A catalyst, its preparation and use

Abstract

The present application relates to a kind of catalyst and its preparation method and application, belong to catalytic field.The catalyst includes metal-based active component and surface metal oxide active component;The metal-based active component includes at least one of nickel-based catalyst or cobalt-based catalyst;The surface metal oxide active component includes at least one of tungsten oxide or molybdenum oxide deposited on the surface of metal-based active component.The catalyst can be used for the preparation of multistage amine, and its operation is simple.The catalyst has high activity, high safety, high selectivity and good stability for reduction amination reaction, can be repeatedly used, is conducive to improving the quality and quality stability of product, reduces process cost, modification cost is low, is conducive to large-scale production.

Description

Technical Field

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

[0002] Organic amine ligands, especially multi-level amine skeleton molecules, are widely used in chemistry, biology, energy, materials, and the environment, particularly in medicine, as high-value-added chemical products. In 2018, 80% of the world's top 200 best-selling drugs contained amines, and research shows that these amine groups play a crucial role in the activity of drug molecules. The preparation and functionalization of these amine compounds typically involve nitro reduction, cyano reduction, and hydroammoniation reactions. However, biomass is not rich in nitro and cyano compounds, which means that the preparation of these substrates requires significant energy consumption. Furthermore, the preparation of nitro compounds often requires nitric acid oxidation, leading to unnecessary pollution. Hydroammoniation reactions require high temperatures and pressures, further increasing energy consumption. Therefore, developing more methods for constructing organic amine ligands, especially multi-level amine skeleton molecules, is crucial to meet the ever-increasing societal demand for chemical products.

[0003] In recent years, the one-step reductive amination of aldehydes / ketones with organic amine molecules to prepare functionalized multi-level amine framework molecules has attracted widespread attention as a green, environmentally friendly, and inexpensive strategy. Among the catalysts for this type of reaction, inexpensive transition metal nickel or cobalt-based catalysts have received considerable attention due to their unique reductive amination catalytic performance and sustainable development. In 2017, Beller, M. et al. reported in Science that a metal Co-MOF catalyst could catalyze the reductive amination of aldehydes with organic amine ligands, successfully achieving the synthesis of a series of organic amine drug molecules. Subsequently, in 2020, Beller, M. et al. again reported in Nature Protocols that Co / C can effectively realize the reductive amination of aldehydes with organic amine molecules to prepare a series of multi-level amine framework ligands.

[0004] While the aforementioned catalysts are applicable to various substrates, the catalytic conditions are quite demanding (120℃, 4MPa), and a large amount of catalyst is used in the catalytic process (TON 28.6, reaction time 24 hours, yield approximately 85%). This results in long reaction times, unsatisfactory yields, and low catalytic efficiency. Furthermore, both nickel-based and cobalt-based catalysts are susceptible to oxidation upon exposure to air, forming a dense oxide layer that leads to loss of activity.

[0005] Therefore, there is an urgent need for a catalyst that is simple to operate, has high catalytic activity, high safety, high selectivity, good stability, and can be reused multiple times. Summary of the Invention

[0006] To address the above problems, this invention provides a catalyst, its preparation method, and its application.

[0007] In a first aspect, the present invention provides a catalyst.

[0008] A catalyst includes a metal-based active component and a surface metal oxide active component; the metal-based active component includes at least one of a nickel-based catalyst or a cobalt-based catalyst; the surface metal oxide active component is at least one of a tungsten oxide or a molybdenum oxide, and the surface metal oxide active component is deposited on the surface of the metal-based active component.

[0009] In some embodiments, the 4f orbital binding energy of tungsten in the tungsten oxide is between 30 eV and 42 eV.

[0010] In some embodiments, the 3d binding energy of the molybdenum element is between 228 eV and 239 eV.

[0011] In some embodiments, the deposition includes liquid phase deposition, solid phase deposition, or gas phase deposition.

[0012] In some embodiments, the catalyst further includes a support.

[0013] In some embodiments, the carrier includes one of activated carbon, aluminum oxide (Al2O3), titanium dioxide (TiO2), cerium dioxide (ZrO2), cerium dioxide (CeO2), ferric oxide (Fe2O3), and silicon dioxide (SiO2).

[0014] In some embodiments, the nickel-based catalyst includes at least one of Raney nickel catalyst, nickel powder, nickel nanoparticles, and supported nickel-based catalyst.

[0015] In some embodiments, the supported nickel-based catalyst includes at least one of carbon-supported nickel catalyst, aluminum oxide-supported nickel catalyst, titanium dioxide-supported nickel catalyst, zirconium dioxide-supported nickel catalyst, cerium dioxide-supported nickel catalyst, ferric oxide-supported nickel catalyst, and silicon dioxide-supported nickel catalyst.

[0016] In some embodiments, the cobalt-based catalyst includes at least one of Raney cobalt catalyst, cobalt powder, cobalt nanoparticles, and supported cobalt-based catalyst.

[0017] In some embodiments, the supported nickel-based catalyst includes at least one of carbon-supported cobalt catalyst, aluminum oxide-supported cobalt catalyst, titanium dioxide-supported cobalt catalyst, zirconium dioxide-supported cobalt catalyst, cerium dioxide-supported cobalt catalyst, ferric oxide-supported cobalt catalyst, and silicon dioxide-supported cobalt catalyst.

