阅读说明：本技术 分子筛限域金属氧化物催化剂、制备方法及催化合成戊二胺的应用 (Molecular sieve confinement metal oxide catalyst, preparation method and application of catalyst in catalytic synthesis of pentamethylene diamine ) 是由 黄玉红 马占玲 辛宗武 秦绍杰 张延强 于 2021-08-16 设计创作，主要内容包括：本发明提供一种分子筛限域金属氧化物催化剂、制备方法及催化合成戊二胺的应用,采用原位合成与动态合成相结合的方法制备出具有良好催化赖氨酸脱羧性能的分子筛限域金属氧化物催化剂。将赖氨酸或赖氨酸盐、水、分子筛限域金属氧化物催化剂置于高压反应釜中,反应得到含有戊二胺的水溶液。本发明采用原位合成的方法制备了一种分子筛限域金属催化剂,该催化剂金属活性组分得到有效固载,避免活性组分团聚,且催化剂结构保持良好；将催化剂用于赖氨酸脱羧反应有效提高了戊二胺生产速率,反应15 min戊二胺选择性达到49%,反应时间大大缩短,反应成本显著降低,工业化应用前景十分广泛。(The invention provides a molecular sieve limited-area metal oxide catalyst, a preparation method and application of catalytic synthesis of pentanediamine. Lysine or lysine salt, water and molecular sieve limited metal oxide catalyst are placed in a high-pressure reaction kettle to react to obtain the water solution containing the pentanediamine. The invention adopts an in-situ synthesis method to prepare the molecular sieve confinement metal catalyst, the metal active component of the catalyst is effectively immobilized, the agglomeration of the active component is avoided, and the catalyst structure is kept good; the catalyst is used for the decarboxylation reaction of lysine, so that the production rate of the pentanediamine is effectively improved, the selectivity of the pentanediamine reaches 49 percent after the reaction for 15 min, the reaction time is greatly shortened, the reaction cost is obviously reduced, and the industrial application prospect is very wide.)

1. A molecular sieve confinement metal oxide catalyst, characterized by: the molecular sieve confinement metal oxide catalyst is a catalyst with a metal reaction active center in a molecular sieve pore channel; the reaction metal reaction active center comprises any one or more of Pd, Pt, Cr, Pb, Co, Cd, Fe, Cu, Nb, Mn, Ni and Ru; the mass fraction of the metal reaction active center in the catalyst is 0.1-50%.

2. The molecular sieve-constrained metal oxide catalyst of claim 1, wherein: the molecular sieve comprises any one of a silicon-aluminum molecular sieve, a phosphorus-aluminum molecular sieve and a silicon-phosphorus-aluminum molecular sieve.

3. The molecular sieve-constrained metal oxide catalyst of claim 1, wherein: the molecular sieve pore channels comprise any one or more of RHO, CHA, FER, MFI, MOR, FAU and beta.

4. The molecular sieve-constrained metal oxide catalyst of claim 1, wherein: the atomic silicon-aluminum ratio of the molecular sieve is 1-50.

5. The molecular sieve-limited metal oxide catalyst of claim 3 or 4, wherein: the molecular sieve also comprises a product obtained by modifying elements except the composition of the characteristic molecular sieve framework elements.

6. The molecular sieve-constrained metal oxide catalyst of claim 1, wherein: the mass fraction of the metal reaction active center in the catalyst is 1-20%, and more preferably 5-10%.

7. A process for preparing a molecular sieve-limited metal oxide catalyst according to any one of claims 1 to 6, characterized in that: the method adopts any one of combination of in-situ synthesis and dynamic synthesis and combination of in-situ synthesis and static synthesis.

8. Use of a molecular sieve-limited metal oxide catalyst according to any of claims 1-6 for the catalytic synthesis of pentanediamines, characterized in that the process is as follows: putting lysine or lysine salt, water and a molecular sieve confinement metal oxide catalyst into a high-pressure reaction kettle, and reacting to obtain an aqueous solution containing high-selectivity pentanediamine; the molar ratio of the molecular sieve confinement metal oxide catalyst to lysine or lysine salt is 1: (0.1-10).

9. Use according to claim 8, characterized in that: the lysine is L-lysine, and the lysine salt is any one of lysine hydrochloride, lysine sulfate, lysine acetate and lysine phosphate.

