AEI-TYPE ZEOLITIC MATERIAL OBTAINED FROM HIGH TEMPERATURE CALCINATION AND USE AS A CATALYST

Abstract

A process for preparing a zeolitic material having an AEI-type framework structure having SiO.sub.2 and X.sub.2O.sub.3 in its framework, X standing for a trivalent element, may involve: (1) preparing a mixture of structure directing agent(s) and a first zeolitic material with SiO.sub.2 and X.sub.2O.sub.3 in its framework, the first zeolitic material having a FER, TON, MTT, FAU, GIS, MOR, BEA, MFI, and LTA framework; (2) heating the mixture to obtain a second zeolitic material having an AEI-type framework with SiO.sub.2 and X.sub.2O.sub.3 in its framework; (3) optionally calcining the second zeolitic material; (4) optionally subjecting the zeolitic material from (2) or (3) to ion-exchange, preferably ion-exchanging ionic extra-framework element(s) in the zeolite framework for H.sup.+ and/or NH.sub.4.sup.+; (5) calcining the zeolitic material from (2), (3), or (4) at greater than 600 to 900° C., the calcining atmosphere containing less than 10 vol.-% of H.sub.2O. Such zeolites can convert oxygenates to olefins.

Claims

1. A process for preparing a zeolitic material, the process comprising: heating a mixture comprising a structure directing agent and a first zeolitic material comprising SiO.sub.2 and X.sub.2O.sub.3 in its framework structure, the first zeolitic material having a FER, TON, MTT, FAU, GIS, MOR, BEA, MFI, and/or LTA framework structure, to obtain a second zeolitic material having an AEI type framework structure comprising SiO.sub.2 and X.sub.2O.sub.3 in its framework structure, X being a trivalent element; optionally, first calcining the second zeolitic material; optionally, subjecting the second zeolitic material to ion-exchange; second calcining the second zeolitic material at a temperature in the range of from greater than 600 to 900° C., wherein the calcining of the second zeolitic material is effected under an atmosphere comprising less than 10 vol.-% of H.sub.2O.

2. The process of claim 1, wherein the first and/or second calcining is effected under air as the atmosphere.

3. The process of claim 1, wherein the heating comprises heating the mixture at a temperature in a range of from 90 to 250° C.

4. The process of claim 1, wherein the heating is conducted under autogenous pressure.

5. The process of claim 1, wherein the first calcining is conducted and an atmosphere under which the first calcining is effected contains H.sub.2 in a range of from 1 to 99 vol.

6. The process of claim 1, wherein X is Al, B, In, and/or Ga.

7. The process of claim 1, wherein the comprises OH.sup.− source.

8. The process of claim 1, wherein the structure directing agent comprises a tetraalkylammonium cation compound comprising R.sup.1R.sup.2R.sup.3R.sup.4N.sup.+, wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are independently alkyl, and wherein R.sup.3 and R.sup.4 form a common alkyl chain.

9. The process of claim 1, wherein the structure directing agent comprises a quaternary phosphonium cation compound comprising R.sup.1R.sup.2R.sup.3R.sup.4P.sup.+, wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are independently (C.sub.1-C.sub.6)alkyl.

10. A zeolitic material having an AEI typo framework structure, obtained by the process of claim 1.

11. A zeolitic material, having an AEI framework structure and comprising SiO.sub.2 and X.sub.2O.sub.3 in its framework structure, wherein X is a trivalent element, wherein a deconvoluted ammonia temperature programmed desorption spectrum of the zeolitic material displays a first peak in a range of from 205 to 270° C. and a second peak in a range of from 300 to 460° C., wherein an integration of the first peak affords an amount of acid sites in a range of from 0.07 to 0.35 mmol/g, and wherein an integration of the second peak affords an amount of acid sites in a range of from 0.25 to 0.4 mmol/g.

12. The zeolitic material of claim 11, wherein a ratio of an amount of acid sites from the integration of the first peak to an amount of acid sites from the integration of the second peak is in a range of from 0.35 to 0.7.

