Hydrogenation catalyst as well as preparation method and application thereof

Abstract

The invention relates to the field of catalysts, in particular to a hydrogenation catalyst and a preparation method and application thereof. The hydrogenation catalyst comprises copper, an auxiliary metal element and a carrier, copper grain particles with the size of 2-10 nm account for more than or equal to 80% of the total copper grain particles, and the average grain size of copper is 4-7 nm. According to the catalyst, copper grain particles with the size of 2-10 nm account for more than or equal to 80% of the total copper grain particles, the average grain size of copper is 4-7 nm, and the catalyst has high catalytic activity.

Description

Technical Field

[0001] This invention relates to the field of catalysts, specifically to a hydrogenation catalyst, its preparation method, and its application. Background Technology

[0002] Isopropanol is a high-grade bactericide and disinfectant used in medicine. Compared to ethanol, it is less irritating to the skin. Isopropanol is also used to produce acetone, among other things. Simultaneously, isopropanol is an important organic solvent, used as a suspension or dispersion in cosmetics, and as a processing solvent for plastics and resins.

[0003] Currently, the main methods for producing isopropanol are propylene hydration and acetone hydrogenation. Among these, acetone hydrogenation is more advantageous in terms of investment, environmental protection, and operating costs, representing the future direction of industrial development. Existing catalysts for the hydrogenation of acetone to isopropanol include Ni catalysts, Ru / C catalysts, Ru / Al₂O₃ catalysts, and copper catalysts. Acetone hydrogenation on these catalysts generally employs a fixed-bed reactor. Acetone and hydrogen enter the catalyst bed in a specific ratio under liquid or gas phase conditions, and hydrogenation is carried out at appropriate temperature and pressure to produce isopropanol. However, the use of existing acetone hydrogenation catalysts suffers from low acetone conversion and low isopropanol selectivity, resulting in a relatively low isopropanol yield. Summary of the Invention

[0004] The purpose of this invention is to overcome the problems of low conversion rate of ketone compounds and low alcohol yield in the prior art, and to provide a hydrogenation catalyst, its preparation method and application, which has the advantages of high conversion rate of ketone compounds and high alcohol yield.

[0005] To achieve the above objectives, the first aspect of the present invention provides a hydrogenation catalyst comprising copper, an auxiliary metal element, and a support, wherein copper grains with a size of 2-10 nm account for ≥80% of the total copper grains, and the average grain size of copper is 4-7 nm.

[0006] The second aspect of the present invention provides a method for preparing the hydrogenation catalyst described in the first aspect, the method comprising the following steps: (1) contacting a solution containing a copper complex and an auxiliary metal complex with a support to obtain a catalyst precursor; (2) subjecting the catalyst precursor to hydrothermal treatment, drying, and calcination; wherein the ligands of the copper complex and the auxiliary metal complex are each independently selected from organic amine ligands and / or inorganic ammonia ligands.

[0007] A third aspect of the present invention provides the application of the hydrogenation catalyst described in the first aspect in the hydrogenation of ketone compounds to prepare alcohol compounds.

[0008] Through the above technical solution, the present invention has the following advantages:

[0009] In the catalyst of this invention, copper crystal particles with a size of 2-10 nm account for ≥80% of the total copper crystal particles, and the average copper crystal size is 4-7 nm, exhibiting high catalytic activity.

[0010] The preparation method of this invention combines complexation impregnation and hydrothermal methods to prepare catalysts with the characteristics of this invention.

[0011] Applying the hydrogenation catalyst described in this invention to the hydrogenation of ketone compounds to prepare alcohols significantly improves the conversion rate of ketone compounds and the yield of alcohols. Attached Figure Description

[0012] Figure 1 This is a Cu particle size distribution diagram of catalyst C1;

[0013] Figure 2 This is a TEM image of catalyst C1. Detailed Implementation

[0014] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0015] The present invention provides a hydrogenation catalyst comprising copper, an auxiliary metal element and a support, wherein copper grains with a size of 2-10 nm account for ≥80% of the total copper grains, and the average copper grain size is 4-7 nm.

