Process for the preparation of cycloaliphatic carbamates and use thereof

Abstract

The application provides a preparation method of alicyclic carbamates and application thereof, and the preparation method comprises the following steps: mixing aromatic carbamates, a catalyst and a solvent, and then introducing hydrogen for reaction to obtain the alicyclic carbamates; the catalyst comprises a carrier and an active component loaded on the carrier; and the active component comprises any one or a combination of at least two of Pt, Rh, Ru, Ir or Pd. The preparation method of the alicyclic carbamates provided by the application has the advantages of mild reaction conditions, simple operation, small safety hidden danger, high yield of alicyclic carbamates, suitability for various reactors, easy large-scale continuous production and good industrial application prospect.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of chemical industry, and particularly relates to a preparation method of alicyclic amino acid ester and application thereof, and especially to a preparation method of alicyclic amino acid ester with high yield and application thereof. BACKGROUND

[0002] The production process of polyurethane has been mature, and the most mature one is the isocyanate route. Polyurethane materials prepared from aliphatic and alicyclic diisocyanate (ADI) have excellent mechanical properties, outstanding chemical stability and excellent weather resistance, and are widely used in high-grade coatings, high-grade synthetic leather, elastomers, adhesives, rocket propellants and other fields. Compared with MDI and TDI in aromatic isocyanate, most varieties of ADI have more excellent performance and lower toxicity.

[0003] Alicyclic diisocyanate belongs to ADI varieties, and its synthesis methods mainly include phosgene method and non-phosgene method. The phosgene method is a commonly used production method in industry, but the phosgene used in the process of preparing isocyanate is a toxic raw material, and a large amount of hydrogen chloride is released in the reaction, which is easy to cause equipment corrosion and environmental pollution, and has high risk and difficulty in operation. From the perspective of green environmental protection, it is necessary to develop non-phosgene technology. The non-phosgene method is mainly the carbamate cleavage method, and carbamate is the key precursor for the thermal synthesis of isocyanate; at the same time, as a non-isocyanate route for synthesizing polyurethane, carbamate can be directly used to synthesize polyurethane through ester exchange with polyol.

[0004] In the current technical route, whether it is the phosgene method or the non-phosgene method, the alicyclic diamine containing aromatic ring needs to be first subjected to benzene ring hydrogenation to obtain alicyclic diamine, and then the ADI is synthesized by the non-phosgene or phosgene method.

[0005] In order to inhibit the deamination (or desmethylamine) side reaction of the amine containing aromatic ring in the benzene ring hydrogenation process, the catalyst often needs to be subjected to alkali modification treatment or adding an alkali metal salt, a nitrite salt or the like as a promoter or ammonia, an organic amine or the like to inhibit the deamination (or desmethylamine) side reaction. However, the loss of alkali increases the regeneration frequency of the catalyst, which increases the cost; the introduction of a large amount of ammonia gas in the industrial device will cause equipment corrosion and bring safety hazards; the recovery cost of the organic amine solvent is high; and the uninterrupted addition of new promoters in the catalyst reuse causes the continuous accumulation of alkali metals, which damages the performance of the catalyst.

[0006] CN110105223A adds m-xylylenediamine into a solvent and a cocatalyst to prepare a mixed solution, and continuously prepares 1,3-cyclohexanedimethylamine in a fixed bed reactor, but the cocatalyst contains a nitrate or nitrite.

[0007] US3697449A1 uses 1-35wt% alkali metal alkoxide or hydroxide aqueous solution to modify the supported ruthenium catalyst, and then carries out the hydrogenation reduction reaction of diaminodiphenylmethane.

[0008] CN111804324A uses lithium amide to modify the metal-supported catalyst for catalyzing the hydrogenation of diaminodiphenylmethane, avoiding the by-product of secondary amine and the large increase of PACM-OH, but lithium is easy to lose during use, increasing the cost of product post-treatment and catalyst regeneration.

