Ammonia etching H-beta molecular sieve supported nickel catalyst, preparation method and application thereof

Abstract

The application provides an ammonia-etching Hbeta molecular sieve supported nickel catalyst and a preparation method and application thereof, and belongs to the technical field of molecular sieve catalyst preparation and application. In the preparation process, a silicon source, an aluminum source, a template agent and sodium hydroxide are dispersed in deionized water, a beta molecular sieve is prepared by using a hydrothermal synthesis method, then an Hbeta molecular sieve is obtained by using an ion exchange method, and finally, the ammonia-etching Hbeta molecular sieve supported nickel catalyst is prepared by using an improved deposition-precipitation method and a hydrothermal synthesis method. The catalyst prepared by the application has high catalytic cracking activity and good stability, and the production cycle is short. The catalyst prepared by the application is applied to the catalytic hydrogenation reaction of benzyl phenyl ether, can effectively crack the benzyl phenyl ether, and obtain benzene and toluene with high yield through the cleavage of >C ar -O- and >CH-O- bridges, and can significantly improve the conversion rate of lignite and the yield of derived aromatic hydrocarbons.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of molecular sieve preparation, in particular to an ammonia-etched Hbeta molecular sieve supported nickel catalyst, a preparation method and application thereof. BACKGROUND

[0002] The organic matter in low metamorphic coal is mainly composed of macromolecules, rich in condensed aromatic rings and heteroatom-containing aromatic rings, and is a fine organic chemical product with high added value. Low metamorphic coal has a complex high-density three-dimensional network structure, and the unit fragments are connected by various >C-C< and >C-X (X=O-, N< and S-) bridges, accompanied by a small amount of free nested groups. Therefore, based on the above characteristics, by designing a high-activity catalyst and using it for catalytic hydrocracking of low metamorphic coal, high-value aromatic hydrocarbon derivatives with different composition and structural characteristics can be obtained.

[0003] As a typical low metamorphic coal, lignite, the catalytic hydrocracking process commonly uses molecular sieve catalysts such as HZSM-5, HY, SBA-15, etc. These single molecular sieve catalysts have good process stability and sufficient acid-base active centers. However, the traditional single molecular sieve catalyst has the problems of easy loss of active components, complex preparation process, long production cycle, poor repeatability, harsh reaction conditions, etc., which cause high consumption and high process cost. Since the high reaction activity is related to the unique pore size distribution, in order to obtain high yield of lignite-derived soluble matter, it is necessary to increase the specific surface area of the catalyst to expose more active sites. In addition, the commonly used catalyst also hydrogenates aromatic rings in the process of catalytic cracking of lignite to obtain small molecular organic components. In order to achieve the purpose of cracking >C-C< and >C-X bridges without hydrogenating aromatic rings, it is necessary to accurately control the generation and transfer of active hydrogen species.

[0004] Therefore, it is urgent to develop a catalyst for lignite catalytic hydrocracking reaction to completely solve the problems of easy loss of active components, complex preparation process, long production cycle, poor repeatability, harsh reaction conditions, and hydrogenation of aromatic rings. SUMMARY

[0005] To solve the above technical problems, the present application provides an ammonia-etched Hbeta molecular sieve supported nickel catalyst, a preparation method and application thereof. The present application modifies Hbeta molecular sieve by metal Ni deposition and ammonia etching to prepare an ammonia-etched Hbeta molecular sieve supported nickel catalyst, which is referred to as ammonia-etched Ni@Hbeta catalyst. The preparation process of the present application is relatively simple, has short production cycle, good stability, and is safe and feasible. The ammonia-etched Ni@Hbeta catalyst obtained by the present application has a large specific surface area, high activity and selectivity, can effectively activate H2 into diatomic active hydrogen (H…H), hydrogen radical and hydrogen proton, and can efficiently catalyze the cracking of lignite to obtain aromatic hydrocarbon components, which has a broad market application prospect.

[0006] To achieve the above object, the present application adopts the following technical solutions:

[0007] In a first aspect, the present application provides a preparation method of an ammonia-etched Hβ zeolite supported nickel catalyst, specifically comprising the following steps:

[0008] a. Preparation of β zeolite:

[0009] a1. Disperse a silicon source, an aluminum source, a template agent and sodium hydroxide in deionized water, stir uniformly at room temperature, transfer the mixed solution to a polytetrafluoroethylene-lined hydrothermal kettle for hydrothermal reaction, after natural cooling to room temperature, centrifuge the suspension, wash with deionized water and anhydrous ethanol alternately for multiple times and vacuum dry to obtain a solid sample;

