High silica AEI zeolite
Provided are a novel form of AEI zeolite, a novel synthesis technique for producing pure phase AEI zeolite, a catalyst comprising the AEI zeolite in combination with a metal, and methods of using the same.
1. A method for making an aluminosilicate zeolite having an AEI framework comprising reacting a synthesis gel comprising at least one zeolite, a structure directing agent (SDA) at a temperature of at least about 100° C. until crystals of AEI zeolite form; wherein the at least one zeolite is the only silica and aluminum source.
2. The method of claim 1 , wherein the AEI zeolite crystals are at least about 90% phase pure.
3. The method of claim 1 , wherein the AEI zeolite crystals have an SAR of about 20 to about 50.
4. The method of claim 1 , wherein the AEI zeolite crystals have a mean crystal size of at least about 100 nm.
5. The method of claim 1 , wherein the at least one zeolite is zeolite Y.
6. The method of claim 1 , wherein the at least one zeolite comprises two or more zeolite Y having different silica-to-alumina ratios.
7. The method of claim 1 , wherein the synthesis gel comprises an alkaline metal source with a molar ratio of alkaline metal to alumina is no more than about 2.
8. The method of claim 1 , wherein the synthesis gel has one or more of the following compositional molar ratios:
SiO 2 /Al 2 O 3 of about 20 to about 60;
Na 2 O/Al 2 O 3 of about 0.5 to about 2;
SDA 2 O/Al 2 O 3 of about 3 to about 10;
H 2 O/Al 2 O 3 of about 600 to about 2500; and/or
OH − /SiO 2 of about 0.4 to about 0.6.
9. The method of claim 1 , wherein the SDA comprises 2,6-N,N-diethyl-cis 2,6-dimethylpiperidium.
10. The method of claim 1 , wherein the reacting step is performed at a temperature of about 120 to about 180° C. for about 2 to about 15 days.
11. The method of claim 1 , wherein the relative yield on silica is at least about 30%.