[0018] In some embodiments, the mass ratio of metal atoms in the metal-based active component to the surface metal oxide active component is 1.000:0.001-1.000:1.000.

[0019] In some embodiments, the metal-based active component is a supported nickel-based catalyst or a supported cobalt-based catalyst; the mass ratio of metal atoms to the surface metal oxide active component in the metal-based active component is 1.0:0.1-1.0:0.4. In some embodiments, the metal-based active component is a supported nickel-based catalyst or a supported cobalt-based catalyst; the mass ratio of metal atoms to the surface metal oxide active component in the metal-based active component is 1.0:0.2-1.0:0.4. In some embodiments, the metal-based active component is a supported nickel-based catalyst or a supported cobalt-based catalyst; the mass ratio of metal atoms to the surface metal oxide active component in the metal-based active component is 1.0:0.2-1.0:0.3.

[0020] In some embodiments, the metal-based active component is at least one of Raney nickel catalyst, nickel powder, nickel nanoparticles, cobalt nanoparticles, Raney cobalt catalyst, or cobalt powder, and the catalyst further includes a support; the mass ratio of metal atoms to the surface metal oxide active component in the metal-based active component is 1.0:0.1-1.0:0.4. In some embodiments, the metal-based active component is at least one of Raney nickel catalyst, nickel powder, nickel nanoparticles, cobalt nanoparticles, Raney cobalt catalyst, or cobalt powder, and the catalyst further includes a support; the mass ratio of metal atoms to the surface metal oxide active component in the metal-based active component is 1.0:0.2-1.0:0.4. In some embodiments, the metal-based active component is at least one of Raney nickel catalyst, nickel powder, nickel nanoparticles, cobalt nanoparticles, Raney cobalt catalyst, or cobalt powder, and the catalyst further includes a support; the mass ratio of metal atoms to the surface metal oxide active component in the metal-based active component is 1.0:0.2-1.0:0.3. In some embodiments, the metal-based active component is at least one of Raney nickel catalyst, nickel powder, nickel nanoparticles, cobalt nanoparticles, Raney cobalt catalyst, or cobalt powder, and the catalyst further includes a support; the mass ratio of metal atoms in the metal-based active component to the surface metal oxide active component is 1.0:0.1, 1.0:0.2, 1.0:0.3, or 1.0:0.4.

[0021] In some embodiments, the metal-based active component is at least one selected from Raney nickel catalyst, nickel powder, nickel nanoparticles, cobalt nanoparticles, Raney cobalt catalyst, or cobalt powder; the mass ratio of metal atoms in the metal-based active component to the surface metal oxide active component is 1.000:0.025-1.000:0.100. In some embodiments, the metal-based active component is at least one selected from Raney nickel catalyst, nickel powder, nickel nanoparticles, cobalt nanoparticles, Raney cobalt catalyst, or cobalt powder; the mass ratio of metal atoms in the metal-based active component to the surface metal oxide active component is 1.000:0.050-1.000:0.075. In some embodiments, the metal-based active component is at least one of Raney nickel catalyst, nickel powder, nickel nanoparticles, cobalt nanoparticles, Raney cobalt catalyst, or cobalt powder; the mass ratio of metal atoms in the metal-based active component to the surface metal oxide active component is 1.000:0.025, 1.000:0.050, 1.000:0.075, or 1.000:0.100.

[0022] In some embodiments, the preparation method of the supported nickel-based catalyst includes: dissolving nickel nitrate or its hydrate in ethanol to obtain a nickel nitrate solution, then mixing the support with ethanol, mixing with the nickel nitrate solution, stirring, drying, and calcining under a hydrogen-argon mixed gas atmosphere to obtain the supported nickel-based catalyst.

[0023] In some embodiments, the volume percentage of hydrogen in the hydrogen-argon mixture during the preparation method of the supported nickel-based catalyst is 5%-100%.

[0024] In a second aspect, the present invention provides a method for preparing the catalyst described in the first aspect.

[0025] A method for preparing the catalyst described in the first aspect comprises: mixing a tungsten oxide cluster or a molybdenum oxide cluster with water to obtain a surface metal oxide active component solution; then impregnating a metal-based active component in the surface metal oxide active component solution; and reacting the solution at a certain temperature under a hydrogen atmosphere to obtain the catalyst.

[0026] In some embodiments, the specific temperature is 80℃-120℃.

[0027] In some embodiments, the reaction time at a certain temperature is 1 hour to 12 hours. In some embodiments, the reaction time at a certain temperature is 2 hours to 12 hours.

[0028] In some embodiments, the molar ratio of metal atoms to tungsten oxide clusters or molybdenum oxide clusters in the metal-based active component is 1.0:0.1-1.0:4.0.

[0029] In some embodiments, the tungsten oxide cluster includes at least one of ammonium metatungstate, silicotungstic acid, phosphotungstic acid, and sodium tungstate.

[0030] In some embodiments, the molybdenum oxide cluster includes at least one of ammonium molybdate, molybdic acid silicomolybdate, phosphomolybdic acid, and sodium molybdate.

[0031] In some embodiments, the molar ratio of metal atoms to tungsten oxide clusters or molybdenum oxide clusters in the metal-based active component is 1.000:0.001-1.000:1.000.