[0009] In view of the adverse effects of using alkali modification or alkali metal salt, nitrite, ammonia or organic amine in the process of directly hydrogenating the benzene ring of amine containing aromatic ring to synthesize alicyclic amine, and the environmental and safety problems of synthesizing isocyanate and polyurethane by phosgene method, it is of great significance to develop a green and safe synthesis technology route of alicyclic urethane. SUMMARY

[0010] In view of the deficiencies of the prior art, the purpose of the present application is to provide a preparation method of alicyclic urethane and its application, especially a preparation method of alicyclic urethane with high yield. The preparation method of alicyclic urethane provided by the present application has mild reaction conditions, simple operation, small safety hazards, high yield of alicyclic urethane, is suitable for various reactors, and is easy to produce on a large scale continuously, so it has good industrial application prospect.

[0011] To achieve the purpose of the present application, the following technical solutions are adopted:

[0012] On the one hand, the present application provides a preparation method of alicyclic urethane, which comprises the following steps: mixing aromatic ring-containing urethane, a catalyst and a solvent, and then introducing hydrogen gas for reaction to obtain the alicyclic urethane.

[0013] The catalyst comprises a carrier and an active component supported on the carrier.

[0014] The active component comprises any one or a combination of at least two of Pt, Rh, Ru, Ir or Pd, such as a combination of Pt and Rh, a combination of Rh and Ru, or a combination of Ir and Pd, etc., but is not limited to the above-mentioned combinations. Other combinations not listed within the above-mentioned combinations are also applicable.

[0015] The above preparation method avoids the problems of amine deamination condensation by-product in the direct hydrogenation of amine containing aromatic ring, as well as the problems of catalyst deactivation caused by tar and the loss of catalyst components; the product alicyclic urethane is an important intermediate for the synthesis of ADI by non-phosgene method, which provides a green production process with less toxicity and safety for the synthesis of ADI; at the same time, the yield of the product can be effectively improved by selecting a specific catalyst.

[0016] Preferably, the active component is any one of a combination of Ru and Pd, a combination of Rh and Ru, a combination of Ru and Pt, a combination of Ru and Ir, a combination of Rh and Pt, a combination of Ir and Pt, a combination of Pd and Pt, or a combination of Ir and Pd, preferably a combination of Ru and Pd.

[0017] The specific active component described above further improves the yield of the product.

[0018] Preferably, the carrier comprises any one of or a combination of at least two of SiO2, Al2O3, ZrO2, TiO2, MgO, kaolin, bentonite, montmorillonite, ZSM-5, X zeolite, Y zeolite, B zeolite, mordenite, spinel, hydrotalcite, activated carbon, graphene, carbon nanotube, g-C3N4 (graphitic carbon nitride), h-BN (hexagonal boron nitride), or nitrogen-doped carbon composite, such as a combination of SiO2and Al2O3, a combination of X zeolite and Y zeolite, or a combination of activated carbon and graphene, etc., but is not limited to the combinations listed above, and other combinations not listed above within the scope of the combinations described above are also applicable.

[0019] Preferably, the catalyst further comprises an additive supported on the carrier, and the additive comprises a metal element and / or an oxide of a metal element.

[0020] Preferably, the metal element comprises any one of or a combination of at least two of Ni, Fe, Co, La, or Ce, such as a combination of Ni and Fe, a combination of Co and La, or a combination of La and Ce, etc., but is not limited to the combinations listed above, and other combinations not listed above within the scope of the combinations described above are also applicable.

[0021] Preferably, the additive is any one of or a combination of at least two of Ni, Fe, Co, La2O3, CeO2, NiO, Ni2O3, FeO, Fe2O3, Fe3O4, CoO, Co2O3, Co3O4, preferably a combination of Ni and Co.

[0022] The selection of the specific additive described above can further improve the effect of the reaction and improve the yield of the product.

[0023] Preferably, the active component has a mass fraction of 0.1-10% of the total mass of the catalyst.

