A PROCESS FOR PREPARING A ZEOLITIC MATERIAL HAVING A FRAMEWORK STRUCTURE TYPE RTH

Abstract

A process for preparing a zeolitic material having a framework structure type RTH and having a framework structure comprising a tetravalent element Y, a trivalent element X and oxygen, said process comprising (i) preparing a synthesis mixture comprising a zeolitic material having a framework structure type FAU and having a framework structure comprising the tetravalent element Y, the trivalent element X and oxygen, water, a source of a base, and an RTH framework structure type directing agent comprising a N-methyl-2, 6-dimethylpyridinium cation containing compound; (ii) subjecting the mixture obtained in (i) to hydrothermal crystallization conditions, obtaining the zeolitic material having a framework structure type RTH

Claims

1. A process for preparing a zeolitic material having a framework structure type RTH and having a framework structure comprising a tetravalent element Y, a trivalent element X, and oxygen, the process comprising: subjecting to hydrothermal crystallization conditions, a synthesis mixture comprising a zeolitic material having a FAU framework structure and having a framework structure comprising the tetravalent element Y, the trivalent element X, and oxygen, water, a source of a base, and an RTH framework structure directing agent comprising a N-methyl-2,6-dimethylpyridinium cation-comprising compound, to obtain the zeolitic material having an RTH framework structure, wherein Y is Si, Sn, Ti, Zr, and/or Ge, and wherein X is Al, B, In, and/or Ga.

2. The process of claim 1, wherein the N-methyl-2,6-dimethylpyridinium cation comprising compound is a salt.

3. The process of claim 1, wherein Y is Si.

4. The process of claim 1, wherein the zeolitic material having a framework structure type FAU is faujasite, zeolite Y, zeolite X, LSZ-210, US Y, or a mixture of two or more thereof.

5. The process of claim 1, wherein, in the synthesis mixture, a molar ratio of H.sub.2O relative to Y, calculated as H.sub.2O:YO.sub.2, is in a range of from 2:1 to 80:1.

6. The process of claim 1, wherein in the synthesis mixture, a molar ratio of the structure directing agent relative to Y, calculated as structure directing agent: YO.sub.2, is in a range of from 0.09:1 to 1:1.

7. The process of claim 1, wherein in the synthesis mixture, a molar ratio of the source of a base relative to Y, calculated as a source of a base: YO.sub.2, is in a range of from 0.02:1 to 0.32:1.

8. The process of claim 1, wherein the source of a base comprises a hydroxide.

9. The process of claim 1, wherein the synthesis mixture is prepared by a process comprising: preparing a mixture comprising a zeolitic material having a FAU framework structure and having a framework structure comprising the tetravalent element Y, the trivalent element X, and oxygen, water, and an RTH framework structure directing agent comprising a N methyl-2,6-dimethylpyridinium cation-comprising compound; adding a source of a base to the mixture obtained in the preparing, to the synthesis mixture.

10. The process of claim 1, wherein the hydrothermal crystallization conditions comprise a crystallization duration in a range of from 10 minutes to 20 hours.

11. The process of claim 1, wherein during hydrothermal crystallization, the synthesis mixture is not stirred.

12. The process of claim 1, further comprising: optionally, cooling the mixture obtained in the subjecting; separating the zeolitic material from the mixture obtained from the subjecting or the cooling; optionally, subjecting the zeolitic material obtained from the separating to ion-exchange conditions.

13. The process of claim 12, comprising the subjecting the zeolitic material obtained from the separating to the ion-exchange conditions, which subjecting comprises subjecting the zeolitic material obtained from the separating to the ion-exchange conditions comprising bringing a solution comprising ammonium ions in contact with the zeolitic material obtained from the separating, to obtain a zeolitic material having an RTH framework structure in its ammonium form; calcining the zeolitic material in its ammonium form in a gas atmosphere, to obtain an H-form of the zeolitic material; optionally subjecting the H form to ion-exchange conditions comprising bringing a solution comprising ions of one or more transition metals; and calcining the H form, optionally after ion-exchange, in a gas atmosphere.

