CN116553575A - Synthesis and application of a spike-shaped nickel-doped ZSM-22 zeolite assembled from nanoparticles - Google Patents

Abstract

The invention belongs to the field of synthesis of zeolite molecular sieves, and in particular relates to a synthesis method and application of a spike-shaped nickel-doped ZSM-22 zeolite assembled from nanoparticles. In the hydrothermal process, by reducing the water content in the gel process and increasing the 1,6-hexanediamine content, the initial gel becomes saturated, providing conditions for forming a large number of crystal nuclei, and suppressing ZSM-22 zeolite Grain growth, on the other hand, small zeolite grains grow axially along the Z axis, forming a zeolite with a wheat ear shape; nickel acetylacetonate was added during the synthesis process, and a high-external-area, exposed Nickel-doped ZSM‑22 zeolite nanobeams with more available acid sites and wheat ear-like morphology, which contain both intracrystalline mesopores and stacked pores, show great potential for deoxygenation of hexadecanoic acid High deoxidation activity.

Description

Synthetic method of a spike-shaped nickel-doped ZSM-22 zeolite assembled from nanoparticles law and application

technical field

The invention belongs to the field of synthesis of zeolite molecular sieves, and in particular relates to a method for synthesizing ZSM-22 zeolite doped with metal nickel and having wheat spike-like appearance, which contains abundant gaps and is assembled from nanoparticles.

Background technique

In the 1980s, the US Mobile Company successfully developed the ZSM-22 zeolite molecular sieve, which is a microporous material with a TON topology, consisting of five-membered rings, six-membered rings and ten-membered rings, forming a ten-membered molecular sieve with one-dimensional openings. The structural characteristics of the ring straight channel. Due to its special pore structure and adjustable acid properties, it exhibits excellent catalytic performance in hydroisomerization, methanol-to-olefins, aromatics alkylation, and xylene isomerization reactions. However, due to the pore structure characteristics of ZSM-22 zeolite itself, there is only a microporous structure, which is not conducive to the diffusion of reactive molecules, resulting in the characteristics that it is prone to cracking and catalyst deactivation during the reaction. In order to solve this problem, a mesoporous structure is introduced in the synthesis process of ZSM-22 zeolite or ZSM-22 zeolite with different morphology is synthesized to improve the diffusion of molecules, reduce its cracking performance and increase the stability of the catalyst.

In recent years, around the synthesis of porous ZSM-22 zeolite, researchers have done a lot of research work. For example, in the synthesis process of ZSM-22 zeolite, MCM-41 was introduced to successfully prepare MCM-41@ZSM-22 composite catalyst material; in addition, structural defects were introduced into the zeolite framework using a conventional combined acid–base treatment. The above method can introduce a mesoporous structure on the surface of ZSM-22 zeolite, which can improve the diffusion effect of reaction molecules and improve its catalytic activity to a certain extent. A large amount of waste water is produced in the process, which causes environmental pollution and limits its further amplification and synthesis. Soft template method is also a kind of method for synthesizing porous ZSM-22 zeolite commonly used, as: patent (CN108529647B) has reported a kind of synthetic method of mesoporous ZSM-22 zeolite, promptly also need to introduce macromolecule polymer as The mesoporous template agent, after high-temperature calcination, removes the mesoporous template agent dispersed inside the zeolite particles, and produces a rich mesoporous structure inside the ZSM-22 zeolite particles, which effectively improves the diffusion effect of molecules. Only when the molecular polymer is a soft template can defects and mesopores be generated in the zeolite crystal grains. However, these methods require the addition of high molecular polymers, which not only make it difficult for aluminum species to enter the zeolite framework during the crystallization process of zeolite, resulting in an increase in the silicon-aluminum ratio of the zeolite and a decrease in the amount of acid, but also reduce the crystallinity of the zeolite . If no polymer soft template is used, only small molecule templates such as 1,6-hexanediamine are used. The final results show that the BET specific surface area, mesopore volume, and external area of the obtained zeolite are all reduced, and the catalytic activity is obvious. reduce.

