PROCESS FOR THE PREPARATION OF AN MWW ZEOLITIC MATERIAL COMPRISING BORON AND TITANIUM

Abstract

A process for the preparation of a zeolitic material having an MWW framework structure and comprising boron and titanium, the process comprising (i) providing an aqueous synthesis mixture comprising a silica source, a boron source, a titanium source, and an MWW templating agent; (ii) heating the aqueous synthesis mixture to a temperature in the range of from 160 to 190° C.; (iii) subjecting the synthesis mixture (ii) to hydrothermal synthesis conditions, obtaining, in its mother liquor, a precursor of the zeolitic material; (iv) separating the precursor from its mother liquor; (v) calcining the separated precursor, obtaining the zeolitic material having an MWW framework structure and comprising boron and titanium.

Claims

1. A process for preparing a zeolitic material having an MWW framework structure and comprising boron and titanium, the process comprising (i) providing an aqueous synthesis mixture comprising a silica source, a boron source, a titanium source, and an MWW templating agent, at a temperature of at most 50° C.; (ii) heating the aqueous synthesis mixture from the temperature of at most 50° C. to a temperature in the range of from 160 to 190° C. within a time period of at most 24 h; (iii) subjecting the aqueous synthesis mixture obtained in (ii) to hydrothermal synthesis conditions under autogenous pressure in a closed system at a temperature in the range of from 160 to 190° C., thereby obtaining, in a mother liquor, a precursor of the zeolitic material having an MWW framework structure and comprising boron and titanium; (iv) separating the precursor of the zeolitic material having an MWW framework structure and comprising boron and titanium from the mother liquor; and (v) calcining the separated precursor of the zeolitic material having an MWW framework structure and comprising boron and titanium obtained in (iv), thereby obtaining the zeolitic material having an MWW framework structure and comprising boron and titanium.

2. The process of claim 1, wherein the aqueous synthesis mixture provided in (i) is prepared by adding the silica source to an aqueous mixture comprising the boron source, the titanium source and the MWW templating agent.

3. The process of claim 2, wherein the aqueous mixture comprising the boron source, the titanium source and the MWW templating agent is prepared by adding a mixture comprising a portion of the MWW templating agent and the titanium source to an aqueous mixture comprising a portion of the MWW templating agent and the boron source.

4. The process of claim 2, wherein after adding the silica source, the aqueous synthesis mixture is stirred at the temperature of at most 50° C. for a time period in the range of from 45 to 180 min.

5. The process of claim 1, wherein in (i), the silica source is selected from the group consisting of fumed silica, colloidal silica, a silicon alkoxide, and a mixture of two or more thereof; the boron source is selected from the group consisting of boric acid, a borate, boron oxide, and a mixture of two or more thereof; the titanium source is selected from the group consisting of a titanium alkoxide, a titanium halide, a titanium salt, titanium dioxide and a mixture of two or more thereof; and the MWW templating agent is selected from the group consisting of piperidine, hexamethylene imine, N,N,N,N′,N′,N′-hexamethyl-1,5-pentanediammonium ion, 1,4-bis(N-methylpyrrolidinium)butane, octyltrimethylammonium hydroxide, heptyltrimethyl-ammonium hydroxide, hexyltrimethylammonium hydroxide, and a mixture of two or more thereof.

6. The process of claim 1, wherein the aqueous synthesis mixture provided in (i) contains the boron source, calculated as elemental boron, relative to the silicon source, calculated as elemental silicon, in a molar ratio in the range of from 0.18:1 to 5.2:1; the titanium source, calculated as elemental titanium, relative to the silicon source, calculated as elemental silicon, in a molar ratio in the range of from 0.005:1 to 0.15:1; the MWW templating agent relative to the silicon source, calculated as elemental silicon, in a molar ratio in the range of from 0.4:1 to 4.2:1; and water relative to the silicon source, calculated as elemental silicon, in a molar ratio in the range of from 1:1 to 30:1.

7. The process of claim 1, wherein the aqueous synthesis mixture provided in (i) has a pH in the range of from 10 to 13 as determined by a pH-sensitive glass electrode.

8. The process of claim 1, wherein in (ii), the heating is carried out for the time period in the range of from 2 to 18 h.

9. The process of claim 1, wherein in (ii), the heating is carried out continuously from the temperature of at most 50° C. to a temperature in the range of from 160 to 190° C.

10. The process of claim 1, wherein in (iii), the synthesis mixture is subjected to the hydrothermal synthesis conditions at autogenous pressure for a time period in the range of from 80 to 200 h.

11. The process of claim 1, wherein the separating (iv) comprises (iv.1) washing the precursor of the zeolitic material having an MWW framework structure and comprising boron and titanium to obtain a washed precursor of the zeolitic material having an MWW framework structure and comprising boron and titanium; and (iv.2) drying the washed precursor of the zeolitic material having an MWW framework structure and comprising boron and titanium.

12. The process of claim 1, wherein neither prior to nor during (iv), the precursor of the zeolitic material having an MWW framework structure and comprising boron and titanium is treated with an aqueous solution having a pH of at most 6, as determined by a pH-sensitive glass electrode.