14. A zeolitic material having an RTH framework structure and having a framework structure comprising a tetravalent element Y, a trivalent element X, and oxygen, wherein Y is Si, Sn, Ti, Zr, and/or Ge, and wherein X is Al, B, In, and/or Ga.

15. The zeolitic material of claim 14, wherein in the framework structure of the zeolitic material, a molar ratio of Y:X, calculated as a YO.sub.2: X.sub.2O.sub.3, is in the range of from 2: 1 to 25:1.

16. The zeolitic material of claim 14, having a BET specific surface area in a range of from 100 to 800 m.sup.2/g, and/or having a N.sub.2 micropore volume in a range of from 0.05 to 0.60 cm.sup.3/g.

17. The zeolitic material of claim 14, having an X-ray diffraction pattern comprising reflections with Cu K (1): a first diffraction angle 2 in a range of from 8.16 to 12.16 at an intensity in a range of from 20 to 40%; a second diffraction angle 2 in a range of from 16.86 to 20.86 at an intensity in a range of from 50 to 80%; a third diffraction angle 2 in a range of from 21.24 to 25.24 at an intensity in a range of from 52 to 82%; a fourth diffraction angle 2 in a range of from 23.10 to 27.10 at an intensity in a range of from 70 to 100%; a fifth diffraction angle 2 in a range of from 23.55 to 27.55 at an intensity in a range of from 70 to 100%; and a sixth diffraction angle 2 in a range of from 28.63 to 32.63 at an intensity in a range of from 30 to 50%, wherein 100% relates to the intensity of a maximum peak in the X-ray powder diffraction pattern.

18. The zeolitic material of claim 14, additionally comprising a transition metals.

19. The zeolitic material of claim 18, having a BET specific surface area in a range of from 100 to 800 m.sup.2/g, and/or having a N.sub.2 micropore volume in a range of from 0.05 to 0.60 cm.sup.3/g.

20. A catalytically active material, catalyst, or catalyst component, comprising the zeolitic material of claim 14.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0374] FIG. 1: shows .sup.13C NMR of N-methyl-2,6-dimethylpyridine iodide obtained according to a) of Example 1.

[0375] FIG. 2: shows .sup.1H NMR of N-methyl-2,6-dimethylpyridine iodide obtained according to a) of Example 1.

[0376] FIG. 3A a: shows the XRD pattern of the respectively obtained zeolitic material according to b) of Example 1.

[0377] FIG. 3B a: shows the N.sub.2 sorption isotherms of the respectively obtained fresh RTH zeolitic material according to b) of Example 1 illustrating that said material does not have any microporous adsorption and suggesting that the microporosity is fully filled with the organic template.

[0378] FIG. 3B b: shows the N.sub.2 sorption isotherms of the RTH zeolitic material according to b) of Example 1 after calcination at 550 C. for 4 hours, these isotherms show a Lang-muir-type curve. The steep increasing occurring in the curve at a relative pressure of 10.sup.6<P/P.sub.o<0.01 is due to the filing of the micropores by N.sub.2 which permits to calculate the BET specific surface area and the N.sub.2 micropore volume.

[0379] FIGS. 3C a: shows the SEM image of the respectively obtained fresh RTH zeolitic material (low magnification: scale bar 2 micrometers) according to b) of Example 1.

[0380] FIG. 3D a: shows the SEM image of the respectively obtained fresh RTH zeolitic material (high magnification: scale bar 500 nm) according to b) of Example 1.

[0381] FIG. 4: shows the crystallization curve of the zeolitic material according to b) of Example 1

[0382] FIG. 5: shows the thermal analysis TG-DTA of the respectively obtained RTH zeolitic material according to Example 1. A major exothermic peak at 200-800 C. is displayed accompanied by a weight loss of 22.4%, which is related to the decomposition of the organic template molecules in the framework.