[0032] In some embodiments, the metal-based active component is a supported nickel-based catalyst or a supported cobalt-based catalyst; the mass ratio of metal atoms to the tungsten oxide cluster or molybdenum oxide cluster in the metal-based active component is 1.0:0.1-1.0:0.4. In some embodiments, the metal-based active component is a supported nickel-based catalyst or a supported cobalt-based catalyst; the mass ratio of metal atoms to the tungsten oxide cluster or molybdenum oxide cluster in the metal-based active component is 1.0:0.2-1.0:0.4. In some embodiments, the metal-based active component is a supported nickel-based catalyst or a supported cobalt-based catalyst; the mass ratio of metal atoms to the tungsten oxide cluster or molybdenum oxide cluster in the metal-based active component is 1.0:0.2-1.0:0.3. In some embodiments, the metal-based active component is a supported nickel-based catalyst or a supported cobalt-based catalyst; the mass ratio of metal atoms to the tungsten oxide cluster or molybdenum oxide cluster in the metal-based active component is 1.0:0.3.

[0033] In some embodiments, the metal-based active component is at least one selected from Raney nickel catalyst, nickel powder, nickel nanoparticles, cobalt nanoparticles, Raney cobalt catalyst, or cobalt powder; the mass ratio of metal atoms to the tungsten oxide cluster or molybdenum oxide cluster in the metal-based active component is 1.000:0.025-1.000:0.100. In some embodiments, the metal-based active component is at least one selected from Raney nickel catalyst, nickel powder, nickel nanoparticles, cobalt nanoparticles, Raney cobalt catalyst, or cobalt powder; the mass ratio of metal atoms to the tungsten oxide cluster or molybdenum oxide cluster in the metal-based active component is 1.000:0.050-1.000:0.075. In some embodiments, the metal-based active component is at least one of Raney nickel catalyst, nickel powder, nickel nanoparticles, cobalt nanoparticles, Raney cobalt catalyst, or cobalt powder; the mass ratio of metal atoms to the tungsten oxide cluster or molybdenum oxide cluster in the metal-based active component is 1.000:0.025, 1.000:0.050, 1.000:0.075, or 1.000:0.100.

[0034] Thirdly, the present invention provides another method for preparing the catalyst described in the first aspect.

[0035] A method for preparing the catalyst described in the first aspect comprises: mixing a metal-based active component with a tungsten oxide cluster or a molybdenum oxide cluster in a solid phase, reacting the mixture at a specific temperature under a hydrogen-argon mixed gas atmosphere, to obtain the catalyst.

[0036] In some embodiments, the tungsten oxide cluster includes at least one of ammonium metatungstate, silicotungstic acid, phosphotungstic acid, and sodium tungstate.

[0037] In some embodiments, the molybdenum oxide cluster includes at least one of ammonium molybdate, molybdic acid silicomolybdate, phosphomolybdic acid, and sodium molybdate.

[0038] In some embodiments, the specific temperature is 120°C-240°C. In some embodiments, the specific temperature is 160°C-200°C.

[0039] In some embodiments, the reaction time at a specific temperature is 1 hour to 12 hours. In some embodiments, the reaction time at a specific temperature is 2 hours to 12 hours. In some embodiments, the reaction time at a specific temperature is 2 hours to 6 hours. In some embodiments, the reaction time at a specific temperature is 1 hour, 2 hours, 6 hours, or 12 hours.

[0040] In some embodiments, the volume percentage of hydrogen in the hydrogen-argon mixture is 5%-100%.

[0041] In some embodiments, the mass ratio of metal atoms to tungsten oxide clusters or molybdenum oxide clusters in the metal-based active component is 1.000:0.001-1.000:1.000.

[0042] In some embodiments, the metal-based active component is a supported nickel-based catalyst or a supported cobalt-based catalyst; the mass ratio of metal atoms to the tungsten oxide cluster or molybdenum oxide cluster in the metal-based active component is 1.0:0.1-1.0:0.4. In some embodiments, the metal-based active component is a supported nickel-based catalyst or a supported cobalt-based catalyst; the mass ratio of metal atoms to the tungsten oxide cluster or molybdenum oxide cluster in the metal-based active component is 1.0:0.2-1.0:0.4. In some embodiments, the metal-based active component is a supported nickel-based catalyst or a supported cobalt-based catalyst; the mass ratio of metal atoms to the tungsten oxide cluster or molybdenum oxide cluster in the metal-based active component is 1.0:0.2-1.0:0.3. In some embodiments, the metal-based active component is a supported nickel-based catalyst or a supported cobalt-based catalyst; the mass ratio of metal atoms to the tungsten oxide cluster or molybdenum oxide cluster in the metal-based active component is 1.0:0.3.

[0043] In some embodiments, the metal-based active component is at least one selected from Raney nickel catalyst, nickel powder, nickel nanoparticles, cobalt nanoparticles, Raney cobalt catalyst, or cobalt powder; the mass ratio of metal atoms to the tungsten oxide cluster or molybdenum oxide cluster in the metal-based active component is 1.000:0.025-1.000:0.100. In some embodiments, the metal-based active component is at least one selected from Raney nickel catalyst, nickel powder, nickel nanoparticles, cobalt nanoparticles, Raney cobalt catalyst, or cobalt powder; the mass ratio of metal atoms to the tungsten oxide cluster or molybdenum oxide cluster in the metal-based active component is 1.000:0.050-1.000:0.075. In some embodiments, the metal-based active component is at least one of Raney nickel catalyst, nickel powder, nickel nanoparticles, cobalt nanoparticles, Raney cobalt catalyst, or cobalt powder; the mass ratio of metal atoms to the tungsten oxide cluster or molybdenum oxide cluster in the metal-based active component is 1.000:0.025, 1.000:0.050, 1.000:0.075, or 1.000:0.100.

