Method for producing AEI zeolite
Provided is a production method by which an AEI zeolite is obtained without inducing a structural transformation in a crystalline aluminosilicate having a Y-structure and without using fluorine or phosphorus, the method including a crystallization step of crystallizing a composition containing an alumina source, a silica source, a structure directing agent, a sodium source, and water, a weight proportion of crystalline aluminosilicate relative to a total weight of the alumina source and the silica source being from 0 wt. % to 10 wt. %, and the crystallization step satisfying at least one of the following conditions: a molar ratio of hydroxide ion to silica in the composition is 0.45 or greater, the composition contains a cation represented by (CH 3 ) 3 RN + (R represents an alkyl group having from 1 to 4 carbons, and the alkyl group may contain at least one substituent), and the crystallization time is 80 hours or longer.
1. A method for producing an AEI zeolite, the method comprising crystallizing a composition containing an alumina source, a silica source, a structure directing agent, a sodium source, and water,
a weight proportion of crystalline aluminosilicate relative to a total weight of the alumina source and the silica source being from 0 wt. % to 10 wt. %, and wherein
the composition contains a cation represented by (CH 3 ) 3 RN + , where R represents an alkyl group having from 1 to 4 carbons, and the alkyl group may contain at least one substituent.
2. The method according to claim 1 , wherein the alumina source is an amorphous alumina compound.
3. The method according to claim 1 , wherein the alumina source is at least one type selected from the group consisting of aluminum sulfate, aluminum chloride, aluminum hydroxide, pseudoboehmite, alumina sol, and amorphous aluminosilicate.
4. The method according to claim 1 , wherein the structure directing agent is a piperidinium cation.
5. The method according to claim 1 , wherein the structure directing agent is at least one type selected from the group consisting of 1,1,3,5-tetramethylpiperidinium cation, 1,1-diethyl-2,6-dimethylpiperidinium cation, 1,1,2,6-tetramethylpiperidinium cation, 1-ethyl-1,2,6-trimethylpiperidinium cation, and 1,1,2-triethylpiperidinium cation.
6. The method according to claim 1 , wherein the composition does not contain crystalline aluminosilicate having a Y-structure.
7. The method according to claim 1 , wherein a fluorine content in the composition is 100 ppm by weight or less.
8. The method according to claim 1 , wherein a molar ratio of silica to alumina of the AEI zeolite is 100 or less.
9. The method according to claim 1 , wherein the cation is at least one type selected from the group consisting of tetramethylammonium, ethyltrimethylammonium, (2-hydroxyethyl)trimethylammonium, and (2-hydroxypropyl)trimethyl ammonium.
10. The method according to claim 1 , wherein a molar ratio of hydroxide ion to silica in the composition is less than 0.45.
11. The method according to claim 1 , wherein a molar ratio of hydroxide ion to silica in the composition is 0.45 or greater.