Process for the production of a zeolitic material via interzeolitic conversion

Abstract

The present invention relates to a process for the preparation of a zeolitic material SiO.sub.2 and X.sub.2O.sub.3 in its framework structure, wherein X stands for a trivalent element, wherein said process comprises interzeolitic conversion of a first zeolitic material comprising SiO.sub.2 and X.sub.2O.sub.3 in its framework structure, wherein the first zeolitic material has an FER-, TON-, MTT-, BEA-, MEL-, MWW-, MFS-, and/or MFI-type framework structure to a second zeolitic material comprising SiO.sub.2 and X.sub.2O.sub.3 in its framework structure, wherein the second zeolitic material obtained in (2) has a different type of framework structure than the first zeolitic material. Furthermore, the present invention relates to a zeolitic material per se as obtainable and/or obtained according to the inventive process and to its use, in particular as a molecular sieve, as an adsorbent, for ion-exchange, or as a catalyst and/or as a catalyst support.

Claims

1. A process for preparing a zeolite material having a framework structure comprising SiO.sub.2 and X.sub.2O.sub.3, wherein X is a trivalent element, the process comprising: (1) preparing a mixture comprising a structure directing agent and a first zeolite material having a framework structure comprising SiO.sub.2 and X.sub.2O.sub.3, wherein the first zeolite material has an FER-, TON-, MTT-, BEA-, MEL-, MWW-, MIS-, and/or MFI-type framework structure; and (2) heating the mixture, to obtain a second zeolite material having a framework structure comprising SiO.sub.2 and X.sub.2O.sub.3, wherein the second zeolite material obtained in (2) has a different type of framework structure than the first zeolite material comprised in the mixture prepared in (1) wherein the second zeolite material obtained in (2) has a CHA-type framework structure or an AEI-type framework structure, and wherein the mixture prepared in (1) and heated in (2) further comprises one source for OH—, wherein said one source consists of sodium hydroxide.

2. The process of claim 1, wherein the mixture prepared in (1) further comprises a solvent.

3. The process of claim 1, wherein the second zeolite material obtained in (2) has a CHA-type framework structure.

4. The process of claim 1, wherein the second zeolite material obtained in (2) has an AEI-type framework structure.

5. The process of claim 1, wherein the structure directing agent comprises a tetraalkylammonium cation R.sup.1R.sup.2R.sup.3R.sup.4N+-containing compound, wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are independently from one another stand for alkyl, and wherein R.sup.3 and R.sup.4 form a common alkyl chain.

6. The process of claim 1, wherein the structure directing agent comprises a quaternary phosphonium cation R.sup.1R.sup.2R.sup.3R.sup.4P.sup.+-containing compound, wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are independently from one another optionally substituted and/or optionally branched (C.sub.1-C.sub.6)alkyl.

7. The process of claim 1, wherein X is selected from the group consisting of Al, B, In, Ga, and mixtures of two or more thereof.

8. The process of claim 1, wherein the heating in (2) is conducted under autogenous pressure.

9. The process of claim 1, further comprising (3) calcining the second zeolite material obtained in (2).

10. The process of claim 1, further comprising (4) subjecting the second zeolite material obtained in (2) to an ion-exchange procedure, optionally after calcining the second zeolite material.

11. A zeolite material, obtainable and/or obtained by the process of claim 1.

12. The zeolite material of claim 11, wherein the zeolite material has a CHA-type framework structure.

13. The zeolite material of claim 11, wherein the zeolite material has an AEI-type framework structure.

14. A process of producing a molecular sieve, an adsorbent, a catalyst and/or a catalyst support, the process comprising obtaining the zeolite material of claim 11.

Description

DESCRIPTION OF THE FIGURES

(1) FIG. 1 shows the x-ray diffraction pattern of the zeolitic material obtained according to Example 1. In the figure, the intensity in arbitrary units is plotted along the ordinate and the diffraction angle in ° 2 Theta is plotted along the abscissa.