13. The zeolitic material of claim 11, having a CO-FTIR spectrum displaying a first peak in a range of from 3290 to 3315 cm.sup.−1, and a second peak in a range of from 3420 to 3470 cm.sup.−1, wherein a maximum absorbance of the second peak is equal to or greater than a maximum absorbance of the first peak.

14. A process for converting one or more oxygenates to one or more olefins, the process comprising contacting a gas stream, comprising an oxygenate.

15. A molecular sieve, catalyst, catalyst support, and/or as an adsorbent, comprising the zeolitic material of claim 11.

16. The process of claim 1, wherein X is Al.

17. The process of claim 1, wherein X is B.

18. The process of claim 1, wherein X is In.

19. The process of claim 1, wherein X is Ga.

Description

DESCRIPTION OF THE FIGURES

[0227] FIG. 1 shows the results from nitrogen adsorption/desorption measurements for determination of BET surface area and micropore volume performed on the materials of Examples 1 to 4 and Comparative Examples 1 and 2. In the figure, the Si/AI molar ratio is indicated as obtained from ICP-AES, the BET surface area, the total pore volume at P/P.sub.0=0.99, and the micropore volume as obtained by the t-plot method are displayed for the respective materials.

[0228] FIG. 2 shows the results from nitrogen adsorption/desorption measurements for determination of BET surface area and micropore volume performed on the materials of Examples 5 to 8 and Comparative Examples 3 and 4. In the figure, the Si/AI molar ratio is indicated as obtained from ICP-AES, the BET surface area, the total pore volume at P/P.sub.0=0.99, and the micropore volume as obtained by the t-plot method are displayed for the respective materials.

[0229] FIG. 3 shows the results from CO-FTIR measurements performed on the materials from Comparative Example 1, Example 1, and Example 2, respectively. In the figure, the absorbance in arbitrary units is displayed along the ordinate and the wavenumber in cm.sup.−1 is displayed along the abscissa.

[0230] FIG. 4 shows the results from CO-FTIR measurements performed on the materials from Comparative Example 2, Example 3, and Example 4, respectively. In the figure, the absorbance in arbitrary units is displayed along the ordinate and the wavenumber in cm.sup.−1 is displayed along the abscissa.

[0231] FIG. 5 shows the results from CO-FTIR measurements performed on the materials from Comparative Example 3, Example 5, and Example 6, respectively. In the figure, the absorbance in arbitrary units is displayed along the ordinate and the wavenumber in cm.sup.−1 is displayed along the abscissa.

[0232] FIG. 6 shows the results from CO-FTIR measurements performed on the materials from Comparative Example 4, Example 7, and Example 8, respectively. In the figure, the absorbance in arbitrary units is displayed along the ordinate and the wavenumber in cm.sup.−1 is displayed along the abscissa.

[0233] FIG. 7 displays the results from catalytic testing in Example 9 using the catalysts SSZ39(N)-A-600 (Comp. Example 1), SSZ-39(N)-A-700 (Example 1), and SSZ-39(N)A-800 (Example 2). In the figure, the conversion and selectivities in % are displayed along the ordinate and the time on stream in hours is displayed along the abscissa, wherein the conversion of methanol is indicated by the symbol “0”, the selectivity in ethylene by “.circle-solid.”, in propylene by “.square-solid.”, in butene by “.box-tangle-solidup.”, in C1-C4 alkanes by “”, in alkanes of C5 or more by “”, and in dimethylether by “.star-solid.”.

[0234] FIG. 8 displays the results from catalytic testing in Example 9 using the SSZ-39(N)-H-600 (Comp. Example 2), SSZ-39(N)-H-700 (Example 3), and SSZ-39(N)-H-800 (Example 4). In the figure, the conversion and selectivities in % are displayed as in FIG. 7.