10. Use according to claim 8, characterized in that: the autoclave reaction conditions are that the reaction temperature is 100-300 ℃, the pressure is 0-5 MPa, the concentration of lysine or lysine salt is 0.01-3M, the pH value of lysine or lysine salt solution is 1-8, the reaction time is 10-600 min, and the reaction atmosphere is any one of nitrogen, hydrogen, argon, helium or carbon monoxide.

Technical Field

The invention relates to the field of chemical synthesis, in particular to a molecular sieve confinement metal oxide catalyst, a preparation method and application thereof.

Background

The nylon 56 material can be produced by polymerizing 1, 5-pentanediamine, which is also called cadaverine, and adipic acid. The nylon 56 material has good comprehensive properties, such as high moisture absorption and sweat releasing rate, good air permeability, good softness and dyeing property, and the like, is wear-resistant, chemical-resistant, good in flame retardance, easy to process, and has strong competitive advantages in nylon material series. The most reported production method of 1, 5-pentanediamine is a biological fermentation method. The Nanjing industry university utilizes bean dreg hydrolysate to ferment and produce pentanediamine (CN201810954086.X), but the pentanediamine has toxicity to microorganisms and influences the production efficiency. Shanghai Kaiser Biotechnology research center, Inc. applied for several Pentanediamine biofermentation method patents (CN201811506539.9, CN201710453415.8, CN201710011198.7, etc.), and the patent contents indicate that the toxicity problem of Pentanediamine to the strain is effectively improved by inoculating the seed liquid of lysine decarboxylase strain in the lysine fermentation process. However, the biological fermentation method still has great difficulties, such as low lysine decarboxylase activity, poor toxicity resistance, low product concentration, excessive separation cost and the like.

Compared with biological fermentation decarboxylation method, the chemical decarboxylation method has obvious advantages, such as that the catalyst activity is not affected by the toxicity of the pentanediamine, the product is easy to separate, and the like. For example, Verduyckt et al, which utilizes Ru/C catalyzed lysine decarboxylation to synthesize pentanediamine, gave a pentanediamine yield of 32% at 1h20min (ACS Sustainable Chemistry and Engineering, 2017, 5, 3290-. But the selectivity of the chemical method for synthesizing the pentanediamine is lower. The use of the new preparation method to prepare more effective catalysts would be a way to increase the selectivity of pentanediamines. Liu et al use an in-situ synthesis method to confine Pt sub-nanoparticles in MCM-22 channels or wrap in an MCM-22 super cage, so as to avoid the agglomeration of metal Pt, and the catalyst shows excellent catalytic performance for the hydrogenation reaction of olefins (Nature materials, 2017, 16(1), 132-138). Wang et al stabilized the Ru site by the presence of cetyltrimethylammonium bromide in MCM-41 pores by using an in-situ synthesis method, avoided the agglomeration and loss of active components, and improved the performance of the catalyst (Applied catalysts B: Environmental,2021, 290, 120036).

Disclosure of Invention

Based on the above, the invention aims to provide a molecular sieve confinement metal oxide catalyst, a preparation method and an application. The invention adopts an in-situ synthesis method to prepare the molecular sieve confinement metal catalyst, the metal active component of the catalyst is effectively immobilized, the agglomeration of the active component is avoided, and the catalyst structure is kept good; the catalyst is used for the decarboxylation reaction of lysine, so that the production rate of the pentanediamine is effectively improved, the reaction process time is shortened, the production cost is greatly reduced, and the industrial application prospect is very wide.

A molecular sieve confinement metal oxide catalyst refers to a catalyst with a metal reaction active center in a molecular sieve pore channel; the reaction metal reaction active center comprises any one or more of Pd, Pt, Cr, Pb, Co, Cd, Fe, Cu, Nb, Mn, Ni and Ru; the mass fraction of the metal reaction active center in the catalyst is 0.1-50%.

In a preferred embodiment, the molecular sieve comprises any one of a silicoaluminophosphate molecular sieve, a aluminophosphate molecular sieve, and a silicoaluminophosphate molecular sieve.

In a preferred embodiment, the molecular sieve has an atomic silicon to aluminum ratio of 1 to 50, preferably 2 to 25.

In a preferred embodiment, the molecular sieve channels comprise any one or any several of LTA, RHO, CHA, FER, MFI, MOR, FAU, beta.

In a preferred embodiment, the molecular sieve further comprises a product modified with elements other than the above-described characteristic molecular sieve framework element composition.