How to use only 1,6-hexanediamine as a template, without adding soft templates such as polymers, can still prepare ZSM-22 zeolite with high acid content and micropores-mesopores, so that it can Exposing more available acidic sites with excellent catalytic performance requires further study.

Contents of the invention

The invention provides a method for synthesizing a novel ZSM-22 zeolite with a wheat ear-shaped appearance containing metallic nickel. In the invention, 1,6-hexamethylenediamine is used as a structural template, and nickel acetylacetonate is added in the synthesis process. In the hydrothermal process, reduce the water content in the gel process and increase the content of 1,6-hexanediamine, the initial gel becomes saturated, providing the conditions for the formation of a large number of crystal nuclei, forming a large number of crystal nuclei, Ostwald ripening is effectively inhibited, to a certain extent inhibiting the grain growth of ZSM-22 zeolite and introducing defects at the same time; Available acidic site ZSM-22 zeolite nanobeams (ZSM-22-S) containing metallic nickel with wheat ear-like morphology.

Concrete implementation steps of the present invention are as follows:

Synthesis of a nickel-doped ZSM-22 zeolite with wheat ear shape:

Add potassium hydroxide solution to aluminum sulfate solution to obtain solution A; then add 1,6-hexamethylenediamine (DHA) structure-directing agent into distilled water, and after it is completely dissolved, add nickel acetylacetonate and stir to clarify to obtain solution B ;Solution B is slowly added dropwise to solution A, the system becomes viscous, and finally add silica sol, stir vigorously to form silica-alumina gel, and finally put it in a kettle for static crystallization at high temperature. After the crystallization is completed, after washing, filtering, drying and high-temperature calcination, the ZSM-22 zeolite with the shape of ears of wheat doped with metal nickel is obtained, which is marked as ZSM-22-S.

The ratio of the components of the silica-alumina gel formed above is Al ₂ O ₃ : 5-15K ₂ O: 2500-3500H ₂ O: 100-140SiO ₂ : 0.02-3Ni ²⁺ : 45-70DHA, preferably Al ₂ O ₃ : 5～10K ₂ O: 2500～3000H ₂ O: 100～130SiO ₂ : 0.38～2.3Ni ²⁺ : 45～65DHA. Further, the molar ratio of H ₂ O:DHA ranges from 42 to 67.

Further, the crystallization temperature is 140-180° C., and the crystallization time is 12-48 hours.

Metallic nickel doped wheat spike ZSM-22 zeolite shows excellent activity in palmitic acid hydrodeoxygenation reaction.

Further, the conditions for the preparation of hexadecane by palmitic acid hydrodeoxygenation reaction are:

The hydrodeoxygenation reaction of hexadecanic acid is carried out in a parr kettle. Before the reaction, the catalyst was reduced. The reduction procedure was as follows: the catalyst was raised from room temperature at 2 °C/min to 550 °C and kept for 2 h, and the _H2 flow rate was 100 mL/min. After cooling down to room temperature, pour the reduced catalyst into a reaction kettle filled with a reaction solution in a hydrogen atmosphere. The reaction conditions are: reaction temperature 260°C, reaction pressure 4.0MPa, reaction speed 500rmp, reaction time 4h; the reaction solution It is a solution of hexadecanic acid with a concentration of 5g/L, the solvent of the reaction solution is decahydronaphthalene, the consumption of the catalyst in the reaction solution is 5g/L, and the reaction solution after the reaction is analyzed by gas chromatography.

Compared with the prior art, ZSM-22-S zeolite has the following points:

(1) The present invention does not use high-molecular polymers as soft templates, but adopts 1,6-hexamethylenediamine small-molecule templates, and through the control of other reaction conditions, only synthesized under static crystallization conditions Pores and stacked pore-shaped ZSM-22 zeolite; Nickel acetylacetonate in the present invention, in addition to providing nickel active components, also interacts with 1,6-hexamethylenediamine, causing zeolite in the process of nucleation and growth In the process, the nickel acetylacetonate molecule is close to 1,6-hexanediamine, which not only inhibits the accumulation of metal nickel and improves the dispersion of metal nickel, but also affects the induced nucleation of 1,6-hexamethylenediamine, resulting in the formation of zeolite During the process of nucleation and growth, the morphology of zeolite is changed to a certain extent.