[0235] FIG. 9 displays the results from catalytic testing in Example 9 using the catalysts SSZ39(P)-A-600 (Comp. Example 3), SSZ-39(P)-A-700 (Example 5), and SSZ-39(P)A-800 (Example 6). In the figure, the conversion and selectivities in % are displayed as in FIG. 7.

[0236] FIG. 10 displays the results from catalytic testing in Example 9 using the catalysts SSZ39(P)-H-600 (Comp. Example 4), SSZ-39(P)-H-700 (Example 7), and SSZ-39(P)H-800 (Example 8). In the figure, the conversion and selectivities in % are displayed as in FIG. 7.

EXAMPLES

[0237] Characterization of the Samples

[0238] Elemental analyses were performed on an inductively coupled plasma-atomic emission spectrometer (ICP-AES, Shimadzu ICPE-9000).

[0239] Nitrogen Adsorption/Desorption Measurements for Determination of BET Surface Area and Micropore Volume

[0240] Nitrogen adsorption/desorption measurements were performed on a Belsorp-mini II analyzer (BEL Japan). Prior to the measurements, all samples were degassed at 350° C. for 3 h. The BET surface area was calculated in the P/P.sub.0 range of 0.01-0.1. The micropore volume was calculated by t-plot method.

[0241] NH.sub.3-TPD Method and Data Interpretation: Calculation of Acid Sites and the Type of the Acid Sites

[0242] Temperature-programmed desorption of ammonia (NH.sub.3-TPD) profiles were recorded on a BELCAT equipment (BEL Japan). Typically, 25 mg catalyst were pretreated at 600° C. in a He flow (50 mL/min) for 1 h and then cooled to 100° C. Prior to the adsorption of NH.sub.3, the sample was evacuated at 100° C. for 1 h. Approximately 2500 Pa of NH.sub.3 were allowed to make contact with the sample at 100° C. for 30 min. Subsequently, the sample was evacuated to remove weakly adsorbed NH.sub.3 at the same temperature for 30 min. Finally, the sample was heated from 100 to 600° C. at a ramping rate of 10° C./min in a He flow (50 mL/min). A thermal conductivity detector (TCD) was used to monitor desorbed NH.sub.3.

[0243] The acid amount calculated according to the deconvolution results form NH.sub.3-TPD profiles and the peak-maximum-temperature listed in Tables 3 and 4 below. Peak III corresponds to NH.sub.3 adsorbed on the non-acidic OH groups and NH.sub.4.sup.+ by hydrogen bonding. Peaks I and II correspond to NH.sub.3 adsorbed on the true acid sites including Brønsted and Lewis acid sites. The acid strength can be estimated by the position of the peak (i.e., peak-maximum-temperature).

[0244] CO FT-IR Measurements: Description of the Measurements Conditions and Analysis of the Type and Amount of Acid Sites

[0245] FTIR spectra were obtained by using a Jasco FTIR 4100 spectrometer equipped with a TGS detector at a 4 cm.sup.−1 resolution; 64 scans were collected for each spectrum. The powdered samples (˜30 mg) were pelletized into a self-supporting disk of 1 cm in diameter, which was held in a glass cell. After evacuation at 500° C. for 1 h, the sample was cooled back to −120° C. prior to background spectra acquisition. Then CO was introduced into the cell in a pulse mode fashion (˜5 Pa for the first pulse, until total pressure in the IR cell reached ˜1000 Pa). After equilibrium pressure was reached after each pulse, an IR spectrum was acquired. The IR spectra resulting from the subtraction of the background spectra from those with NO adsorbed are shown unless otherwise noted.

[0246] The Brønsted acid amount with different strength can be compared for different AEI samples, based on the intensities of bands at ˜3303 and ˜3450 cm.sup.−1 related to the strong and medium acid sites, respectively.

Comparative Example 1: Synthesis of SSZ-39(N)-A-600 Using a Quaternary Ammonium Containing Structure Directing Agent and Calcination Thereof in Air at 600° C.

