A method for synthesizing pentamethylenediamine and carbon dioxide by catalytic one-step synthesis of pentamethylenediamine

Abstract

The present invention relates to a one-step catalytic synthesis method for pentamethylenedicarbamate from pentamethylenediamine and carbon dioxide. The method comprises: mixing pentamethylenediamine with an alcohol and reacting the mixture with carbon dioxide in the presence of a cerium-based catalyst to obtain pentamethylenedicarbamate. The present invention provides a method for preparing pentamethylenedicarbamate, a raw material for bio-based isocyanates. The synthetic route is simple and low-cost. The cerium-based catalyst involved is simple to prepare, has high catalytic efficiency, and is easily separated and recovered. Furthermore, CO2 is directly utilized, converting an inexpensive carbon resource into a high-value-added product, thus having significant significance.

Description

Technical Field

[0001] The invention belongs to the technical field of catalytic synthesis and relates to a green synthesis method of pentamethylenediaminocarbamate, in particular to a method for synthesizing pentamethylenediaminocarbamate by catalytically synthesizing pentamethylenediaminocarbamate through one step of pentamethylenediamine and carbon dioxide. Background Art

[0002] Dicarbamates are high-value-added chemicals. Diphenylmethane dicarbamate (MDC), hexamethylene diisocyanate (HDC), and xylylene diisocyanate (XDC) are widely used in pesticides, pharmaceuticals, isocyanates, and polyurethanes. Dicarbamates can be pyrolyzed to prepare polyurethane precursor isocyanates and can also be used directly in polyurethane synthesis, effectively avoiding the traditional phosgene route. To date, a series of methods have been reported for the synthesis of dicarbamates, primarily including oxidative carbonylation of diamines, carbonate aminolysis, urea alcoholysis, and carbonylation of carbamates.

[0003] Pentamethylenedicarbamate (PDC) is a bio-based carbamate synthesized from pentamethylenediamine, which is converted from biomass. Due to its green origin and mild preparation methods, the pentamethylene diisocyanate (PDI) and polyurethane synthesized from PDC not only offer green and sustainable advantages but also exhibit superior performance in terms of quick-drying properties and compatibility.

[0004] CN108689884A discloses the use of zinc compounds (such as zinc acetate, zinc oxalate, etc.) to catalyze urea and pentamethylenediamine extracts to synthesize butyl carbamate by carbamate conversion, and is applied to the preparation of isocyanates. The extraction solvent in this method can not only remove a large amount of salt contained in the conversion solution, but also serve as a raw material for synthesizing PDU, and PDI can be prepared by thermal cracking. The byproduct extraction solvent can also be recycled. However, this method is relatively complex, the yield of the prepared product is low, and there are many by-products.

[0005] CN113603613A discloses a catalytic synthesis method for pentamethylenediamine carbamate. Pentamethylenediamine and a carbonylating agent are dissolved in a solvent, and the synthesis reaction is catalyzed by a titanium dioxide catalyst. The carbonylating agent may include methyl carbamate, ethyl carbamate, propyl carbamate, butyl carbamate, dimethyl carbonate, diethyl carbonate, or urea. This method is suitable for industrial production, and the titanium dioxide catalyst used is simple to synthesize, stable, non-degradable, easily recyclable, and reusable.

[0006] CO₂ is an abundant, safe, and inexpensive small molecule. With the intensification of the greenhouse effect, its utilization has attracted significant attention. Directly using CO₂ to prepare carbamates offers both cost savings and simplified operations. With increasing carbon emissions, efficient CO₂ utilization is crucial for achieving carbon reduction. Therefore, the one-step synthesis of dicarbamates from CO₂ and diamines is expected to be an efficient, inexpensive, safe, and promising method. Summary of the Invention

[0007] In view of the shortcomings of the prior art, the object of the present invention is to provide a green synthesis method of pentamethylenediaminocarbamate, in particular to provide a one-step catalytic synthesis method of pentamethylenediaminocarbamate using pentamethylenediamine and carbon dioxide.