In a preferred embodiment, the mass fraction of the metal reactive centers in the catalyst is between 1% and 20%, more preferably between 5% and 10%.

In a preferred embodiment, the molecular sieve confinement metal oxide is prepared by any one of in-situ synthesis combined with dynamic synthesis and in-situ synthesis combined with static synthesis.

The molecular sieve confinement metal oxide catalyst is used for catalytically synthesizing pentanediamine, and the method comprises the following steps: putting lysine or lysine salt, water and molecular sieve limited domain metal oxide catalyst into a high-pressure reaction kettle, and reacting to obtain the aqueous solution containing the 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 metal oxide catalyst to lysine or lysine salt is 1: (0.1-10).

In a preferred embodiment, the autoclave reaction conditions are that the reaction temperature is 100-300 ℃, the pressure is 0-5 MPa, the concentration of lysine or lysine salt is 0.01-3M, the pH value of the lysine or lysine salt solution is 1-8, the reaction time is 10-600 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 adopts an in-situ synthesis method to prepare the molecular sieve confinement metal catalyst, the metal active component of the catalyst is effectively immobilized, the agglomeration of the active component is avoided, and the catalyst structure is kept good; the catalyst is used for the decarboxylation reaction of lysine, so that the production rate of the pentanediamine is effectively improved, the reaction process time is shortened, the production cost is greatly reduced, and the industrial application prospect is very wide.

Drawings

FIG. 1 XRD pattern of the catalyst in example 1;

FIG. 2 isothermal adsorption curves for the catalyst in example 1;

FIG. 3 XRD pattern of the catalyst in example 2;

figure 4 isothermal adsorption curve of the catalyst in example 2.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments of the present invention, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without any inventive work are within the scope of the present invention.

Example 1

The preparation method of the molecular sieve confinement metal oxide catalyst of the embodiment is as follows:

the Ru @ FAU-1 catalyst is prepared by a method combining in-situ synthesis and static synthesis, and the preparation method comprises the following specific steps: dissolving 5.6 g of sodium hydroxide in 50ml of deionized water, vigorously stirring until the sodium hydroxide is completely dissolved, then adding 0.675g of sodium metaaluminate, adding 25.38 g of silica sol (the content of silicon dioxide is 25%) after the mixed solution is uniformly stirred, then adding 0.665 g of ruthenium trichloride, stirring the obtained mixed solution at room temperature for 4 hours, transferring the mixed solution into a stainless steel reaction kettle, and crystallizing the mixed solution in an oven at 100 ℃ for 12 hours. And after the reaction is finished, cooling the reaction kettle to room temperature, pouring the suspension into a centrifuge tube, performing centrifugal separation, washing the suspension with deionized water until the pH value is equal to 7, and placing the suspension in an oven at 80 ℃ for drying overnight to obtain Ru @ FAU-1.

The XRD characterization result of the prepared catalyst is shown in figure 1, and the molecular sieve has a good structure. FIG. 2 is an isothermal adsorption curve of a catalyst, which is a type I adsorption isothermal curve, and the catalyst has a microporous structure. The specific surface area of the catalyst reaches 493.7823m²G, pore volume of 0.235235cm³The ruthenium content of the catalyst was 1.57% by ICP. This shows that the in-situ synthesis effectively supports ruthenium and the catalyst structure has good performance.

The molecular sieve confinement metal oxide catalyst prepared in the embodiment is used for catalytically synthesizing pentamethylene diamine by the following steps:

0.1826 g of lysine hydrochloride is put into a 25 ml reaction kettle lining, 10 ml of water is added for dissolving, then 0.101g of Ru/FAU-1 catalyst is added for stirring until the mixture is completely and uniformly mixed, and the pH value of the mixed solution is adjusted to 2.0 by phosphoric acid; installing a reaction kettle, replacing air in the kettle with nitrogen, then replacing the nitrogen with hydrogen, and pressurizing to 2 MPa after replacement is finished; the reaction kettle is started to carry out reaction under the conditions of 200 ℃ and the stirring speed of 800 r/min. The reaction was carried out in 0-3 hours. And detecting the concentration of lysine and pentanediamine in the solution after reaction by adopting liquid chromatography after the reaction solution is derived. It was found that at 1 hour of the reaction, the lysine conversion reached 100%, the pentamethylenediamine selectivity reached 38.07%, and the pentamethylenediamine concentration reached 3.88 g/L.