[0016] In the catalyst of this invention, copper crystal particles with a size of 2-10 nm account for ≥80% of the total copper crystal particles, and the average copper crystal size is 4-7 nm, exhibiting high catalytic activity.

[0017] According to a preferred embodiment of the present invention, the proportion of copper grain particles with a size of 2-10 nm to the total number of copper grain particles is ≥85%, more preferably ≥90%, for example, 90%, 95%, or 98%, and preferably the remaining copper grain particles have a size of 0-2 nm and / or 10-30 nm.

[0018] According to a preferred embodiment of the present invention, the average grain size of the copper is 4-6 nm, for example, it can be 5 nm or 6 nm.

[0019] In this invention, the auxiliary metal is a transition metal. According to a preferred embodiment of the invention, the auxiliary metal is at least one selected from titanium, manganese, iron, cobalt, nickel, zinc, zirconium, molybdenum, lanthanum and cerium, preferably zinc and / or nickel.

[0020] In this invention, there are no special requirements for the type of carrier. This is an illustrative example and does not limit the scope of the invention. For example, the carrier is selected from at least one of silicon dioxide, alumina, and zirconium oxide.

[0021] In this invention, as long as the purpose of this invention can be achieved, there are no special requirements for the content of each component in the catalyst. This is an illustrative example, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the hydrogenation catalyst comprises, by weight and by oxide, 5-50 parts of copper, 0.05-60 parts of auxiliary metal element, and 5-90 parts of support.

[0022] According to a preferred embodiment of the present invention, the hydrogenation catalyst comprises, by weight and by oxide, 5-30 parts of copper, 0.1-10 parts of auxiliary metal element, and 60-90 parts of support.

[0023] According to a preferred embodiment of the present invention, the hydrogenation catalyst comprises, by weight and by oxide, 10-25 parts of copper, 0.4-5 parts of auxiliary metal element, and 70-89.6 parts of support.

[0024] The hydrogenation catalyst products that meet the foregoing requirements of this invention can all achieve the desired purpose, and there are no special requirements for their preparation methods. The following is an illustrative description, but it does not limit the scope of this invention. This invention provides a method for preparing the aforementioned hydrogenation catalyst, which includes the following steps:

[0025] (1) A solution containing copper complex and auxiliary metal complex is contacted with a support to obtain a catalyst precursor; (2) The catalyst precursor is subjected to hydrothermal treatment, drying and calcination; wherein the ligands of the copper complex and auxiliary metal complex are each independently selected from organic amine ligands and / or inorganic amine ligands.

[0026] In the case of copper complex and auxiliary metal complex, as long as the copper and auxiliary metal are fully complexed with the organic ligand to form a complex, there are no special requirements for the specific preparation method. Generally, simple mixing and dissolution are sufficient, and temperature control and dynamic mixing conditions can be arbitrarily selected.

[0027] The preparation method of this invention combines complexation impregnation and hydrothermal methods to prepare catalysts with the characteristics of this invention.

[0028] According to a preferred embodiment of the present invention, the organic amine ligand is selected from fatty amines and / or quaternary ammonium bases.

[0029] According to a preferred embodiment of the present invention, the fatty amine is a polyamine and / or an alcoholic amine, preferably a polyamine, wherein the alcoholic amine may be, for example, ethanolamine, and the polyamine is a C2-C6 polyamine.

[0030] According to a preferred embodiment of the present invention, the quaternary ammonium base is a tetra-C1-C3 alkyl ammonium hydroxide.

[0031] According to a preferred embodiment of the present invention, the organic amine ligand is at least one selected from triethylamine, ethylenediamine, tetramethylammonium hydroxide, and tetraethylammonium hydroxide.

[0032] According to a preferred embodiment of the present invention, the inorganic amine ligand is selected from ammonia and / or urea.

[0033] According to a preferred embodiment of the present invention, the solvent in the solution is at least one of water, alcohol and ketone, wherein the alcohol is a C2-C5 alcohol and the ketone is a C2-C5 ketone.

[0034] According to a preferred embodiment of the present invention, the solvent in the solution is a mixed solvent with an alcohol-ketone mass ratio of 0.25-4, for example, a mixed solvent with an alcohol-ketone mass ratio of 0.5, 1.0, 2, 2.5, 3, 3.5, and 4.