[0383] FIG. 6: shows the XRD patterns of the respectively obtained zeolitic material after a crystallization temperature of 3 h (a), 6 h (b), 9 h (c), 10 h (d), 11 h (e), 12 h (f)-according to b) of Example 1-, 15 h (g), 288 h (h) and 432 h (i). After 3 h of crystallization, the XRD pattern of the zeolitic material shows the characteristic peaks of zeolite Y, namely a high intensity peak around 6 (2Theta), a high intensity peak around 12 (2Theta), a high intensity peak around 16 (2Theta), a high intensity peak around 24 (2Theta) and a high intensity peak around 27 (2Theta). After 6 h of crystallization, the XRD pattern still shows peaks related to zeolite Y. After 9 h of crystallization, the XRD pattern shows peaks associated with the framework structure type RTH at 25 (2Theta). After 10 and 11 h of crystallization, the intensity of the peaks at 25 (2Theta) increases. After 12 h of crystallization, the XRD pattern shows the characteristic peaks of a RTH framework structure. Further, increasing the duration of crystallization to 288 h and 432 h does not change the intensity of the peaks of the XRD patterns associated with the framework structure type RTH. This illustrates that the zeolitic material having a framework structure type RTH obtained according to the invention has a high stability in the synthesis mixture.

[0384] FIG. 7: shows the SEM image of the respectively obtained zeolitic material after a crystallization temperature of 3 h (a), 6 h (b), 9 h (c), 10 h (d), 11 h (e), 12 h (f)-according to b) of Example 1-, 15 h (g), 288 h (h) and 432 h (i). After 9 h of crystallization, block-like crystals appear indicating the formation of zeolitic materials having a framework structure type RTH. After 10 to 12 h of crystallization, the number of crystals increases.

[0385] FIG. 8: shows the XRD patterns of the respectively obtained fresh Cu-RTH zeolitic material according to Example 1 (a) and after ageing in air with 10 vol. % H.sub.2O at 750 C. for 16 hours (b).

[0386] FIG. 9: shows the N.sub.2 sorption isotherms of the respectively obtained fresh Cu-RTH zeolitic material according to Example 1 (a) and after ageing in air with 10 vol. % H.sub.2O at 750 C. for 16 hours (b), giving Langmuir-type curve. The isotherms for (b) are offset vertically by 20 cm.sup.3/g.

[0387] FIG. 10: shows the crystallization curve of the zeolitic material according to Example 2.

[0388] FIG. 11: shows the XRD patterns of the respectively obtained fresh Cu-RTH zeolitic material according to Example 2 (a) and according to Example 3 (b).

[0389] FIG. 12: shows the crystallization curve of the zeolitic material according to Example 3.

[0390] FIG. 13: shows .sup.13C, .sup.27Al, and .sup.29Si MAS NMR of the respectively obtained RTH zeolitic materials according to b) of Example 1, i.e. before ion-exchange, and to a) of Examples 2 and 3, i.e. before ion-exchange, obtained at different temperatures, namely 130, 180 and 240 C. respectively.

[0391] FIG. 13A: shows the comparison of the .sup.13C MAS NMR spectrum of the respectively obtained RTH zeolitic materials according to b) of Example 1, i.e. before ion-exchange, and to a) of Examples 2 and 3, i.e. before ion-exchange, with the liquid .sup.13C NMR spectrum of 2,6-methyl-N-methylpridinium iodide. It is apparent that 2,6-methyl-N-methylpyridinium cations mostly exist in the channel of the zeolitic materials having a framework structure type RTH obtained at different temperatures, namely 130, 180 and 240 C. respectively.