(2) The present invention has used the 1,6-hexamethylenediamine of high concentration, has reduced the content of the water in the gel system, suppresses ZSM-22 zeolite crystal grain growth to a certain extent, makes zeolite small crystal grain along certain direction of growth. Compared with the existing ZSM-22 zeolite with traditional needle-like morphology, ZSM-22-S zeolite has a wheat ear shape, that is, one end of the nanorod is formed by the accumulation of thinner nanofiber bundles, and the diameter of the nanofiber bundles is 50-70nm, while the nanorod diameter of traditional acicular ZSM-22 is 500-600nm. These morphological differences lead to more suitable acidity of ZSM-22-S zeolite;

(3) The zeolite synthesized ZSM-22-S increases the interaction between metal nickel and the carrier, so that many nickel species are dispersed on the outer surface of zeolite nanofiber bundles, which increases the utilization rate of metal nickel. Its activity in the hydrodeoxygenation reaction of hexadecanic acid is significantly higher than that of traditional ZSM-22 zeolite-supported nickel and traditional ZSM-22 zeolite-doped nickel catalysts.

Description of drawings

FIG. 1 is an X-ray powder diffraction pattern of Example 1.

2 is a scanning electron micrograph of Example 1.

Fig. 3 is the transmission electron micrograph of embodiment 1.

Fig. 4 is the N ₂ - adsorption isotherm diagram and pore size distribution curve diagram of Example 1.

FIG. 5 is a scanning electron micrograph of Comparative Example 1.

FIG. 6 is an X-ray powder diffraction pattern of Comparative Example 2.

FIG. 7 is an X-ray powder diffraction pattern of Comparative Example 3.

FIG. 8 is a scanning electron micrograph of Comparative Example 3.

FIG. 9 is a scanning electron micrograph of Comparative Example 4.

Detailed ways

In order to further understand the purpose, content and advantages of the present invention, the specific embodiments of the present invention are now described in detail as follows, but it should not be limited to the examples mentioned below, and should be freely matched according to actual conditions. Composition of silica sol: 70 wt.% H ₂ O and 30 wt.% SiO ₂ .

Example 1:

0.56g potassium hydroxide was dissolved in 5.0g distilled water to obtain a potassium hydroxide solution; 0.67g aluminum sulfate octadecahydrate was dissolved in 5.0g distilled water to obtain an aluminum sulfate solution, and the potassium hydroxide solution was added to the aluminum sulfate solution to obtain solution A; then Add 7.0g of 1,6-hexamethylenediamine structure-directing agent into 20.6g of distilled water. After it is completely dissolved, add 0.6g of nickel acetylacetonate, stir and clarify to obtain solution B; solution B is slowly added dropwise to solution A, and the system becomes Viscous, finally add 20.0g of silica sol, stir vigorously to form silica-alumina gel, the gel composition is: Al ₂ O ₃ :5K ₂ O:2500H ₂ O:100SiO ₂ :2.3Ni ²⁺ :60DHA. Finally, the kettle was loaded, and the high-temperature static crystallization was carried out. The crystallization temperature was 160° C. and the time was 48 hours. After the crystallization is completed, after washing, filtering, drying and high-temperature calcination, the nickel-doped ZSM-22 zeolite with the appearance of ears of wheat is obtained. The skeleton silicon-aluminum (Si/Al) ratio of zeolite is 40, and the theoretical loading of Ni in zeolite is 2.1%, and actual mass fraction is 1% (the actual loading of nickel carries out X-ray fluorescence spectrometry or atomic emission spectrometer according to catalyst characterize). Fig. 2 is the scanning electron micrograph of embodiment 1; Wherein Fig. 2 (b) is the enlarged view of Fig. 2 (a), the obtained ZSM-22-S zeolite has wheat ear shape, and nanorod one end is made of finer nanometer The fiber bundles are accumulated, the diameter of the nanofiber bundles is 50-70nm, and the fiber bundles are formed by the arrangement of nanoparticles along the axial direction. FIG. 4 is the N ₂ -adsorption isotherm diagram and pore size distribution curve diagram of the ZSM-22-S zeolite prepared in Example 1. FIG.