[0024] Preferably, the additive has a mass fraction of 0-10% of the total mass of the catalyst, and 0 indicates that the catalyst does not contain the additive.

[0025] Preferably, the mass ratio of the aromatic ring-containing carbamic acid ester to the catalyst is (30-100):0.1.

[0026] The active component can be 0.1%, 0.2%, 0.3%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10% or the like of the total mass of the catalyst, the auxiliary component can be 0.1%, 0.2%, 0.3%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10% or the like of the total mass of the catalyst, and the mass ratio of the aromatic ring-containing carbamic acid ester to the catalyst can be 30:0.1, 40:0.1, 50:0.1, 60:0.1, 70:0.1, 80:0.1, 90:0.1, or 100:0.1 or the like, but is not limited to the values listed above, and other values not listed within the above range are also applicable.

[0027] Preferably, the solvent includes any one of or a combination of at least two of methanol, water, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, tetrahydrofuran, dimethylformamide, dimethyl sulfoxide, 2-methyltetrahydrofuran, 1,4-dioxane, ethyl acetate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, methylcyclohexane, or cyclohexane, such as a combination of methanol and water, a combination of ethanol and n-propanol, or a combination of dimethyl carbonate and diethyl carbonate or the like, but is not limited to the combinations listed above, and other combinations not listed within the above range are also applicable, preferably any one of a combination of methanol and water, a combination of methanol and ethanol, a combination of ethanol and water, a combination of tetrahydrofuran and water, a combination of tetrahydrofuran and ethanol, or a combination of tetrahydrofuran and methanol, and further preferably a combination of ethanol and water.

[0028] The specific solvent described above can effectively improve the effect of the reaction, and the use of a preferred solvent combination can further improve the yield of the product.

[0029] Preferably, the aromatic ring-containing carbamic acid ester has the following general formula:

[0030]

[0031] wherein R1 is selected from a C6-C30 substituted or unsubstituted aromatic ring-containing hydrocarbon group, a substituted or unsubstituted aryl group, and the substituent of the substitution is selected from any one of a nitro group, a hydroxyl group, an alkylmercapto group, an arylmercapto group, a sulfonyl group, a carbonyl group, a halogen atom, a cyano group, an amino group, a carboxyl group, an ester group, an alkoxy group, or an aryloxy group, and the aryl group and the aromatic ring are independently selected from any one of a benzene ring, a biphenyl, a naphthalene, or a diphenylmethane.

[0032] n is an integer selected from 1 to 5, such as 1, 2, 3, 4, or 5.

[0033] R2 is selected from a C1-C8 straight chain or branched chain saturated hydrocarbon group or a C5-C10 saturated cyclic hydrocarbon group.

[0034] C6-C30 respectively means that the group contains six carbon atoms, seven carbon atoms, eight carbon atoms, nine carbon atoms, and so on, and the rest of C1-C8 and C5-C10 are the same.

[0035] Preferably, R2 is selected from any one of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, pentyl, hexyl, heptyl, octyl, isooctyl, 2-ethylhexyl, cyclopentyl or cyclohexyl.

[0036] It should be noted that, in terms of aromatic ring-containing hydrocarbyl group, as long as it contains 1 or more benzene rings in the hydrocarbyl group, it can also be bonded to aliphatic hydrocarbyl group, etc. In this case, the amino group in the aromatic ring-containing carbamic acid ester can be directly bonded to the aromatic hydrocarbon, or it can be bonded to the aliphatic hydrocarbyl group on the aromatic hydrocarbon, both of which are possible.

[0037] As an aromatic ring-containing carbamic acid ester, its structure can be cited as shown in formula I-IX (not limited to the examples cited):

[0038]

[0039]

[0040]

[0041] But not limited to the above listed compounds, wherein R2 has the same range of limitations as described above.

[0042] Preferably, the mass fraction of the aromatic ring-containing carbamic acid ester in the solvent is 0.5-30%, for example 0.5%, 1%, 3%, 6%, 9%, 12%, 15%, 18%, 21%, 24%, 27% or 30%, etc., but not limited to the above listed values, other values not listed in the above range are also applicable.

