CN117085727A

CN117085727A - Double-layer coated metal particle catalyst, preparation method and application of catalyst in catalytic synthesis of pentanediamine

Info

Publication number: CN117085727A
Application number: CN202311051106.XA
Authority: CN
Inventors: 马占玲; 黄玉红; 辛宗武; 秦绍杰; 董闪闪; 王肖行; 张锁江
Original assignee: Institute of Process Engineering of CAS; Zhengzhou Institute of Emerging Industrial Technology
Current assignee: Institute of Process Engineering of CAS; Zhengzhou Institute of Emerging Industrial Technology
Priority date: 2023-08-21
Filing date: 2023-08-21
Publication date: 2023-11-21

Abstract

The invention discloses a double-layer coated metal particle catalyst, a preparation method and application of the catalyst in catalytic synthesis of pentanediamine. The transition metal nano-particles are active sites of decarboxylation reaction, and are used as cores of catalysts, firstly, the molecular sieve rich pore channel structure is utilized to limit the domain of the metal nano-particles, so that the highly-dispersed metal nano-particles with the size of 1.5-nm are obtained, and agglomeration of the metal nano-particles in the reaction is prevented; secondly, a layer of acid-resistant silicon shell grows in situ on the outer layer of the molecular sieve by utilizing a hydrothermal synthesis crystallization mode, so that corrosion of inorganic acid in the reaction solution is prevented. Compared with the single-layer coated catalyst, the double-layer coated catalyst provided by the invention has the advantages that the stability of the catalyst is obviously improved, the lysine conversion rate is 80% after the catalyst is circulated for 5 times, and the pentylene diamine selectivity is 60%. The invention provides a new industrialization opportunity for producing the pentanediamine by the decarboxylation of the lysine by a chemical method, and has good industrial application prospect.

Description

Double-layer coated metal particle catalyst, preparation method and application of catalyst in catalytic synthesis of pentanediamine

Technical Field

The invention relates to the field of chemical synthesis, in particular to a double-layer coated metal particle catalyst, a preparation method and application of catalytic synthesis of pentanediamine.

Background

Nylon 56 materials can be produced from polymerization of 1, 5-pentanediamine, also known as cadaverine, and adipic acid. The nylon 56 material has good comprehensive properties, such as high moisture absorption and sweat release rate, good air permeability, good softness and dyeing property, and the like, is resistant to abrasion, chemicals, good in flame retardance and easy to process, and has strong competitive advantages in nylon material series. A more reported production method of 1, 5-pentanediamine is a biological fermentation method. The industrial university of Nanjing utilizes bean dreg hydrolysate to ferment and produce the pentanediamine (CN201810954086. X), however, the pentanediamine has toxicity to microorganisms and affects the production efficiency. A plurality of pentanediamine biological fermentation method patents (CN 201811506539.9, CN201710453415.8, CN201710011198.7 and the like) are applied by Shanghai Kaiser biotechnology research and development center limited company, and the patent content indicates that seed liquid of lysine decarboxylase strain is inoculated in the lysine fermentation process, so that the toxicity problem of the pentanediamine to the strain is effectively improved. However, the biological fermentation method still has great difficulties such as low lysine decarboxylase activity, poor toxicity resistance, low product concentration, excessively high separation cost, and the like.

Compared with the biological fermentation decarboxylation method, the chemical decarboxylation method has obvious advantages, such as the catalyst activity is not affected by the toxicity of the pentanediamine, the product is easy to separate, and the like. However, the chemical method for preparing the pentanediamine reported at present has two main problems, namely, the generation rate of the pentanediamine is lower, and the main reason is that the catalyst performance is lower; the currently reported catalyst for decarboxylation of lysine to generate pentamethylenediamine mainly uses a supported ruthenium catalyst, and in 2017, the L-lysine decarboxylation reaction by using Ru/C as a catalyst is reported for the first time, wherein the selectivity of the pentamethylenediamine is 32%.