[0008] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0009] The present invention provides a method for synthesizing pentamethylenediaminocarbamate by catalytically synthesizing pentamethylenediaminocarbamate from pentamethylenediamine and carbon dioxide in one step. The method comprises: mixing pentamethylenediamine with alcohol, and reacting the mixture with carbon dioxide in the presence of a cerium-based catalyst to obtain pentamethylenediaminocarbamate.

[0010] The present invention provides a method for preparing pentamethylenedicarbamate, a raw material for bio-based isocyanate. The synthetic route is simple and low-cost. The cerium-based catalyst involved has a simple preparation process, high catalytic efficiency, and is easy to separate and recover. At the same time, CO2 is directly utilized, converting cheap carbon resources into high-value-added products, which is of great significance.

[0011] Preferably, the cerium-based catalyst is prepared by a preparation method comprising the following steps:

[0012] The cerium salt aqueous solution is added to the alkaline solution, the obtained mixture is precipitated, and the precipitated product is dried, ground and calcined to obtain the cerium-based catalyst.

[0013] The cerium-based catalyst of the present invention not only has high conversion rate of pentamethylenediamine and high selectivity of pentamethylenedicarbamate, but also has the advantages of mild reaction conditions and short reaction time.

[0014] Preferably, the cerium salt aqueous solution further contains other metal salts, and the other metal salts include any one or a combination of at least two of magnesium salts, zinc salts, manganese salts, zirconium salts, aluminum salts, calcium salts, lanthanum salts, and cobalt salts;

[0015] The combination of at least two salts can be, for example, a combination of magnesium salt and zinc salt, a combination of manganese salt and zirconium salt, a combination of aluminum salt and calcium salt, a combination of lanthanum salt and cobalt salt, and any other combination can be selected, which will not be described in detail here.

[0016] Combinations of manganese and zirconium salts are preferred.

[0017] The role of other metal salts added to the reaction system is to adjust the catalyst structure to promote the generation of more surface defects, such as oxygen vacancies, which is beneficial to promote the conversion of CO2. The combination of manganese salts and zirconium salts makes this effect more significant.

[0018] Preferably, the molar ratio of the cerium salt to the other metal salt is (1-40):1, for example 1:1, 2:1, 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, etc. Other specific values within this numerical range can be selected and will not be repeated here.

[0019] The molar ratio of the cerium salt to the other metal salt is specifically selected to be (1-40):1. The reason for selecting this range is that when the amount of other metal salts added is too small, the structure of cerium oxide cannot be adjusted to promote the generation of surface defects; when the content of other metals is too high, the content of cerium oxide decreases, thereby losing the catalytic effect.

[0020] Preferably, the alkali solution comprises any one of ammonia water, sodium hydroxide solution, potassium hydroxide solution, sodium carbonate solution or potassium carbonate solution, or a combination of at least two thereof;

[0021] The combination of at least two of the above mentioned solutions can be, for example, a combination of sodium hydroxide solution and potassium hydroxide solution, a combination of sodium carbonate solution and potassium carbonate solution, or any other combination, which will not be described in detail here.

[0022] Preferably, the concentration of the alkali solution is 0.5-10 mol / L, for example, 0.5 mol / L, 1 mol / L, 2 mol / L, 3 mol / L, 4 mol / L, 5 mol / L, 6 mol / L, 7 mol / L, 8 mol / L, 9 mol / L, 10 mol / L, etc.

[0023] Preferably, the sedimentation time is 1-8 hours, for example, 1 hour, 1.5 hours, 2 hours, 3 hours, 4 hours, 4.5 hours, 5 hours, 6 hours, 7 hours, 8 hours, etc.

[0024] Preferably, the drying temperature is 60-150°C, such as 60°C, 70°C, 80°C, 90°C, 100°C, 120°C, 130°C, 150°C, etc.; the drying time is 1-12h, such as 1h, 2h, 4h, 5h, 7h, 9h, 11h, 12h, etc.

[0025] Preferably, the calcination temperature is 300-600°C, such as 300°C, 350°C, 400°C, 450°C, 500°C, 550°C, 600°C, etc.; the calcination time is 1-7h, such as 1h, 2h, 3h, 4h, 5h, 6h, 7h, etc.

