weight ratio of the seed crystals relative to silica in the aluminosilicate zeolite having the FAU framework is in a range of from 0.001:1 to 0.2:1.
8. The method of claim 1 , wherein the heating is conducted under autogenous pressure at a temperature of from 100° C. to 200° C.