[0392] FIG. 13B: shows the .sup.27Al MAS NMR spectrum of the respectively obtained RTH zeolitic materials according to b) of Example 1, i.e. before ion-exchange, and to a) of Examples 2 and 3, i.e. before ion-exchange. The materials give a sharp band at 59 ppm associated with tetrahedral coordinated aluminum species in the framework and the absence of a signal around zero ppm indicates that there is no extra framework Al species in the sample.

[0393] FIG. 13C: shows the .sup.29Si MAS NMR spectrum of the respectively obtained RTH zeolitic materials according to b) of Example 1, i.e. before ion-exchange, and to a) of Examples 2 and 3, i.e. before ion-exchange. The materials exhibit peaks at about 112.2, 107.7, and 102.1 ppm. The peaks at 112.2 and 107.7 ppm are assigned to Si (4Si) species, while the peak at -102.1 ppm is assigned to Si(3Si) species. The signal intensity of Si(3Si) species is of 9.3% at the synthesis temperature of 130 C., while the signal intensity of Si(3Si) species are of 6.3% and 4.2% at the synthesis temperature of 180 and 240 C., respectively. Considering the same Si/Al ratios in the products, the lower intensity of Si(3Si) species means the less amounts of structure defects.

[0394] FIG. 14: shows .sup.1H NMR of 1,2,3-trimethylimidazolium iodide obtained according to a) of Comparative Example 1.

[0395] FIG. 15: shows the XRD patterns of the respectively obtained fresh RTH zeolitic material obtained according to b) of Comparative Example 1.

[0396] FIG. 16: shows the crystallization curve of the zeolitic material according to comparative Example 1.

[0397] FIG. 17: shows the XRD patterns of the respectively obtained fresh zeolite Y obtained according to Comparative Example 2.

[0398] FIG. 18: shows the XRD patterns of the respectively obtained mixture of fresh zeolitic materials Y and RTH obtained according to Comparative Example 3.

[0399] FIG. 19: shows the XRD patterns of the amorphous product obtained according to Comparative Example 4.

[0400] FIG. 20: shows the XRD patterns of the respectively obtained mixture of fresh zeolitic materials Y and RTH obtained according to Comparative Example 5.

[0401] FIG. 21: shows the XRD patterns of the respectively obtained fresh zeolite Y obtained according to Comparative Example 6.

[0402] FIG. 22: shows the NOx conversions of catalysts comprising a zeolitic material according to Examples 1 (a), 2 (b) and 3 (c) respectively and of a catalyst comprising a zeolitic material according to Example 1 after ageing at 750 C. (d).

[0403] FIG. 23: shows the .sup.27Al MAS NMR spectrum of the catalyst comprising a zeolitic material according to Example 1.

[0404] FIG. 24: shows the XRD patterns of the respectively obtained fresh zeolite RTH obtained according to Example 5, Table 1.

[0405] FIG. 25: shows the XRD patterns of the respectively obtained fresh zeolite RTH obtained according to Example 6, Table 1.

[0406] FIG. 26: shows the XRD patterns of the respectively obtained fresh zeolite RTH obtained according to Example 7, Table 1.

[0407] FIG. 27: shows the XRD patterns of the respectively obtained fresh zeolite RTH obtained according to Example 8, Table 1.

[0408] FIG. 28: shows the XRD patterns of the respectively obtained fresh zeolite RTH obtained according to Example 9, Table 1.

[0409] FIG. 29: shows the XRD patterns of the respectively obtained fresh zeolite RTH obtained according to Example 10, Table 1.

CITED LITERATURE

[0410] Greg S. Lee et al., Polymethylated [4.11] Octanes Leading to Zeolite SSZ_50, Journal of Solid State Chemistry 167, p. 289-298 (2002) [0411] Joel E. Schmidt et al., Facile preparation of Aluminosilicate RTH across a wide composition range using a new organic structure-directing agent, Chemistry of Materials (ACS Publications) 26, p. 7099-7105 (2014) [0412] US 2017/0050858 A1