[0026] Other specific point values within the above numerical range can be selected and will not be described in detail here.

[0027] Preferably, the mass of the cerium-based catalyst is 1-30% of the mass of pentamethylenediamine, for example 1%, 5%, 8%, 10%, 12%, 15%, 20%, 25%, 30%, etc. Other specific values within this numerical range can be selected and will not be repeated here.

[0028] Preferably, the alcohol includes any one of methanol, ethanol, propanol, butanol, pentanol or 2-propanol, or a combination of at least two of them; the combination of at least two of them can be, for example, a combination of methanol and ethanol, a combination of propanol and butanol, a combination of pentanol and 2-propanol, etc. Any other combination can be selected and will not be described in detail here.

[0029] Methanol and / or ethanol are preferred.

[0030] The alcohol added to the reaction system of the present invention serves as both a reaction solvent and one of the reactants for synthesizing PDC. Short-chain alcohols are more preferred because they react more easily with PDA and CO2, and thus have a higher yield than long-chain alcohols.

[0031] Preferably, the molar ratio of the alcohol to pentamethylenediamine is (20-200):1, for example, 20:1, 30:1, 50:1, 70:1, 100:1, 120:1, 140:1, 150:1, 170:1, 200:1, etc. Other specific values within this numerical range can be selected and will not be described here one by one.

[0032] The molar ratio of the alcohol to pentamethylenediamine is specifically selected to be (20-200):1 because further increasing the amount of alcohol relative to pentamethylenediamine will reduce the PDC yield because excess alcohol will dilute the concentrations of reactants and catalyst, reducing catalytic efficiency. Further decreasing the amount of alcohol relative to pentamethylenediamine will also reduce the PDC yield because alcohol is one of the reactants. Properly increasing the amount of reactants will promote the forward reaction and also increase the absorption of CO2.

[0033] Preferably, a water scavenger is also present in the reaction.

[0034] In the synthesis system involved in the present invention, the selectivity of the target product pentamethylenediaminocarbamate can be further improved under the condition of adding a desiccant, and a combination of diethoxypropane and cyanopyridine is more preferably used as the desiccant.

[0035] Preferably, the dehydrating agent includes any one of acetonitrile, ethylene, diethoxypropane, butylene oxide or cyanopyridine, or a combination of at least two of them; the combination of at least two of them is, for example, a combination of acetonitrile and ethylene, a combination of diethoxypropane and butylene oxide, a combination of butylene oxide and cyanopyridine, etc. Any other combination can be selected and will not be described in detail here.

[0036] The combination of diethoxypropane and cyanopyridine is preferred.

[0037] Preferably, the molar ratio of the water scavenger to pentamethylenediamine is (1-50):1, for example, 1:1, 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 45:1, 50:1, etc.

[0038] Preferably, the pressure of the carbon dioxide in the reaction system is 0.5-3 MPa, for example, 0.5 MPa, 1 MPa, 1.5 MPa, 2 MPa, 2.5 MPa, 3 MPa, etc.

[0039] Preferably, the reaction temperature is 100-220°C, for example, 100°C, 120°C, 130°C, 150°C, 170°C, 180°C, 190°C, 200°C, 220°C, etc.; the reaction time is 1-12h, for example, 1h, 3h, 4h, 5h, 6h, 7h, 10h, 11h, 12h, etc.

[0040] Other specific point values within the above numerical range can be selected and will not be described in detail here.

[0041] As a preferred embodiment of the present invention, the method for synthesizing pentamethylenediamine and carbon dioxide into pentamethylenediaminocarbamate by one-step catalysis comprises:

[0042] Pentamethylenediamine and alcohol are mixed and reacted with carbon dioxide in the presence of a cerium-based catalyst and a water scavenger. The reaction temperature is controlled at 100-220° C., the reaction time is 1-12 hours, and the system pressure is 0.5-3 MPa to obtain pentamethylenediaminocarbamate.