[0044] Fourthly, the present invention provides an application of the catalyst described in the first aspect, the catalyst obtained by the method described in the second aspect, or the catalyst obtained by the method described in the third aspect.

[0045] The use of a catalyst as a catalyst for a reductive amination reaction, a catalyst obtained by the method described in the first aspect, or a catalyst obtained by the method described in the second aspect.

[0046] Fifthly, the present invention provides a method for preparing a multi-level amine.

[0047] A method for preparing a multi-level amine includes: mixing a catalyst as described in the first aspect, a catalyst obtained by the method described in the second aspect, or a catalyst obtained by the method described in the third aspect, an aldehyde compound or a ketone compound, an amine source, and a solvent, and carrying out a reductive amination reaction under certain pressure and temperature conditions in a reducing gas atmosphere to obtain a multi-level amine.

[0048] In some embodiments, the reaction pressure of the reductive amination reaction is 0.5 MPa to 3.0 MPa. In some embodiments, the reaction pressure of the reductive amination reaction is 1.0 MPa to 2.0 MPa. In some embodiments, the reaction pressure of the reductive amination reaction is 1.5 MPa.

[0049] In some embodiments, the reaction temperature of the reductive amination reaction is 50°C to 100°C. In some embodiments, the reaction temperature of the reductive amination reaction is 50°C to 80°C.

[0050] In some embodiments, the reductive amination reaction takes 0.1 h to 3 h. In some embodiments, the reductive amination reaction takes 0.5 h to 3 h. In some embodiments, the reductive amination reaction takes 1 h to 3 h. In some embodiments, the reductive amination reaction takes 1 h to 2 h.

[0051] In some embodiments, the amine source comprises an organic amine ligand. In some embodiments, the amine source comprises an organic molecule containing an aromatic amine or an aliphatic amine. In some embodiments, the general structural formula of the amine source is: Where R 1 R 2 Each amine source is independently selected from aliphatic or aromatic groups. In some embodiments, the amine source includes at least one of dimethylamine, aniline, 4-methylaniline, 4-chloroaniline, 4-fluoroaniline, 4-methoxyaniline, n-butylamine, and isopropylamine.

[0052] In some embodiments, the multi-level amines include N,N-dimethylbenzylamine, N,N-dimethyl-4-methylbenzylamine, N,N-dimethyl-3-methylbenzylamine, N,N-dimethyl-2-methylbenzylamine, N,N-dimethyl-4-chlorobenzylamine, N,N-dimethyl-3-chlorobenzylamine, N,N-dimethyl-2-chlorobenzylamine, N,N-dimethyl-4-fluorobenzylamine, N,N-dimethyl-3-fluorobenzylamine, N,N-dimethyl-2-fluorobenzylamine, N,N-dimethyl-4-methoxybenzylamine, N,N-dimethyl-3-methoxybenzylamine, N,N-di... At least one of methyl-2-methoxybenzylamine, N,N-dimethyl-3,5-dimethylbenzylamine, N,N-dimethyl-4-trifluoromethylbenzylamine, N,N-dimethyl-2-trifluoromethylbenzylamine, N,N-dimethyl-4-phenylbenzylamine, N,N-dimethyl-3-phenylbenzylamine, N,N-dimethyl-2-octylamine, N,N-dimethylcyclohexylamine, N-benzylaniline, N-benzyl-4-methylaniline, N-benzyl-4-chloroaniline, N-benzyl-4-fluoroaniline, N-benzyl-4-methoxyaniline, N-butylbenzylamine, and N-isopropylbenzylamine.

[0053] In some embodiments, the reducing gas is hydrogen.

[0054] In some embodiments, the solvent includes at least one selected from methanol, ethanol, isopropanol, DMF, DMSO, dichloromethane, and tetrahydrofuran.

[0055] In some embodiments, the aldehyde compounds include aromatic aldehydes or aliphatic aldehydes. In some embodiments, the general structural formula of the aldehyde compounds is R. 3 CHO, where R 3The groups are selected from aliphatic or aromatic groups. In some embodiments, the aldehyde compounds include at least one of benzaldehyde, 4-methylbenzaldehyde, 3-methylbenzaldehyde, 2-methylbenzaldehyde, 4-chlorobenzaldehyde, 3-chlorobenzaldehyde, 2-chlorobenzaldehyde, 4-fluorobenzaldehyde, 3-fluorobenzaldehyde, 2-fluorobenzaldehyde, 4-methoxybenzaldehyde, 3-methoxybenzaldehyde, 2-methoxybenzaldehyde, 3,5-dimethylbenzaldehyde, 4-trifluoromethylbenzaldehyde, 2-trifluoromethylbenzaldehyde, and 4-phenylbenzaldehyde.

[0056] In some embodiments, the ketone compounds include aromatic ketone compounds or aliphatic ketone compounds. In some embodiments, the general structural formula of the ketone compounds is R. 4 COR 5 , where R 4 R 5 Each ketone is independently selected from aliphatic or aromatic groups. In some embodiments, the ketone compound includes at least one of 2-octanone or cyclohexanone.