[0247] The following synthesis of SSZ-39(N) is based on the synthetic methodologies described in U.S. Pat. No. 5,958,370 and M. Moliner et al. in Chem. Commun. 2012, 48, pages 8264-8266.

Synthesis of N,N-dimethyl-3,5-dimethylpiperidinium hydroxide (DMPOH)

[0248] First, 24 g of 3,5-dimethylpiperidine (TCI, 98%, cis-trans mixture) were mixed with 220 ml of methanol (Wako, 99.9%) and 42 g of potassium carbonate (Wako, 99.5%). Then, 121 g of methyl iodide (Wako, 99.5%) were added dropwise, and the resultant mixture maintained under reflux for 1 day. After evaporation to partially remove the methanol, chloroform was added and stirred, followed by filtration to remove potassium carbonate. This step was repeated to completely remove the methanol and potassium carbonate. Then, ethanol was added for recrystallization, and diethylether was added to precipitate the iodide salt. After filtration, the solid product was dried and mixed with hydroxide ion exchange resin (DIAION SA10AOH, Mitsubishi) and distilled water. After 1 day, the resin was removed by filtration and the DMPOH aqueous solution with density of 1.051 g mL.sup.−1 and molar concentration of 1.817 M was obtained.

Synthesis of SSZ-39(N)

[0249] First, 12.85 of DMPOH aqueous solution were mixed with 10.99 g of 8 M NaOH aqueous solution (Wako) and 62.42 g of distilled water. Then, 1.33 g of Y zeolite (JRC-HY-5.5, Si/Al.sub.2=5.5, JGC Catalysts and Chemicals) were added to the above solution, with stirring for 1 h. Then, 7.91 g fumed silica (Cab-O-SilM5, Cabot) were added to the mixture and stirred for 1 h. The molar composition of the resultant gel was 1 SiO.sub.2:0.05 Al:0.15 DMPOH:0.45 Na:30 H.sub.2O. The thus prepared mother gel was crystallized in an autoclave at 150° C. for 3 days under tumbling condition (30 r.p.m.). The solid crystalline product, a zeolitic material having framework type AEI, was recovered by filtration, washed with distilled water, and dried overnight at 100° C. under air. The thus obtained product displayed an SiO.sub.2: Al.sub.2O.sub.3 molar ratio of 20 as determined from elemental analysis by ICP. The thus obtained SSZ-39(N) product was then calcined in air (“A”) in a muffle furnace at 600° C. for 6 hours which provided the Na-SSZ-39(N)-A. Subsequently, the Na-SSZ-39(N)-A was then NH.sub.4.sup.+ ion exchanged using 2.5 molar aqueous solution of NH.sub.4NO.sub.3, wherein the weight ratio of the ammonium nitrate solution:zeolite was 100:1, and the resulting mixture was heated to 80° C. for 3 hours, followed by filtration of the solid. The procedure was repeated once to provide NH.sub.4.sup.+-SSZ-39(N)-A. The thus obtained NH.sub.4.sup.+-SSZ-39(N)-A was then calcined in air in a muffle furnace at 600° C. for 5 hours which provided the H-form, HSSZ-39(N)-A-600.

Example 1: Synthesis of SSZ-39(N)-A-700 Using Quaternary Ammonium Containing Structure Directing Agent and Calcination Thereof after Ammonium Ion Exchange at 700° C.

[0250] The method of Comparative Example 1 was repeated, wherein the ion exchanged product NH.sub.4.sup.+-SSZ-39(N)-A was calcined in air in a muffle furnace at 700° C. for 5 hours which provided the H-form, H-SSZ-39(N)-A-700.

Example 2: Synthesis of SSZ-39(N)-A-800 Using Quaternary Ammonium Containing Structure Directing Agent and Calcination Thereof after Ammonium Ion Exchange at 800° C.

[0251] The method of Comparative Example 1 was repeated, wherein the ion exchanged product NH.sub.4.sup.+-SSZ-39(N)-A was calcined in air in a muffle furnace at 800° C. for 5 hours which provided the H-form, H-SSZ-39(N)-A-800.