(2) FIG. 2 shows the x-ray diffraction pattern of the zeolitic material obtained according to Example 2. In the figure, the intensity in arbitrary units is plotted along the ordinate and the diffraction angle in ° 2 Theta is plotted along the abscissa.

(3) FIG. 3: shows the NO.sub.x conversion relative to the applied reaction temperature in the range of from 100 to 550° C. in the selective catalytic reduction using ammonia over the zeolites Cu—Z—SSZ-39 (.circle-solid.-line designated as a), Cu—B—SSZ-39 (.box-tangle-solidup.-line designated as b) and Cu—Y—SSZ-39 (.square-solid.-line designated as c) according to Example 2, Example 1, and Reference Example 3, respectively, as catalysts.

EXPERIMENTAL SECTION

Reference Example 1: Synthesis of 1,1-diethyl-cis-2,6-dimethyl-piperidinium hydroxide (ROH)

(4) 1,1-diethyl-cis-2,6-dimethyl-piperidinium iodide was synthesized by dissolving 36 g of cis-2,6-dimethyl-piperidine and 200 g of iodoethane in 100 g of methanol, adding 64 g of KHCO.sub.3, then heating the mixture to 50° C. under stirring and keep it in a dark place for 4 days. The solvent and excess iodoethane were removed under rotary evaporation. The product was dissolved by trichloromethane. After removing the solid by filtration, the solvent was eliminated under rotary evaporation. The product was washed with ether. The product was converted from the iodide to the hydroxide form (denoted as ROH) using an anion exchange resin.

Reference Example 2: Synthesis of N,N-dimethyl-3,5-dimethylpiperidinium hydroxide (DMPOH) for Use as Organic Structure Directing Agent (OSDA)

(5) 24 g 3,5-dimethylpiperidine (98%, cis-trans mixture, TCI) were mixed with 220 ml methanol (99.9%, Wako) and 42 g potassium carbonate (99.5%, Wako). Then, 121 g methyl iodide (99.5%, Wako) were added dropwise, and the resulting mixture was heated under reflux for 1 day. After partially removing the methanol by evaporation, chloroform was added and the resulting suspension was stirred. Then, the solids fraction including potassium carbonate was removed by filtration. Then, the remaining mixture was concentrated anew by evaporation to completely remove remaining methanol. Chloroform was added to the resultant and the mixture was stirred. The mixture was subsequently filtered to remove remaining solids. For recrystallization, ethanol was added, and then diethylether was added to precipitate the iodide salt of the desired product. The solids were filtered off and then dried. After that, the solids were mixed with hydroxide ion exchange resin (DIAION SA10AOH, Mitsubishi) and distilled water. The resulting mixture was kept for 1 day. Then, the resin was removed by filtration and an aqueous solution of DMPOH was obtained. The solution had a density of 1.0396 g ml-1 and a molar concentration of 2.254 M.

Reference Example 3: Synthesis of an AEI Zeolite Using FAU Zeolite as Raw Material

(6) An AEI zeolite was prepared according to prior art Maruo, T. et al. in Chem. Lett. 2014, 43, page 302-304 by hydrothermal conversion of FAU zeolites in the presence of tetraethylphosphonium cations. The obtained AEI zeolite was ion-exchanged according to the method described herein for Examples 1 and 2 to obtain a Cu-exchanged AEI zeolite prepared from a zeolite Y. The obtained Cu-exchanged zeolite is also designated herein as Cu—Y—SSZ-39. The copper loading of the resulting Cu—Y—SSZ-39 was approximately 2.4 weight-%.

Example 1: Synthesis of AEI Zeolite Using BEA Zeolite as Raw Material

(7) With the organotemplate compound (ROH) obtained according to Reference Example 1, a synthetic mixture with a molar composition of 0.14 ROH:0.11-0.15 Na.sub.2O:1.0 SiO.sub.2:0.04 Al.sub.2O.sub.3:32 H.sub.2O was prepared by mixing BEA zeolite, ROH, sodium hydroxide, and deionized water. In a typical synthesis, 1 g of zeolite beta (from NANKAI Catalyst Company; Si:Al molar ratio=12.5) was mixed with 10 g of ROH solution (0.23 mol/L ROH) and stirred at room temperature for 2 h. Then, 0.20 g of NaOH was added. The synthesis mixture was stirred at room temperature for 2 h, transferred in a Teflon-lined autoclave oven and crystallized at 140° C. for 1-3 days. After filtrating, washing, and drying, the product was finally obtained.

