Process for preparing a zeolitic material having a framework type FER

Abstract

The present invention relates to a process for preparing a zeolitic material having a framework type FER and having a framework structure comprising silicon, aluminum, and oxygen, said process comprising (i) preparing an aqueous synthesis mixture comprising water; a zeolitic material having a framework type other than FER and having a framework structure comprising silicon, aluminum, and oxygen; a source of silicon other than the zeolitic material having a framework type other than FER; an organic structure directing agent comprising piperidine; a source of an alkali metal; and a source of a base; (ii) subjecting the aqueous synthesis mixture prepared according to (i) to hydrothermal synthesis conditions comprising heating the synthesis mixture to a temperature in the range of from 140 to 190° C. and keeping the synthesis mixture at a temperature in this range under autogenous pressure, obtaining a mother liquor comprising a solid material which comprises the zeolitic material having a framework type FER.

Claims

1. A process for preparing a zeolitic material having a framework type FER and having a framework structure comprising silicon, aluminum, and oxygen, the process comprising: preparing an aqueous synthesis mixture comprising water; a zeolitic material having a framework type other than FER and having a framework structure comprising silicon, aluminum, and oxygen; a source of silicon other than the zeolitic material having a framework type other than FER; an organic structure directing agent comprising piperidine; a source of an alkali metal; and a source of a base; subjecting the aqueous synthesis mixture to hydrothermal synthesis conditions comprising heating the aqueous synthesis mixture to a temperature in the range of from 140 to 190° C. and keeping the synthesis mixture at a temperature in this range under autogenous pressure, obtaining a mother liquor comprising a solid material which comprises the zeolitic material having a framework type FER.

2. The process of claim 1, wherein in in the framework structure of the zeolitic material having a framework type other than FER, the molar ratio of silicon relative to aluminum, calculated as SiO.sub.2:Al.sub.2O.sub.3, is in the range of from 2:1 to 40:1.

3. The process of claim 1, wherein the framework type of the zeolitic material having a framework type other than FER is at least one selected from the group consisting of FAU, CHA, LEV, and AEI.

4. The process of claim 1, wherein the framework type of the zeolitic material having a framework type other than FER is CHA, wherein in the framework structure of the zeolitic material having a framework type other than FER, the molar ratio of silicon relative to aluminum, calculated as SiO.sub.2:Al.sub.2O.sub.3, is in the range of from 5:1 to 30:1.

5. The process of claim 1, wherein the framework type of the zeolitic material having a framework type other than FER is FAU, wherein in the framework structure of the zeolitic material having a framework type other than FER, the molar ratio of silicon relative to aluminum, calculated as SiO.sub.2:Al.sub.2O.sub.3, is in the range of from 2:1 to 8:1.

6. The process of claim 1, wherein the framework type of the zeolitic material having a framework type other than FER is AEI, wherein in the framework structure of the zeolitic material having a framework type other than FER, the molar ratio of silicon relative to aluminum, calculated as SiO.sub.2:Al.sub.2O.sub.3, is in the range of from 2:1 to 30:1.

7. The process of claim 1, wherein the framework type of the zeolitic material having a framework type other than FER is LEV, wherein in the framework structure of the zeolitic material having a framework type other than FER, the molar ratio of silicon relative to aluminum, calculated as SiO.sub.2:Al.sub.2O.sub.3, is in the range of from 2:1 to 30:1.

8. The process of claim 1, wherein the organic structure directing agent comprises from 95 to 100 weight-% piperidine and from 0 to 1 weight % hexamethylene imine, each relative to the weight of the organic structure directing agent.

9. The process of claim 1, wherein the source of silicon other than the zeolitic material having a framework type other than FER comprises at least one selected from the group consisting of a silicate, a silica gel, a silica sol, a silica powder, a solid silica gel, and a colloidal silica.

10. The process of claim 1, wherein in the aqueous synthesis mixture, the weight ratio of the zeolitic material having a framework type other than FER relative to the source of a base is in the range of from 1:1 to 1:4.

11. The process of claim 1, wherein the preparing the aqueous synthesis mixture comprises: mixing water with the source of an alkali metal and the source of a base, obtaining a first mixture; adding the source of silicon other than the zeolitic material having a framework type other than FER to the first mixture, obtaining a second mixture; adding the zeolitic material having a framework type other than FER to the second mixture, obtaining a third mixture; and adding the organic structure directing agent comprising piperidine to the third mixture, obtaining a fourth mixture; or wherein the preparing the aqueous synthesis mixture according to (i) comprises: mixing water with the source of an alkali metal and the source of a base, obtaining a first mixture; adding the organic structure directing agent comprising piperidine and the zeolitic material having a framework type other than FER to the first mixture, obtaining a second mixture; and adding the source of silicon other than the zeolitic material having a framework type other than FER to the second mixture, obtaining a third mixture.

12. The process of claim 1, further comprising: optionally cooling the mother liquor to a temperature in the range of from 10 to 50° C.; and separating the solid material from the mother liquor.

13. The process of claim 12, further comprising: calcining the solid material in a gas atmosphere having a temperature in the range of from 450 to 650° C.

14. The process of claim 12, further comprising subjecting the solid material to ion-exchange conditions.

15. The process of claim 14, wherein the subjecting the solid material to ion-exchange conditions comprises bringing a solution comprising ammonium ions in contact with the solid material, obtaining a solid material in its ammonium form; optionally drying the solid material in its ammonium form in a gas atmosphere; optionally calcining the solid material in its ammonium form in a gas atmosphere, obtaining the H-form of the solid material; and bringing a solution comprising ions of one or more transition metals in contact with the solid material in its ammonium form or in contact with the H-form of the solid material.

16. A solid material comprising a zeolitic material having a framework type FER, or obtained by the process of claim 1.

17. The solid material of claim 16, having a molar ratio of silicon relative to aluminum, calculated as SiO.sub.2:Al.sub.2O.sub.3, in the range of from 2:1 to 150:1.

18. The solid material of claim 16, having a micropore volume in the range of from 0.01 to 0.50 ml/g.

19. A method for catalytic reduction of nitrogen oxides in an exhaust gas stream of a diesel engine, comprising contacting the solid material of claim 16 with the exhaust gas stream.

20. A method for isomerization of olefins, comprising contacting the solid material of claim 16 with the olefins.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) FIG. 1 shows the XRD patterns of the respectively obtained CHA zeolitic material according to Reference Example 3.

(2) FIG. 2 shows the NOx conversions of a fresh catalyst comprising the ion-exchanged solid material at 200 to 600° C. (X-NOx=NOx conversion).

(3) FIG. 3 shows the NOx conversions of an aged catalyst comprising the ion-exchanged solid material at 200 to 600° C. (X-NOx=NOx conversion).

CITED LITERATURE

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