Introduction of mesoporosity into zeolite materials with sequential acid, surfactant, and base treatment
View Patent ↗Compositions and methods for introducing mesoporosity into zeolitic materials employing sequential acid, surfactant, and base treatments are disclosed herein. Mesopores can be introduced into zeolitic materials, such as zeolites, by treatment with an acid and surfactant followed by treatment with a base. The resulting mesoporous zeolitic materials can have a total 20 to 135 Å diameter mesopore volume of at least 0.05 cc/g. Additionally, the resulting mesoporous zeolitic materials can have a total 0 to 20 Å micropore volume of at least 0.10 cc/g.
1. A method of forming a material comprising a mesoporous zeolitic material having long-range crystallinity, said method comprising:
(a) contacting an initial zeolitic material having long-range crystallinity with an acid to thereby form an acid-treated zeolitic material having long-range crystallinity, wherein said initial zeolitic material comprises zeolite A, faujasites, mordenite, CHA, ZSM-5, ZSM-12, ZSM-22, beta zeolite, synthetic ferrierite, synthetic mordenite, or mixtures thereof;
(b) contacting said acid-treated zeolitic material having long-range crystallinity with a surfactant to thereby form a first treatment mixture comprising said surfactant and an intermediate surfactant-treated material;
(c) recovering at least a portion of said intermediate surfactant-treated material from said first treatment mixture thereby forming an at least partially isolated intermediate surfactant-treated material; and
(d) contacting said at least partially isolated intermediate surfactant-treated material with a base thereby forming said mesoporous zeolitic material having long-range crystallinity.
2. The method of claim 1 , wherein said mesoporous zeolitic material having long-range crystallinity has a total 20 to 135 Å diameter mesopore volume of at least 0.1 cc/g.
3. The method of claim 1 , wherein said mesoporous zeolitic material having long-range crystallinity has a crystalline content of at least 40 weight percent as measured by X-ray diffraction (“XRD”).
4. The method of claim 3 , wherein said mesoporous zeolitic material having long-range crystallinity exhibits said crystalline content after steaming at 1,450° F. for 8 hours with 100% steam.
5. The method of claim 1 , wherein said mesoporous zeolitic material having long-range crystallinity has a total 20 to 135 Å diameter mesopore volume that is at least 0.05 cc/g greater than the 20 to 135 Å diameter mesopore volume of said initial zeolitic material having long-range crystallinity.
6. The method of claim 1 , wherein said mesoporous zeolitic material having long-range crystallinity is a mesostructured zeolite.
7. The method of claim 1 , wherein said mesoporous zeolitic material having long-range crystallinity has a total 0 to 20 Å diameter micropore volume in the range of from about 0.12 to about 0.25 cc/g.
8. The method of claim 1 , wherein said initial zeolitic material having long-range crystallinity is a zeolite.
9. The method of claim 1 , wherein said acid is present in an initial amount in the range of from about 0.5 to about 6 milliequivalents per gram of said initial zeolitic material having long-range crystallinity.
10. The method of claim 1 , wherein said acid is selected from the group consisting of hydrochloric acid, sulfuric acid, nitric acid, acetic acid, sulfonic acid, oxalic acid, citric acid, ethylenediaminetetraacetic acid, tartaric acid, malic acid, glutaric acid, succinic acid, and mixtures of two or more thereof.
11. The method of claim 1 , wherein said first treatment mixture comprises at least a portion of said acid, wherein said first treatment mixture has a pH in the range of from about 2 to about 6.
12. The method of claim 1 , wherein said surfactant is selected from the group consisting of cetyltrimethylammomium bromide, cetyltrimethylammonium chloride, and mixtures thereof.
13. The method of claim 1 , wherein said base is selected from the group consisting of NaOH, NH 4 OH, KOH, Na 2 CO 3 , TMAOH, and mixtures of two or more thereof.