[0010] a2. Place the solid sample obtained in step a1 in a high-temperature tube furnace for calcination to remove the template agent and obtain β zeolite;

[0011] b. Preparation of Hβ zeolite:

[0012] b1. Disperse the β zeolite obtained in step a2 into an ion exchange solution, stir, stand and centrifuge to pour out the supernatant, repeat step b1 for 1-3 times to obtain a solid product;

[0013] b2. Wash the solid product obtained in step b1 with deionized water multiple times, then vacuum dry and calcine in a high-temperature tube furnace to obtain Hβ zeolite;

[0014] c. Preparation of ammonia-etched Ni@Hβ catalyst:

[0015] c1. Disperse the Hβ zeolite obtained in step b2, ammonium nitrate and nickel salt into deionized water, drop in dilute ammonia water drop by drop under continuous stirring, after stirring, transfer into a polytetrafluoroethylene-lined hydrothermal kettle for nickel deposition and ammonia etching reaction, finally wash alternately with deionized water and anhydrous ethanol after centrifugation, vacuum dry to obtain a solid powder;

[0016] c2. Place the solid powder obtained in step c1 in a tube furnace for high-temperature reduction under hydrogen atmosphere to obtain an ammonia-etched Hβ zeolite supported nickel catalyst.

[0017] Preferably, in step a1, the silicon source is selected from at least one of silicon dioxide, solid silica gel or sodium silicate.

[0018] Preferably, in step a1, the aluminum source is selected from at least one of aluminum oxide, sodium metaaluminate or aluminum hydroxide.

[0019] Preferably, in step a1, the template agent is selected from at least one of tetraethylammonium hydroxide, sodium carboxymethyl cellulose or triethanolamine.

[0020] Preferably, in step a1, the ratio of the added mass of the silicon source, the aluminum source, sodium hydroxide, and the added volume of the template agent, deionized water is g:g:g:mL:mL=(1-4):(0.1-0.5):(0.03-0.2):(0.5-3):(1-5).

[0021] Preferably, in step a1, the volume ratio of the mixed solution to the volume of the polytetrafluoroethylene-lined hydrothermal kettle is (70-90):100.

[0022] Preferably, in step a1, the temperature of the hydrothermal reaction is 100-130℃, and the hydrothermal reaction time is 24-48h.

[0023] Preferably, in step a1, the centrifugal speed is 4500-5500rpm, and the centrifugal time is 5-15min.

[0024] Preferably, in step a1, the vacuum drying temperature is 65-85℃, and the vacuum drying time is 4-24h.

[0025] Preferably, in step a2, the calcination temperature is 450-550℃, and the calcination time is 2-8h.

[0026] Preferably, in step b1, the ion exchange solution is selected from at least one of ammonium chloride, ammonium nitrate, and ammonium sulfate solution.

[0027] Preferably, in step b1, the molar concentration of the ion exchange solution is 0.5-2mol / L.

[0028] Preferably, in step b1, the ratio of the mass of the β molecular sieve to the volume of the ion exchange solution is g:mL=1:(20-50).

[0029] Preferably, in step b2, the vacuum drying temperature is 65-85℃, and the vacuum drying time is 4-24h.

[0030] Preferably, in step b2, the calcination temperature is 450-550℃, and the calcination time is 2-8h.

[0031] Preferably, in step c1, the nickel salt is selected from nickel nitrate hexahydrate.

[0032] Preferably, in step c1, the concentration of the dilute ammonia water is 2.8-3.2wt%, and the ratio of the added volume of deionized water, ammonia water, and the added mass of Hβ molecular sieve is mL:mL:g=(25-50):(25-100):1.

[0033] Preferably, in step c1, the ratio of the added mass of Hβ molecular sieve, ammonium nitrate, and nickel salt is 1:(0.2-2):(0.2-1.2).

[0034] Preferably, in step c1, the temperature of the nickel deposition and ammonia etching reaction is 110-130℃, and the time of the nickel deposition and ammonia etching reaction is 2-8h.

[0035] Preferably, in step c1, the centrifugal speed is 4500-5500rpm, and the centrifugal time is 5-15min.

[0036] Preferably, in step c1, the vacuum drying temperature is 65-85℃, and the vacuum drying time is 4-24h.

[0037] Preferably, in step c2, the high-temperature reduction temperature is 400-500℃, and the high-temperature reduction time is 3-5h.

[0038] Preferably, in step c2, the loading amount of the metal nickel of the ammonia-etched Hβ zeolite-supported nickel catalyst is 5-20wt%.

[0039] More preferably, in step c2, the loading amount of the metal nickel of the ammonia-etched Hβ zeolite-supported nickel catalyst is 5-15wt%.