Example 2:

Dissolve 1.0g of potassium hydroxide in 5.0g of distilled water to obtain a potassium hydroxide solution; dissolve 0.67g of aluminum sulfate octadecahydrate in 5.0g of distilled water to obtain an aluminum sulfate solution, and add the potassium hydroxide solution to the aluminum sulfate solution to obtain solution A; Then 5.8g of 1,6-hexamethylenediamine structure-directing agent was added to 19.2g of distilled water, after it was completely dissolved, 0.21g of nickel acetylacetonate was added, stirred and clarified to obtain solution B; solution B was slowly added dropwise to solution A, and the system It becomes viscous, and finally add 22.0g of silica sol and stir vigorously to form a silica-alumina gel. The gel composition is: Al ₂ O ₃ :9K ₂ O:2500H ₂ O:110SiO ₂ :0.8Ni ²⁺ :50DHA. Finally, the kettle was loaded, and the high-temperature static crystallization was carried out. The crystallization temperature was 180° C. and the time was 36 hours. After the crystallization is completed, after washing, filtering, drying and high-temperature calcination, the nickel-doped ZSM-22 zeolite with the appearance of ears of wheat is obtained. The framework silicon-aluminum (Si/Al) ratio of the zeolite is 45, the theoretical loading of Ni in the zeolite is 0.77%, and the actual mass fraction is 0.5%. (The actual loading of nickel is characterized by X-ray fluorescence spectrometry or atomic emission spectrometer according to the catalyst).

Example 3:

1.1g of potassium hydroxide was dissolved in 5.0g of distilled water to obtain a potassium hydroxide solution; 0.67g of aluminum sulfate octadecahydrate was dissolved in 5.0g of distilled water and mixed to obtain an aluminum sulfate solution, and the potassium hydroxide solution was added to the aluminum sulfate solution to obtain solution A; Then 5.2g of 1,6-hexamethylenediamine structure-directing agent was added to 25.4g of distilled water, after it was completely dissolved, 0.39g of nickel acetylacetonate was added, stirred and clarified to obtain solution B; solution B was slowly added dropwise to solution A, and the system It becomes viscous, and finally 26.0g of silica sol is added and stirred vigorously to form a silica-alumina gel. The gel composition is: Al ₂ O ₃ :10K ₂ O:3000H ₂ O:130SiO ₂ :1.5Ni ²⁺ :45DHA. Finally, the kettle was loaded, and the high-temperature static crystallization was carried out. The crystallization temperature was 170° C. and the time was 48 hours. After the crystallization is completed, after washing, filtering, drying and high-temperature calcination, the nickel-doped ZSM-22 zeolite with the appearance of ears of wheat is obtained. The framework silicon-aluminum ratio (Si/Al) of the zeolite is 50, the theoretical loading of Ni in the zeolite is 1.5%, and the actual mass fraction is 0.8%. (The actual loading of nickel is characterized by X-ray fluorescence spectrometry or atomic emission spectrometer according to the catalyst).

Comparative example 1:

1.1g potassium hydroxide was dissolved in 5.0g distilled water to obtain a potassium hydroxide solution; 0.67g aluminum sulfate octadecahydrate was dissolved in 5.0g distilled water to obtain an aluminum sulfate solution, and the potassium hydroxide solution was added to the aluminum sulfate solution to obtain solution A; then Add 2.3g of 1,6-hexamethylenediamine structure-directing agent into 25.4g of distilled water, after it is completely dissolved, add 0.59g of nickel acetylacetonate, stir and clarify to obtain solution B; solution B is slowly added dropwise into solution A, and the system becomes Viscous, finally add 26.0g silica sol, stir vigorously to form silica-alumina gel, the gel composition is: Al ₂ O ₃ :10K ₂ O:3000H 2 O:130SiO _{2 :} 2.3Ni ²⁺ :20DHA. Finally, the kettle was loaded, and the high-temperature static crystallization was carried out. The crystallization temperature was 160° C. and the time was 40 hours. After the crystallization is completed, ZSM-22 zeolite is obtained after washing, filtering, drying and high-temperature calcination. Fig. 5 is a scanning electron micrograph of Comparative Example 1, the morphology of the synthesized zeolite is a rod-like morphology composed of fiber bundles. It is not a wheat spike ZSM-22 zeolite assembled by nano ions.