14. The method of claim 1 , wherein said base is present in a ratio with the initial quantity of said initial zeolitic material in the range of from about 0.5 to 4 mmol per gram of initial zeolitic material.
15. The method of claim 1 , wherein said at least partially isolated intermediate surfactant-treated material comprises a cation of said surfactant in an amount in the range of from about 1 to about 30 weight percent.
16. A method of forming a material comprising a mesoporous zeolite, said method comprising:
(a) combining an initial zeolite with an acid and a surfactant to thereby form a treated zeolite, wherein said initial zeolite comprises zeolite A, faujasites, mordenite, CHA, ZSM-5, ZSM-12, ZSM-22, beta zeolite, synthetic ferrierite, synthetic mordenite, or mixtures thereof;
(b) recovering at least a portion of said treated zeolite to thereby form an at least partially isolated intermediate treated zeolite; and
(c) contacting said at least partially isolated intermediate treated zeolite with a base to thereby form said mesoporous zeolite.
17. The method of claim 16 , wherein said mesoporous zeolite has a total 20 to 135 Å diameter mesopore volume of at least 0.1 cc/g.
18. The method of claim 16 , wherein said mesoporous zeolite has a total 20 to 135 Å diameter mesopore volume in the range of from about 0.05 to about 0.35 cc/g, wherein said mesoporous zeolite exhibits said 20 to 135 Å diameter mesopore volume after steaming at 1,450° F. for 8 hours with 100% steam.
19. The method of claim 16 , wherein said mesoporous zeolite has a crystalline content of at least 50 weight percent as measured by X-ray diffraction (“XRD”), wherein said mesoporous zeolite exhibits said crystalline content after steaming at 1,450° F. for 8 hours with 100% steam.
20. The method of claim 16 , wherein said mesoporous zeolite has a total 20 to 135 Å diameter mesopore volume that is at least 0.04 cc/g greater than the 20 to 135 Å diameter mesopore volume of said initial zeolite.
21. The method of claim 16 , wherein said mesoporous zeolite is a mesostructured zeolite.
22. The method of claim 16 , wherein said mesoporous zeolite has a total 0 to 20 Å diameter micropore volume in the range of from about 0.12 to about 0.25 cc/g, wherein said mesoporous zeolite exhibits said 0 to 20 Å diameter micropore volume after steaming at 1,450° F. for 8 hours with 100% steam.
23. The method of claim 16 , wherein said initial zeolite comprises a zeolite Y selected from the group consisting of USY, NH 4 Y, NaY, a rare earth ion zeolite Y, or mixtures thereof.
24. The method of claim 16 , wherein said acid is selected from the group consisting of hydrochloric acid, sulfuric acid, nitric acid, acetic acid, sulfonic acid, oxalic acid, citric acid, ethylenediaminetetraacetic acid, tartaric acid, malic acid, glutaric acid, succinic acid, and mixtures of two or more thereof.
25. The method of claim 16 , wherein said acid is present in an initial amount in the range of from about 0.5 to about 6 milliequivalents per gram of initial zeolite.
26. The method of claim 16 , wherein said base is selected from the group consisting of NaOH, NH 4 OH, KOH, Na 2 CO 3 , TMAOH, and mixtures of two or more thereof.
27. The method of claim 16 , wherein said base is present in a ratio with the initial quantity of said initial zeolite in the range of from about 0.5 to 4 mmol per gram of initial zeolite.
28. The method of claim 16 , wherein said material comprises a composite material, wherein said composite material comprises at least one binder.
29. The method of claim 16 , wherein said surfactant is selected from the group consisting of cetyltrimethylammomium bromide, cetyltrimethylammonium chloride, and mixtures thereof.
30. The method of claim 1 , wherein said contacting of step (a) occurs in the substantial absence of hydrofluoric acid.
31. The method of claim 16 , wherein said combining of step (a) occurs in the substantial absence of hydrofluoric acid.