Comparative Example 2: Synthesis of SSZ-39(N)-H-600 Using a Quaternary Ammonium Containing Structure Directing Agent and Calcination Thereof in a Hydrogen-Atmosphere at 600° C.

[0252] The method of Comparative Example 1 was repeated, wherein the SSZ-39(N) product was calcined in a flow of hydrogen/nitrogen (H.sub.2: 15 mL/min, N.sub.2: 60 mL/min) (“H”) in a muffle furnace at 600° C. for 6 hours which provided the Na-SSZ-39(N)-H.

[0253] As in Comparative Example 1, the Na-SSZ-39(N)-H was then NH.sub.4.sup.+ ion exchanged as described in Reference Example 1 to provide NH.sub.4.sup.+-SSZ-39(N)-H, which was then calcined in air at 600° C. for 5 hours which provided the H-form, H-SSZ-39(N)-H-600.

Example 3: Synthesis of SSZ-39(N)-H-700 Using Quaternary Ammonium Containing Structure Directing Agent and Calcination Thereof after Ammonium Ion Exchange at 700° C.

[0254] The method of Comparative Example 2 was repeated, wherein the ion exchanged product NH.sub.4.sup.+-SSZ-39(N)-H was calcined in air in a muffle furnace at 700° C. for 5 hours which provided the H-form, H-SSZ-39(N)-H-700.

Example 4: Synthesis of SSZ-39(N)-H-800 Using Quaternary Ammonium Containing Structure Directing Agent and Calcination Thereof after Ammonium Ion Exchange at 800° C.

[0255] The method of Comparative Example 2 was repeated, wherein the ion exchanged product NH.sub.4.sup.+-SSZ-39(N)-H was calcined in air in a muffle furnace at 800° C. for 5 hours which provided the H-form, H-SSZ-39(N)-H-800.

Comparative Example 3: Synthesis of SSZ-39(P)-A Using Quaternary Phosphonium Containing Structure Directing Agent and Calcination Thereof in Air at 600° C.

[0256] The following synthesis of SSZ-39(P) is based on the synthetic methodology described in T. Sano et al., Chem. Lett. 2014, 43, page 302.

Synthesis of Tetraethylphosphonium Hydroxide (TEPOH)

[0257] 50 g of tetraethylphosphonium bromide (TCI, 98%) and 55 g of hydroxide ion exchange resin (DIAION SA10AOH, Mitsubishi Chemical) were mixed in distilled water. After 1 day, the resin was removed by filtration and the TEPOH aqueous solution with density of 1.075 g mL.sup.−1 and molar concentration of 1.9 M was obtained.

Synthesis of SSZ-39(P)

[0258] First, 5 g of TEPOH aqueous solution were mixed with 0.18 g of NaOH (Wako, 96%) and 0.45 g of distilled water. Then, 2.8 g of Y zeolite (CBV720, Si/Al.sub.2=30, Zeolyst) were added to the above solution, with stirring for 1 h. The molar composition of the resultant gel was 1 SiO.sub.2:0.067 Al:0.2 TEPOH:0.1 NaOH:5 H.sub.2O. The thus prepared mother gel was crystallized in an autoclave at 170° C. for 5 days under tumbling condition (40 r.p.m.). The solid crystalline product, a zeolitic material having framework type AEI, was recovered by filtration, washed with distilled water, and dried overnight at 100° C. under air. The thus obtained product displayed an SiO.sub.2: Al.sub.2O.sub.3 molar ratio of 24 as determined from elemental analysis by ICP.

[0259] The thus obtained SSZ-39(P) product was then calcined in air (A) in a muffle furnace at 600° C. for 6 hours which provided the sodium form, Na-SSZ-39(P)-A.

[0260] Subsequently, the Na-SSZ-39(P)-A was then NH.sub.4.sup.+ ion exchanged using NH.sub.4NO.sub.3 in accordance with the treatment described in Comparative Example 1.