Comparative example 2:

0.56g potassium hydroxide was dissolved in 5.0g distilled water to obtain a potassium hydroxide solution; 0.67g aluminum sulfate octadecahydrate was dissolved in 5.0g distilled water to obtain an aluminum sulfate solution, and the potassium hydroxide solution was added to the aluminum sulfate solution to obtain solution A; then Add 9.3g of 1,6-hexamethylenediamine structure-directing agent into 20.6g of distilled water. After it is completely dissolved, add 0.6g of nickel acetylacetonate, stir and clarify to obtain solution B; solution B is slowly added dropwise to solution A, and the system becomes Viscous, finally add 20.0g of silica sol, stir vigorously to form silica-alumina gel, the gel composition is: Al ₂ O ₃ :5K ₂ O:2500H ₂ O:100SiO ₂ :2.3Ni ²⁺ :80DHA. Finally, the kettle was loaded, and the high-temperature static crystallization was carried out. The crystallization temperature was 160° C. and the time was 48 hours. After the crystallization is completed, the zeolite is obtained after washing, filtering, drying and high-temperature calcination. FIG. 6 is an X-ray powder diffraction pattern of Comparative Example 2. As can be seen from the figure, in addition to the obvious characteristic diffraction peaks of ZSM-22 zeolite, the diffraction peaks of ZSM-5 zeolite have appeared at diffraction angles of 8.7°, 13.8°, 14.7°, 15.8°, 17.7° and 23.0°, indicating that The synthesized zeolite is the coexistence of ZSM-22 and ZSM-5. This shows that increasing the content of DHA in the gel system will promote the formation of ZSM-5 zeolite crystals.

Comparative example 3:

0.56g potassium hydroxide was dissolved in 5.0g distilled water to obtain a potassium hydroxide solution; 0.67g aluminum sulfate octadecahydrate was dissolved in 5.0g distilled water to obtain an aluminum sulfate solution, and the potassium hydroxide solution was added to the aluminum sulfate solution to obtain solution A; then Add 7.0g of 1,6-hexamethylenediamine structure-directing agent into 20.6g of distilled water. After it is completely dissolved, add 0.6g of nickel acetylacetonate, stir and clarify to obtain solution B; solution B is slowly added dropwise to solution A, and the system becomes Viscous, finally add 20.0g of silica sol, stir vigorously to form silica-alumina gel, the gel composition is: Al ₂ O ₃ :5K ₂ O:2500H ₂ O:100SiO ₂ :2.3Ni ²⁺ :60DHA. Finally, the kettle was loaded, and high-temperature dynamic crystallization was carried out. The crystallization temperature was 160° C. and the time was 48 hours. After the crystallization is completed, the zeolite is obtained after washing, filtering, drying and high-temperature calcination.

FIG. 7 is an X-ray powder diffraction pattern of Comparative Example 3. As can be seen from Figure 7, in addition to the obvious characteristic diffraction peaks of ZSM-22 zeolite, the diffraction peaks of ZSM-5 zeolite also appeared at diffraction angles of 8.7°, 13.8°, 14.7°, 15.8°, 17.7° and 23.0°, It shows that the synthesized zeolite is the coexistence of ZSM-22 and ZSM-5. Fig. 8 is a scanning electron micrograph of Comparative Example 3, and the larger prismatic particles in Fig. 8 are heterogeneous ZSM-5 zeolite.