[0040] In a second aspect, the present application provides an ammonia-etched Hβ zeolite-supported nickel catalyst obtained by the preparation method described above.

[0041] In a third aspect, the present application provides an application of the ammonia-etched Hβ zeolite-supported nickel catalyst described above in a catalytic hydrocracking reaction of lignite.

[0042] The present application has the following advantages:

[0043] The present application adopts a hydrothermal synthesis method to obtain β zeolite, then obtains Hβ zeolite through an ion exchange method, and finally obtains an ammonia-etched Hβ zeolite-supported nickel catalyst by using an improved deposition-precipitation method and a hydrothermal synthesis method. Compared with the prior art, the ammonia-etched Hβ zeolite-supported nickel catalyst prepared by the present application has the following advantages:

[0044] (1) The preparation process of the ammonia-etched Hβ zeolite-supported nickel catalyst is simple, the production cycle is short, and the safety is high; the dispersion degree of nickel species is high, and there is no obvious agglomeration.

[0045] (2) The surface of the ammonia-etched Hβ zeolite-supported nickel catalyst becomes rough due to ammonia etching and Ni deposition, the specific surface area is large, the acidity is strong, the activity and selectivity are high, and it is more beneficial to crack >C-C< and >C-X< bridge bonds and remove heteroatoms.

[0046] (3) The catalyst is used in a catalytic hydrogenation reaction of benzyl phenyl ether, and phenyl and toluene with high yield are obtained; the catalyst is applied in a catalytic hydrocracking reaction process of lignite, and the conversion rate of lignite and the yield of derived aromatic hydrocarbons are significantly improved. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 X-ray diffraction pattern of the ammonia-etched Ni@Hβ catalyst prepared in Example 1.

[0048] Figure 2 Transmission electron microscopy image, scanning electron microscopy image and element distribution map of the ammonia-etched Ni@Hβ catalyst prepared in Example 1.

[0049] Figure 3 X-ray photoelectron spectroscopy of the ammonia-etched Ni@Hβ catalyst prepared in Example 1.

[0050] Figure 4 Derivative yield plot of the ammonia-etched Ni@Hβ catalyst prepared in Example 1 for catalytic hydrocracking of Xinjiang Zhunnan lignite.

[0051] Figure 5 Light component core group component distribution plot of the ammonia-etched Ni@Hβ catalyst prepared in Example 1 for catalytic hydrocracking of Xinjiang Zhunnan lignite. DETAILED DESCRIPTION

[0052] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0053] Example 1

[0054] A preparation method of an ammonia-etched Hβ zeolite supported nickel catalyst, the specific process is as follows:

[0055] a. Preparation of β zeolite:

[0056] a1. 7.6 g of silicon dioxide, 0.762 g of aluminum oxide, 15.9 mL of tetraethylammonium hydroxide, and 0.346 g of sodium hydroxide were dispersed in 30 mL of deionized water, stirred uniformly, and transferred to a polytetrafluoroethylene-lined hydrothermal kettle. The kettle body was heated to 120℃ and kept for 24 h, then taken out, and naturally cooled to room temperature. Centrifugal separation was performed at a centrifugal speed of 5000 rpm for 5 min, and deionized water and anhydrous ethanol were used for alternating washing 3 times. Vacuum drying was performed at 75℃ for 4 h to obtain a solid sample;

[0057] a2. The solid sample obtained in step a1 was placed in a high-temperature tube furnace and calcined at 500℃ for 2 h to obtain β zeolite.

[0058] b. Preparation of Hβ zeolite:

[0059] b1. Add the 2g β molecular sieve obtained in step a2 to 100mL of 0.5mol / L ammonium nitrate solution, stir, let stand and centrifuge at 5000rpm for 5min, pour out the supernatant, and repeat the above operation 3 times.

[0060] b2. The solid product obtained in step b1 is washed multiple times with deionized water, dried under vacuum at 75°C for 4 hours, and then calcined in a high-temperature tube furnace at 500°C for 2 hours to obtain Hβ molecular sieve.

[0061] c. Preparation of Ni@Hβ catalyst etched by ammonia:

[0062] c1. Disperse 2g of Hβ molecular sieve, 1.05g of ammonium nitrate, and 1.01g of nickel nitrate hexahydrate obtained in step b2 into 60mL of deionized water. Add 100mL of 3wt% dilute ammonia water dropwise while stirring continuously. After stirring for 15min, transfer the mixture to a polytetrafluoroethylene-lined hydrothermal reactor and carry out Ni deposition and ammonia etching reaction at 120℃ for 6h. Then, centrifuge at 5000rpm for 5min. Finally, wash the mixture alternately with deionized water and anhydrous ethanol and vacuum dry it at 75℃ for 4h to obtain a solid powder.