[0035] In this invention, there are no special requirements for the contact conditions. According to a preferred embodiment of the invention, the contact conditions include: a temperature of 20-80°C, a solution concentration of 4-20 wt% based on the weight of Cu in the solution, and a contact time adjusted according to the contact temperature.

[0036] In this invention, there are no special requirements for the contact method. According to a preferred embodiment of the invention, the contact method is immersion, preferably equal volume immersion.

[0037] In this invention, the objective of the invention can be achieved as long as hydrothermal treatment is performed. The range of selectable conditions for hydrothermal treatment is relatively wide. The following is an illustrative description, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the conditions for hydrothermal treatment include: a temperature of 100-300°C, and a heat treatment time adjusted according to the heat treatment temperature, for example, a time of 5-48 hours.

[0038] In this invention, the roasting conditions can be conventional choices in the art. For example, the roasting conditions include a temperature of 300-800℃ and a roasting time adjusted according to the hot roasting temperature.

[0039] This invention provides the application of the hydrogenation catalyst described above in the hydrogenation of ketone compounds to prepare alcohol compounds, wherein the ketone compound is preferably acetone.

[0040] The present invention will be described in detail below through examples. Unless otherwise specified, the raw materials are all commercially available products; conversion rate and selectivity were measured by conventional methods in the art.

[0041] Example 1

[0042] 9.3 g of copper nitrate trihydrate and 2.3 g of zinc nitrate hexahydrate were dissolved in 10 g of water with 7.0 g of ethylenediamine. An equal volume of this solution was then impregnated onto 10 g of silica support. The mixture was placed in a hydrothermal reactor and hydrothermally treated at 120 °C for 15 h. After treatment, it was dried at 110 °C for 10 h and calcined at 500 °C for 4 h. This mixture is designated as catalyst C1. TEM analysis showed that C1 contained... Figure 1-2 As shown, copper grains with a size of 2-10 nm account for 93.5% of the total copper grains, and the average copper grain size is 4.8 nm.

[0043] Catalyst C1 was used at an inlet temperature of 120℃, a reaction pressure of 6.0 MPa, and an acetone space velocity of 0.8 h⁻¹. -1 Under the given conditions, the acetone conversion rate was 99.0%, and the isopropanol selectivity was 98.7%.

[0044] Example 2

[0045] 9.3 g of copper nitrate trihydrate and 0.23 g of zinc nitrate hexahydrate were dissolved in 10 g of water with 7.0 g of ethylenediamine. An equal volume of this solution was then impregnated onto 10 g of silica support. The mixture was placed in a hydrothermal reactor and hydrothermally treated at 120 °C for 15 h. After treatment, it was dried at 110 °C for 10 h and calcined at 500 °C for 4 h. This mixture was designated as catalyst C2. TEM analysis showed that copper grains with a size of 2-10 nm accounted for 94.3% of the total copper grains in C2, with an average copper grain size of 4.2 nm.

[0046] Catalyst C2 was used at an inlet temperature of 120℃, a reaction pressure of 6.0 MPa, and an acetone space velocity of 0.8 h⁻¹. -1 Under the given conditions, the acetone conversion rate was 98.8%, and the isopropanol selectivity was 99.3%.

[0047] Example 3

[0048] 3.9 g of copper nitrate trihydrate and 0.23 g of zinc nitrate hexahydrate were dissolved in 10 g of water along with 7.0 g of ethylenediamine. An equal volume of this solution was then impregnated onto 10 g of silica support. The mixture was placed in a hydrothermal reactor and hydrothermally treated at 120 °C for 15 h. After treatment, it was dried at 110 °C for 10 h and calcined at 500 °C for 4 h. This mixture was designated as catalyst C3. TEM analysis showed that 95% of the copper grains in C3 had a size between 2 and 10 nm, with an average copper grain size of 4.3 nm.

[0049] Catalyst C3 was used at an inlet temperature of 120℃, a reaction pressure of 6.0 MPa, and an acetone space velocity of 0.8 h⁻¹. -1 Under the given conditions, the acetone conversion rate was 98.2%, and the isopropanol selectivity was 99.4%.