The patent of Chinese patent application No. 202110938327.3 discloses a molecular sieve domain-limited metal oxide catalyst, a preparation method and application thereof. The invention adopts an in-situ synthesis method to prepare a molecular sieve domain-limited metal catalyst, wherein the metal active components of the catalyst are effectively immobilized, the agglomeration of the active components is avoided, and the catalyst structure is kept good; the catalyst is used for lysine decarboxylation reaction, so that the production rate of the pentanediamine is effectively improved, the reaction process time is shortened, and the selectivity is required to be improved.

The patent of China patent application No. 202211265811.5 discloses a metal ion modified molecular sieve limited transition metal nanoparticle and a method for synthesizing pentamethylene diamine by catalysis, wherein the surface alkalinity of a catalyst is changed, so that the directional adsorption of carboxyl is promoted, the generation of byproducts is inhibited, the selectivity is improved, the pentamethylene diamine is efficiently synthesized, the surface alkalinity of the catalyst is changed, the directional adsorption of lysine carboxyl is effectively improved, the side reaction is inhibited from the source, the process of directly decarboxylating lysine to generate pentamethylene diamine is further enhanced, the pentamethylene diamine selectivity is greatly improved, and the selectivity of the pentamethylene diamine is catalyzed and synthesized by adopting the metal ion modified molecular sieve limited transition metal nanoparticle as a catalyst to reach 77.4 percent, so that the process is at the international leading level at present. However, the decarboxylation reaction of lysine is carried out under the conditions of high temperature, high pressure and acidity, and the poor stability of the catalyst is still the biggest difficulty in restricting industrial production. For example, carbon in a conventional Ru/C catalyst undergoes methanation, the catalyst structure collapses, and the catalyst deactivates. The catalyst taking the molecular sieve as a carrier also has the phenomenon of deactivation of the catalyst after reaction, and aluminum in the molecular sieve falls off to cause collapse of the molecular sieve structure, so that the catalyst with the selectivity and stability of the pentanediamine is prepared, and the catalyst is extremely important for preparing the pentanediamine by decarboxylation of lysine.

In view of this, the present invention has been made.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a double-layer coated metal particle catalyst and a preparation method thereof, and the catalyst is used for preparing the pentanediamine by using the chemical lysine decarboxylation, and has higher pentanediamine selectivity in the lysine decarboxylation reaction, and meanwhile, the catalyst has good stability and good industrial application prospect.

In order to solve the technical problems, the invention adopts the following technical scheme:

a preparation method of a double-layer coated metal particle catalyst and a catalytic synthesis method of pentanediamine are provided, wherein the preparation method of the double-layer coated metal particle catalyst is to utilize a pore canal structure rich in molecular sieve (ZEO) to carry out domain-limited coating on metal nano particles (M) to form M@ZEO; then adding a guiding agent and a silicon source, carrying out secondary wrapping, crystallizing at a certain temperature and for a certain time, washing, drying and calcining to form the double-layer wrapping structure catalyst taking the metal nano particles as the cores.

In a preferred embodiment, the M@ZEO comprises any one of Ru@MFI, ru@GIS, ru@FAU and Ru@LTA, and the mass fraction of the M@ZEO, namely the catalyst wrapped by the metal particles, in the catalyst is 1-80%.

In a preferred embodiment, the structure directing agent is one or more of tetrapropylammonium hydroxide, sodium hydroxide, BMP.

In a preferred embodiment, the structure directing agent, water, the silicon source and the catalyst coated by the metal particles are added and stirred at normal temperature for 1-20 hours, the stirring speed is 50-1000rpm, the stirred mixture is placed into a reaction kettle, and the mixture is taken out after the temperature is raised to 80-350 ℃ and then the crystallization reaction is carried out for 5-72 hours. Preferably, the stirring time is 2-10h, the crystallization temperature is 100-300 ℃ and the crystallization time is 12-48h.

In a preferred embodiment, the mass ratio of M@ZEO, directing agent and silicon source is 1:1:1 to 1:10:10.

In a preferred embodiment, the calcination temperature is 300 to 600℃and the calcination time is 2 to 8 hours.