[0043] Wherein, the dehydrating agent comprises any one or a combination of at least two of acetonitrile, ethylene, diethoxypropane, butylene oxide or cyanopyridine;

[0044] The cerium-based catalyst is prepared by a preparation method comprising the following steps: adding a cerium salt aqueous solution to an alkaline solution, precipitating the resulting mixture for 1-8 hours, drying the precipitated product at 60-150° C. for 1-12 hours, grinding, and calcining at 300-600° C. for 1-7 hours.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] The present invention uses abundant and inexpensive CO2 as a raw material to synthesize bio-based pentamethylenediamine in a one-step process, providing a new green and sustainable reaction route. The catalytic synthesis method achieves high conversion rates of pentamethylenediamine and high selectivity for pentamethylenediamine. The cerium-based catalyst used in the catalytic synthesis method has high catalytic efficiency, simple synthesis, easy recovery, and reusability. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 is a gas chromatogram of the supernatant in Example 1;

[0048] Figure 2 is a gas chromatogram of the supernatant in Example 2;

[0049] Figure 3 It is the gas chromatogram of the supernatant in Example 3. DETAILED DESCRIPTION

[0050] In order to further illustrate the technical means and effects adopted by the present invention, the technical solutions of the present invention are further described below in conjunction with the preferred embodiments of the present invention, but the present invention is not limited to the scope of the embodiments.

[0051] The gas chromatography analysis conditions involved in the following examples are as follows:

[0052] Chromatographic column model GsBP-1;

[0053] The column temperature was initially set at 50°C, maintained for 1 min, then raised to 150°C at 20°C / min, maintained for 1 min, then raised to 220°C at 20°C / min, and maintained at 220°C for 12 min.

[0054] The control mode is pressure control, pressure 110 kPa, nitrogen purge flow rate 3 mL / min, split ratio 25;

[0055] Vaporization temperature 250℃.

[0056] Preparation Example 1

[0057] This preparation example prepares a cerium-based catalyst as follows:

[0058] Dissolve 0.012 mol of cerium nitrate and 0.005 mol of zinc nitrate in deionized water and stir evenly. Slowly add the above solution dropwise into 2 mol / L sodium hydroxide with continuous stirring. Then, precipitate the resulting mixture at 25°C for 3 hours. Rinse the resulting suspension with distilled water at least three times until neutral, then place it in an oven at 100°C and dry it for 12 hours. The ground solid product is placed in a muffle furnace at 500°C and calcined for 3 hours to obtain a cerium-based catalyst.

[0059] Preparation Example 2

[0060] This preparation example prepares a cerium-based catalyst as follows:

[0061] 0.012 mol of cerium nitrate and 0.005 mol of zinc nitrate were dissolved in deionized water and stirred evenly. The above solution was slowly added dropwise to 6 mol / L sodium carbonate with continuous stirring. The resulting mixture was then precipitated at 25°C for 5 hours. The resulting suspension was rinsed with distilled water at least three times until neutral, and then placed in a 120°C oven to dry for 10 hours. The ground solid product was placed in a muffle furnace at 400°C and calcined for 7 hours to obtain a cerium-based catalyst.

[0062] Preparation Example 3

[0063] This preparation example prepares a cerium-based catalyst as follows:

[0064] Dissolve 0.012 mol of cerium nitrate and 0.005 mol of zinc nitrate in deionized water and stir evenly. Slowly add the above solution dropwise into 5 mol / L potassium hydroxide with continuous stirring. Then, precipitate the resulting mixture at 25°C for 8 hours. Rinse the resulting suspension with distilled water at least three times until neutral, then dry it in an oven at 100°C for 12 hours, and calcine the ground solid product in a muffle furnace at 600°C for 2 hours to obtain a cerium-based catalyst.

[0065] Preparation Example 4

[0066] This preparation example prepares a cerium-based catalyst. The method differs from that of Preparation Example 1 only in that an equimolar amount of zinc nitrate is replaced by manganese nitrate, and other conditions remain unchanged.

[0067] Preparation Example 5

[0068] This preparation example prepares a cerium-based catalyst. The method differs from that of Preparation Example 1 only in that an equimolar amount of zinc nitrate is replaced by zirconium nitrate, and other conditions remain unchanged.