13. The process of claim 1, wherein in (v), the calcining is carried out at a temperature in the range of from 500 to 700° C.

14. The process of claim 1, wherein prior to (v), the precursor of the zeolitic material having an MWW framework structure and comprising boron and titanium, obtained from (iii), is not treated with an aqueous solution having a pH of at most 6, as determined by a pH-sensitive glass electrode, and wherein after (v), the calcined zeolitic material having an MWW framework structure and comprising boron and titanium is not treated with an aqueous solution having a pH of at most 6, as determined by a pH-sensitive glass electrode.

15. The process of claim 1, further comprising (vi) shaping the zeolitic material having an MWW framework structure and comprising boron and titanium obtained from (v), thereby obtaining a molding; and (vii) optionally drying and/or calcining the molding obtained from (vi).

16. A zeolitic material having an MWW framework structure and comprising boron and titanium, obtainable or obtained by the process according to claim 1.

17. A zeolitic material having an MWW framework structure and comprising boron and titanium, optionally obtainable or obtained by the process according to claim 1, wherein at least 99 weight-% of the zeolitic framework structure consist of boron, titanium, silicon, oxygen, and hydrogen, and wherein a molar ratio of boron, relative to silicon, is in the range of from 0.05:1 to 0.15:1, and a molar ratio of titanium, relative to silicon, is in the range of from 0.017:1 to 0.025:1.

18. The zeolitic material of claim 17, which is in a calcined state.

19. The zeolitic material of claim 16, having an MWW templating agent content of at most 0.5 weight-% based on a total weight of the zeolitic material, wherein said MWW templating agent content is determined as a total organic carbon (TOC) content of the calcined zeolitic material.

20. The zeolitic material of claim 16, wherein a .sup.29Si-NMR spectrum of the zeolitic material comprises a first signal in the range of from −95.0 to −105.0 ppm, a second signal in the range of from −105.0 to −115.0 ppm, and a third signal in the range of from −115.0 to −125.0 ppm.

21. The zeolitic material of claim 16, wherein a .sup.11B-NMR spectrum of the zeolitic material comprises a first signal in the range of from 20.0 to 10.0 ppm, a second signal in the range of from 10.0 to 1.0 ppm, a third signal in the range of from 1.0 to −7.0 ppm, and a fourth signal in the range of from −7.0 to −16.0 ppm.

22. The zeolitic material of claim 16, having a water uptake in the range of from 12.0 to 16.0 weight-%.

23. A molding, comprising the zeolitic material according to claim 16 and optionally at least one binder.

24. A catalyst, comprising the zeolitic material according to claim 16.

25. A bifunctional catalyst, comprising the zeolitic material according to claim 16.

Description

EXAMPLES

[0223] The following starting materials were employed: [0224] Piperidine; from Sigma-Aldrich [0225] Boric acid; from Bernd Kraft GmbH [0226] Tetrabutyl orthotitanate; from Alfa Aesar [0227] Fumed silica CAB-O-SIL® M7D and CAB-O-SIL® M5, from Cabot Corporation

Reference Example 1: Determination of the .SUP.11.B Solid State NMR Spectra

[0228] .sup.11B solid-state NMR experiments were performed using a Bruker Avance III spectrometer with 400 MHz .sup.1H Larmor frequency (Bruker Biospin, Germany). Samples were stored at 63% relative humidity at room temperature prior to packing in 4 mm ZrO.sub.2 rotors. Measurements were performed under 10 kHz Magic Angle Spinning at room temperature. .sup.11B spectra were obtained using .sup.11B 15°-pulse excitation of 1 microsecond (μs) pulse width, a .sup.11B carrier frequency corresponding to −4 ppm in the referenced spectrum, and a scan recycle delay of 1 s. Signal was acquired for 10 ms, and accumulated with 5000 scans. Spectra were processed using Bruker Topspin with 30 Hz exponential line broadening, phasing, and baseline correction over the full spectrum width. Spectra were indirectly referenced to 1% TMS in CDCl.sub.3 on the unified chemical shift scale, according to IUPAC (Pure Appl. Chem., Vol. 80, No. 1, pp. 59) using glycine with carbonyl peak at 175.67 ppm as a secondary standard.

Reference Example 2: Determination of the .SUP.29.Si Solid State NMR Spectra

[0229] .sup.29Si solid-state NMR experiments were performed using a Bruker Avance III spectrometer with 400 MHz .sup.1H Larmor frequency (Bruker Biospin, Germany). Samples were stored at 63% relative humidity at room temperature prior to packing in 4 mm ZrO.sub.2 rotors. Measurements were performed under 10 kHz Magic Angle Spinning at room temperature. .sup.29Si spectra were obtained using .sup.29Si 90°-pulse excitation of 5 microsecond (μs) pulse width, a .sup.29Si carrier frequency corresponding to −112 ppm in the referenced spectrum, and a scan recycle delay of 120 s. Signal was acquired for 20 milliseconds (ms) under 63 kHz high-power proton decoupling, and accumulated for at least 16 hours. Spectra were processed using Bruker Topspin with 50 Hz exponential line broadening, phasing, and baseline correction over the full spectrum width. Spectra were indirectly referenced to 1% TMS in CDCl.sub.3 on the unified chemical shift scale, according to IUPAC (Pure Appl. Chem., Vol. 80, No. 1, pp. 59) using glycine with carbonyl peak at 175.67 ppm as a secondary standard.