The double-layer coated metal particle catalyst is used for catalyzing and synthesizing the pentanediamine, and the method comprises the following steps: lysine or lysine salt, water and a catalyst are placed in a high-pressure reaction kettle to react to obtain an aqueous solution containing pentanediamine.

In a preferred embodiment, the lysine is L-lysine, and the lysine salt is any one of lysine hydrochloride, lysine sulfate, lysine acetate, and lysine phosphate.

In a preferred embodiment, the molar ratio of the catalyst to lysine or lysine salt is 1 (0.1-10).

In a preferred embodiment, the autoclave reaction condition is that the reaction temperature is 120-250 ℃, the pressure is 1-3 mpa, the concentration of lysine or lysine salt is 0.01-3M, the pH value of lysine or lysine salt solution is 1-5, the reaction time is 0-600 min, and the reaction atmosphere is any one of nitrogen, hydrogen, argon, helium or carbon monoxide.

Compared with the prior art, the invention has the beneficial effects that: the invention provides a double-layer coated metal particle catalyst, wherein transition metal nano particles are active sites of decarboxylation reaction, and are used as cores of the catalyst, firstly, a molecular sieve rich pore channel structure is utilized to limit the metal nano particles to obtain high-dispersion metal nano particles with the size of 1.5-nm, so that agglomeration of the metal nano particles in the reaction is prevented; secondly, a layer of acid-resistant silicon shell grows in situ on the outer layer of the molecular sieve by utilizing a hydrothermal synthesis crystallization mode, so that corrosion of inorganic acid in the reaction solution is prevented. The catalyst has the advantages that the stability of the catalyst is obviously improved, the double-layer coated metal particle catalyst is used for preparing the pentanediamine through lysine decarboxylation by a chemical method, the catalyst has high pentanediamine selectivity in the lysine decarboxylation reaction, and meanwhile, the catalyst has good stability and good industrial application prospect.

Drawings

FIG. 1 XRD patterns of catalysts in examples 1-3 and comparative example 1;

FIG. 2 XRD patterns of the catalyst before and after the reaction of the catalyst in example 1;

FIG. 3 XRD patterns of the catalyst before and after the reaction of the catalyst in example 2;

FIG. 4 XRD patterns of the catalyst before and after the reaction of the catalyst in example 3;

figure 5 XRD patterns of the catalyst before and after the reaction of the catalyst of comparative example 1.

Detailed Description

The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without any inventive effort, are within the scope of the present invention.

Example 1

The synthesis method of the double-layer coated metal particle catalyst in the embodiment is as follows:

(1) Synthesis of Ru@FAU: adding 2.8. 2.8 g sodium hydroxide into 25ml of deionized water, stirring for dissolution, adding 0.3375. 0.3375 g sodium metaaluminate, and stirring for clarification; 12.68g of silica sol was slowly added dropwise, and after completion of the dropwise addition, 0.34g of ruthenium chloride was added and stirred at 600rpm for 4 hours at room temperature. The obtained solution is transferred into a stainless steel hydrothermal synthesis kettle and crystallized for 12 hours at 100 ℃. After the hydrothermal synthesis kettle is completely cooled, the hydrothermal synthesis kettle is washed by deionized water until the pH value of the filtrate is neutral. 100. Drying overnight at the temperature to obtain the Ru@FAU catalyst;

(2) 5.084g of tetrapropylammonium hydroxide are mixed with 39.2g of deionized water, the solution is stirred until uniform, 1g of Ru@FAU catalyst is slowly added during stirring, 5.208g of ethyl orthosilicate is added to the solution, and the solution is magnetically stirred for 6 hours at room temperature. Placing the stirred solution into a stainless steel high-pressure reaction kettle, heating and crystallizing by using a drying oven, and crystallizing for 12 hours at 180 ℃; after crystallization, cooling the reaction kettle to room temperature, taking out the reaction liquid, and centrifuging and washing the reaction liquid until the pH value of the centrifuged solution reaches neutrality; the centrifugally washed solid was dried at 100℃and calcined at 550℃for 6 hours to give catalyst 1.