Example 2

The preparation method of the molecular sieve confinement metal oxide catalyst of the embodiment is as follows:

the 5% Ru @ FAU-2 catalyst is prepared by a method combining in-situ synthesis and static synthesis, and the preparation method specifically comprises the following steps: dissolving 5.6 g of sodium hydroxide in 50ml of deionized water, vigorously stirring until the sodium hydroxide is completely dissolved, then adding 0.675g of sodium metaaluminate, adding 4.23 g of silica sol (the content of silicon dioxide is 25%) after the mixed solution is uniformly stirred, then adding 0.342 g of ruthenium trichloride, stirring the obtained mixed solution at room temperature for 4 hours, transferring the mixed solution into a stainless steel reaction kettle, and crystallizing the mixed solution in an oven at 100 ℃ for 12 hours. And after the reaction is finished, cooling the reaction kettle to room temperature, pouring the suspension into a centrifuge tube, performing centrifugal separation, washing the suspension with deionized water until the pH value is equal to 7, and placing the suspension in an oven at 80 ℃ for drying overnight to obtain 5% Ru @ FAU-2.

The XRD characterization result of the prepared catalyst is shown in figure 2, and the molecular sieve has a good structure. FIG. 3 is an isothermal adsorption curve of the catalyst. The specific surface area of the catalyst reaches 424.0009m²G, pore volume of 0.176631 cm³The ruthenium content of the catalyst was 1.48% by ICP. This shows that the in-situ synthesis effectively supports ruthenium and the catalyst structure has good performance.

The molecular sieve confinement metal oxide catalyst prepared in the embodiment is used for catalytically synthesizing pentamethylene diamine by the following steps:

0.1826 g of lysine hydrochloride is put into a 25 ml reaction kettle lining, 10 ml of water is added for dissolving, then 0.101g of Ru/FAU-2 catalyst is added for stirring until the mixture is completely and uniformly mixed, and the pH value of the mixed solution is adjusted to 2.0 by phosphoric acid; installing a reaction kettle, replacing air in the kettle with nitrogen, then replacing the nitrogen with hydrogen, and pressurizing to 2 MPa after replacement is finished; the reaction kettle is started to carry out reaction under the conditions of 200 ℃ and the stirring speed of 800 r/min. The reaction was carried out in different 0-3 hours. And detecting the concentration of lysine and pentanediamine in the solution after reaction by adopting liquid chromatography after the reaction solution is derived. It was found that at 2 h, the lysine conversion reached 100%, the pentanediamine selectivity reached 34.75%, and the pentanediamine concentration reached 3.54 g/L.

Example 3

The preparation method of the molecular sieve confinement metal oxide catalyst of the embodiment is as follows:

the Ru @ FAU-3 catalyst is prepared by adopting a method combining in-situ synthesis and static synthesis and dealuminizing citric acid, and the preparation method specifically comprises the following steps: dissolving 5.6 g of sodium hydroxide in 50ml of deionized water, vigorously stirring until the sodium hydroxide is completely dissolved, then adding 0.675g of sodium metaaluminate, adding 25.38 g of silica sol (the content of silicon dioxide is 25%) after the mixed solution is uniformly stirred, then adding 0.665 g of ruthenium trichloride, stirring the obtained mixed solution at room temperature for 4 hours, transferring the mixed solution into a stainless steel reaction kettle, and crystallizing the mixed solution in an oven at 100 ℃ for 12 hours. And after the reaction is finished, cooling the reaction kettle to room temperature, pouring the suspension into a centrifuge tube, performing centrifugal separation, washing the suspension with deionized water until the pH value is equal to 7, drying the suspension in an oven at 80 ℃ overnight, and grinding the suspension to powder for later use.

Adding 1g of powder into deionized water, uniformly stirring, adjusting the pH value of the solution to about 5.5 by using a 20% sulfuric acid solution, adding 0.192g of citric acid to prepare a solution, slowly adding the solution, uniformly stirring, placing the solution into a 75 ℃ water bath, stirring for 2.5 hours, washing the solution with the deionized water after the reaction is finished until the pH value is equal to 7, and placing the solution into an 80 ℃ oven for drying overnight to obtain the Ru @ FAU-3 catalyst.