[0063] c2. The solid powder obtained in step c1 is placed in a tube furnace and reduced at 450°C for 4 hours under a hydrogen atmosphere to obtain an ammonia etching nickel catalyst with a loading of 10 wt% Hβ, denoted as Ni. 10％ @Hβ catalyst.

[0064] Ni etched with ammonia obtained in Example 1 10％ The X-ray diffraction pattern of the Hβ catalyst is attached. Figure 1 As shown in the figure, ammonia etching of Ni 10％ The XRD patterns of the @Hβ catalyst showed consistent β-zeolite characteristic diffraction peaks at 2θ of 7.4° and 22.4° with those in the standard spectrum. After modifying the Hβ molecular sieve with elemental Ni deposition and ammonia etching using an improved deposition-precipitation method and hydrothermal synthesis, characteristic diffraction peaks at 44.6° (111), 51.9° (200), and 76.4° (220) were related to elemental Ni crystal planes. The results indicate that the intensity of the characteristic diffraction peaks remained essentially consistent before and after Hβ modification, suggesting that the Ni deposition and ammonia etching modification did not significantly damage the crystal structure of the β-zeolite.

[0065] Ni etched with ammonia obtained in Example 1 10％ Transmission electron microscopy (TEM) images, scanning electron microscopy (SEM) images, and elemental distribution maps of the @Hβ catalyst are attached. Figure 2 As shown in the figure, ammonia etching of Ni 10％The @Hβ catalyst exhibits a rough surface and uniform particle size. Highly dispersed nickel species, along with a Ni loading comparable to theoretical values, are further observed in the elemental distribution map. Transmission electron microscopy confirms the presence of Ni etched by ammonia. 10％ The Hβ catalyst did not exhibit significant particle agglomeration. This indicates that the prepared ammonia-etched Ni... 10％ @Hβ catalyst is a catalyst with uniform nickel species distribution on the Hβ surface and a roughened surface due to etching.

[0066] Ni etched with ammonia obtained in Example 1 10％ The X-ray photoelectron spectrum of the @Hβ catalyst is attached. Figure 3 As shown, XPS analysis results confirm the presence of ammonia-etched Ni. 10％ The Hβ catalyst contains O, Si, Al, and Ni elements. A Ni₂P binding energy peak was observed in the 848-883 eV range, with a Ni₂P peak near 852.6 eV. 3 / 2 The peak corresponds to the reduced state Ni 0 Ni 2P near 873.3 eV 1 / 2 Ni 2P peak and near 855.4 eV 3 / 2 The peaks are all attributed to the weak NiO interaction induced by oxidation on the Ni nanoparticle surface. Additionally, two vibrational satellite peaks were observed near 861.4 eV and 879.7 eV, further confirming the effectiveness of ammonia-etched Ni. 10％ The vast majority of Ni species in the @Hβ catalyst are in the form of Ni 0 It exists in the form of NiO, with only a small amount of NiO produced on the surface due to oxidation.

[0067] Example 2

[0068] A method for preparing a nickel catalyst supported on an ammonia-etched Hβ molecular sieve, the specific process of which is as follows:

[0069] a. Preparation of β-molecular sieves:

[0070] a1. Disperse 7.6g of silica, 3.8g of alumina, 20.4mL of tetraethylammonium hydroxide, and 1.583g of sodium hydroxide in 30mL of deionized water, stir well, and transfer to a polytetrafluoroethylene-lined hydrothermal reactor. Heat the reactor to 120℃ and keep it at that temperature for 32h. After removing the reactor and allowing it to cool naturally to room temperature, centrifuge at 5000rpm for 5min. Wash the sample three times alternately with deionized water and anhydrous ethanol, and vacuum dry at 75℃ for 6h to obtain a solid sample.

[0071] a2. Place the solid sample obtained in step a1 in a high-temperature tube furnace and calcine it at 500℃ for 3 hours to obtain β molecular sieve.

[0072] b. Preparation of Hβ molecular sieves:

[0073] b1, 2g of the β molecular sieve obtained in step a2 was added to 80 mL of 0.5 mol / L ammonium nitrate solution, stirred, allowed to stand and centrifuged at 5000 rpm for 5 min, the supernatant was poured out, and the above operation was repeated for 3 times;

[0074] b2, the solid product obtained in step b1 was washed with deionized water for several times, vacuum dried at 75℃ for 6h, and then calcined at 500℃ for 3h in a high-temperature tube furnace to obtain Hβ molecular sieve.