[0069] Preparation Example 6

[0070] In this preparation example, a cerium-based catalyst is prepared. The method is different from that in Preparation Example 1 only in that 0.005 mol of zinc nitrate is replaced by 0.0025 mol of zirconium nitrate and 0.0025 mol of manganese nitrate, and other conditions remain unchanged.

[0071] Example 1

[0072] This embodiment provides a method for synthesizing pentamethylenediamine and carbon dioxide into pentamethylenediaminocarbamate by one-step catalysis, as follows:

[0073] 0.25 g of pentamethylenediamine and 1.04 g of cyanopyridine were dissolved in 9 mL of anhydrous ethanol, and then 0.07 g of the cerium-based catalyst prepared in Preparation Example 1 was added. CO2 was charged to 2 MPa, and the reaction temperature was controlled to be 180°C. The reaction time was 6 h. After the reaction was completed, the cerium-based catalyst was separated by centrifugation, and the supernatant was analyzed for composition by gas chromatography. Figure 1 As shown in the figure, there are five main peaks: the ethanol peak at around 2.0 min, the peak at 6.0 min is characteristic of the internal standard, and PDC peaks at around 20.0 min. Comparison of the gas chromatography-mass spectrometry (GC-MS) with the GC-MS spectra of a PDC standard substance confirmed that the peak at 20.0 min is PDC. The specific results are listed in Table 1.

[0074] Example 2

[0075] This embodiment provides a method for synthesizing pentamethylenediamine and carbon dioxide into pentamethylenediaminocarbamate by one-step catalysis, as follows:

[0076] 0.25 g of pentamethylenediamine and 1.04 g of cyanopyridine were dissolved in 9 mL of anhydrous ethanol, and then 0.07 g of the cerium-based catalyst prepared in Preparation Example 2 was added. CO2 was charged to 1 MPa, and the reaction temperature was controlled to 200 ° C. The reaction time was 10 h. After the reaction was completed, the cerium-based catalyst was separated by centrifugation, and the supernatant was analyzed by gas chromatography for composition, as shown in FIG. Figure 2 As shown in the figure, there are five characteristic peaks. The characteristic peak of PDC appears around 20 minutes, and the others include the characteristic peaks of the solvent ethanol, intermediates, and by-products. The specific results are listed in Table 1.

[0077] Example 3

[0078] This embodiment provides a method for synthesizing pentamethylenediamine and carbon dioxide into pentamethylenediaminocarbamate by one-step catalysis, as follows:

[0079] 0.25 g of pentamethylenediamine and 1.04 g of cyanopyridine were dissolved in 9 mL of anhydrous ethanol, and then 0.07 g of the cerium-based catalyst prepared in Preparation Example 3 was added. CO2 was charged to 3 MPa, the reaction temperature was controlled to 150 ° C, and the reaction time was 12 h. After the reaction was completed, the cerium-based catalyst was separated by centrifugation, and the supernatant was analyzed by gas chromatography for composition, as shown in FIG. Figure 3 As shown, the characteristic peaks shown in the figure are Figure 1 and Figure 2 Similarly, it is proved that PDC is also generated. The specific results are listed in Table 1.

[0080] Examples 4-6

[0081] This example provides three methods for the one-step catalytic synthesis of pentamethylenediamine and carbon dioxide into pentamethylenedicarbamate. The method differs from Example 1 only in that the cerium-based catalyst prepared in Preparation Example 1 is replaced with an equal molar amount of the cerium-based catalysts prepared in Preparation Examples 4-6; all other conditions remain unchanged. After completion of the reaction, the cerium-based catalysts are separated by centrifugation, and the supernatant is analyzed for composition by gas chromatography. The results are listed in Table 1.

[0082] Example 7

[0083] This example provides a one-step catalytic synthesis of pentamethylenediaminocarbamate using pentamethylenediamine and carbon dioxide. This method differs from Example 1 only in that cyanopyridine is replaced with diethoxypropane; all other conditions remain unchanged. After the reaction, the cerium-based catalyst is separated by centrifugation, and the supernatant is analyzed for composition by gas chromatography. The results are listed in Table 1.