The molecular sieve confinement metal oxide catalyst prepared in the embodiment is used for catalytically synthesizing pentamethylene diamine by the following steps:

0.1826 g of lysine hydrochloride is put into a 25 ml reaction kettle lining, 10 ml of water is added for dissolving, then 0.101g of Ru/FAU-3 catalyst is added for stirring until the mixture is completely and uniformly mixed, and the pH value of the mixed solution is adjusted to 2.0 by phosphoric acid; installing a reaction kettle, replacing air in the kettle with nitrogen, then replacing the nitrogen with hydrogen, and pressurizing to 2 MPa after replacement is finished; the reaction kettle is started to carry out reaction under the conditions of 200 ℃ and the stirring speed of 800 r/min. The reaction was carried out in 0-3 hours. And detecting the concentration of lysine and pentanediamine in the solution after reaction by adopting liquid chromatography after the reaction solution is derived. It was found that at 15 min of the reaction, the lysine conversion reached 88%, the pentamethylenediamine selectivity reached 49%, and the pentamethylenediamine concentration reached 3.89 g/L.

Example 4

The preparation method of the molecular sieve confinement metal oxide catalyst of the embodiment is as follows:

the 5% Ru @ FAU-4 catalyst is prepared by a method combining in-situ synthesis and dynamic synthesis, and the preparation method specifically comprises the following steps: dissolving 5.34 g of sodium hydroxide in 50ml of deionized water, vigorously stirring until the sodium hydroxide is completely dissolved, then adding 2.42 g of sodium metaaluminate, adding 3.42 g of silicon dioxide after the mixed solution is uniformly stirred, then adding 0.419 g of ruthenium trichloride trihydrate, stirring the obtained mixed solution at room temperature for two days, and crystallizing at 90 ℃ for 12 hours. And after the reaction is finished, cooling to room temperature, pouring the suspension into a centrifuge tube, performing centrifugal separation, washing with deionized water until the pH value is equal to 7, and placing in an oven at 80 ℃ for drying overnight to obtain the Ru @ FAU-4 catalyst.

The molecular sieve confinement metal oxide catalyst prepared in the embodiment is used for catalytically synthesizing pentamethylene diamine by the following steps:

0.1826 g of lysine hydrochloride is put into a 25 ml reaction kettle lining, 10 ml of water is added for dissolving, then 0.101g of 1% Ru/FAU-4 catalyst is added, the mixture is stirred until the mixture is completely and uniformly mixed, and the pH value of the mixed solution is adjusted to 2.0 by phosphoric acid; installing a reaction kettle, replacing air in the kettle with nitrogen, then replacing the nitrogen with hydrogen, and pressurizing to 2 MPa after replacement is finished; the reaction kettle is started to carry out reaction under the conditions of 200 ℃ and the stirring speed of 800 r/min. The reaction was carried out in 0-3 hours. And detecting the concentration of lysine and pentanediamine in the solution after reaction by adopting liquid chromatography after the reaction solution is derived. It was found that at 2.5h the lysine conversion reached 100%, the pentanediamine selectivity reached 41.11%, and the pentanediamine concentration reached 4.19 g/L.

Example 5

The preparation method of the molecular sieve confinement metal oxide catalyst of the embodiment is as follows:

the 25% Ru @ FAU-5 catalyst is prepared by a method combining in-situ synthesis and dynamic synthesis, and the preparation method specifically comprises the following steps: dissolving 5.34 g of sodium hydroxide in 50ml of deionized water, vigorously stirring until the sodium hydroxide is completely dissolved, then adding 2.42 g of sodium metaaluminate, adding 3.42 g of silicon dioxide after the mixed solution is uniformly stirred, then adding 2.31 g of ruthenium trichloride trihydrate, stirring the obtained mixed solution at room temperature for two days, and crystallizing at 90 ℃ for 12 hours. And after the reaction is finished, cooling to room temperature, pouring the suspension into a centrifuge tube, performing centrifugal separation, washing with deionized water until the pH value is equal to 7, and placing in an oven at 80 ℃ for drying overnight to obtain the 25% Ru @ FAU-5 catalyst.

The molecular sieve confinement metal oxide catalyst prepared in the embodiment is used for catalytically synthesizing pentamethylene diamine by the following steps:

0.1826 g of lysine hydrochloride is put into a 25 ml reaction kettle lining, 10 ml of water is added for dissolving, then 0.101g of 25% Ru @ FAU-5 catalyst is added, the mixture is stirred until the mixture is completely and uniformly mixed, and the pH value of the mixed solution is adjusted to 2.0 by phosphoric acid; installing a reaction kettle, replacing air in the kettle with nitrogen, then replacing the nitrogen with hydrogen, and pressurizing to 2 MPa after replacement is finished; the reaction kettle is started to carry out reaction under the conditions of 200 ℃ and the stirring speed of 800 r/min. The reaction was carried out in different 0-3 hours. And detecting the concentration of lysine and pentanediamine in the solution after reaction by adopting liquid chromatography after the reaction solution is derived. It was found that at 2 h the lysine conversion reached 100%, the pentanediamine selectivity reached 41.34%, and the pentanediamine concentration reached 4.21 g/L.