The XRD characterization result of the prepared catalyst is shown in figure 1, wherein 6.09 degrees, 15.4 degrees, 23.31 degrees belong to diffraction peaks of the inner core FAU, 7.89 degrees, 8.85 degrees, 23.21 degrees and belong to diffraction peaks of the shell S-1. This indicates that S-1 was successfully wrapped on Ru@FAU.

The double-layer coated metal particle catalyst prepared in the embodiment 1 is used for catalyzing and synthesizing the pentanediamine, and the method is as follows:

putting 0.1826 g lysine hydrochloride into a reaction kettle lining of 25ml, adding 10ml water for dissolution, then adding 0.101g of catalyst, stirring until the mixture is completely and uniformly mixed, and regulating the pH value of the mixed solution to 2.0 by using phosphoric acid; installing a reaction kettle, replacing air in the kettle with nitrogen, replacing the nitrogen with hydrogen, and pressurizing to 2MPa after the replacement is completed; the reaction kettle is started to react at 200 ℃ and the stirring speed is 800 r/min. The reaction was carried out in different 0-3 hours. And detecting the concentration of lysine and pentanediamine in the reacted solution by adopting liquid chromatography after the reaction solution is derived. It was found that at reaction 2.5. 2.5 h, the lysine conversion reached 71.1%. The selectivity of the pentanediamine reaches 70.1 percent.

As shown in the XRD characterization result of the catalyst 1 after the reaction, as shown in FIG. 2, the diffraction peak of the shell S-1 in the catalyst is not obviously weakened, and the catalyst structure is good.

Example 2

(1) The synthesis of Ru@FAU was the same as in example 1;

(2) 5.084g of tetrapropylammonium hydroxide are mixed with 39.2g of deionized water, the solution is stirred until uniform, 1g of Ru@FAU catalyst is slowly added during stirring, 5.208g of ethyl orthosilicate is added to the solution, and the solution is magnetically stirred for 6 hours at room temperature. Placing the stirred solution into a stainless steel high-pressure reaction kettle, heating and crystallizing by using a drying oven, and crystallizing for 36 hours at 180 ℃; after crystallization, cooling the reaction kettle to room temperature, taking out the reaction liquid, and centrifuging and washing the reaction liquid until the pH value of the centrifuged solution reaches neutrality; the centrifugally washed solid was dried at 100℃and calcined at 550℃for 6 hours to give catalyst 2.

The double-layer coated metal particle catalyst prepared in the embodiment 2 is used for catalyzing and synthesizing the pentanediamine, and the method is as follows:

putting 0.1826 g lysine hydrochloride into a reaction kettle lining of 25ml, adding 10ml water for dissolution, then adding 0.101g of catalyst, stirring until the mixture is completely and uniformly mixed, and regulating the pH value of the mixed solution to 2.0 by using phosphoric acid; installing a reaction kettle, replacing air in the kettle with nitrogen, replacing the nitrogen with hydrogen, and pressurizing to 2MPa after the replacement is completed; the reaction kettle is started to react at 200 ℃ and the stirring speed is 800 r/min. The reaction was carried out in different 0-3 hours. And detecting the concentration of lysine and pentanediamine in the reacted solution by adopting liquid chromatography after the reaction solution is derived. It was found that at reaction 2.5. 2.5 h, the lysine conversion reached 71.9%. The selectivity of the pentanediamine reaches 64.5 percent.

As shown in the XRD characterization result of the catalyst 2 after the reaction, as shown in FIG. 3, the diffraction peak of the shell S-1 in the catalyst is not obviously weakened, and the catalyst structure is good.