Reference Example 3: Determination of the Water Uptake

[0230] Water adsorption/desorption isotherms were performed on a VTI SA instrument from TA Instruments following a step-isotherm program. The experiment consisted of a run or a series of runs performed on a sample material that has been placed on the microbalance pan inside of the instrument. Before the measurement was started, the residual moisture of the sample was removed by heating the sample to 100° C. (heating ramp of 5 K/min) and holding it for 6 h under a nitrogen flow. After the drying program, the temperature in the cell was decreased to 25° C. and kept isothermal during the measurement. The microbalance was calibrated, and the weight of the dried sample was balanced (maximum mass deviation 0.01 weight-%). Water uptake by the sample was measured as the increase in weight over that of the dry sample. First, as adsorption curve was measured by increasing the relative humidity (RH) (expressed as weight-% water in the atmosphere inside of the cell) to which the sample was exposed and measuring the water uptake by the sample as equilibrium. The RH was increased with a step of 10 weight-% from 5% to 85% and at each step the system controlled the RH and monitored the sample weight until reaching the equilibrium conditions after the sample was exposed from 85 weight-% to 5 weight-% with a step of 10% and the change in the weight of the sample (water uptake) was monitored and recorded.

Reference Example 4: Determination of the Infrared Spectra

[0231] The FT-IR (Fourier-Transformed-Infrared) measurements were performed on a Nicolet 6700 spectrometer. The powdered material was pressed into a self-supporting pellet without the use of any additives. The pellet was introduced into a high vacuum (HV) cell placed into the FT-IR instrument. Prior to the measurement the sample was pretreated in high vacuum (10.sup.−5 mbar) for 3 h at 300° C. The spectra were collected after cooling the cell to 50° C. The spectra were recorded in the range of 4000 to 800 cm.sup.−1 at a resolution of 2 cm.sup.−1. The obtained spectra are represented in a plot having on the x axis the wavenumber (cm.sup.−1) and on the y axis the absorbance (arbitrary units, a.u.). For the quantitative determination of the peak heights and the ratio between these peaks a baseline correction was carried out. Changes in the 3000-3900 cm.sup.−1 region were analyzed and for comparing multiple samples, as reference the band at 1880±5 cm.sup.−1 was taken.

Reference Example 5: Determination of the XRD Spectra

[0232] The XRD spectra were made with an D8 Advance Serie 2 from Bruker/AXS having a multiple sample changer.

Example 1: Preparation of a Zeolitic Material Having an MWW Framework Structure and Comprising Boron and Titanium According to the Invention

[0233] To 841.82 g deionized water in a beaker glass, piperidine (200 g) was added and the resulting mixture was stirred for 5 min at room temperature. Boric acid (203.8 g) was added to the mixture and dissolved for 20 min, and then, a solution of tetrabutyl orthotitanate (17.75 g) dissolved in piperidine (99.24 g) was added under stirring at a stirring rate of 70 r.p.m., and the resulting mixture was stirred for 30 min at room temperature. Fumed silicon dioxide (Cab-O-Sil M7D, 147.9 g) was added to the mixture with stirring, and the resulting mixture was stirred for 90 min at room temperature. The mixture had a pH of 11.3.

[0234] The mixture was loaded into a 2.5 l autoclave, and slowly continuously heated to 170° C. within 10 hours, and then kept at this temperature for 160 h under stirring at a stirring speed of 100 r.p.m. The pressure during the reaction was within a range of 8.3 to 9 bar. The suspension obtained had a pH of 11.2. The suspension was filtered and the filter cake was washed with deionized water until the washings had a pH of less than 10. The filter cake was dried in a drying oven at 120° C. for 48 h, heated at a heating rate of 2 K/min to a temperature of 650° C., and calcined at 650° C. for 10 h in air atmosphere.

[0235] A colorless powder (101.3 g) was obtained. The powder had a boron content of 1.3 weight-%, calculated as elemental boron, a titanium content of 1.3 weight-%, calculated as elemental titanium, and a silicon content 40 weight-%, calculated as elemental titanium. The total organic carbon content (TOC) was 0.1 weight-%.