Example 6

The preparation method of the molecular sieve confinement metal oxide catalyst of the embodiment is as follows:

the Ru @ FAU-6 is prepared by combining in-situ synthesis and dynamic synthesis and carrying out ion exchange modification on a catalyst, and the preparation method specifically comprises the following steps: dissolving 5.34 g of sodium hydroxide in 50ml of deionized water, vigorously stirring until the sodium hydroxide is completely dissolved, then adding 2.42 g of sodium metaaluminate, adding 3.42 g of silicon dioxide after the mixed solution is uniformly stirred, then adding 2.31 g of ruthenium trichloride trihydrate, stirring the obtained mixed solution for two days at room temperature, and crystallizing for 12 hours at the temperature of 90 ℃. And after the reaction is finished, cooling to room temperature, pouring the suspension into a centrifuge tube, repeatedly centrifuging, washing with deionized water until the pH value is equal to 7, drying in an oven at 80 ℃ overnight, and grinding to powder.

Taking 1g of powder, adding 10 ml of ammonium chloride solution, wherein the concentration of the ammonium chloride solution is 1mol/l, stirring uniformly at room temperature, putting into a 70 ℃ water bath, and stirring for 1 h; after centrifugal washing, 10 ml of ammonium chloride solution is added,

putting the mixture into a water bath kettle at 70 ℃, stirring for 1 hour, centrifugally washing until the pH is about =7, drying overnight, and calcining at 400 ℃ in an air atmosphere to obtain the Ru @ FAU-6 catalyst.

The molecular sieve confinement metal oxide catalyst prepared in the embodiment is used for catalytically synthesizing pentamethylene diamine by the following steps:

0.1826 g of lysine hydrochloride is put into a 25 ml reaction kettle lining, 10 ml of water is added for dissolving, then 0.101g of Ru/FAU-6 catalyst is added, the mixture is stirred until the mixture is completely and uniformly mixed, and the pH value of the mixed solution is adjusted to 2.0 by phosphoric acid; installing a reaction kettle, replacing air in the kettle with nitrogen, then replacing the nitrogen with hydrogen, and pressurizing to 2 MPa after replacement is finished; the reaction kettle is started to carry out reaction under the conditions of 200 ℃ and the stirring speed of 800 r/min. The reaction was carried out in 0-3 hours. And detecting the concentration of lysine and pentanediamine in the solution after reaction by adopting liquid chromatography after the reaction solution is derived. It was found that at 3 h, the lysine conversion reached 87.02%, the pentamethylene diamine selectivity reached 38.67%, and the pentamethylene diamine concentration reached 3.67 g/L.

Example 7

The preparation method of the molecular sieve confinement metal oxide catalyst of the embodiment is as follows:

the specific preparation steps of the Ru @ LTA catalyst are as follows: dissolving 11.03g of sodium hydroxide in 150ml of deionized water, vigorously stirring until the sodium hydroxide is completely dissolved, then adding 10.46g of sodium metaaluminate, adding 7.38 g of silicon dioxide after the mixed solution is uniformly stirred, adding 0.420 g of ruthenium trichloride trihydrate into the mixed solution after stirring for 4 hours at room temperature, stirring for 1 hour, and stirring for crystallization for 12 hours in an oil bath at 100 ℃. And after the reaction is finished, cooling the reaction kettle to room temperature, pouring the suspension into a centrifuge tube, performing centrifugal separation, washing the suspension with deionized water until the pH value is equal to 7, and placing the suspension in an oven at 80 ℃ for drying overnight to obtain Ru @ LTA.