[0050] Example 4

[0051] 9.3 g of copper nitrate trihydrate and 2.3 g of zinc nitrate hexahydrate were dissolved in 10 g of water with 7.0 g of ethanolamine. An equal volume of this solution was then impregnated onto 10 g of silica support. The mixture was placed in a hydrothermal reactor and hydrothermally treated at 120 °C for 15 h. After treatment, it was dried at 110 °C for 10 h and calcined at 500 °C for 4 h. This mixture was designated as catalyst C4. TEM analysis showed that copper grains with a size of 2-10 nm accounted for 89.5% of the total copper grains in C4, with an average copper grain size of 5.7 nm.

[0052] Catalyst C4 was used at an inlet temperature of 120℃, a reaction pressure of 6.0 MPa, and an acetone space velocity of 0.8 h⁻¹. -1 Under the given conditions, the acetone conversion rate was 98.1%, and the isopropanol selectivity was 97.8%.

[0053] Example 5

[0054] 9.3 g of copper nitrate trihydrate and 2.3 g of zinc nitrate hexahydrate were dissolved in 10 g of water with 7.0 g of ethanolamine. An equal volume of this solution was then impregnated onto 10 g of silica support. The mixture was placed in a hydrothermal reactor and hydrothermally treated at 80 °C for 15 h. After treatment, it was dried at 110 °C for 10 h and calcined at 500 °C for 4 h. This was designated as catalyst C5. TEM analysis showed that in C5, copper grains with a size of 2-10 nm accounted for 87.5% of the total copper grains, with an average copper grain size of 6.8 nm.

[0055] Catalyst C5 was used at an inlet temperature of 120℃, a reaction pressure of 6.0 MPa, and an acetone space velocity of 0.8 h⁻¹. -1 Under the given conditions, the acetone conversion rate was 97.8%, and the isopropanol selectivity was 98.2%.

[0056] Example 6

[0057] 9.3 g of copper nitrate trihydrate and 6.9 g of zinc nitrate hexahydrate were dissolved in 10 g of water with 7.0 g of ethylenediamine. An equal volume of this solution was then impregnated onto 10 g of silica support. The mixture was placed in a hydrothermal reactor and hydrothermally treated at 120 °C for 15 h. After treatment, it was dried at 110 °C for 10 h and calcined at 500 °C for 4 h. This was designated as catalyst C6. TEM analysis showed that in C6, copper grains with a size of 2-10 nm accounted for 93.4% of the total copper grains, with an average copper grain size of 4.5 nm.

[0058] Catalyst C6 was used at an inlet temperature of 120℃, a reaction pressure of 6.0 MPa, and an acetone space velocity of 0.8 h⁻¹. -1 Under the given conditions, the acetone conversion rate was 98.0%, and the isopropanol selectivity was 97.7%.

[0059] Example 7

[0060] 9.3 g of copper nitrate trihydrate and 0.23 g of nickel nitrate hexahydrate were dissolved in 10 g of water with 7.0 g of ethylenediamine. An equal volume of this solution was then impregnated onto 10 g of silica support. The mixture was placed in a hydrothermal reactor and hydrothermally treated at 120 °C for 15 h. After treatment, it was dried at 110 °C for 10 h and calcined at 500 °C for 4 h. This was designated as catalyst C7. TEM analysis showed that in C7, copper grains with a size of 2-10 nm accounted for 95.6% of the total copper grains, with an average copper grain size of 4.3 nm.

[0061] Catalyst C7 was used at an inlet temperature of 120℃, a reaction pressure of 6.0 MPa, and an acetone space velocity of 0.8 h⁻¹. -1 Under the given conditions, the acetone conversion rate was 99.2%, and the isopropanol selectivity was 98.9%.