[0057] Beneficial effects

[0058] Compared with the prior art, one embodiment of the present invention has at least one of the following beneficial effects:

[0059] (1) This invention modifies metal-based active components (such as nickel-based catalysts or cobalt-based catalysts) by using tungsten oxide clusters or molybdenum oxide clusters as precursors, thereby improving the activity and selectivity of metal-based active components (such as nickel-based catalysts or cobalt-based catalysts) in aldehyde reduction amination reactions. Under relatively harsh reaction conditions (120°C, 4MPa H2, yield of about 85%) compared to traditional literature, the catalysts modified with tungsten oxide clusters or molybdenum oxide clusters can achieve a multi-stage amine yield of 99% under mild conditions (80°C, 1.5MPa H2), which is expected to be applied in the biopharmaceutical field.

[0060] (2) The catalyst prepared by this invention has high activity. Compared with the traditional literature which uses a large amount of catalyst (TON is about 28.6, reaction time is 24 hours, yield is about 85%), the tungsten oxide cluster or molybdenum oxide cluster modified catalyst can achieve high-selectivity and rapid conversion of substrate with a very small amount of catalyst (e.g. 0.1 mol%, TON is 1000, reaction time is 0.5 hours, yield is 99%), which is more active than the traditional process.

[0061] (3) By modifying nickel-based or cobalt-based catalysts with tungsten oxide or molybdenum oxide, the reduction temperature of oxides formed on the surface exposed to air is reduced from 150 degrees Celsius to 80 degrees Celsius. This means that the modified metal-active catalyst can catalyze the reduction amination reaction under mild conditions. This indicates that tungsten oxide or molybdenum oxide modification can act as a passivation layer, effectively preventing the catalyst from undergoing violent oxidation and combustion when exposed to air, thus improving the experimental feasibility and safety of metal-active catalysts (such as nickel-based or cobalt-based catalysts).

[0062] (4) The method of modifying metal active catalysts (such as nickel-based catalysts or cobalt-based catalysts) in this invention uses tungsten oxide clusters or molybdenum oxide clusters as precursors with low cost. The catalyst performance can be greatly improved with very little precursor. The operation is simple, the modification cost is low, and it is conducive to large-scale production.

[0063] (5) The modification method of metal active catalysts (such as nickel-based catalysts or cobalt-based catalysts) of the present invention can be extended to catalysts such as nickel powder, nickel nanoparticles, cobalt nanoparticles, Raney nickel, and Raney cobalt, which provides convenience for the industrialization of catalyst preparation.

[0064] (6) The catalyst described in this invention can be used as a substrate for the reduction amination of aldehydes or ketones containing various functional groups. The catalyst has high activity, high selectivity and good stability for the reduction amination reaction. It can be reused multiple times, which further improves the quality and stability of the product and reduces the process cost.

[0065] (7) Compared with nickel-based nanocatalysts or cobalt-based nanocatalysts, tungsten oxide, molybdenum oxide, and direct mixtures of molybdenum oxide or tungsten oxide with nickel-based nanocatalysts or cobalt-based nanocatalysts without surface modification of tungsten oxide or molybdenum oxide, the catalyst obtained by depositing molybdenum oxide or tungsten oxide on the surface of nickel-based nanocatalysts or cobalt-based nanocatalysts in this invention has a synergistic effect on the catalytic activity of reduction amination reaction, and has unexpected technical effects. Attached Figure Description

[0066] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0067] Figure 1 The figure shows the catalyst cycle stability test results of the catalyst obtained in Example 8 of Example 55 and the carbon-supported nickel catalyst obtained in Comparative Example 2.

[0068] Figure 2 The kinetic curves are for the catalysts of Examples 7-9 and Comparative Example 1.

[0069] Figure 3The kinetic curves are for the catalysts of Examples 10-13 and Comparative Example 3.

[0070] Figure 4 Temperature program reduction (TPR) curves of the catalysts in Examples 10-13 and Comparative Example 3.

[0071] Figure 5 This is a temperature-programmed reduction (TPR) diagram of tungsten oxide and nickel tungstate.

[0072] Figure 6 The X-ray photoelectron spectrum (XPS) of tungsten for the catalyst prepared in Example 8 is shown.

[0073] Terminology Explanation

[0074] In this invention, "room temperature" refers to the ambient temperature, which can be 10℃-40℃, 15℃-35℃, or 20℃-30℃; in some embodiments, it is 22℃-28℃; in some embodiments, it is 24℃-26℃; and in some embodiments, it is 25℃.

[0075] In the foregoing description of this invention, all figures disclosed herein, whether or not the words “approximately” or “about” are used, are approximate values. Based on the disclosed figures, the value of each figure may vary by less than ±10% or by a difference that is considered reasonable by those skilled in the art, such as ±1%, ±2%, ±3%, ±4%, or ±5%.

[0076] "Multi-level amines" refer to organic amine ligands with multiple functional groups.

[0077] The term "more" means ≥2, such as 2, 3, 4 or 5, etc.

[0078] “TON” indicates the ratio of substrate to catalyst, representing the maximum number of times the catalyst can rotate.

[0079] The terms “optional,” “optional,” or “optionally” mean that the event or situation described below may, but is not necessarily, occur. For example, “optionally, the reaction pressure of the reductive amination reaction is 0.5 MPa to 3 MPa” means that the situation “the reaction pressure of the reductive amination reaction is 0.5 MPa to 3 MPa” may or may not occur.