Example 3

(1) The synthesis of Ru@FAU was the same as in example 1;

(2) 5.084g of tetrapropylammonium hydroxide are mixed with 39.2g of deionized water, the solution is stirred until uniform, 1g of Ru@FAU catalyst is slowly added during stirring, 5.208g of ethyl orthosilicate is added to the solution, and the solution is magnetically stirred for 6 hours at room temperature. Placing the stirred solution into a stainless steel high-pressure reaction kettle, heating and crystallizing by using a drying oven, and crystallizing for 24 hours at 180 ℃; after crystallization, cooling the reaction kettle to room temperature, taking out the reaction liquid, and centrifuging and washing the reaction liquid until the pH value of the centrifuged solution reaches neutrality; the centrifugally washed solid was dried at 100℃and calcined at 550℃for 6 hours to give catalyst 3.

putting 0.1826 g lysine hydrochloride into a reaction kettle lining of 25ml, adding 10ml water for dissolution, then adding 0.101g of catalyst, stirring until the mixture is completely and uniformly mixed, and regulating the pH value of the mixed solution to 2.0 by using phosphoric acid; installing a reaction kettle, replacing air in the kettle with nitrogen, replacing the nitrogen with hydrogen, and pressurizing to 2MPa after the replacement is completed; the reaction kettle is started to react at 200 ℃ and the stirring speed is 800 r/min. The reaction was carried out in different 0-3 hours. And detecting the concentration of lysine and pentanediamine in the reacted solution by adopting liquid chromatography after the reaction solution is derived. It was found that at a reaction of 2.5. 2.5 h, the lysine conversion reached 81.5%. The selectivity of the pentanediamine reaches 65.8 percent.

As shown in the XRD characterization result of the catalyst 3 after the reaction, as shown in FIG. 4, the diffraction peak of the shell S-1 in the catalyst is not obviously weakened, and the catalyst structure is good.

The double-layer coated metal particle catalyst 3 was subjected to a repeatability test by the following method:

the catalyst after lysine decarboxylation reaction was separated and washed with distilled water centrifugally for 3 times, then added to the reactor, 10mL of a 0.1mol/L L-lysine solution was added, the pH of the mixed solution was adjusted to 2 by adding a phosphoric acid solution, and the reactor was sealed at 200℃and reacted under 2MPa of hydrogen for 1.5 hours. After the process is repeatedly carried out for 5 times, the activity of the catalyst can still reach 80% of lysine conversion rate and 60% of pentylene diamine selectivity.

Comparative example 1

5.084g of tetrapropylammonium hydroxide were mixed with 39.2g of deionized water, the solution was stirred until homogeneous, 1g of Ru@FAU catalyst was slowly added during stirring, and magnetically stirred at room temperature for 6h.

Placing the stirred solution into a stainless steel high-pressure reaction kettle, heating and crystallizing by using a drying oven, and crystallizing for 24 hours at 180 ℃; after crystallization, cooling the reaction kettle to room temperature, taking out the reaction liquid, and centrifuging and washing the reaction liquid until the pH value of the centrifuged solution reaches neutrality; the centrifugally washed solid was dried at 100℃and calcined at 550℃for 6 hours to give catalyst 4.

The XRD characterization result of the prepared catalyst is shown in figure 1, only 6.09 degrees, 15.4 degrees and 23.31 degrees belong to the diffraction peak of FAU, and the characteristic peak of S-1 does not appear, so that the double-layer coated metal particle catalyst is not synthesized.

In the method, the catalyst is regarded as Ru@FAU, and in order to compare the advantages and disadvantages of the core Ru@FAU and the synthesized silicon-coated core-shell catalyst in the aspects of synthesizing the pentanediamine and stabilizing the catalyst, the catalyst prepared by the embodiment is used for catalyzing and synthesizing the pentanediamine, and the method is as follows:

putting 0.1826 g lysine hydrochloride into a reaction kettle lining of 25ml, adding 10ml water for dissolution, then adding 0.101g of catalyst, stirring until the mixture is completely and uniformly mixed, and regulating the pH value of the mixed solution to 2.0 by using phosphoric acid; installing a reaction kettle, replacing air in the kettle with nitrogen, replacing the nitrogen with hydrogen, and pressurizing to 2MPa after the replacement is completed; the reaction kettle is started to react at 200 ℃ and the stirring speed is 800 r/min. The reaction was carried out in different 0-3 hours. And detecting the concentration of lysine and pentanediamine in the reacted solution by adopting liquid chromatography after the reaction solution is derived. It was found that the optimum lysine conversion was achieved at 1h and the pentylene diamine selectivity was 80% at 46.9%.