[0236] The .sup.11B solid state NMR spectrum of the zeolitic material is shown in FIG. 1, the .sup.29Si solid state NMR spectrum in FIG. 5. The FT-IR spectrum of the zeolitic material is shown in FIG. 9, the XRD spectrum in FIG. 10. Further, the XRD spectrum exhibits the following characteristics:

TABLE-US-00001 Angle d value Intensity Intensity 2-Theta ° Angstrom Cps % 7.013 12.59532 274 20.3 7.238 12.20307 468 34.7 8.058 10.96352 326 24.2 10.137 8.71933 362 26.9 13.007 6.80071 134 10 14.278 6.19805 313 23.2 14.476 6.11373 408 30.3 14.924 5.93142 209 15.5 16.143 5.48597 249 18.5 18.048 4.91111 119 8.8 19.22 4.61418 192 14.3 20.448 4.33988 313 23.3 21.418 4.14544 239 17.8 21.857 4.06307 403 29.9 22.142 4.01139 424 31.5 22.687 3.91637 413 30.7 22.974 3.8681 747 55.5 23.97 3.70954 539 40 25.277 3.5206 446 33.1 26.321 3.38327 1346 100 27.289 3.26537 498 37 28.094 3.17361 511 37.9 28.947 3.08203 357 26.5 30.059 2.97051 210 15.6 32.004 2.79431 217 16.1 32.669 2.73889 229 17 33.757 2.65307 319 23.7 34.829 2.57383 233 17.3 36.837 2.43798 209 15.5 37.535 2.39427 197 14.6 38.316 2.34724 240 17.8 41.141 2.19233 204 15.2 41.982 2.15035 205 15.2 43.358 2.08522 213 15.8 45.169 2.00577 255 19 46.654 1.94533 266 19.8 46.968 1.93304 284 21.1 48.908 1.86079 255 19 49.494 1.84015 259 19.2 49.992 1.82295 232 17.2 51.38 1.77694 246 18.3 52.019 1.75659 255 18.9 53.699 1.70552 240 17.8 54.686 1.67707 230 17.1 57.016 1.61393 233 17.3 57.764 1.5948 225 16.7 58.87 1.56745 240 17.8 60.68 1.52495 248 18.4 62.067 1.49415 261 19.4 63.043 1.47336 262 19.5 65.449 1.42489 286 21.2 66.425 1.40631 348 25.9

Comparative Example 1: Preparation of a Zeolitic Material Having an MWW Framework Structure and Comprising Boron and Titanium, Based on Wu et al

[0237] The preparation was carried out analogously to P. Wu et al. However, in order to allow for a comparison between the respectively obtained material with the material according to the present invention, the process according to Wu et al. was modified in that the acid treatment step was not carried out. This is the only possibility that with respect to the finally obtained materials, characteristics can be compared on a reasonable basis since only if the acid treatment step and, thus, the step of removing the boron is not carried out, the resulting calcined material of prepared analogously to Wu et al. still contains boron.

[0238] To 841.22 g deionized water in a beaker, piperidine (299.24 g) was added and the resulting mixture was stirred for 5 min at room temperature. The aqueous piperidine solution was split into two equal parts. To the first part of the aqueous piperidine solution, boric acid (203.80 g) was added under stirring at a stirring rate of 70 r.p.m., and the resulting mixture was stirred for 30 min at room temperature, and then, fumed silicon dioxide (Cab-O-Sil® M7D, 73.95 g) was added to the mixture with stirring, and the resulting mixture was stirred for 1 h at room temperature. To the second part of the aqueous piperidine solution, tetrabutyl orthotitanate (17.75 g) was added under stirring, and the resulting mixture was stirred for 30 min at room temperature and then, fumed silicon dioxide (Cab-O-Sil® M7D, 73.95 g) was added to the mixture with stirring, and the resulting mixture was stirred for 1 h at room temperature. The mixtures prepared from the first and the second part of the aqueous piperidine solution were combined and stirred at room temperature for 1.5 h at room temperature. The resulting mixture had a pH of 11.1.

[0239] The mixture was loaded into a 2.5 l autoclave, and kept at a temperature of 130° C. for 24 h, then at 150° C. for 24 h and then at 170° C. for 120 h, while it was stirred at a stirring rate of 100 r.p.m. The pressure during the reaction was within a range of 8 to 9 bar. The suspension obtained had a pH of about 11.1. The suspension was filtered and the filter cake was washed with deionized water until the washings had a pH of less than 10. The filter cake was dried in a drying oven at 50° C. for 24 h and subsequently, the dried filter cake was heated at a heating rate of 2 K/min to a temperature of 530° C., and calcined at 530° C. for 10 h in air atmosphere. A colorless powder (111.5 g) was obtained. The powder had a boron content of 1.3 weight-%, calculated as elemental boron, a titanium content of 1.6 weight-%, calculated as elemental titanium, and a silicon content 42.0 weight-%, calculated as elemental titanium. The total organic carbon content (TOC) was less than 0.1 weight-%.