[0080] The term “weight percentage” or “percentage by weight” or “wt%” is defined as the weight of a single component in the composition divided by the total weight of all components in the composition and then multiplied by 100%.

[0081] The term “and / or” should be understood to mean any one of the options or any combination of two or more of the options.

[0082] The term "aliphatic" or "aliphatic group" refers to a straight-chain (i.e., unbranched) or branched, substituted or unsubstituted, fully saturated or containing one or more degrees of unsaturation of a hydrocarbon chain. Unless otherwise specified, an aliphatic group contains 1-20 carbon atoms, with some embodiments containing 1-10 carbon atoms, others containing 1-8 carbon atoms, still others containing 1-6 carbon atoms, still others containing 1-4 carbon atoms, and still others containing 1-3 carbon atoms. Suitable aliphatic groups include, but are not limited to, straight-chain or branched, substituted or unsubstituted alkyl, alkenyl, or alkynyl groups, such as methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, hexyl, isobutyl, sec-butyl, and vinyl groups, etc.

[0083] The term "aromatic" or "aromatic group" refers to a class of hydrocarbons that contain at least one delocalized benzene ring and possess unique properties (called aromaticity) that differ from open-chain compounds or alicyclic hydrocarbons; such as benzene, naphthalene, anthracene, phenanthrene and their derivatives.

[0084] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples. Detailed Implementation

[0085] To enable those skilled in the art to better understand the technical solutions of the present invention, some non-limiting embodiments are further disclosed below to provide a more detailed description of the present invention.

[0086] All reagents used in this invention can be purchased commercially or prepared by the methods described in this invention.

[0087] In this invention, "MPa" represents megapascal; "°C" represents degrees Celsius; "h" represents hours; "mmol" represents millimoles; "g" represents grams; "mg" represents milligrams; "Ni" represents nickel; "WO" represents... x " " indicates tungsten oxide; "C" indicates carbon; "Co" indicates cobalt.

[0088] Example 1: Liquid Phase Deposition Method - Deposition Time Investigation (2h)

[0089] (1) Weigh 1g of nickel nitrate and dissolve it in 20mL of anhydrous ethanol to obtain a nickel nitrate solution; at the same time, weigh 0.8g of activated carbon support and disperse it in 50mL of anhydrous ethanol to obtain an activated carbon support dispersion; add the nickel nitrate solution dropwise to the activated carbon support dispersion, stir for 30min, and evaporate the anhydrous ethanol at 80℃ to obtain a crude carbon-supported nickel catalyst with a loading of 20wt%.

[0090] (2) The crude carbon-supported nickel catalyst obtained above was placed in an alumina crucible and then placed in a tube furnace. A 5% hydrogen-argon mixture was first introduced at 25°C for 30 minutes to remove the oxygen in the tube. Then, the temperature was increased to 400°C at a rate of 5°C per minute, and the catalyst was reduced at 400°C for 1 hour under a 5% hydrogen-argon mixture atmosphere to obtain the carbon-supported nickel catalyst.

[0091] (3) Dissolve 250 mg of ammonium metatungstate in 10 mL of water, and add 300 mg of the carbon-supported nickel catalyst obtained above. Stir at 80 °C (deposition temperature) for 2 hours under a hydrogen atmosphere to prepare tungsten oxide-modified Ni@WO3. x / C-1-80-2h catalyst.

[0092] Hydrogenation catalytic efficiency

[0093] The performance of the catalyst prepared in Example 1 was evaluated: 10 mmol benzaldehyde and 3 mg of Ni@WO3 from Example 1 were added. x / C-1-80-2h catalyst, 15 mmol dimethylamine, and 10 mL anhydrous methanol were added to a reaction vessel to form a mixture. Nitrogen gas was introduced into the reaction vessel three times to replace the air. After sealing the reaction vessel, hydrogen gas was introduced into the reaction vessel. When the pressure inside the reaction vessel reached 1.5 MPa, the stirrer was started at a speed of 750 rpm, and the reaction temperature was maintained at 50℃-80℃. The hydrogen consumption per minute was observed until there was no more pressure drop, at which point the reaction was stopped. The reaction time was 1 hour. After the reaction was completed, gas chromatography analysis was performed. The amine yield of the product was 88%.

[0094] Example 2: Liquid Phase Deposition Method - Deposition Time Investigation (12h)

[0095] The preparation steps and material selection in Example 2 are the same as in Example 1, except that the stirring time in Example 2 is 12 hours. The remaining preparation steps and material selection are the same as in Example 1, yielding Ni@WO3. x / C-1-80-12h catalyst.

[0096] Hydrogenation catalytic efficiency

[0097] The catalyst prepared in Example 2 was evaluated for performance. The catalytic reaction conditions were the same as in Example 1. The amine yield of the product was 98% according to gas chromatography analysis.

[0098] Example 3: Liquid Phase Deposition Method - Investigation of Ammonium Metatungstate Content

[0099] The preparation steps and material selection in Example 3 are the same as in Example 1, except that 125 mg of ammonium metatungstate is used in Example 3. The remaining preparation steps and material selection are the same as in Example 1, yielding Ni@WO3. x / C-0.5-80-2h catalyst.

[0100] Hydrogenation catalytic efficiency

[0101] The catalyst prepared in Example 3 was evaluated for performance. The catalytic reaction conditions were the same as in Example 1. The amine yield of the product was 81% according to gas chromatography analysis.

