Zeolite with tuned aluminum content and mesoporosity
Compositions and methods for preparing mesoporous and/or mesostructured materials from low SAR zeolites are provided herewith. In particular, methods are provided that involve: (a) providing a low SAR zeolite, (b) optionally subjecting the low SAR zeolite to an acid framework modification, and (c) subjecting the framework-modified zeolite to a mesopore formation treatment. The resulting mesoporous zeolites can have bi-modal mesoporosity and higher aluminum contents relative to existing mesoporous zeolites.
1. A low SAR zeolite, wherein said low SAR zeolite is selected from the group consisting of a ZSM-5 having a silica to alumina molar ratio of 17 or less, wherein said low SAR zeolite has a total 20 to 300 A diameter mesopore volume of at least 0.08 cc/g and a dV/log(d) of at least 0.19.
2. The low SAR zeolite of claim 1 , wherein said low SAR zeolite has a mesopore ratio in the range of 0.1 to 0.9.
3. The low SAR zeolite of claim 1 , wherein said low SAR zeolite has a total 20 to 300 Å diameter mesopore volume in the range of 0.10 to 0.70 cc/g.
4. The low SAR zeolite of claim 1 , wherein said low SAR zeolite has a dV/log(d) in the range of 0.3 to 100 and a mesopore ratio in the range of 0.2 to 1.2.
5. A mesoporous zeolite, comprising a ZSM-5 zeolite having a silica to alumina molar ratio of 17 or less, wherein said mesoporous zeolite has a dV/log(d) in the range of 0.3 to 100, a mesopore ratio in the range of 0.2 to 1.2, and a total 20 to 300 A diameter mesopore volume of at least 0.08 cc/g.
6. The mesoporous zeolite of claim 5 , wherein said mesoporous zeolite has a crystalline content of at least 20 weight percent as measured by XRD.
7. The mesoporous zeolite of claim 5 , wherein said mesoporous zeolite has a total 20 to 80 Å diameter mesopore volume of at least 0.05 cc/g.
8. The mesoporous zeolite of claim 5 , wherein said mesoporous zeolite has a total 20 to 300 Å diameter mesopore volume of at least 0.10 cc/g.
9. The low SAR zeolite of claim 5 , wherein said mesoporous zeolite is said ZSM-5 having a silica to alumina molar ratio in the range of 2 to 16.