The molecular sieve confinement metal oxide catalyst prepared in the embodiment is used for catalytically synthesizing pentamethylene diamine by the following steps:

0.1826 g of lysine hydrochloride is put into a 25 ml reaction kettle lining, 10 ml of water is added for dissolving, then 0.101g of Ru @ LTA catalyst is added for stirring until the mixture is completely and uniformly mixed, and the pH value of the mixed solution is adjusted to 2.0 by phosphoric acid; installing a reaction kettle, replacing air in the kettle with nitrogen, then replacing the nitrogen with hydrogen, and pressurizing to 2 MPa after replacement is finished; the reaction kettle is started to carry out reaction under the conditions of 200 ℃ and the stirring speed of 800 r/min. The reaction was carried out in 0-3 hours. And detecting the concentration of lysine and pentanediamine in the solution after reaction by adopting liquid chromatography after the reaction solution is derived. It was found that at 3 h, the lysine conversion reached 62.91%, the pentanediamine selectivity reached 36.65%, and the pentanediamine concentration reached 2.35 g/L.

Example 8

This example was prepared as in example 4.

The molecular sieve confinement metal oxide catalyst prepared in the embodiment is used for catalytically synthesizing pentamethylene diamine by the following steps:

0.1826 g of lysine hydrochloride is put into a 25 ml reaction kettle lining, 10 ml of water is added for dissolving, then 0.505g of Ru/FAU-4 catalyst is added, the mixture is stirred until the mixture is completely and uniformly mixed, and the pH value of the mixed solution is adjusted to 1 by phosphoric acid; installing a reaction kettle, replacing air in the kettle with nitrogen, then replacing the nitrogen with hydrogen, and pressurizing to 2 MPa after replacement is finished; the reaction kettle is started to carry out reaction under the conditions of 200 ℃ and the stirring speed of 800 r/min. The reaction was carried out in 0-3 hours. And detecting the concentration of lysine and pentanediamine in the solution after reaction by adopting liquid chromatography after the reaction solution is derived. It was found that at 2 h the lysine conversion reached 100%, the pentanediamine selectivity reached 25.08%, and the pentanediamine concentration reached 2.59 g/L.

Example 9

This example was prepared as in example 4.

The molecular sieve confinement metal oxide catalyst prepared in the embodiment is used for catalytically synthesizing pentamethylene diamine by the following steps:

0.1826 g of lysine hydrochloride is put into a 25 ml reaction kettle lining, 10 ml of water is added for dissolving, then 0.505g of Ru/FAU-4 catalyst is added, the mixture is stirred until the mixture is completely and uniformly mixed, and the pH value of the mixed solution is adjusted to 1 by phosphoric acid; installing a reaction kettle, replacing air in the kettle with nitrogen, then replacing the nitrogen with hydrogen, and pressurizing to 3 MPa after replacement is finished; the reaction kettle is started to carry out reaction under the conditions of 200 ℃ and the stirring speed of 800 r/min. The reaction was carried out in 0-3 hours. And detecting the concentration of lysine and pentanediamine in the solution after reaction by adopting liquid chromatography after the reaction solution is derived. It was found that at 2 h the lysine conversion reached 98.03%, the pentanediamine selectivity reached 40.08%, and the pentanediamine concentration reached 4.08 g/L.

Example 10

This example was prepared as in example 4.

The molecular sieve confinement metal oxide catalyst prepared in the embodiment is used for catalytically synthesizing pentamethylene diamine by the following steps:

0.1826 g of lysine hydrochloride is put into a 25 ml reaction kettle lining, 10 ml of water is added for dissolving, then 0.505g of Ru/FAU-4 catalyst is added, the mixture is stirred until the mixture is completely and uniformly mixed, and the pH value of the mixed solution is adjusted to 1 by phosphoric acid; installing a reaction kettle, replacing air in the kettle with nitrogen, then replacing the nitrogen with hydrogen, and pressurizing to 2 MPa after replacement is finished; the reaction kettle is started to carry out the reaction at the temperature of 220 ℃ and the stirring speed of 800 r/min. The reaction was carried out in 0-3 hours. And detecting the concentration of lysine and pentanediamine in the solution after reaction by adopting liquid chromatography after the reaction solution is derived. It was found that at 1.5 h the lysine conversion reached 98.03%, the pentanediamine selectivity reached 39.29, and the pentanediamine concentration reached 3.93 g/l.

The invention provides a molecular sieve confinement metal oxide catalyst which is used for synthesizing pentanediamine, effectively solves the problem of agglomeration of metal nanoparticles in a single metal catalyst, remarkably improves the generation rate of the pentanediamine, greatly saves the production cost and has good industrial application prospect.

The foregoing shows and describes the general principles and features of the present invention, together with the advantages thereof. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.