[0075] c, preparation of ammonia-etched Ni@Hβ catalyst:

[0076] c1, 2g of the Hβ molecular sieve obtained in step b2, 0.65g of ammonium nitrate and 0.505g of nickel nitrate hexahydrate were dispersed in 50 mL of deionized water, 50 mL of 3wt% dilute ammonia water was added dropwise under continuous stirring, and then the stirring was continued for 15 min before being transferred into a polytetrafluoroethylene-lined hydrothermal kettle for Ni deposition and ammonia etching reaction at 110℃ for 8h. Then, centrifugal separation was performed at 5000 rpm for 5 min. Finally, the solid powder was obtained by alternating washing with deionized water and anhydrous ethanol, vacuum drying at 75℃ for 6h.

[0077] c2, the solid powder obtained in step c1 was placed in a tube furnace and reduced at 400℃ for 5h under hydrogen atmosphere to obtain a Hβ catalyst with a nickel loading of 5wt%, which was denoted as Ni 5％ @Hβ catalyst.

[0078] Example 3

[0079] A method for preparing an ammonia-etched Hβ molecular sieve supported nickel catalyst, the specific process is as follows:

[0080] a, preparation of β molecular sieve:

[0081] a1, 7.6g of silicon dioxide, 3.04g of aluminum oxide, 20.4 mL of tetraethylammonium hydroxide and 1.583g of sodium hydroxide were dispersed in 30 mL of deionized water, stirred uniformly and transferred into a polytetrafluoroethylene-lined hydrothermal kettle, the kettle was heated to 120℃ and kept for 40h, then taken out and allowed to cool to room temperature, centrifuged at 5000 rpm for 5 min, washed with deionized water and anhydrous ethanol alternately for 3 times, and vacuum dried at 75℃ for 12h to obtain a solid sample;

[0082] a2, the solid sample obtained in step a1 was calcined at 500℃ for 6h in a high-temperature tube furnace to obtain β molecular sieve.

[0083] b, preparation of Hβ molecular sieve:

[0084] b1, 2g of the β molecular sieve obtained in step a2 was added to 100 mL of 1.0 mol / L ammonium nitrate solution, stirred, allowed to stand, and centrifuged at 5000 rpm for 5 min, and the supernatant was poured out, and the above operation was repeated 3 times;

[0085] b2, the solid product obtained in step b1 was washed with deionized water for several times, vacuum dried at 75℃ for 12h, and then placed in a high-temperature tube furnace and calcined at 450℃ for 6h to obtain Hβ molecular sieve.

[0086] c, preparation of ammonia-etched Ni@Hβ catalyst:

[0087] c1, 2g of the Hβ molecular sieve obtained in step b2, 2.55g of ammonium nitrate, and 1.515g of nickel nitrate hexahydrate were dispersed in 80 mL of deionized water, 150 mL of 3wt% dilute ammonia water was added dropwise under continuous stirring, and after stirring for 15 min, it was transferred into a polytetrafluoroethylene-lined hydrothermal kettle and subjected to Ni deposition and ammonia etching reaction at 120℃ for 8h, then centrifuged at 5000 rpm for 5 min, and finally washed with deionized water and anhydrous ethanol alternately, vacuum dried at 75℃ for 12h to obtain a solid powder;

[0088] c2, the solid powder obtained in step c1 was placed in a tube furnace and reduced at 500℃ for 2h under hydrogen atmosphere to obtain an ammonia-etched nickel-loaded Hβ catalyst with a nickel loading of 15wt%, denoted as Ni 15％ @Hβ catalyst.

[0089] Example 4

[0090] A method for preparing an ammonia-etched Hβ molecular sieve supported nickel catalyst, the specific process is as follows:

[0091] a, preparation of β molecular sieve:

[0092] a1, 7.6g of silicon dioxide, 2.28g of aluminum oxide, 20.4mL of tetraethylammonium hydroxide, and 0.6g of sodium hydroxide were dispersed in 30mL of deionized water, stirred uniformly, and transferred into a polytetrafluoroethylene-lined hydrothermal kettle, the kettle was heated to 120℃ and kept for 48h, then taken out and allowed to cool to room temperature, centrifuged at 5000 rpm for 5 min, washed with deionized water and anhydrous ethanol alternately for 3 times, and vacuum dried at 75℃ for 24h to obtain a solid sample;

[0093] a2, the solid sample obtained in step a1 was placed in a high-temperature tube furnace and calcined at 500℃ for 8h to obtain β molecular sieve.