Comparative example 4:

0.56g potassium hydroxide was dissolved in 5.0g distilled water to obtain a potassium hydroxide solution; 0.67g aluminum sulfate octadecahydrate was dissolved in 5.0g distilled water to obtain an aluminum sulfate solution, and the potassium hydroxide solution was added to the aluminum sulfate solution to obtain solution A; then Add 7.0g of 1,6-hexamethylenediamine structure-directing agent to 20.6g of distilled water, stir and clarify after it is completely dissolved to obtain solution B; slowly add solution B to solution A, the system becomes viscous, and finally add 20.0g Silica sol, stirred vigorously to form silica-alumina gel, the gel composition is: Al ₂ O ₃ :5K ₂ O:2500H ₂ O:100SiO ₂ :60DHA. Finally, the kettle was loaded, and the high-temperature static crystallization was carried out. The crystallization temperature was 160° C. and the time was 48 hours. After the crystallization is completed, after washing, filtering, drying and high-temperature calcination, the ZSM-22 zeolite with the shape of ears of wheat is obtained. The properties of the texture parameters of Comparative Example 4 are shown in Table 1. It can be seen from Table 1 that the external area (80m ² /g) and mesoporous pore volume (0.12cm ³ /g) of Comparative Example 4 are lower than those of Example 1 (116m ² /g) and mesoporous pore volume (0.20cm ³ /g), which shows that the addition of nickel acetylacetonate is beneficial to improve the external area and mesoporous pore volume of synthetic zeolite, because nickel acetylacetonate is easily dissolved in the aqueous solution of 1,6-hexanediamine And it interacts with 1,6-hexanediamine, which affects the induced nucleation of 1,6-hexanediamine, which causes the morphology of zeolite to be changed to a certain extent during the process of nucleation and growth of zeolite. The SEM electron microscope in Fig. 9 also shows that in the gel system without adding nickel acetylacetonate, the synthesized zeolite is a nano-bundle assembled from nano-wires.

Comparative example 5: traditional ZSM-22 synthesis method

0.67g of aluminum sulfate octadecahydrate and 1.1.85g of potassium hydroxide were dissolved in 67.2g of distilled water in a beaker, and after stirring at room temperature for 30 minutes, 4.1g of 1,6-hexamethylenediamine structure-directing agent was slowly added to the mixed solution, Then 21.8 g of silica sol was added under vigorous stirring, and then the mixture was stirred at room temperature for 20 minutes to form a silica-alumina gel. The gel composition was: Al ₂ O ₃ :16.5K ₂ O:4600H ₂ O:109SiO ₂ :35DHA. Finally, the kettle was loaded, and high-temperature dynamic crystallization was carried out. The crystallization temperature was 160° C. and the time was 48 hours. After the crystallization is completed, after washing, filtering, drying and high-temperature calcination, the traditional needle-shaped ZSM-22 zeolite is obtained, which is marked as ZSM-22-C.

Comparative Example 6: Method for Synthesizing Traditional ZSM-22 Doped with Metallic Nickel

0.67g of aluminum sulfate octadecahydrate and 1.85g of potassium hydroxide were dissolved in 67.2g of distilled water in a beaker, and after stirring at room temperature for 30 minutes, 4.1g of 1,6-hexamethylenediamine structure-directing agent was slowly added to the mixed solution, and then Add 0.6g of nickel acetylacetonate, add 21.8g of silica sol under vigorous stirring, and then stir the mixture at room temperature for 20 minutes to form a silica-alumina gel. The gel composition is: Al ₂ O ₃ :16.5K ₂ O:4600H ₂ O :109SiO ₂ :2.3Ni ²⁺ :35DHA. Finally, the kettle was loaded, and high-temperature dynamic crystallization was carried out. The crystallization temperature was 160° C. and the time was 48 hours. After the crystallization is completed, after washing, filtering, drying and high-temperature calcination, the traditional needle-shaped ZSM-22 zeolite is obtained, which is marked as ZSM-22-C. The silicon-aluminum ratio of the zeolite is 60, and the mass fraction of Ni in the zeolite is 1.5%. (The actual loading of nickel is characterized by X-ray fluorescence spectrometry or atomic emission spectrometer according to the catalyst).