[0043] Preferably, the reaction is carried out in a reactor, which is any one of a fixed bed, a fluidized bed or a tank reactor.

[0044] Preferably, the reactor is a fixed bed or a fluidized bed, the temperature of the reaction is 0-180°C, the pressure of the reaction is 0.1-10 MPa, the molar ratio of hydrogen to aromatic ring-containing carbamic acid ester is (20-300): 1, and the liquid hourly space velocity of the aromatic ring-containing carbamic acid ester is 0.1-10 h -1 .

[0045] The reaction temperature can be 0℃, 20℃, 40℃, 60℃, 80℃, 100℃, 120℃, 140℃, 160℃, or 180℃, etc.; the reaction pressure can be 0.1MPa, 0.2MPa, 0.3MPa, 0.5MPa, 1MPa, 2MPa, 3MPa, 4MPa, 5MPa, 6MPa, 7MPa, 8MPa, 9MPa, or 10MPa, etc.; the molar ratio of hydrogen to aromatic cyclic carbamate can be 20:1, 40:1, 60:1, 80:1, 100:1, 120:1, 140:1, 160:1, 180:1, 200:1, 220:1, 240:1, 260:1, 280:1, or 300:1, etc.; and the liquid hourly space velocity (LHSV) of the aromatic cyclic carbamate can be 0.1 h⁻¹. -1 0.2h -1 0.3h -1 0.5h -1 1h -1 2h -1 3h -1 4h -1 5h -1 6h -1 7h -1 8h -1 9h -1 or 10h -1 The values ​​listed above, but not limited to those listed above, also apply to other unlisted values ​​within the range mentioned above.

[0046] Preferably, the reactor is a batch reactor, the reaction temperature is 0-180℃, and the reaction pressure is 0.1-10MPa.

[0047] The reaction temperature can be 0℃, 20℃, 40℃, 60℃, 80℃, 100℃, 120℃, 140℃, 160℃, or 180℃, etc., and the reaction pressure can be 0.1MPa, 0.2MPa, 0.3MPa, 0.5MPa, 1MPa, 2MPa, 3MPa, 4MPa, 5MPa, 6MPa, 7MPa, 8MPa, 9MPa, or 10MPa, etc., but is not limited to the values ​​listed above. Other unlisted values ​​within the above range are also applicable.

[0048] On the other hand, the present invention provides the application of the preparation method of the alicyclic urethane as described above in the preparation of polyurethane.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] The application provides a preparation method of alicyclic carbamic acid ester, which avoids problems of amine deamination condensation byproducts caused by direct hydrogenation of an amine containing an aromatic ring, and problems of catalyst deactivation caused by tar and loss of catalyst components; the alicyclic carbamic acid ester is an important intermediate for non-phosgene synthesis of ADI, and provides a green production process which is less toxic and safe for synthesis of ADI; meanwhile, the yield of the product can be effectively improved by selecting a specific catalyst; and the yield of the product is further improved by selecting a specific additive and a specific solvent. DETAILED DESCRIPTION

[0051] In order to further clarify the technical means adopted by the application and its effects, the technical solutions of the application will be further described below in combination with preferred embodiments of the application, but the application is not limited in the scope of the embodiments.

[0052] Example 1

[0053] The application provides a preparation method of alicyclic carbamic acid ester, which avoids problems of amine deamination condensation byproducts caused by direct hydrogenation of an amine containing an aromatic ring, and problems of catalyst deactivation caused by tar and loss of catalyst components; the alicyclic carbamic acid ester is an important intermediate for non-phosgene synthesis of ADI, and provides a green production process which is less toxic and safe for synthesis of ADI; meanwhile, the yield of the product can be effectively improved by selecting a specific catalyst; and the yield of the product is further improved by selecting a specific additive and a specific solvent.