[0094] b, preparation of Hβ molecular sieve:

[0095] b1, 2g of the β molecular sieve obtained in step a2 was added into 50 mL of 1.0 mol / L ammonium nitrate solution, and stirred, settled and centrifuged at 5000 rpm for 5 min, and the supernatant was poured out, and the above operation was repeated for 3 times;

[0096] b2, the solid product obtained in step b1 was washed with deionized water for several times, vacuum dried at 75℃ for 24 h, and then calcined in a high-temperature tube furnace at 500℃ for 4 h to obtain Hβ molecular sieve.

[0097] c, preparation of ammonia-etched Ni@Hβ catalyst:

[0098] c1, 2g of the Hβ molecular sieve obtained in step b2, 3.35g of ammonium nitrate and 2.02g of nickel nitrate hexahydrate were dispersed into 100 mL of deionized water, 200 mL of 3wt% dilute ammonia water was added dropwise under continuous stirring, and after stirring for 15 min, it was transferred into a polytetrafluoroethylene-lined hydrothermal kettle for Ni deposition and ammonia etching reaction at 120℃ for 6 h, and then centrifuged at 5000 rpm for 5 min, and finally washed with deionized water and anhydrous ethanol alternately, vacuum dried at 75℃ for 24 h to obtain a solid powder;

[0099] c2, the solid powder obtained in step c1 was placed in a tube furnace and reduced at 500℃ under hydrogen atmosphere for 4 h to obtain an ammonia-etched Ni@Hβ catalyst with a nickel loading of 20wt%, which was denoted as Ni 20％ @Hβ catalyst.

[0100] The ammonia-etched Ni 10％ @Hβ catalyst prepared in Example 1 above was applied to lignite catalytic hydrocracking reaction process, and the product of non-catalytic hydroconversion and catalytic hydroconversion reaction was compared to explain and illustrate, wherein the lignite was Xinjiang Zhunnan lignite as the test object; in addition, the Ni 10％ @Hβ catalyst prepared in Example 1 above was applied to lignite related model compounds.

[0101] The following two applications of the ammonia-etched Ni 10％ @Hβ catalyst prepared in Example 1 were exemplified and described.

[0102] Application Example 1

[0103] In the non-catalytic hydrocracking reaction of Xinjiang Zhunnan lignite, the ammonia-etched Ni 10％ @Hβ catalyst prepared in Example 1 was not added, and the specific application process was as follows:

[0104] (1) Place 20g of Xinjiang Jungnan lignite in a 1000mL high-pressure reactor and add 200mL of cyclohexane;

[0105] (2) Replace the air in the reactor with N2 and then introduce 1 MPa of H2. React at 300℃ for 4 hours. After the reaction is completed, cool to room temperature.

[0106] (3) The reaction mixture was completely extracted with cyclohexane to obtain cyclohexane-soluble matter, i.e. light components, and the light components were detected, analyzed and compared.

[0107] (4) Then, extraction was continued with an equal volume of acetone and carbon disulfide mixed solvent to obtain an equal volume of acetone and carbon disulfide mixed solvent soluble matter, i.e. heavy component.

[0108] Ni etching with ammonia, as shown in the attached diagram 10％ The preparation method, performance indicators and catalytic effect of the @Hβ catalyst are described in detail. This example is only used to explain the present invention and does not constitute a limitation on the scope of protection of the present invention.

[0109] Application Example 2

[0110] The ammonia-etched Ni prepared in Example 1 10％ The Hβ catalyst was applied to the catalytic hydrocracking reaction of lignite from Zhunnan, Xinjiang. The specific application process is as follows:

[0111] (1) Add 5g Ni 10％ @Hβ catalyst and 20g of lignite extraction residue from Zhunnan, Xinjiang were placed in a 1000mL high-pressure reactor and 200mL of cyclohexane was added.

[0112] (2) Replace the air in the reactor with N2 and then introduce 1 MPa of H2. React at 300℃ for 4 hours. After the reaction is completed, cool to room temperature.

[0113] (3) The reaction mixture was completely extracted with cyclohexane to obtain cyclohexane-soluble material, i.e., light component;

[0114] (4) Then, extraction was continued with an equal volume of acetone and carbon disulfide mixed solvent to obtain an equal volume of acetone and carbon disulfide mixed solvent soluble matter, i.e. heavy component.