[0084] Example 8

[0085] This example provides a one-step catalytic synthesis of pentamethylenediaminocarbamate using pentamethylenediamine and carbon dioxide. This method differs from Example 1 only in that cyanopyridine is replaced by a mixture of cyanopyridine and diethoxypropane (w / w = 1:1); all other conditions remain unchanged. After the reaction, the cerium-based catalyst is separated by centrifugation, and the supernatant is analyzed for composition by gas chromatography. The results are listed in Table 1.

[0086] Example 9

[0087] This example provides a one-step catalytic synthesis of pentamethylenediaminocarbamate using pentamethylenediamine and carbon dioxide. This method differs from Example 1 only in that an equal volume of anhydrous methanol is substituted for anhydrous ethanol; all other conditions remain unchanged. After the reaction, the cerium-based catalyst is separated by centrifugation, and the supernatant is analyzed for composition by gas chromatography. The results are listed in Table 1.

[0088] Example 10

[0089] This example provides a one-step catalytic synthesis of pentamethylenediaminocarbamate using pentamethylenediamine and carbon dioxide. This method differs from Example 1 only in that an equal volume of anhydrous butanol is substituted for anhydrous ethanol; all other conditions remain unchanged. After the reaction, the cerium-based catalyst is separated by centrifugation, and the supernatant is analyzed for composition by gas chromatography. The results are listed in Table 1.

[0090] Comparative Example 1

[0091] This example provides a one-step catalytic synthesis of pentamethylenedicarbamate using pentamethylenediamine and carbon dioxide. This method differs from Example 1 only in that the cerium-based catalyst prepared in Preparation Example 1 is replaced with an equimolar amount of a commercially available cerium oxide catalyst; all other conditions remain unchanged. After the reaction, the cerium-based catalyst is separated by centrifugation, and the supernatant is analyzed for composition by gas chromatography. The results are listed in Table 1.

[0092] Comparative Example 2

[0093] This example provides a one-step catalytic synthesis of pentamethylenedicarbamate using pentamethylenediamine and carbon dioxide. This method differs from Example 1 only in that the cerium-based catalyst prepared in Preparation Example 2 is replaced with an equimolar amount of a commercially available zirconium oxide catalyst; all other conditions remain unchanged. After the reaction, the cerium-based catalyst is separated by centrifugation, and the supernatant is analyzed for composition by gas chromatography. The results are listed in Table 1.

[0094] Table 1

[0095] PDA conversion rate (%) PDC selectivity (%) Example 1 100 55 Example 2 100 67 Example 3 100 51 Example 4 100 70 Example 5 100 75 Example 6 100 86 Example 7 100 53 Example 8 100 65 Example 9 100 62 Example 10 100 50 Comparative Example 1 100 34 Comparative Example 2 100 0

[0096] The data in Table 1 demonstrates that the method disclosed herein successfully produces PDC in a one-step process using CO2 and pentamethylenediamine, achieving high-value CO2 utilization and the synthesis of bio-based formate. Furthermore, the catalyst used is simple to synthesize, easily recyclable, and reusable. Furthermore, the preparation method of the cerium-based catalyst and the choice of desiccant significantly influence the selectivity of PDC.

[0097] The applicant states that while the above-described embodiments illustrate a method for the one-step catalytic synthesis of pentamethylenediamine and carbon dioxide, the present invention is not limited to these embodiments. This does not necessarily mean that the present invention must rely on these embodiments in order to be implemented. Those skilled in the art will appreciate that any improvements to the present invention, equivalent substitutions for the raw materials of the product, addition of auxiliary components, and selection of specific methods are all within the scope of protection and disclosure of the present invention.