[0261] The thus obtained NH.sub.4.sup.+-SSZ-39(P)-A was then calcined in air in a muffle furnace at 600° C. for 5 hours which provided the H-form, H-SSZ-39(P)-A-600.

Example 5: Synthesis of SSZ-39(P)-A-700 Using Quaternary Phosphonium Containing Structure Directing Agent and Calcination Thereof after Ammonium Ion Exchange at 700° C.

[0262] The method of Comparative Example 3 was repeated, wherein the ion exchanged product NH.sub.4.sup.+-SSZ-39(P)-A was calcined in air in a muffle furnace at 700° C. for 5 hours which provided the H-form, H-SSZ-39(P)-A-700.

Example 6: Synthesis of SSZ-39(P)-A-800 Using Quaternary Phosphonium Containing Structure Directing Agent and Calcination Thereof after Ammonium Ion Exchange at 800° C.

[0263] The method of Comparative Example 3 was repeated, wherein the ion exchanged product NH.sub.4.sup.+-SSZ-39(P)-A was calcined in air in a muffle furnace at 800° C. for 5 hours which provided the H-form, H-SSZ-39(P)-A-800.

Comparative Example 4: Synthesis of SSZ-39(P)-H-600 Using Quaternary Phosphonium Containing Structure Directing Agent and Calcination Thereof in a Hydrogen-Atmosphere at 600° C.

[0264] The method of Comparative Example 3 was repeated, wherein the SSZ-39(P) product was calcined in a flow of hydrogen/nitrogen (H.sub.2: 15 mL/min, N.sub.2: 60 mL/min) (“H”) in a muffle furnace at 600° C. for 6 hours which provided the Na-SSZ-39(P)-H.

[0265] As in Comparative Example 1, the Na-SSZ-39(P)-H was then NH.sub.4.sup.+ ion exchanged as described in Reference Example 1 to provide NH.sub.4.sup.+-SSZ-39(P)-H, which was then calcined in air at 600° C. for 5 hours which provided the H-form, H-SSZ-39(P)-H-600.

Example 7: Synthesis of SSZ-39(P)-H-700 Using Quaternary Phosphonium Containing Structure Directing Agent and Calcination Thereof after Ammonium Ion Exchange at 700° C.

[0266] The method of Comparative Example 2 was repeated, wherein the ion exchanged product NH.sub.4.sup.+-SSZ-39(P)-H was calcined in air in a muffle furnace at 700° C. for 5 hours which provided the H-form, H-SSZ-39(P)-H-700.

Example 8: Synthesis of SSZ-39(P)-H-800 Using Quaternary Phosphonium Containing Structure Directing Agent and Calcination Thereof after Ammonium Ion Exchange at 800° C.

[0267] The method of Comparative Example 2 was repeated, wherein the ion exchanged product NH.sub.4.sup.+-SSZ-39(P)-H was calcined in air in a muffle furnace at 800° C. for 5 hours which provided the H-form, H-SSZ-39(P)-H-800.

Example 9: Catalytic Testing in the Conversion of Methanol to Olefins (MTO)

[0268] The methanol-to-olefins (MTO) reaction was carried out at 350° C. under atmospheric pressure by using a fixed-bed reactor. Typically, 50 mg of 50/80 mesh zeolite pellets without a binder were loaded in a 6 mm quartz tubular flow microreactor and centered at the reactor in a furnace. The catalyst was activated in flowing He at 500° C. for 1 h prior to the reaction and then cooled to the desired reaction temperature. The pressure of methanol was set at 5 kPa. He was used as a carrier gas. W/F for methanol was set at 33.7 g-cat*h*mol.sup.−1. The MTO reaction gives ethene (C2=), propene (C3=), butenes (C4=), paraffins (C1-C4), over-05 hydrocarbons, and dimethyl ether (DME) as products. The reaction products were analyzed by an online gas chromatograph (GC-2014, Shimadzu) equipped with an HP-PLOT/Q capillary column and an FID detector. The selectivities of the products were calculated on the basis of carbon number.