The XRD characterization results of the catalyst after the reaction are shown in fig. 5, and it can be seen that the diffraction peak in XRD gradually decreases with the extension of the reaction time, and a new diffraction peak appears, which indicates that the structure gradually collapses and changes in the catalyst during the reaction.

Comparative example 2

Comparative example 2 is a single layer package, ru@fau synthesis, the method is as follows:

adding 2.8. 2.8 g sodium hydroxide into 25ml of deionized water, stirring for dissolution, adding 0.3375. 0.3375 g sodium metaaluminate, and stirring for clarification; 12.68g of silica sol was slowly added dropwise, and after completion of the dropwise addition, 0.34g of ruthenium chloride was added and stirred at 600rpm for 4 hours at room temperature. The obtained solution is transferred into a stainless steel hydrothermal synthesis kettle and crystallized for 12 hours at 100 ℃. And after the hydrothermal synthesis kettle is completely cooled, washing the kettle by deionized water until the pH value of the filtrate is neutral, and drying the kettle overnight at 100 ℃ to obtain Ru@FAU.

The Ru@FAU prepared in comparative example 1 is used for catalytic synthesis of pentamethylene diamine, and the method is as follows:

putting 0.1826 g lysine hydrochloride into a reaction kettle lining of 25ml, adding 10ml water for dissolution, then adding 0.101g of catalyst, stirring until the mixture is completely and uniformly mixed, and regulating the pH value of the mixed solution to 2.0 by using phosphoric acid; installing a reaction kettle, replacing air in the kettle with nitrogen, replacing the nitrogen with hydrogen, and pressurizing to 2MPa after the replacement is completed; the reaction kettle is started to react at 200 ℃ and the stirring speed is 800 r/min. The reaction was carried out in different 0-3 hours. After the reaction solution was derived, the concentrations of lysine and pentamethylene diamine in the solution after the reaction were detected by liquid chromatography, and it was found that the conversion rate of lysine reached 100% when the reaction was 1h. The selectivity of the pentanediamine reaches 32 percent.

The single-layer package, namely Ru@FAU, is subjected to a repeatability experiment, and the method is as follows:

the catalyst after lysine decarboxylation reaction was separated and washed with distilled water centrifugally for 3 times, then added to the reactor, 10mL of a 0.1mol/L L-lysine solution was added, the pH of the mixed solution was adjusted to 2 by adding a phosphoric acid solution, and the reactor was sealed at 200℃and reacted under 2MPa of hydrogen for 1 hour. After the process is repeatedly carried out for 5 times, the activity of the catalyst can still reach 20 percent of lysine conversion rate, the selectivity of the pentanediamine is 2 percent, and the performance of the catalyst is greatly reduced.

Comparative example 3

Comparative example 3 is a single layer coated Ru@S-1 synthesis, and the method is as follows:

after 5.084g tetrapropylammonium hydroxide and 39.2g deionized water are mixed and stirred uniformly, 0.34g of ruthenium chloride and 5.208g g of ethyl orthosilicate are added in sequence, and the mixture is magnetically stirred for 6 hours at room temperature.

Placing the stirred solution into a stainless steel high-pressure reaction kettle, heating and crystallizing by using a drying oven, and crystallizing for 12 hours at 180 ℃; after crystallization, cooling the reaction kettle to room temperature, taking out the reaction liquid, and centrifuging and washing the reaction liquid until the pH value of the centrifuged solution reaches neutrality; drying the centrifugally washed solid at 100 ℃, and calcining at 550 ℃ for 6 hours to obtain Ru@S-1.