[0054] 2g of 0.5% Pd-0.5% Ru-0.1% Co-0.1% Ni / Al2O3 is weighed and loaded into a fixed bed reactor with a length of 600 mm and an inner diameter of 10 mm; the reaction solvent is ethanol and water (volume ratio 1:1), the mass fraction of p-phenylenediamine dicarbamic acid ethyl ester (formula II) in the solvent is 5%, the reaction temperature is 30 DEG C, the reaction pressure is 2.0 MPa, the molar ratio of H2 to p-phenylenediamine dicarbamic acid ethyl ester is 100:1, and the liquid hourly space velocity of p-phenylenediamine dicarbamic acid ethyl ester is 0.2 h -1 ; after the reaction is stable, sampling analysis is conducted, the conversion rate of p-phenylenediamine dicarbamic acid ethyl ester is 99.5%, and the yield of 1,4-cyclohexyldiamino carbamic acid ethyl ester is 99.3%.

[0055] Example 2

[0056] The application provides a preparation method of alicyclic carbamic acid ester, which avoids problems of amine deamination condensation byproducts caused by direct hydrogenation of an amine containing an aromatic ring, and problems of catalyst deactivation caused by tar and loss of catalyst components; the alicyclic carbamic acid ester is an important intermediate for non-phosgene synthesis of ADI, and provides a green production process which is less toxic and safe for synthesis of ADI; meanwhile, the yield of the product can be effectively improved by selecting a specific catalyst; and the yield of the product is further improved by selecting a specific additive and a specific solvent.

[0057] 2g of 0.5% Pd-0.5% Ru-0.1% Co-0.1% Ni / Al2O3 is weighed and loaded into a fixed bed reactor with a length of 600 mm and an inner diameter of 10 mm; the reaction solvent is ethanol and water (volume ratio 1:1), the mass fraction of p-phenylenediamine dicarbamic acid ethyl ester (formula II) in the solvent is 5%, the reaction temperature is 30 DEG C, the reaction pressure is 2.0 MPa, the molar ratio of H2 to p-phenylenediamine dicarbamic acid ethyl ester is 100:1, and the liquid hourly space velocity of p-phenylenediamine dicarbamic acid ethyl ester is 0.2 h -1 ; after the reaction is stable, sampling analysis is conducted, the conversion rate of p-phenylenediamine dicarbamic acid ethyl ester is 99.5%, and the yield of 1,4-cyclohexyldiamino carbamic acid ethyl ester is 99.3%.

[0058] Example 3

[0059] The present example provides a preparation method of alicyclic carbamates, which specifically comprises the following steps:

[0060] 1% Ru / g-C3N4 2 g was weighed and loaded into a fixed bed reactor with a length of 600 mm and an inner diameter of 10 mm; the reaction solvent was tetrahydrofuran, the mass fraction of p-phenylenediamine carbamate (formula II) in the solvent was 10%, the reaction temperature was 160°C, the reaction pressure was 5.0 MPa, the molar ratio of H2 to p-phenylenediamine carbamate was 200:1, and the liquid hourly space velocity of p-phenylenediamine carbamate was 2.0 h-1. -1 After the reaction was stable, sampling analysis was performed, and the conversion rate of p-phenylenediamine carbamate was 99.3%, and the yield of 1,4-cyclohexyl diamino carbamate was 99.1%.

[0061] Example 4

[0062] The present example provides a preparation method of alicyclic carbamates, which specifically comprises the following steps:

[0063] 1% Ru / g-C3N4 0.6 g, 4-methylphenyl carbamate (formula IX) 12 g, and solvent methanol 228 g were weighed and put into a 500 mL stainless steel autoclave, the autoclave was replaced with nitrogen after the air in the autoclave was replaced with nitrogen, hydrogen was introduced, stirring was started, the reaction temperature was controlled at 60°C, the reaction pressure was 3.0 MPa, after 1 h of reaction, the reaction was stopped, sampling analysis was performed, the conversion rate of 4-methylphenyl carbamate was 99.6%, and the yield of 4-methylcyclohexyl diamino carbamate was 99.3%.