[0240] The .sup.11B solid state NMR spectrum of the zeolitic material is shown in FIG. 2, the .sup.29Si solid state NMR spectrum in FIG. 6. Further, the XRD spectrum exhibits the following characteristics:

TABLE-US-00002 Angle d value Intensity Intensity 2-Theta ° Angstrom Cps % 7.013 12.59532 274 20.3 7.238 12.20307 468 34.7 8.058 10.96352 326 24.2 10.137 8.71933 362 26.9 13.007 6.80071 134 10 14.278 6.19805 313 23.2 14.476 6.11373 408 30.3 14.924 5.93142 209 15.5 16.143 5.48597 249 18.5 18.048 4.91111 119 8.8 19.22 4.61418 192 14.3 20.448 4.33988 313 23.3 21.418 4.14544 239 17.8 21.857 4.06307 403 29.9 22.142 4.01139 424 31.5 22.687 3.91637 413 30.7 22.974 3.8681 747 55.5 23.97 3.70954 539 40 25.277 3.5206 446 33.1 26.321 3.38327 1346 100 27.289 3.26537 498 37 28.094 3.17361 511 37.9 28.947 3.08203 357 26.5 30.059 2.97051 210 15.6 32.004 2.79431 217 16.1 32.669 2.73889 229 17 33.757 2.65307 319 23.7 34.829 2.57383 233 17.3 36.837 2.43798 209 15.5 37.535 2.39427 197 14.6 38.316 2.34724 240 17.8 41.141 2.19233 204 15.2 41.982 2.15035 205 15.2 43.358 2.08522 213 15.8 45.169 2.00577 255 19 46.654 1.94533 266 19.8 46.968 1.93304 284 21.1 48.908 1.86079 255 19 49.494 1.84015 259 19.2 49.992 1.82295 232 17.2 51.38 1.77694 246 18.3 52.019 1.75659 255 18.9 53.699 1.70552 240 17.8 54.686 1.67707 230 17.1 57.016 1.61393 233 17.3 57.764 1.5948 225 16.7 58.87 1.56745 240 17.8 60.68 1.52495 248 18.4 62.067 1.49415 261 19.4 63.043 1.47336 262 19.5 65.449 1.42489 286 21.2 66.425 1.40631 348 25.9

Comparative Example 2: Preparation of a Zeolitic Material Having an MWW Framework Structure and Comprising Boron and Titanium, Based on US 2011190517 A1

[0241] The preparation was carried out analogously to the recipe of US 2011190517 A1, in example 1, catalyst 1A. However, in order to allow for a comparison between the respectively obtained material with the material according to the present invention, the process according to Wu et al. was modified in that the acid treatment step was not carried out. This is the only possibility that with respect to the finally obtained materials, characteristics can be compared on a reasonable basis since only if the acid treatment step and, thus, the step of removing the boron is not carried out, the resulting calcined material of prepared analogously to US 2011190517 A1 still contains boron.

[0242] To 835.83 g deionized water in a beaker glass, piperidine (324 g) was added and the resulting mixture was stirred for 5 min at room temperature. The aqueous piperidine solution was split into two equal portions. To the first portion of the aqueous piperidine solution, boric acid (195.36 g) was added under stirring, and the resulting mixture was stirred at a stirring rate of 70 r.p.m. for 30 min at room temperature, and then, fumed silicon dioxide (Cab-O-Sil® M5, 73.95 g) was added to the mixture with stirring, and the resulting mixture was stirred for 1.5 h at room temperature. To the second portion of the aqueous piperidine solution, tetrabutyl orthotitanate (21.09 g) was added under stirring, and the resulting mixture was stirred for 30 min at room temperature and then, fumed silicon dioxide (Cab-O-Sil M5®, 73.95 g) was added to the mixture with stirring, and the resulting mixture was stirred for 1.5 h at room temperature. The mixtures prepared from the first and the second part of the aqueous piperidine solution were combined and stirred at room temperature for 1.5 h. The resulting mixture had a pH of 11.3.

[0243] The mixture was loaded into a 2.5 l autoclave, and kept at a temperature of 130° C. for 24 h, then at 150° C. for 24 h and then at 170° C. for 240 h, while it was stirred at a stirring rate of 100 r.p.m. The pressure during the reaction was within a range of 8 to 9 bar. The suspension obtained had a pH of 11.4. The suspension was filtered and the filter cake was washed with deionized water until the washings had a pH of less than 10. The filter cake was dried in a drying oven at 50° C. for 24 h and subsequently, the dried filter cake was heated at a heating rate of 2 K/min to a temperature of 530° C., and calcined at 530° C. for 10 h in air atmosphere. A colorless powder (133 g) was obtained. The powder had a boron content of 1.6 weight-%, calculated as elemental boron, a titanium content of 1.4 weight-%, calculated as elemental titanium, and a silicon content 44 weight-%, calculated as elemental titanium. The total organic carbon content (TOC) was less than 0.1 weight-%.

