Method for preparing zeolite catalyst

1. A method for manufacturing a zeolite catalyst, the method comprising steps of:

manufacturing a first Linde Type A (LTA) zeolite, which includes first ions, using an LTA seed;

manufacturing a second LTA zeolite including second ions by substituting the second ions in place of the first ions in the first LTA zeolite; and

manufacturing a copper LTA zeolite by substituting copper ions in place of the second ions in the second LTA zeolite;

wherein an Si/Al molar ratio of the zeolite catalyst is 5 to 30.

2. The method for of claim 1 , wherein the step of manufacturing the second LTA zeolite comprises mixing the first LTA zeolite with an ammonium salt solution to react them and then performing drying, and

wherein the ammonium salt is ammonium nitrate (NH 4 NO 3 ).

3. The method of claim 1 , wherein the step of substituting the copper ions in place of the second ions in the second LTA zeolite comprises: mixing the second LTA zeolite to a copper precursor solution and then stirring.

4. The method of claim 3 , further comprising, after the step of manufacturing the copper LTA zeolite: performing heat treatment on the copper LTA zeolite.

5. The method of claim 4 , wherein the heat treatment is performed while increasing a temperature to 400° C. to 750° C. at a rate of 1 to 30° C./min.

6. The method of claim 5 , wherein the heat treatment is performed for about 1 to 24 h.

7. A method for manufacturing a zeolite catalyst, the method comprising steps of:

manufacturing a first LTA zeolite, which includes first ions, using an LTA seed;

manufacturing a second LTA zeolite including ions by substituting second ions in place of ions in the first LTA zeolite; and

manufacturing an iron LTA zeolite by substituting iron ions in place of the second species ions in the second LTA zeolite.

8. The method of claim 7 , wherein the step of manufacturing the second LTA zeolite comprises: mixing the first LTA zeolite with an ammonium salt solution to react them and then performing drying, and

wherein the ammonium salt is ammonium nitrate (NH 4 NO 3 ).

9. The method of claim 8 , wherein the step of substituting the iron ions in place of the second ions in the second LTA zeolite further comprises: mixing the second LTA zeolite with at least one of iron(III) nitrate nonahydrate (Fe(NO 3 ) 3 .9H 2 O), sulfuric acid hydrate (FeSO 4 .7H 2 O), iron(II) oxalate dihydrate (FeC 2 O 4 .2H 2 O), and iron(III) chloride tetrahydrate (FeCl 2 .4H 2 O) and stirring.

10. The method of claim 9 , further comprising, after the step of substituting iron ions in place of the second ions in the second LTA zeolite:

performing heat treatment on the iron LTA zeolite.

11. The method for manufacturing the zeolite catalyst of claim 7 , wherein a Si/Al molar ratio of the zeolite catalyst is 5 to 30.

12. A method for manufacturing a zeolite catalyst, the method comprising:

preparing a first mixture by mixing a 1,2-dimethyl-3-(4-methylbenzyl)imidazolium hydroxide aqueous solution, aluminum hydroxide (Al(OH) 3 ), and tetramethylammonium hydroxide pentahydrate;

preparing a second mixture by mixing tetraethyl orthosilicate (TEOS) (Si(OC 2 H 5 ) 4 ) into the first mixture and then mixing an LTA seed thereto;

preparing a third mixture by evaporating ethanol and water contained in the second mixture;

preparing a first LTA zeolite by mixing a hydrofluoric aqueous solution into the third mixture, heating, and then performing drying;

preparing a second LTA zeolite including NH 4 + ions by mixing the first LTA zeolite with an ammonium nitrate (NH 4 NO 3 ) solution to react them and then drying; and

preparing a third LTA zeolite by mixing the second LTA zeolite with copper acetate monohydrate solution to react them and then performing drying.