[0115] The yields of light components, heavy components, and coal residue from non-catalytic and catalytic hydrocracking of lignite from Zhunnan, Xinjiang, were calculated (see Appendix). Figure 4 From the appendix Figure 4 It can be seen that the introduction of ammonia etching Ni 10％The yield of soluble derivatives was significantly improved after Hβ catalyst. Among them, the yield of light components increased from 5% to 10%, and the yield of heavy components increased from 12% to 20%. The light component products of Xinjiang Zhunnan lignite non-catalytic and catalytic hydrocracking were analyzed by gas chromatography / mass spectrometry (GC / MS), as shown in the following figures: Figure 5 As can be seen from the following figures Figure 5 It can be seen that the yield of derived aromatic hydrocarbons in the light component is greatly improved, and the relative content increases from 26% to 90%. This proves that the ammonia etched Ni@Hβ catalyst can effectively promote the activation of H2 to form active hydrogen species, which is crucial for the generation of derived aromatic hydrocarbons. 10％ The Hβ catalyst can effectively promote the catalytic hydrocracking of Xinjiang Zhunnan lignite and achieve the purpose of obtaining higher derived aromatic hydrocarbons.

[0116] Application Example 3

[0117] The ammonia etched Ni@Hβ catalyst prepared in Example 1 was applied to the catalytic hydrocracking of lignite related model compounds (benzyl phenyl ether). 10％ The Hβ catalyst was applied to the catalytic hydrocracking of lignite related model compounds (benzyl phenyl ether).

[0118] The specific application process is as follows:

[0119] (1) 1g of benzyl phenyl ether, 0.5g of Ni@Hβ catalyst and 200mL of n-hexane were placed in a 1000mL stainless steel high-pressure reaction kettle; 10％ @Hβ catalyst and 200mL of n-hexane were placed in a 1000mL stainless steel high-pressure reaction kettle;

[0120] (2) The high-pressure reaction kettle was purged with N2 for 3 times, and then pressurized with 1MPa H2 at room temperature;

[0121] (3) Then, the high-pressure reaction kettle was heated to 200-300℃ and kept at the set temperature for a set time;

[0122] (4) After the reaction was completed, the high-pressure reaction kettle was cooled to room temperature and the reaction mixture was taken out, and the filtrate after filtration was detected and analyzed by GC / MS, and the Ni@Hβ catalyst was separated and analyzed by GC / MS. 10％ The results of the catalytic hydrocracking of benzyl phenyl ether by the Hβ catalyst are shown in the following Table 1.

[0123] Table 1

[0124]

[0125] As can be seen from Table 1, the ammonia etched Ni@Hβ catalyst prepared in Example 1 can effectively promote the catalytic hydrocracking of benzyl phenyl ether, and the yield of light components is significantly improved. 10％ The main products of the catalytic hydrocracking of benzyl phenyl ether by the ammonia etched Ni@Hβ catalyst are benzene and toluene. The active hydrogen species formed by the activation of H2 on the Hβ catalyst plays a crucial role in the generation of derived aromatic hydrocarbons. 10％ The ammonia etched Ni@Hβ catalyst can promote the generation of diatomic active hydrogen (H…H) and H+ from activated H2, which is crucial for the generation of derived aromatic hydrocarbons. +Due to the low bond dissociation energy of H…H, H…H tends to homolytically cleave into hydrogen radicals (H·) at higher temperatures, and the synergistic transfer of H…H, H· and H + The conversion of benzyl phenyl ether and its intermediates to derived aromatic hydrocarbons is promoted by the synergistic transfer of H…H, H· and H

[0126] The present application adopts improved deposition-precipitation method and hydrothermal synthesis method to prepare the ammonia-etching Hbeta molecular sieve supported nickel catalyst, solves the problems of traditional single molecular sieve catalyst active component easy to flow, complex preparation process, long production cycle, harsh reaction conditions and catalytic cracking of >C-C< and >C-X< bridge bond and hydrogenation of aromatic ring, etc. The high-activity ammonia-etching Ni@Hbeta catalyst achieves the effect of obtaining high content of aromatic hydrocarbons by catalytic hydrogenolysis of lignite related model compounds and Xinjiang South China lignite.

[0127] Of course, the above description is not a limitation of the present application, and the present application is not limited to the above examples, and the changes, modifications, additions or replacements made by the person skilled in the art within the essential scope of the present application should also belong to the protection scope of the present application.