[0269] The results from the catalytic testing experiments for the examples and comparative examples are displayed in Tables 1 and 2 below.

TABLE-US-00001 TABLE 1 Results from methanol to olefin conversion testing performed with the materials of Examples 1 to 4 and Comparative Examples 1 and 2. conversion. C2 = selectivity C3 = selectivity C4 = selectivity Catalyst >99% initial (final) [%] initial (final) [%] initial (final) [%] SSZ-39(N)-A-600 11 h 21.3 (27.9) 37.1 (43.2) 14.3 (16.3) (Comp. Example 1) SSZ-39(N)-A-700 11 h 21.2 (27.4) 40.2 (45.6) 15.2 (18.7) (Example 1) SSZ-39(N)-A-800 12 h 20.3 (25.0) 48.3 (46.8) 19.2 (16.9) (Example 2) SSZ-39(N)-H-600 10 h 21.6 (27.8) 38.2 (42.9) 15.1 (15.5) (Comp. Example 2) SSZ-39(N)-H-700 15 h 18.6 (26.3) 41.3 (45.9) 17.6 (17.4) (Example 3) SSZ-39(N)-H-800  6 h 19.7 (23.9) 49.1 (47.3) 18.8 (17.7) (Example 4)

[0270] As concerns the SSZ-39(N)-A catalysts wherein the organotemplate material was removed in air at 600° C., the results of which are displayed in Table 1, SSZ-39(N)-A-800 showed high C3= and C4=selectivities and long catalytic lifetime (12 h at >99% methanol conversion). Upon deactivation, the methanol conversion slowly decreased. This could be due to the decrease in the acid strength and amount when the catalyst was calcined at high temperature of 800° C.

[0271] Among SSZ-39(N)-H catalysts wherein the organotemplate material was removed in H.sub.2/N.sub.2 at 600° C., the results of which are displayed in Table 1, SSZ-39(N)-H-700 showed high C3= and C4=selectivities and long catalytic lifetime (15 h at >99% methanol conversion) compared to SSZ-39(N)-A-700. This could be due to the high amount of medium acids.

TABLE-US-00002 TABLE 2 Results from methanol to olefin conversion testing performed with the materials of Examples 5 to 8 and Comparative Examples 3 and 4. conversion. C2 = selectivity C3 = selectivity C4 = selectivity Catalyst >99% initial (final) [%] initial (final) [%] initial (final) [%] SSZ-39(P)-A-600 7 h 24.2 (33.3) 46.3 (42.2) 19.6 (15.9) (Comp. Example 3) SSZ-39(P)-A-700 4 h 21.2 (23.3) 48.1 (47.4) 19.7 (18.7) (Example 5) SSZ-39(P)-A-800 1 h 19.7 (20.6) 48.3 (46.8) 19.2 (20.0) (Example 6) SSZ-39(P)-H-600 15 h  24.1 (33.7) 41.1 (41.0) 15.3 (14.2) (Comp. Example 4) SSZ-39(P)-H-700 7 h 21.0 (27.8) 46.5 (44.2) 19.2 (16.8) (Example 7) SSZ-39(P)-H-800 4 h 18.5 (24.6) 47.3 (45.0) 21.9 (17.9) (Example 8)

[0272] Regarding the SSZ-39(P)-A catalysts wherein the organotemplate material was removed in air at 600° C., the results of which are displayed in Table 2, these showed high C3= and C4=selectivities, however comparatively shorter catalytic lifetimes (1-7 h at >99% methanol conversion). This could be due to the low amount of acid sites with medium and strong acid strength.

[0273] Among SSZ-39(P)-H catalysts wherein the organotemplate material was removed in H.sub.2/N.sub.2 at 600° C., the results of which are displayed in Table 2, these showed long catalytic life time (up to 15 h at >99% methanol conversion), however comparatively lower C3= and C4=selectivities compared to SSZ-39(P)-H-700 or 800. This could be due to the high amount of medium and strong acid sites.