(8) The x-ray diffraction pattern of the product is displayed in FIG. 1 and displays a reflection pattern characteristic of an AEI-type zeolitic material.

(9) The zeolite obtained displayed a BET surface area of 438 m.sup.2/g, a Langmuir surface area of 573 m.sup.2/g, a micropore area (t-plot) of 412 m.sup.2/g, and a micropore volume (t-plot) of 0.19 cm.sup.3/g.

(10) After calcining at 550° C. for 4 h, the calcined product was obtained, which is designated herein as B—SSZ-39. The H-form of the sample (H—B—SSZ-39) was prepared by ion-exchange with 1 M NH.sub.4NO.sub.3 solution and calcination at 550° C. for 4 h. This ion-exchange procedure was repeated once. The Cu-form of the sample (Cu—B—SSZ-39) was prepared by ion-exchange the H—B—SSZ-39 zeolite with 0.1 M Cu(NO.sub.3).sub.2 solution and calcination at 550° C. for 4 h. The copper loading of the resulting zeolite Cu—B—SSZ-39 was approximately 2.4 weight-%.

Example 2: Synthesis of AEI Zeolite Using ZSM-5 Zeolite as Raw Material

(11) With the organotemplate compound (ROH) obtained according to Reference Example 1, a synthetic mixture with a molar composition of 0.14 ROH:0.14 Na.sub.2O:1.0 SiO.sub.2:0.03 Al.sub.2O.sub.3:32 H.sub.2O was prepared by mixing ZSM-5 zeolite, ROH, sodium hydroxide, and deionized water. In a typical synthesis, 1 g of ZSM-5 zeolite (from NANKAI Catalyst Company; Si:Al molar ratio=16.7) was mixed with 10 g of ROH solution (0.23 mol/L ROH) and stirred at room temperature for 2 h. Then, 0.20 g of NaOH was added. After stirring at room temperature for 2 h, 0.02 g of H-AEI (SSZ-39) seeds was added. The synthesis mixture was stirred at room temperature for 15 minutes, transferred in a Teflon-lined autoclave oven and crystallized at 140° C. for 2-3 days. After filtrating, washing, and drying, the product was finally obtained.

(12) The x-ray diffraction pattern of the product is displayed in FIG. 2 and displays a reflection pattern characteristic of an AEI-type zeolitic material.

(13) Elemental analysis of the zeolite product revealed an Si:Al molar ratio of 9.5.

(14) After calcining at 550° C. for 4 h, the calcined product was obtained, which is designated herein as Z—SSZ-39. The H-form of the sample (H—Z—SSZ-39) was prepared by ion-exchange with 1 M NH.sub.4NO.sub.3 solution and calcination at 550° C. for 4 h. This ion-exchange procedure was repeated once. The Cu-form of the sample (Cu—Z—SSZ-39) was prepared by ion-exchange the H—Z—SSZ-39 zeolite with 0.1 M Cu(NO.sub.3).sub.2 solution and calcination at 550° C. for 4 h. The copper loading of the resulting Cu—Z—SSZ-39 was approximately 2.4 weight-%.

Examples 3-7: Synthesis of AEI Zeolite Using Different Zeolites as Starting Material

(15) AEI zeolites have been synthesized starting from zeolites having different framework structures. The general preparation method is disclosed in the following, whereby for each Example a zeolite has been used as starting material having the characteristics as listed in table 1. The molar composition of the reaction mixture is also listed in table 1.