Catalyst activity evaluation:

(1) The hydrodeoxygenation reaction of hexadecanoic acid was carried out in a 300mL parr kettle. Before the reaction, the catalyst was reduced. The reduction procedure was as follows: the catalyst was raised from room temperature at 2 °C/min to 550 °C and kept for 2 h, and the _H2 flow rate was 100 mL/min. After cooling down to room temperature, the catalyst was poured into a reaction kettle filled with a reaction liquid in a hydrogen atmosphere. The reaction conditions are: reaction temperature 260°C, reaction pressure 4.0 MPa, 0.5 g hexadecanoic acid, 0.5 g catalyst of Example 1, 100 mL decahydronaphthalene, rotation speed 500 rpm, reaction for 4 hours. The reaction solution was analyzed by gas chromatography. Activity data are shown in Table 2.

(2) The deoxidation performance was evaluated on the catalysts of Comparative Example 1, Comparative Example 2, and Comparative Example 3 according to the above reaction conditions. Activity data are shown in Table 2.

(3) with the zeolite of comparative example 4 and comparative example 5 as carrier, the Ni catalyst of loading 1wt.%, catalyst preparation process is as follows: take the nickel nitrate hexahydrate of required amount (Ni loading is 1wt.% in the catalyst) , dissolved in distilled water in a centrifuge tube to obtain solution A, after it was completely dissolved until transparent, solution A was added dropwise to the carrier. After impregnation, the sample was placed in the air atmosphere for 10 hours, then dried at 100°C for 10 hours, and finally calcined at 450°C for 3 hours in the air atmosphere, and the obtained catalysts were marked as Ni/Comparative Example 4 and Ni/Comparative Example 5, and then The catalyst was reduced: the catalyst was raised from room temperature at 2°C/min to 550°C and kept for 2h, and the _H2 flow rate was 100mL/min. After cooling down to room temperature, the catalyst was poured into the reactor containing the reaction solution in a hydrogen atmosphere to evaluate the activity of the catalyst according to the above reaction conditions. Activity data are shown in Table 2.

Texture property parameters of samples in Table 1

Table 2 Catalysts to the deoxygenation performance of hexadecanoic acid hydrodeoxygenation

Claims (4)

1. A synthesis method of wheat ear-shaped nickel doped ZSM-22 zeolite assembled by nano particles is characterized in that: adding potassium hydroxide solution into aluminum sulfate solution to obtain solution A; then adding 1, 6-hexamethylenediamine (DHA) into water, adding nickel acetylacetonate after the 1, 6-hexamethylenediamine is completely dissolved, and stirring and clarifying to obtain a solution B; dropwise adding the solution B into the solution A, enabling the system to become viscous, adding silica sol, stirring to form silica-alumina gel, loading into a kettle, crystallizing at a high temperature in a static state, washing, filtering, drying and calcining at a high temperature after crystallization is completed to obtain ZSM-22 zeolite with a metallic nickel doped wheat ear morphology, and marking the ZSM-22 zeolite as ZSM-22-S; wherein the mole ratio of each component of the silica-alumina gel is Al ₂ O ₃ :5～15K ₂ O:2500～3500H ₂ O:100～140SiO ₂ :0.02～3Ni ²⁺ :45～70DHA。

2. The method for synthesizing the wheat-ear nickel doped ZSM-22 zeolite assembled by nano-particles according to claim 1, wherein: the high-temperature static crystallization condition is that the crystallization is carried out for 12 to 48 hours at the temperature of 140 to 180 ℃.

3. The method for synthesizing the wheat-ear nickel doped ZSM-22 zeolite assembled by nano-particles according to claim 1, wherein: the mole ratio of each component of the silica-alumina gel is Al ₂ O ₃ :5～10K ₂ O:2500～3000H ₂ O:100～130SiO ₂ :0.38～2.3Ni ²⁺ ：45～65DHA。

4. Use of the method according to any one of claims 1-3 for the synthesis of a spiked nickel doped ZSM-22 zeolite assembled from nanoparticles, characterized in that: the wheat spike-shaped nickel doped ZSM-22 zeolite is used as a catalyst for the hexadecanoic acid hydrodeoxygenation reaction.