[0244] The .sup.11B solid state NMR spectrum of the zeolitic material is shown in FIG. 3, the .sup.29Si solid state NMR spectrum in FIG. 7. Further, the XRD spectrum exhibits the following characteristics:

TABLE-US-00003 Angle d value Intensity Intensity 2-Theta ° Angstrom Cps % 7.013 12.59532 274 20.3 7.238 12.20307 468 34.7 8.058 10.96352 326 24.2 10.137 8.71933 362 26.9 13.007 6.80071 134 10 14.278 6.19805 313 23.2 14.476 6.11373 408 30.3 14.924 5.93142 209 15.5 16.143 5.48597 249 18.5 18.048 4.91111 119 8.8 19.22 4.61418 192 14.3 20.448 4.33988 313 23.3 21.418 4.14544 239 17.8 21.857 4.06307 403 29.9 22.142 4.01139 424 31.5 22.687 3.91637 413 30.7 22.974 3.8681 747 55.5 23.97 3.70954 539 40 25.277 3.5206 446 33.1 26.321 3.38327 1346 100 27.289 3.26537 498 37 28.094 3.17361 511 37.9 28.947 3.08203 357 26.5 30.059 2.97051 210 15.6 32.004 2.79431 217 16.1 32.669 2.73889 229 17 33.757 2.65307 319 23.7 34.829 2.57383 233 17.3 36.837 2.43798 209 15.5 37.535 2.39427 197 14.6 38.316 2.34724 240 17.8 41.141 2.19233 204 15.2 41.982 2.15035 205 15.2 43.358 2.08522 213 15.8 45.169 2.00577 255 19 46.654 1.94533 266 19.8 46.968 1.93304 284 21.1 48.908 1.86079 255 19 49.494 1.84015 259 19.2 49.992 1.82295 232 17.2 51.38 1.77694 246 18.3 52.019 1.75659 255 18.9 53.699 1.70552 240 17.8 54.686 1.67707 230 17.1 57.016 1.61393 233 17.3 57.764 1.5948 225 16.7 58.87 1.56745 240 17.8 60.68 1.52495 248 18.4 62.067 1.49415 261 19.4 63.043 1.47336 262 19.5 65.449 1.42489 286 21.2 66.425 1.40631 348 25.9

Comparative Example 3: Preparation of a Zeolitic Material Having an MWW Framework Structure and Comprising Boron and Titanium, Based on WO 2012/046881 A1

[0245] The preparation was carried out analogously to the recipe of WO 2012/046881 A1. However, in order to allow for a comparison between the respectively obtained material with the material according to the present invention, the process according to Wu et al. was modified in that the acid treatment step was not carried out. This is the only possibility that with respect to the finally obtained materials, characteristics can be compared on a reasonable basis since only if the acid treatment step and, thus, the step of removing the boron is not carried out, the resulting calcined material of prepared analogously to WO 2012/046881 A1 still contains boron.

[0246] In a vessel, 323.64 g piperidine were dissolved in 864.32 g de-ionized (DI) water. Subsequently, tetrabutylorthotitanate (40.32 g) was added under stirring, and subsequently, boric acid (203.4 g) was added under further stirring. Finally, fumed silicon dioxide (Cab-O-Sil M5®, 40.32 g) was added to the mixture. The thus obtained mixture was stirred for 1.5 h at room temperature.

[0247] The resulting mixture was transferred into an autoclave and heated to 160° C. within 8 h. The thus heated mixture was kept at 160° C. for 120 h. The resulting suspension had a pH of 11.1. The zeolitic material was separated by filtration (suction filter), washed with DI water until the pH of the filtrate was below 10. The filter cake was dried in a drying oven at 50° C. for 24 h and subsequently, the dried filter cake was heated at a heating rate of 2 K/min to a temperature of 530° C., and calcined at 530° C. for 10 h in air atmosphere. A colorless powder (170 g) was obtained. The powder had a boron content of 2.0 weight-%, calculated as elemental boron, a titanium content of 2.8 weight-%, calculated as elemental titanium, and a silicon content 42 weight-%, calculated as elemental titanium. The total organic carbon content (TOC) was 0.1 weight-%.

[0248] The .sup.11B solid state NMR spectrum of the zeolitic material is shown in FIG. 4, the .sup.29Si solid state NMR spectrum in FIG. 8. Further, the XRD spectrum exhibits the following characteristics:

TABLE-US-00004 Angle d value Intensity Intensity 2-Theta ° Angstrom Cps % 7.013 12.59532 274 20.3 7.238 12.20307 468 34.7 8.058 10.96352 326 24.2 10.137 8.71933 362 26.9 13.007 6.80071 134 10 14.278 6.19805 313 23.2 14.476 6.11373 408 30.3 14.924 5.93142 209 15.5 16.143 5.48597 249 18.5 18.048 4.91111 119 8.8 19.22 4.61418 192 14.3 20.448 4.33988 313 23.3 21.418 4.14544 239 17.8 21.857 4.06307 403 29.9 22.142 4.01139 424 31.5 22.687 3.91637 413 30.7 22.974 3.8681 747 55.5 23.97 3.70954 539 40 25.277 3.5206 446 33.1 26.321 3.38327 1346 100 27.289 3.26537 498 37 28.094 3.17361 511 37.9 28.947 3.08203 357 26.5 30.059 2.97051 210 15.6 32.004 2.79431 217 16.1 32.669 2.73889 229 17 33.757 2.65307 319 23.7 34.829 2.57383 233 17.3 36.837 2.43798 209 15.5 37.535 2.39427 197 14.6 38.316 2.34724 240 17.8 41.141 2.19233 204 15.2 41.982 2.15035 205 15.2 43.358 2.08522 213 15.8 45.169 2.00577 255 19 46.654 1.94533 266 19.8 46.968 1.93304 284 21.1 48.908 1.86079 255 19 49.494 1.84015 259 19.2 49.992 1.82295 232 17.2 51.38 1.77694 246 18.3 52.019 1.75659 255 18.9 53.699 1.70552 240 17.8 54.686 1.67707 230 17.1 57.016 1.61393 233 17.3 57.764 1.5948 225 16.7 58.87 1.56745 240 17.8 60.68 1.52495 248 18.4 62.067 1.49415 261 19.4 63.043 1.47336 262 19.5 65.449 1.42489 286 21.2 66.425 1.40631 348 25.9