[0062] Example 8

[0063] 9.3 g of copper nitrate trihydrate and 0.23 g of zinc nitrate hexahydrate were dissolved in 7.0 g of ammonia in 10 g of water, and an equal volume of this solution was impregnated onto 10 g of silica support. The mixture was placed in a hydrothermal reactor and hydrothermally treated at 120 °C for 15 h. After treatment, it was dried at 110 °C for 10 h and calcined at 500 °C for 4 h. This was designated as catalyst C8. TEM analysis showed that in C8, copper grains with a size of 2-10 nm accounted for 90.2% of the total copper grains, with an average copper grain size of 5.3 nm.

[0064] Catalyst C8 was used at an inlet temperature of 120℃, a reaction pressure of 6.0 MPa, and an acetone space velocity of 0.8 h⁻¹. -1 Under the given conditions, the acetone conversion rate was 97.8%, and the isopropanol selectivity was 99.3%.

[0065] Example 9

[0066] Same as Example 1, except that 9.3g of copper nitrate trihydrate and 2.3g of zinc nitrate hexahydrate, along with 7.0g of ethylenediamine, were dissolved in a mixed solvent of 10g of ethanol / acetone with a mass ratio of 1.0.

[0067] TEM analysis showed that copper crystal particles with a size of 2-10 nm accounted for 97.5% of the total copper crystal particles, with an average crystal size of 5.1 nm.

[0068] Catalyst C1 was used at an inlet temperature of 120℃, a reaction pressure of 6.0 MPa, and an acetone space velocity of 0.8 h⁻¹. -1Under the given conditions, the acetone conversion rate was 99.5%, and the isopropanol selectivity was 99.7%.

[0069] Comparative Example 1

[0070] Solution A consists of 9.3 g of copper nitrate hexahydrate and 2.3 g of zinc nitrate hexahydrate dissolved in 100 mL of water, and solution B consists of 2.4 g of NaOH dissolved in 100 mL of water. Solutions A and B are added dropwise in a silica support and 50 mL of water under slurry conditions. The resulting catalyst is filtered, washed, dried at 110 °C for 10 h, and calcined at 500 °C for 4 h. This catalyst is designated as catalyst DC1. TEM analysis shows that in DC1, copper grains with a size of 2-10 nm account for 73.1% of the total copper grains, with an average copper grain size of 9.5 nm.

[0071] Catalyst DC1 was used at an inlet temperature of 120℃, a reaction pressure of 6.0 MPa, and an acetone space velocity of 0.8 h⁻¹. -1 Under the given conditions, the acetone conversion rate was 95.0%, and the isopropanol selectivity was 97.5%.

[0072] Comparative Example 2

[0073] 9.3 g of copper nitrate trihydrate and 2.3 g of zinc nitrate hexahydrate were dissolved in 80 g of water, and ammonia was added to adjust the pH to 11.0 to prepare a copper ammonia solution. 10 g of SiO2 support was added to the solution, and ammonia was removed at 90 °C. Heating was stopped when the pH reached 5. The resulting solid was filtered, washed, dried at 110 °C for 4 h, and then calcined at 500 °C for 4 h to obtain catalyst DC2. TEM analysis showed that copper grains with a size of 2-10 nm accounted for 90.2% of the total copper grains in DC2, with an average copper grain size of 3.5 nm.

[0074] Catalyst DC2 was used at an inlet temperature of 120℃, a reaction pressure of 6.0 MPa, and an acetone space velocity of 0.8 h⁻¹. -1 Under the given conditions, the acetone conversion rate was 97.0%, and the isopropanol selectivity was 96.7%.

[0075] Comparative Example 3

[0076] 9.3 g of copper nitrate trihydrate and 2.3 g of zinc nitrate hexahydrate were dissolved in 10 g of water along with 7.0 g of ethylenediamine. An equal volume of this solution was then impregnated onto 10 g of silica support. The mixture was dried at 110 °C for 10 h and calcined at 500 °C for 4 h. This mixture was designated as catalyst DC3. TEM analysis showed that copper grains with a size of 2-10 nm accounted for 78.5% of the total copper grains in DC3, with an average copper grain size of 4.3 nm.

[0077] Catalyst DC3 was used at an inlet temperature of 120℃, a reaction pressure of 6.0 MPa, and an acetone space velocity of 0.8 h⁻¹. -1Under the given conditions, the acetone conversion rate was 97.5%, and the isopropanol selectivity was 95.7%.