[0064] Example 5

[0065] The present example provides a preparation method of alicyclic carbamates, which is identical to example 1 except that the catalyst is replaced with an equal amount of 0.5% Pd-0.5% Ru / Al2O3.

[0066] The final conversion rate of p-phenylenediamine carbamate was 92.5%, and the yield of 1,4-cyclohexyl diamino carbamate was 90.3%.

[0067] Example 6

[0068] The present example provides a preparation method of alicyclic carbamates, which is identical to example 1 except that the catalyst is replaced with an equal amount of 0.5% Pd-0.5% Pt-0.1% Co-0.1% Ni / Al2O3.

[0069] The final conversion rate of p-phenylenediamine carbamate was 93.4%, and the yield of 1,4-cyclohexyl diamino carbamate was 90.5%.

[0070] Example 7

[0071] This example provides a method for preparing an alicyclic urethane, which is identical to that of Example 1 except that the catalyst is replaced with an equal amount of 0.5% Rh-0.5% Ru-0.1% Co-0.1% Ni / Al2O3.

[0072] The final ethyl carbamate conversion rate is 91.8%, and the 1,4-cyclohexyl ethyl carbamate yield is 90.3%.

[0073] Example 8

[0074] This example provides a method for preparing an alicyclic urethane, which is identical to that of Example 1 except that the catalyst is replaced with an equal amount of 0.5% Pd-0.5% Ru-0.1% Co-0.1% Fe / Al2O3.

[0075] The final ethyl carbamate conversion rate is 94.5%, and the 1,4-cyclohexyl ethyl carbamate yield is 93.6%.

[0076] Example 9

[0077] This example provides a method for preparing an alicyclic urethane, which is identical to that of Example 1 except that the catalyst is replaced with an equal amount of 0.5% Pd-0.5% Ru-0.2% CeO2 / Al2O3.

[0078] The final ethyl carbamate conversion rate is 95.5%, and the 1,4-cyclohexyl ethyl carbamate yield is 94.8%.

[0079] Example 10

[0080] This example provides a method for preparing an alicyclic urethane, which is identical to that of Example 1 except that the solvent is replaced with an equal amount of methanol.

[0081] The final ethyl carbamate conversion rate is 88.9%, and the 1,4-cyclohexyl ethyl carbamate yield is 88.3%.

[0082] Example 11

[0083] This example provides a method for preparing an alicyclic urethane, which is identical to that of Example 1 except that the solvent is replaced with an equal amount of a cyclohexane and methanol mixed solvent (volume ratio 1:1).

[0084] The final ethyl carbamate conversion rate is 93.5%, and the 1,4-cyclohexyl ethyl carbamate yield is 92.5%.

[0085] The above results show that the preparation method of the alicyclic urethane provided by the present application is suitable for various reactors, has high reaction conversion rate and high yield; it can be found from comparative examples 1, 5-11 that the present application further improves the reaction conversion rate and yield by using the combination of specific active components, additives and solvents.

[0086] The applicant declares that the preparation method of the alicyclic urethane of the present application and the application thereof are illustrated by the above examples, but the present application is not limited to the above examples, i.e. it does not mean that the present application must rely on the above examples to be implemented. It should be understood by those skilled in the art that any improvement of the present application, equivalent replacement of each raw material of the product of the present application, addition of auxiliary ingredients, selection of specific modes, etc. all fall within the protection scope and disclosure scope of the present application.

[0087] The preferred embodiments of the present application are described in detail above, but the present application is not limited to the specific details in the above embodiments, and within the technical concept scope of the present application, various simple modifications can be made to the technical solutions of the present application, and these simple modifications all belong to the protection scope of the present application.

[0088] In addition, it should be noted that each specific technical feature described in the above specific embodiments can be combined by any suitable method without contradiction, and in order to avoid unnecessary repetition, the present application will not further illustrate various possible combination methods.