Example 2: Comparison of the .SUP.11.B and .SUP.29.Si NMR Spectra of the Zeolitic Materials

[0249] A comparison of the .sup.11B solid state NMR spectra of the zeolitic materials according to Example 1 and Comparative Examples 1, 2 and 3 shows that the zeolitic material according to the invention has the highest ratio of the integral of the range of the third signal relative to the integral of the range of the second signal, as shown in Table 1 below:

TABLE-US-00005 TABLE 1 Comparison of the integrals of the signals ratio Catalyst integral integral integral integral integral 3/ obtained from signal 1 signal 2 signal 3 signal 4 integral 2 Example 1 0.1755 0.3685 0.4209 0.0352 1.14 Comp. Example 1 0.0928 0.4783 0.2772 0.0517 0.79 Comp. Example 2 0.1079 0.3685 0.4209 0.0352 0.96 Comp. Example 3 0.1852 0.4825 0.2951 0.0371 0.61

[0250] A comparison of the .sup.29Si solid state NMR spectra of the zeolitic materials according to Example 1 and Comparative Examples 1, 2 and 3 shows that the zeolitic material according to the invention has the highest ratio of the integral of the range of the first signal relative to the integral of the range of the third signal, as shown in Table 2 below:

TABLE-US-00006 TABLE 2 Comparison of the integrals of the signals ratio Catalyst integral integral integral integral 1/ obtained from signal 1 signal 2 signal 3 integral 3 Example 1 0.187 0.6005 0.2125 0.88 Comp. Example 1 0.1157 0.5806 0.3037 0.38 Comp. Example 2 0.1241 0.6133 0.2626 0.47 Comp. Example 3 0.1316 0.6181 0.2503 0.53

Example 3: Test of the Zeolitic Materials as a Catalytic Material

[0251] The zeolitic materials obtained in Example 1, Comparative Example 1 and Comparative Example 2 were employed as catalysts in an oxidation reaction, specifically in the reaction of cyclohexene with hydrogen peroxide to give 2-methoxycyclohexanol.

[0252] In a reaction vessel, 1 g of the respective zeolitic material was admixed with 3.92 g of cyclohexene in 20 ml methanol. To the resulting mixture, 1 g of a 50 weight-% aqueous hydrogen peroxide solution were added. The mixture was heated for 4 h at 65° C. under stirring.

[0253] After removal of the catalyst by means of filtration, and after weighing the thus obtained filtrate, a sample was taken from the filtrate. From this sample, the content of hydrogen peroxide was measured by means of cerimetry, in order to determine the hydrogen peroxide conversion rate.

[0254] To the remaining filtrate, sodium sulfite was added in order to decompose the remaining hydrogen peroxide, and a sample was taken from this filtrate for gas chromatography analysis to determine the molar amounts of the compounds of formulae (I) to (V) formed according to the reaction scheme below. From the molar amounts, the selectivity was calculated as the molar amount of the 2-methoxycyclohexanol (compound of formula (I)) relative to the total molar amount of all compounds of formulae (I) to (V). The abbreviation “B-Ti-MWW” stand for the respectively employed zeolitic material.

##STR00006##

[0255] The experimental results are shown in Table 3 below.

TABLE-US-00007 TABLE 3 Experimental results of Example 1 and Comparative Examples 1, 2, and 3 Catalyst H.sub.2O.sub.2 conversion Selectivity/ obtained from rate/% % Example 1 67 84 Comparative Example 1 27 79 Comparative Example 2 31 71 Comparative Example 3 45 73

[0256] These results clearly show that the zeolitic material prepared according to Example 1 provides for a significantly improved selectivity and, at the same time, a higher conversion rate compared with the zeolitic material prepared according to Comparative Examples 1, 2, and 3.

SUMMARY OF THE EXAMPLES

[0257] As shown hereinabove, although the process of the prior art had to be modified according to a certain aspect of the concept of the present invention and no acid treatment step was carried according to Comparative Examples 1 and 2 to allow for preparing a calcined zeolitic material comprising titanium as well as boron, and not only titanium, the materials according to the prior art significantly differ from the inventive material; in particular, reference is made to the comparison of the zeolitic materials with respect to their .sup.11B and .sup.29Si solid state NMR spectra in Example 2 above and, further, to the test of the zeolitic materials as catalytic materials according to Example 3 above.