Claims

1. A method for preparing a nickel catalyst supported on an ammonia-etched Hβ molecular sieve, characterized in that, Specifically, the following steps are included: a. Preparation of β-molecular sieves: a1. Disperse the silicon source, aluminum source, template agent and sodium hydroxide in deionized water, stir evenly at room temperature, transfer the mixed solution to a polytetrafluoroethylene-lined hydrothermal reactor for hydrothermal reaction, and after naturally cooling to room temperature, centrifuge the suspension, wash it alternately with deionized water and anhydrous ethanol multiple times and vacuum dry it to obtain a solid sample. a2. Place the solid sample obtained in step a1 in a high-temperature tube furnace for calcination to remove the template agent and obtain β molecular sieve; b. Preparation of Hβ molecular sieves: b1. Disperse the β molecular sieve obtained in step a2 into an ion exchange solution, stir, let stand, centrifuge and pour out the supernatant. Repeat step b1 1 to 3 times to obtain a solid product. b2. The solid product obtained in step b1 is washed multiple times with deionized water, then vacuum dried and calcined in a high-temperature tube furnace to obtain Hβ molecular sieve. c. Preparation of Ni@Hβ catalyst etched by ammonia: c1. Disperse the Hβ molecular sieve, ammonium nitrate, and nickel salt obtained in step b2 into deionized water, add dilute ammonia dropwise under continuous stirring, and after stirring, transfer to a polytetrafluoroethylene-lined hydrothermal reactor for nickel deposition and ammonia etching reaction. Finally, after centrifugation, washing with deionized water and anhydrous ethanol alternately, and vacuum drying, a solid powder can be obtained. c2. The solid powder obtained in step c1 is placed in a tube furnace and subjected to high-temperature reduction under a hydrogen atmosphere to obtain an ammonia-etched Hβ molecular sieve supported nickel catalyst. In step a1, the silicon source is selected from at least one of silicon dioxide, solid silica gel, or sodium silicate; In step a1, the aluminum source is selected from at least one of alumina, sodium aluminate, or aluminum hydroxide; In step a1, the template agent is selected from at least one of tetraethylammonium hydroxide, sodium carboxymethyl cellulose, or triethanolamine; In step a1, the ratio of the added mass of silicon source, aluminum source, and sodium hydroxide to the added volume of template agent and deionized water is g:g:g:mL:mL = (1-4):(0.1-0.5):(0.03-0.2):(0.5-3):(1-5); In step a1, the volume ratio of the mixed solution to the volume of the polytetrafluoroethylene-lined hydrothermal reactor is (70-90):100; In step a1, the hydrothermal reaction temperature is 100-130 ℃, and the hydrothermal reaction time is 24-48 h; In step a1, the centrifugation speed is 4500-5500 rpm and the centrifugation time is 5-15 min; In step a1, the vacuum drying temperature is 65-85 ℃, and the vacuum drying time is 4-24 h; In step b1, the ion exchange solution is selected from at least one of ammonium chloride, ammonium nitrate, and ammonium sulfate solutions; In step b1, the molar concentration of the ion exchange solution is 0.5-2 mol / L; In step b1, the mass ratio of the β-molecular sieve to the volume ratio of the ion exchange solution is g:mL = 1:(20-50). In step c1, the nickel salt is selected from nickel nitrate hexahydrate; In step c1, the concentration of dilute ammonia is 2.8-3.2 wt%, and the ratio of the added volume of deionized water and ammonia to the added mass of Hβ molecular sieve is mL:mL:g = (25-50):(25-100):1; In step c1, the mass ratio of Hβ molecular sieve to ammonium nitrate and nickel salt is 1:(0.2-2):(0.2-1.2). In step c1, the temperature of the nickel deposition and ammonia etching reaction is 110-130 °C, and the reaction time is 2-8 h. In step c1, the centrifugation speed is 4500-5500 rpm and the centrifugation time is 5-15 min; In step c1, the vacuum drying temperature is 65-85 ℃, and the vacuum drying time is 4-24 h; In step c2, the loading of metallic nickel in the nickel catalyst supported on the Hβ molecular sieve by ammonia etching is 5-20 wt%.

2. The method for preparing the nickel catalyst supported on the ammonia-etched Hβ molecular sieve as described in claim 1, characterized in that, In step a2, the calcination temperature is 450-550 ℃ and the calcination time is 2-8 h.

3. The method for preparing the nickel catalyst supported on the ammonia-etched Hβ molecular sieve as described in claim 1, characterized in that, It includes one or more of the following characteristics: (1) In step b2, the vacuum drying temperature is 65-85 ℃ and the vacuum drying time is 4-24 h; (2) In step b2, the calcination temperature is 450-550 ℃ and the calcination time is 2-8 h.

4. The method for preparing the nickel catalyst supported on the ammonia-etched Hβ molecular sieve as described in claim 1, characterized in that, In step c2, the high-temperature reduction temperature is 400-500 ℃, and the high-temperature reduction time is 3-5 h.

5. The ammonia-etched Hβ molecular sieve-supported nickel catalyst obtained by the preparation method according to any one of claims 1 to 4.

6. The application of the ammonia-etched Hβ molecular sieve-supported nickel catalyst as described in claim 5 in the catalytic hydrocracking reaction of lignite.

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