The Ru@S-1 catalyst prepared in comparative example 3 is used for catalytic synthesis of pentamethylene diamine, and the method is as follows:

putting 0.1826 g lysine hydrochloride into a reaction kettle lining of 25ml, adding 10ml water for dissolution, then adding 0.101g of catalyst, stirring until the mixture is completely and uniformly mixed, and regulating the pH value of the mixed solution to 2.0 by using phosphoric acid; installing a reaction kettle, replacing air in the kettle with nitrogen, replacing the nitrogen with hydrogen, and pressurizing to 2MPa after the replacement is completed; the reaction kettle is started to react at 200 ℃ and the stirring speed is 800 r/min. The reaction was carried out in different 0-3 hours. And detecting the concentration of lysine and pentanediamine in the reacted solution by adopting liquid chromatography after the reaction solution is derived. It was found that no pentylene diamine was formed in reaction 3 h.

The invention provides a preparation method of a double-layer coated metal particle catalyst and a method for synthesizing pentanediamine by catalysis. The method effectively improves the selectivity of the pentanediamine in the reaction for preparing the pentanediamine by lysine decarboxylation, solves the problem of unstable structure of the catalyst in the reaction for decarboxylating the lysine, provides a new industrialization opportunity for producing the pentanediamine by the decarboxylation of the lysine by a chemical method, and has good industrial application prospect.

The invention has been described in detail above but is not limited to the specific embodiments described herein. Those skilled in the art will appreciate that other modifications and variations may be made without departing from the scope of the invention. The scope of the invention is defined by the appended claims.

Claims

1. A preparation method of a double-layer coated metal particle catalyst is characterized by comprising the following steps of: firstly, carrying out limited-domain wrapping on metal nano particles M by utilizing a pore channel structure rich in molecular sieve ZEO to form M@ZEO; then adding a guiding agent and a silicon source, carrying out secondary coating, crystallizing at a certain temperature and for a certain time, washing, drying and calcining to form the double-layer coated metal particle catalyst taking the metal nano particles as cores.

2. The method for preparing the double-layer coated metal particle catalyst according to claim 1, wherein: m in the M@ZEO comprises any one or more of Pd, ru, pt, au, cu, ni.

3. The method for preparing the double-layer coated metal particle catalyst according to claim 1, wherein: the ZEO in the M@ZEO is any one or more of FAU, LTA, GIS.

4. The method for preparing the double-layer coated metal particle catalyst according to claim 1, wherein: the structure directing agent is one or more of tetrapropylammonium hydroxide, sodium hydroxide and BMP.

5. The method for preparing the double-layer coated metal particle catalyst according to claim 1, wherein: the silicon source is one or more of silica sol, tetraethoxysilane and sodium silicate.

6. The method for preparing the double-layer coated metal particle catalyst according to claim 1, wherein: the mass ratio of the M@ZEO, the guiding agent and the silicon source is 1:1:1-1:10:10.

7. The method for preparing the double-layer coated metal particle catalyst according to claim 1, wherein: the crystallization temperature is 80-350 ℃, the crystallization time is 5-72h, the calcination temperature is 300-600 ℃, and the calcination time is 2-8h.

8. A double-layered coated metal particle catalyst produced by the production method of any one of claims 1 to 7.

9. The use of the double-layer coated metal particle catalyst according to claim 8 in synthesizing pentylene diamine by decarboxylation of lysine, characterized by: the preparation method comprises the steps of performing decarboxylation of lysine to synthesize the pentanediamine in a high-pressure reaction kettle, adding lysine or lysine salt, an acid solution with a certain pH value and a double-layer coated metal particle catalyst into the high-pressure reaction kettle, and reacting to obtain the pentanediamine aqueous solution.

10. The use according to claim 9, characterized in that: the reaction temperature is 120-250 ℃, the pressure is 0.5-6 MPa, the concentration of lysine or lysine salt is 0.01-3M, the pH value of an acid solution is 1-8, the molar ratio of a double-layer coated metal particle catalyst to lysine or lysine salt is 1 (0.1-10), the reaction time is 0-3 h, the reaction atmosphere is any one of nitrogen, hydrogen, argon, helium or carbon monoxide, the lysine is L-lysine, and the lysine salt is any one of lysine hydrochloride and lysine sulfate.