SHORT DESCRIPTION OF THE FIGURES

[0258] FIG. 1 shows the .sup.11B solid-state NMR spectrum of the zeolitic material according to Example 1, determined according to Reference Example 1. On the x axis, the .sup.11B chemical shift (in ppm) is shown, on the y axis, the intensity (*10.sup.6). Tick mark labels on the x axis are, from left to right, at 40, 20, 0, −20. Tick mark labels on the y axis are, from bottom to top, at 0, 1, 2, 3, 4.

[0259] FIG. 2 shows the .sup.11B solid-state NMR spectrum of the zeolitic material according to Comparative Example 1, determined according to Reference Example 1. On the x axis, the .sup.11B chemical shift (in ppm) is shown, on the y axis, the intensity (*10.sup.6). Tick mark labels on the x axis are, from left to right, at 40, 20, 0, −20. Tick mark labels on the y axis are, from bottom to top, at 0.0, 0.5, 1.0, 1.5.

[0260] FIG. 3 shows the .sup.11B solid-state NMR spectrum of the zeolitic material according to Comparative Example 2, determined according to Reference Example 1. On the x axis, the .sup.11B chemical shift (in ppm) is shown, on the y axis, the intensity (*10.sup.6). Tick mark labels on the x axis are, from left to right, at 40, 20, 0, −20. Tick mark labels on the y axis are, from bottom to top, at 0.0, 0.5, 1.0, 1.5, 2.0.

[0261] FIG. 4 shows the .sup.11B solid-state NMR spectrum of the zeolitic material according to Comparative Example 3, determined according to Reference Example 1. On the x axis, the .sup.11B chemical shift (in ppm) is shown, on the y axis, the intensity (*10.sup.6). Tick mark labels on the x axis are, from left to right, at 40, 20, 0, −20. Tick mark labels on the y axis are, from bottom to top, at 0, 1, 2, 3.

[0262] FIG. 5 shows the .sup.29Si solid-state NMR spectrum of the zeolitic material according to Example 1, determined according to Reference Example 2. On the x axis, the .sup.29Si chemical shift (in ppm) is shown, on the y axis, the intensity (*10.sup.3). Tick mark labels on the x axis are, from left to right, at −90, −100, −110, −120, −130. Tick mark labels on the y axis are, from bottom to top, at 0, 20, 40, 60, 80, 100.

[0263] FIG. 6 shows the .sup.29Si solid-state NMR spectrum of the zeolitic material according to Comparative Example 1, determined according to Reference Example 2. On the x axis, the .sup.29Si chemical shift (in ppm) is shown, on the y axis, the intensity (*10.sup.3). Tick mark labels on the x axis are, from left to right, at −90, −100, −110, −120, −130. Tick mark labels on the y axis are, from bottom to top, at 0, 10, 20, 30, 40.

[0264] FIG. 7 shows the .sup.29Si solid-state NMR spectrum of the zeolitic material according to Comparative Example 2, determined according to Reference Example 2. On the x axis, the .sup.29Si chemical shift (in ppm) is shown, on the y axis, the intensity (*10.sup.3). Tick mark labels on the x axis are, from left to right, at −90, −100, −110, −120, −130. Tick mark labels on the y axis are, from bottom to top, at 0, 20, 40.

[0265] FIG. 8 shows the .sup.29Si solid-state NMR spectrum of the zeolitic material according to Comparative Example 3, determined according to Reference Example 2. On the x axis, the .sup.29Si chemical shift (in ppm) is shown, on the y axis, the intensity (*10.sup.3). Tick mark labels on the x axis are, from left to right, at −90, −100, −110, −120, −130. Tick mark labels on the y axis are, from bottom to top, at 0, 50, 100, 150.

[0266] FIG. 9 shows the FT-IR spectrum of the zeolitic material according to Example 1, determined according to Reference Example 4. On the x axis, the wavenumber (in cm.sup.−1) is shown, on the y axis, the extinction. Tick mark labels on the x axis are, from left to right, at 4000, 3500, 3000, 2500, 2000, 1500. Tick mark labels on the y axis are, from bottom to top, at −0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18. The wave numbers in cm.sup.−1 given at the individual peaks are, from left to right, 3748, 3719, 3689, 3623, 3601, 3536, 1872.

[0267] FIG. 10 shows the X-ray diffraction pattern (copper K alpha radiation) of the zeolitic material according to Example 1, determined according to Reference Example 5. On the x axis, the degree values (2 Theta) are shown, on the y axis, the intensity (Lin (Counts)). Tick mark labels on the x axis are, from left to right, at 2, 10, 20, 30, 40, 50, 60, and 70. Tick mark labels on the y axis are, from bottom to top, at 0 and 3557.

CITED LITERATURE

[0268] P. Wu et al., “A novel titanosilicate with MWW structure. I. Hydrothermal synthesis, elimination of extraframework titanium, and characterizations”, J. Phys. Chem. B., 2001, vol. 105, no. 15, pp 2897 to 2905 [0269] US 20110190517 A1 [0270] WO 2012/046881 A1 [0271] WO 2010/067855 A1