[0098] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

[0099] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A method for synthesizing pentamethylenediamine and carbon dioxide in one step, characterized in that: The method comprises: mixing pentamethylenediamine and alcohol, reacting the mixture with carbon dioxide in the presence of a cerium-based catalyst to obtain pentamethylenediaminocarbamate; The pressure of the carbon dioxide in the reaction system is 0.5-3 MPa; The reaction temperature is 100-220°C and the reaction time is 1-12h; The cerium-based catalyst is prepared by a preparation method comprising the following steps: Add the cerium salt aqueous solution to the alkali solution, and precipitate the resulting mixture for 1-8 hours. The precipitated product is dried at 60-150°C for 1-12 hours, ground, and calcined at 300-600°C for 1-7 hours to obtain; The cerium salt aqueous solution further contains other metal salts, wherein the other metal salts are any one of zinc salts, manganese salts or zirconium salts or a combination of at least two thereof; The alcohol includes any one of methanol, ethanol, propanol, butanol, pentanol or 2-propanol, or a combination of at least two thereof.

2. The method for synthesizing pentamethylenediamine and carbon dioxide in one step according to claim 1, wherein: The other metal salts consist of a combination of manganese salts and zirconium salts.

3. The method for synthesizing pentamethylenediamine and carbon dioxide in one step according to claim 1, wherein: The molar ratio of the cerium salt to other metal salts is (1-40):

1.

4. The method for synthesizing pentamethylenediamine and carbon dioxide in one step according to claim 1, wherein: The alkali solution includes any one of ammonia water, sodium hydroxide solution, potassium hydroxide solution, sodium carbonate solution or potassium carbonate solution, or a combination of at least two of them.

5. The method for synthesizing pentamethylenediamine and carbon dioxide into pentamethylenediaminocarbamate by one-step catalysis according to claim 1, wherein: The concentration of the alkali solution is 0.5-10 mol / L.

6. The method for synthesizing pentamethylenediamine and carbon dioxide into pentamethylenediaminocarbamate by one-step catalysis according to claim 1, wherein: The mass of the cerium-based catalyst is 1-30% of the mass of pentamethylenediamine.

7. The method for synthesizing pentamethylenediamine and carbon dioxide into pentamethylenediaminocarbamate by one-step catalysis according to claim 1, wherein: The alcohol consists of methanol and / or ethanol.

8. The method for synthesizing pentamethylenediamine and carbon dioxide into pentamethylenediaminocarbamate by one-step catalysis according to claim 1, wherein: The molar ratio of the alcohol to pentamethylenediamine is (20-200):

1.

9. The method for synthesizing pentamethylenediamine and carbon dioxide into pentamethylenedicarbamate by one-step catalysis according to claim 1, wherein: The reaction also involves the presence of a water scavenger.

10. The method for synthesizing pentamethylenediamine and carbon dioxide into pentamethylenediaminocarbamate by one-step catalysis according to claim 9, characterized in that: The dehydrating agent includes any one of acetonitrile, ethylene, diethoxypropane, butylene oxide or cyanopyridine, or a combination of at least two thereof.

11. The method for synthesizing pentamethylenediamine and carbon dioxide into pentamethylenedicarbamate by one-step catalysis according to claim 10, characterized in that: The dehydrating agent is composed of a combination of diethoxypropane and cyanopyridine.

12. The method for synthesizing pentamethylenediamine and carbon dioxide into pentamethylenediaminocarbamate by one-step catalysis according to claim 9, characterized in that: The molar ratio of the water scavenger to pentamethylenediamine is (1-50):

1.

13. The method for synthesizing pentamethylenediamine and carbon dioxide into pentamethylenedicarbamate by one-step catalysis according to claim 1, wherein: The method comprises: Pentamethylenediamine and alcohol are mixed and reacted with carbon dioxide in the presence of a cerium-based catalyst and a water scavenger. The reaction temperature is controlled at 100-220° C., the reaction time is 1-12 hours, and the system pressure is 0.5-3 MPa to obtain pentamethylenediaminocarbamate. Wherein, the dehydrating agent comprises any one or a combination of at least two of acetonitrile, ethylene, diethoxypropane, butylene oxide or cyanopyridine; The cerium-based catalyst is prepared by a preparation method comprising the following steps: adding a cerium salt aqueous solution to an alkaline solution, precipitating the resulting mixture for 1-8 hours, drying the precipitated product at 60-150° C. for 1-12 hours, grinding, and calcining at 300-600° C. for 1-7 hours.

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