Low silicon SAPO-42 and method of making
A porous crystalline silico-alumino-phosphate molecular sieve is described. The molecular sieve has a framework composition on an anhydrous and calcined basis expressed by an empirical formula (Si x Al y P z )O 2 where x is the mole fraction of Si and has a value from 0.001 to about 0.5, y is the mole fraction of Al and has a value of at least 0.01, z is the mole fraction of P has a value of at least 0.01, and x+y+z=1, where the molecular sieve is characterized as having a LTA framework with an average crystal size of less than 5 micrometers. Methods of making the molecular sieves are also described.
1. A porous crystalline silico-alumino-phosphate molecular sieve having a framework composition on an anhydrous and calcined basis expressed by an empirical formula
(Si x Al y P z )O 2
where x is the mole fraction of Si and has a value from 0.001 to about 0.15, y is the mole fraction of Al and has a value of at least 0.01, z is the mole fraction of P has a value of at least 0.01, and x+y+z=1, where the molecular sieve is characterized as having a LTA framework with an average crystal size of less than 5 μm.
2. The molecular sieve of claim 1 characterized in that it has the x-ray diffraction pattern having at least the d-spacings and intensities given in Table A below:
TABLE A
2Θ
d(Å)
I/Io
7.43-7.46
11.84-11.87
s-vs
10.51-10.52
8.38-8.4
m
12.88-12.9
6.85-6.86
vs
14.88-14.9
5.94-5.94
m
16.65-16.66
5.31-5.31
w
21.1-21.13
4.19-4.2
m
22.39-22.42
3.96-3.96
vs
23.61-23.63
3.75-3.76
w
24.79-24.82
3.58-3.58
m
26.99-27.02
3.29-3.29
m
28.03-28.05
3.17-3.17
m
30.96-30.97
2.88-2.88
m
31.87-31.89
2.8-2.8
w
35.35-35.36
2.53-2.53
w-m
45.7-45.73
1.98-1.98
w.
3. The molecular sieve of claim 1 where x has a value from about 0.005 to about 0.01.
4. A process for the preparation of a porous crystalline silico-alumino-phosphate molecular sieve having a framework composition on an anhydrous and calcined basis expressed by an empirical formula
(Si x Al y P z )O 2
where x is the mole fraction of Si and has a value from 0.001 to 0.5, y is the mole fraction of Al and has a value of at least 0.01, z is the mole fraction of P has a value of at least 0.01, and x+y+z=1, the process comprising:
providing a reaction mixture comprising an aluminum source, a silicon source comprising a zeolite selected from the group consisting of UZM-9, UZM-5, UZM-12, or combinations thereof, a phosphorous source, and a dual organic template source comprising an organic amine template source and a quaternary ammonium organic template source; and crystallizing the molecular sieves at a temperature between about 100° C. to about 200° C., to provide the molecular sieve, and calcining the molecular sieve in air, where the molecular sieve is characterized as having a LTA framework with an average crystal size of less than 5 μm.
5. The process of claim 4 characterized in that it has the x-ray diffraction pattern having at least the d-spacings and intensities given in Table A below
TABLE A
2Θ
d(Å)
I/Io
7.43-7.46
11.84-11.87
s-vs
10.51-10.52
8.38-8.4
m
12.88-12.9
6.85-6.86
vs
14.88-14.9
5.94-5.94
m
16.65-16.66
5.31-5.31
w
21.1-21.13
4.19-4.2
m
22.39-22.42
3.96-3.96
vs
23.61-23.63
3.75-3.76
w
24.79-24.82
3.58-3.58
m
26.99-27.02
3.29-3.29
m
28.03-28.05
3.17-3.17
m
30.96-30.97
2.88-2.88
m
31.87-31.89
2.8-2.8
w
35.35-35.36
2.53-2.53
w-m
45.7-45.73
1.98-1.98
w.
6. The process of claim 4 where x has a value from about 0.005 to about 0.15.
7. The process of claim 4 where x has a value from about 0.005 to about 0.01.
8. The process of claim 4 wherein the dual organic template source is present in the reaction mixture in an amount on a molar basis from about 0.5 to about 3.0 times an amount of the aluminum source.
9. The process of claim 4 wherein the dual organic template source is present in the reaction mixture in an amount on a molar basis from about 1.4 to about 2.5 times an amount of the phosphorous source.
10. The process of claim 4 wherein the quaternary ammonium organic template source is selected from the group consisting of tetramethylammonium hydroxide, tetramethylammonium fluoride, tetramethylammonium bromide, tetramethylammonium chloride, tetramethylphosphonium hydroxide, tetramethylphosphonium fluoride, or combinations thereof.
11. The process of claim 10 wherein the quaternary ammonium organic template source is tetramethylammonium fluoride.
12. The process of claim 4 wherein the organic amine template source is selected from the group consisting of diethanolamine, diisopropanolamine, or combinations thereof.
13. The process of claim 12 wherein the organic amine template source is diethanolamine.
14. The process of claim 4 wherein the silicon source comprises UZM-9.
15. The process of claim 4 wherein the reaction mixture is heated at a temperature in the range of about 125° C. to about 175° C. for a period of about 24 hr or less.
16. The process of claim 4 wherein the molecular sieve is calcined at a temperature in a range of about 550 to about 650° C.
17. The process of claim 4 the molecular sieve is stable to hydration after calcination.
18. The process of claim 4 wherein the average crystal size is less than about 2 μm.
19. The process of claim 4 wherein a ratio of the quaternary ammonium organic template source to the organic amine template source is in a range of about 0.05 to about 0.2.
20. A process for the preparation of a porous crystalline silico-alumino-phosphate molecular sieve having a framework composition on an anhydrous and calcined basis expressed by an empirical formula
(Si x Al y P z )O 2
where x is the mole fraction of Si and has a value from 0.001 to 0.5, y is the mole fraction of Al and has a value of at least 0.01, z is the mole fraction of P has a value of at least 0.01, and x+y+z=1, the process comprising:
providing a reaction mixture comprising an aluminum source, a silicon source comprising a zeolite selected from the group consisting of UZM-9, UZM-5, UZM-12, or combinations thereof, a phosphorous source, and a dual organic template source comprising an organic amine template source and a quaternary ammonium organic template source; and crystallizing the molecular sieves at a temperature between about 100° C. to about 200° C., to provide the molecular sieve, and calcining the molecular sieve in air, where the molecular sieve is characterized as having a LTA framework with an average crystal size of less than 5 μm;
wherein the quaternary ammonium organic template source is selected from the group consisting of tetramethylammonium hydroxide, tetramethylammonium fluoride, tetramethylammonium bromide, tetramethylammonium chloride, tetramethylphosphonium hydroxide, tetramethylphosphonium fluoride, or combinations thereof;
wherein the organic amine template source is selected from the group consisting of diethanolamine, diisopropanolamine, or combinations thereof;
wherein the dual organic template source is present in the reaction mixture in an amount on a molar basis from about 0.5 to about 2.5 times an amount of the aluminum source;
wherein the dual organic template source is present in the reaction mixture in an amount on a molar basis from about 1.4 to about 2.0 times an amount of the phosphorous source; and
wherein a ratio of the quaternary ammonium organic template source to the organic amine template source is in a range of about 0.05 to about 0.2.