Claims

1. A process for the preparation of an alicyclic urethane, characterized in that, The preparation method includes the following steps: mixing aromatic ring carbamate, catalyst and solvent, and then passing hydrogen gas through to react and obtain the alicyclic carbamate; The catalyst includes a support, an additive, and an active component supported on the support; The active component is selected from any one or a combination of at least two of Pt, Rh, Ru, Ir or Pd; The active component accounts for 0.1-1% of the total mass of the catalyst; The additive is any one or a combination of at least two of Ni, Fe, Co, Ce, La2O3, CeO2, NiO, Ni2O3, FeO, Fe2O3, Fe3O4, CoO, Co2O3, and Co3O4; The mass of the additive is 0.1-1% of the total mass of the catalyst; The solvent is a combination of ethanol and water.

2. The method of preparing an alicyclic urethane according to claim 1, characterized by, The active component is any one of the following combinations: Ru and Pd, Rh and Ru, Ru and Pt, Ru and Ir, Rh and Pt, Ir and Pt, Pd and Pt, or Ir and Pd.

3. The method of preparing an alicyclic urethane according to claim 2, characterized by, The active component is a combination of Ru and Pd.

4. The method of making an alicyclic urethane according to claim 1, wherein The carrier includes any one or a combination of at least two of the following: SiO2, Al2O3, ZrO2, TiO2, MgO, kaolin, bentonite, montmorillonite, ZSM-5, X-type zeolite, Y-type zeolite, B-type zeolite, mordenite, spinel, magnesium aluminum hydrotalcite, activated carbon, graphene, carbon nanotubes, g-C3N4, h-BN, or nitrogen-doped carbon composite materials.

5. The method for preparing alicyclic carbamate according to claim 1, characterized in that, The additive is a combination of Ni and Co.

6. The method for preparing alicyclic carbamate according to claim 1, characterized in that, The mass ratio of the aromatic cyclic carbamate to the catalyst is (30-100):0.

1.

7. The method for preparing alicyclic carbamate according to claim 1, characterized in that, The aromatic ring-containing carbamate has the following general formula: ； Wherein, R1 is selected from C6-C30 substituted or unsubstituted aromatic ring hydrocarbon groups, substituted or unsubstituted aryl groups, wherein the substituted substituents are selected from any one of nitro, hydroxyl, alkyl mercapto, aryl mercapto, sulfonyl, carbonyl, halogen atom, cyano, amino, carboxyl, ester, alkoxy or aryloxy, and the aryl group and aromatic ring are independently selected from any one of benzene ring, biphenyl, naphthalene or diphenylmethane; n is an integer selected from 1 to 5; R2 is selected from straight-chain or branched saturated hydrocarbon groups of C1-C8 or saturated cyclic hydrocarbon groups of C5-C10.

8. The method for preparing alicyclic carbamate according to claim 7, characterized in that, R2 is selected from any one of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, pentyl, hexyl, heptyl, octyl, isooctyl, 2-ethylhexyl, cyclopentyl, or cyclohexyl.

9. The method for preparing alicyclic carbamate according to claim 1, characterized in that, The aromatic ring carbamate has a mass fraction of 0.5-30% in the solvent.

10. The method for preparing alicyclic carbamate according to claim 1, characterized in that, The reaction is carried out in a reactor, which is any one of a fixed bed, fluidized bed, or batch reactor.

11. The method for preparing the alicyclic carbamate according to claim 10, characterized in that, The reactor is a fixed bed or a fluidized bed, the reaction temperature is 0-180℃, the reaction pressure is 0.1-10 MPa, the molar ratio of hydrogen to aromatic amino formate is (20-300):1, the liquid hourly space velocity of aromatic amino formate is 0.1-10 h -1 .

12. The method for preparing alicyclic carbamate according to claim 10, characterized in that, The reactor is a batch reactor, and the reaction temperature is 0-180℃, and the reaction pressure is 0.1-10 MPa.

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