[0102] Example 4: Liquid Phase Deposition Method - Investigation of Ammonium Metatungstate Content

[0103] The preparation steps and material selection in Example 4 are the same as in Example 1, except that 1 gram of ammonium metatungstate is used in Example 4. The remaining preparation steps and material selection are the same as in Example 1, yielding Ni@WO3. x / C-4-80-2h catalyst.

[0104] Hydrogenation catalytic efficiency

[0105] The catalyst prepared in Example 4 was evaluated for performance. The catalytic reaction conditions were the same as in Example 1. According to the gas chromatography analysis, the amine yield of the product was 99%.

[0106] Example 5: Liquid Phase Deposition Method - Deposition Temperature Investigation (100℃)

[0107] The preparation steps and material selection in Example 5 are the same as in Example 1, except that the deposition temperature in Example 5 is 100℃. The remaining preparation steps and material selection are the same as in Example 1, yielding Ni@WO3. x / C-1-100-2h catalyst.

[0108] Hydrogenation catalytic efficiency

[0109] The catalyst prepared in Example 5 was evaluated for performance. The catalytic reaction conditions were the same as in Example 1. According to the gas chromatography analysis, the yield of the product amine was 95%.

[0110] Example 6: Liquid Phase Deposition Method - Deposition Temperature Investigation (120℃)

[0111] The preparation steps and material selection for Example 6 are the same as in Example 1, except that the deposition temperature in Example 6 is 120°C. The remaining preparation steps and material selection are the same as in Example 1, yielding Ni@WO3. x / C-1-120-2h catalyst.

[0112] Hydrogenation catalytic efficiency

[0113] The catalyst prepared in Example 6 was evaluated for performance. The catalytic reaction conditions were the same as in Example 1. The amine yield of the product was 99% according to gas chromatography analysis.

[0114] Summary of reaction data for the reductive amination of benzaldehyde with dimethylamine in Examples 1 to 6: see Table 1.

[0115] Table 1: Reaction data for the reductive amination of benzaldehyde with dimethylamine in Examples 1 to 6

[0116]

[0117] As shown in Table 1, the activity of the modified catalyst significantly increases with the increase of tungsten oxide cluster liquid-phase deposition time or tungsten oxide cluster solution concentration, and the yield of multi-stage amines increases from 81% to 99%. This indicates that the more tungsten oxide deposited on the catalyst surface, the higher the catalyst activity. Therefore, the modification method of tungsten oxide cluster liquid-phase deposition nickel-based catalyst provided by this invention can effectively improve the catalytic efficiency of the reductive amination reaction.

[0118] Example 7: Solid-phase deposition method - Investigation of ammonium metatungstate dosage (the percentage of ammonium metatungstate to nickel in the carbon-supported nickel catalyst is 20 wt%)

[0119] The preparation steps and material selection in Example 7 are the same as in Example 1. The difference is that in Example 7, a solid-phase deposition method is used. 300 mg of carbon-supported nickel catalyst and 12 mg of ammonium metatungstate are thoroughly mixed and placed in an alumina crucible, which is then placed in a tube furnace. A 5% hydrogen-argon mixed gas is first introduced at 25°C for 30 minutes to purge oxygen from the tube. Then, the temperature is increased to 200°C at a rate of 5°C per minute, and reduction is performed at 200°C for 2 hours under a 5% hydrogen-argon mixed atmosphere to prepare Ni@WO. x / C-20%-200-2h catalyst.

[0120] Hydrogenation catalytic efficiency

[0121] The catalyst prepared in Example 7 was evaluated for performance. The catalytic reaction conditions were the same as in Example 1, and the reaction time was 30 minutes. According to the gas chromatography analysis, the amine yield of the product was 98.5%.

[0122] Example 8: Solid-phase deposition method - Investigation of ammonium metatungstate dosage (the percentage of ammonium metatungstate to nickel in the carbon-supported nickel catalyst is 30 wt%)

[0123] The preparation steps and material selection in Example 8 are the same as in Example 7, except that 18 mg of ammonium metatungstate is used in Example 8 to prepare Ni@WO x / C-30%-200-2h catalyst.

[0124] The X-ray photoelectron spectroscopy (XPS) spectrum of tungsten obtained from the catalyst in Example 8 is shown in the figure. Figure 6 .

[0125] Hydrogenation catalytic efficiency

[0126] The catalyst prepared in Example 8 was evaluated for performance. The catalytic reaction conditions were the same as in Example 1, and the reaction time was 20 minutes. According to the gas chromatography analysis, the amine yield of the product was 99.5%.

[0127] Example 9: Solid-phase deposition method - Investigation of ammonium metatungstate dosage (the percentage of ammonium metatungstate to nickel in the carbon-supported nickel catalyst is 40 wt%)

[0128] The preparation steps and material selection in Example 9 are the same as in Example 7, except that 24 mg of ammonium metatungstate is used in Example 9 to prepare Ni@WO x / C-40%-200-2h catalyst.

[0129] Hydrogenation catalytic efficiency

[0130] The catalyst prepared in Example 9 was evaluated for performance. The catalytic reaction conditions were the same as in Example 1, and the reaction time was 20 minutes. The gas chromatography analysis showed that the amine yield was 97.6%.