(16) A reaction mixture with a molar composition as listed in table 1 was obtained by mixing a zeolite, DMPOH, sodium hydroxide, deionized water and SSZ-39 zeolite seeds. In a typical synthesis, 1 g of a zeolite was mixed with 10 g of DM POH solution (0.23 mol/L in water), stirring at room temperature for 2 h. Then, 0.31 g of sodium hydroxide was added. After stirring at room temperature for 2 h, 0.02 g of H-AEI (SSZ-39) zeolite seeds was added. After stirring for 10 min at room temperature, the mixture was transferred into a Teflon-lined autoclave oven and crystallized at 140° C. for 3 days under rotation conditions (50 rpm). After filtering, washing, drying, and calcining at 550° C. for 4 h, the product was finally obtained.

(17) After calcining at 550° C. for 4 h, the calcined product was obtained, which is designated herein as Z—SSZ-39. The H-form of the sample (H—Z—SSZ-39) was prepared by ion-exchange with 1 M NH.sub.4NO.sub.3 solution and calcination at 550° C. for 4 h. This ion-exchange procedure was repeated once. The Cu-form of the sample (Cu—Z—SSZ-39) was prepared by ion-exchange the H—Z—SSZ-39 zeolite with 0.1 M Cu(NO.sub.3).sub.2 solution and calcination at 550° C. for 4 h.

(18) TABLE-US-00001 TABLE 1 List of characteristics for the different zeolites used as starting materials in Examples 3-7 as well as molar composition of the reaction mixtures for each respective Example Molar ratio Si:Al of the Molar composition of reaction # Zeolite zeolite mixture Example 3 ZSM-35 30 1.0 SiO.sub.2:0.017 Al.sub.2O.sub.3:0.22 (FER) Na.sub.2O:0.14 DMPOH:30 H.sub.2O:0.02 seeds Example 4 ZSM-11 20 1.0 SiO.sub.2:0.025 Al.sub.2O.sub.3:0.22 (MEL) Na.sub.2O:0.14 DMPOH:30 H.sub.2O:0.02 seeds Example 5 ZSM-22 40 1.0 SiO.sub.2:0.013 Al.sub.2O.sub.3:0.22 (TON) Na.sub.2O:0.14 DMPOH:30 H.sub.2O:0.02 seeds Example 6 MCM-22 15 1.0 SiO.sub.2:0.030 Al.sub.2O.sub.3:0.22 (MWW) Na.sub.2O:0.14 DMPOH:30 H.sub.2O:0.02 seeds Example 7 ZSM-57 16.6 1.0 SiO.sub.2:0.030 Al.sub.2O.sub.3:0.11 (MFS) Na.sub.2O:0.14 DMPOH:30 H.sub.2O:0.02 seeds

Example 8: NO.SUB.x .Conversion in Selective Catalytic Reduction Using Ammonia (NH.SUB.3.—SCR)

(19) FIG. 3 shows the dependence of NO.sub.x conversion on reaction temperature in the range of from 100 to 550° C. in the selective catalytic reduction using ammonia over the zeolites Cu—Z—SSZ-39 (.circle-solid.-line designated as a), Cu—B—SSZ-39 (.box-tangle-solidup.-line designated as b) and Cu—Y—SSZ-39 (.square-solid.-line designated as c) as catalysts with similar copper loading (2.4 weight-%). As it can be seen from the figure, both Cu—Z—SSZ-39 and Cu—B—SSZ-39 catalysts exhibit excellent catalytic performances, which are completely comparable with those of the Cu—Y—SSZ-39 catalyst. In particular, it can be seen that the conversion of both Cu—Z—SSZ-39 and Cu—B—SSZ-39 is higher in the range of from 200 to 350° C. than of Cu—Y—SSZ-39.

LIST OF THE CITED PRIOR ART REFERENCES

(20) Moliner, M. et al. in Chem. Commun. 2012, 48, pages 8264-8266 Martin, N. et al. in Chem. Commun. 2015, 51, 11030-11033 Maruo, T. et al. in Chem. Lett. 2014, 43, page 302-304 Unpublished international patent application PCT/CN2017/115938 Unpublished international patent application PCT/CN2017/112343 U.S. Pat. No. 5,958,370