[0274] For investigating the influence of the acidic properties of the catalysts on their performance, NH.sub.3-TPD measurements were performed on the fresh catalysts obtained according to the examples and comparative examples, the results of which are displayed in Tables 3 and 4 below.

TABLE-US-00003 TABLE 3 Deconvolution results from the NH.sub.3-TPD measurements (temperature and integration values of the deconvoluted desorption profile) performed on the materials of Examples 1 to 4 and Comparative Examples 1 and 2. peak I [mmol/g]/ peak II [mmol/g]/ peak III [mmol/g]/ Catalyst (temperature) (temperature) (temperature) SSZ-39(N)-A-600 0.352/(390° C.) 0.413/(480° C.) 0.445/(173° C.) (Comp. Example 1) SSZ-39(N)-A-700 0.196/(261° C.) 0.427/(453° C.) 0.366/(174° C.) (Example 1) SSZ-39(N)-A-800 0.147/(217° C.) 0.338/(340° C.) 0.137/(168° C.) (Example 2) SSZ-39(N)-H-600 0.406/(403° C. 0.450/(483° C.) 0.412/(172° C.) (Comp. Example 2) SSZ-39(N)-H-700 0.218/(246° C.) 0.380/(438° C.) 0.280/(172° C.) (Example 3) SSZ-39(N)-H-800 0.134/(217° C.) 0.308/(335° C.) 0.114/(169° C.) (Example 4)

TABLE-US-00004 TABLE 4 Deconvolution results from the NH.sub.3-TPD measurements (temperature and integration values of the deconvoluted desorption profile) performed on the materials of Examples 5 to 8 and Comparative Examples 3 and 4. peak I [mmol/g]/ peak II [mmol/g]/ peak III [mmol/g]/ Catalyst (temperature) (temperature) (temperature) SSZ-39(P)-A-600 0.249/(223° C.) 0.329/(364° C.) 0.201/(172° C.) (Comp. Example 3) SSZ-39(P)-A-700 0.163/(209° C.) 0.216/(321° C.) 0.143/(164° C.) (Example 5) SSZ-39(P)-A-800 0.143/(206° C.) 0.153/(301° C.) 0.114/(164° C.) (Example 6) SSZ-39(P)-H-600 0.240/(251° C.) 0.560/(442° C.) 0.302/(172° C.) (Comp. Example 4) SSZ-39(P)-H-700 0.174/(212° C.) 0.310/(355° C.) 0.160/(167° C.) (Example 7) SSZ-39(P)-H-800 0.158/(207° C.) 0.271/(328° C.) 0.135/(165° C.) (Example 8)

[0275] As may be taken from the results in Tables 3 and 4, it has surprisingly been found that the acid amount and strength of the SSZ-39(N) and SSZ-39(P) catalysts can be fine tuned by changing the calcination atmosphere and temperature, which allows for a substantial improvement in the C3= and C4=selectivities and catalytic lifetime as may be taken from the results from catalytic testing described in Tables 1 and 2. In particular, it has quite unexpectedly been found that the inventive zeolitic materials obtained according to the inventive method displaying specific quantities of acid sites and in particular displaying particular ratios of the amount of different acid sites to one another display both a considerably improved activity and a surprisingly high selectivity towards C2 to C4 olefins, and in particular towards C3 olefins in the catalytic conversion of methanol to olefins.

LIST OF THE CITED PRIOR ART REFERENCES

[0276] Moliner, M. et al. in Chem. Commun. 2012, 48, pages 8264-8266 [0277] Maruo, T. et al. in Chem. Lett. 2014, 43, page 302-304 [0278] Martin, N. et al. in Chem. Commun. 2015, 51, 11030-11033 [0279] Unpublished international patent application PCT/CN2016/111314 [0280] Unpublished international patent application PCT/CN2017/112343 [0281] U.S. Pat. No. 5,958,370