[0078] Comparative Example 4

[0079] 9.3 g of copper nitrate trihydrate and 2.3 g of zinc nitrate hexahydrate were dissolved in 7.0 g of ethylene glycol in 10 g of water, and an equal volume of this solution was impregnated onto 10 g of silica support. The mixture was placed in a hydrothermal reactor and hydrothermally treated at 120 °C for 15 h. After treatment, it was dried at 110 °C for 10 h and calcined at 500 °C for 4 h. This mixture was designated as catalyst DC4. TEM analysis showed that copper grains with a size of 2-10 nm accounted for 78.1% of the total copper grains in DC4, with an average copper grain size of 9.0 nm.

[0080] Catalyst DC4 was used at an inlet temperature of 120℃, a reaction pressure of 6.0 MPa, and an acetone space velocity of 0.8 h⁻¹. -1 Under the given conditions, the acetone conversion rate was 96.0%, and the isopropanol selectivity was 97.3%.

[0081] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A hydrogenation catalyst, characterized in that, The hydrogenation catalyst comprises copper, auxiliary metal elements, and a support, wherein copper grains with a size of 2-10 nm account for ≥80% of the total copper grains, and the average copper grain size is 4-7 nm.

2. The hydrogenation catalyst according to claim 1, wherein, The proportion of copper grains with a size of 2-10 nm to the total number of copper grains is ≥85%; preferably ≥90%, more preferably 90-98%; and / or The average grain size of copper is 4-6 nm.

3. The hydrogenation catalyst according to claim 1 or 2, wherein, The auxiliary metal is a transition metal, preferably at least one of titanium, manganese, iron, cobalt, nickel, zinc, zirconium, molybdenum, lanthanum and cerium, more preferably zinc and / or nickel.

4. The hydrogenation catalyst according to any one of claims 1-3, wherein, The carrier is selected from at least one of silicon dioxide, aluminum oxide, and zirconium oxide.

5. The hydrogenation catalyst according to any one of claims 1-4, wherein, On a weight basis, on an oxide basis, The hydrogenation catalyst comprises: 5-50 parts of copper, 0.05-60 parts of auxiliary metal element, and 5-90 parts of support; Preferably, the hydrogenation catalyst comprises: 5-30 parts of copper, 0.1-10 parts of auxiliary metal element, and 60-90 parts of support.

6. A method for preparing the hydrogenation catalyst according to any one of claims 1-5, characterized in that, The method includes the following steps: (1) A solution containing copper complex and auxiliary metal complex is contacted with a support to obtain a catalyst precursor; (2) The catalyst precursor is subjected to hydrothermal treatment, drying and calcination; The ligands of the copper complex and the auxiliary metal complex are each independently selected from organic amine ligands and / or inorganic amine ligands.

7. The preparation method according to claim 6, wherein, The organic amine ligand is selected from aliphatic amines and / or quaternary ammonium bases. Preferably, the aliphatic amine is a polyamine and / or an alcohol amine, and the quaternary ammonium base is a tetra-C1-C3 alkyl ammonium hydroxide. More preferably, the aliphatic amine is a polyamine. More preferably, the organic amine ligand is at least one selected from triethylamine, ethylenediamine, tetramethylammonium hydroxide, and tetraethylammonium hydroxide; and / or The inorganic amine ligand is selected from ammonia and / or urea.

8. The preparation method according to claim 6 or 7, wherein, The solvent in the solution is at least one of water, alcohol and ketone, preferably a mixed solvent with an alcohol-ketone mass ratio of 0.25-4.

9. The preparation method according to any one of claims 6-8, wherein, The contact conditions include: a temperature of 20-80°C, a solution concentration of 4-20 wt% based on the weight of Cu in the solution; and / or The conditions for the hydrothermal treatment include: a temperature of 100-300℃ and a time of 5-48 hours; and / or The roasting conditions include a temperature of 300-800℃.

10. The application of the hydrogenation catalyst according to any one of claims 1-6 in the hydrogenation of ketone compounds to prepare alcohol compounds, wherein the ketone compound is preferably acetone.

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