[0131] Results analysis: Figure 2 Kinetic curves are shown for the catalysts prepared by solid-phase deposition with different amounts of ammonium metatungstate in Examples 7-9 and Comparative Example 1. The results show that when the weight ratio of ammonium metatungstate to nickel in the carbon-supported nickel catalyst is less than 30 wt%, the catalyst activity increases significantly with increasing tungsten-oxygen cluster content. This indicates that solid-phase deposition is more efficient than liquid-phase deposition. Even with a small amount of ammonium metatungstate, the catalyst activity is significantly improved, even surpassing the activity obtained by liquid-phase deposition. However, when the weight ratio of ammonium metatungstate to nickel in the carbon-supported nickel catalyst exceeds 30 wt%, the catalyst activity decreases. This excessive deposition reduces the activator activity. The activity values ​​for the weight ratio of ammonium metatungstate to nickel in the carbon-supported nickel catalyst are 0 wt% < 40 wt% < 20 wt% < 30 wt%.

[0132] Example 10: Solid-phase deposition method - nickel powder as a model catalyst (ammonium metatungstate to nickel powder weight ratio is 2.5 wt%)

[0133] The preparation steps in Example 10 are the same as in Example 7, except that 1 gram of nickel powder is used instead of the carbon-supported nickel catalyst, and the amount of ammonium metatungstate is 25 mg, to prepare Ni@WO x -2.5%-200-2h catalyst.

[0134] Hydrogenation catalytic efficiency

[0135] The performance of the catalyst prepared in Example 10 was evaluated. The catalytic reaction conditions were the same as in Example 1, except that the reaction time was 90 minutes and 6 mg of Ni@WO3 was used in Example 10. x The catalyst, with a yield of -2.5%-200-2h, showed an amine yield of 97% according to gas chromatography analysis.

[0136] Example 11: Solid-phase deposition method - nickel powder as a model catalyst (ammonium metatungstate to nickel powder weight ratio is 5 wt%)

[0137] The preparation steps in Example 11 are the same as in Example 7, except that 1 gram of nickel powder is used instead of the carbon-supported nickel catalyst, and the amount of ammonium metatungstate is 50 mg, to prepare Ni@WO x -5%-200-2h catalyst.

[0138] Hydrogenation catalytic efficiency

[0139] The catalyst prepared in Example 11 was evaluated for performance. The catalytic reaction conditions were the same as in Example 1. Gas chromatography analysis showed that the amine yield was 99%.

[0140] Example 12: Solid-phase deposition method - nickel powder as a model catalyst (ammonium metatungstate to nickel powder weight ratio is 7.5 wt%)

[0141] The preparation steps in Example 12 are the same as in Example 7, except that 1 gram of nickel powder is used instead of the carbon-supported nickel catalyst, and the amount of ammonium metatungstate is 75 mg, to prepare Ni@WO x -7.5%-200-2h catalyst.

[0142] Hydrogenation catalytic efficiency

[0143] The performance of the catalyst prepared in Example 12 was evaluated. The catalytic reaction conditions were the same as in Example 1, except that 6 mg of Ni@WO3 was used in Example 12. xThe catalyst, with a yield of -2.5%-200-2h, showed an amine yield of 95% according to gas chromatography analysis.

[0144] Example 13: Solid-phase deposition method - nickel powder as a model catalyst (ammonium metatungstate to nickel powder weight ratio is 10 wt%)

[0145] The preparation steps in Example 13 are the same as in Example 7, except that in Example 13, 1 gram of nickel powder is used instead of the carbon-supported nickel catalyst, and the amount of ammonium metatungstate is 100 mg, to prepare Ni@WO x -10%-200-2h catalyst.

[0146] Hydrogenation catalytic efficiency

[0147] The performance of the catalyst prepared in Example 13 was evaluated. The catalytic reaction conditions were the same as in Example 1, except that 6 mg of Ni@WO3 was used in Example 13. x The catalyst, with a yield of -10%-200-2h, showed an amine yield of 93% according to gas chromatography analysis.

[0148] Results analysis: Figure 3 Kinetic curves of tungsten oxide-modified nickel powder catalysts prepared by solid-phase deposition with different amounts of ammonium metatungstate are shown. Within a certain range, when the weight ratio of ammonium metatungstate to nickel powder is within a certain range, the catalyst activity increases significantly with increasing solid-phase deposition dosage. However, when the weight ratio of ammonium metatungstate to nickel powder exceeds a certain range, the catalyst activity slightly decreases with increasing tungsten oxide cluster content. The activity values ​​for the weight ratio of ammonium metatungstate to nickel powder are 0 wt% < 10 wt% < 7.5 wt% < 2.5 wt% < 5 wt%.

[0149] Example 14: Temperature-Programmed Reduction Test

[0150] Procedure: Weigh 200 mg each of tungsten oxide, nickel tungstate, catalysts from Examples 10-13 and Comparative Example 3, place them in U-shaped tubes, install them in a chemisorption analyzer, and perform programmed temperature-progression reduction detection.

[0151] Result: See Figure 4 and Figure 5 .

[0152] Results Analysis: Figure 4 It can be seen that the reduction peak in the low-temperature region of 100℃ can be attributed to the reduction peak of trace nickel oxide on the surface, the reduction peak in the 200℃-500℃ region can be considered as the reduction peak of tungsten oxide on the surface of the nickel-based catalyst, and the reduction peak above 500℃ is a discrete reduction peak of tungsten oxide. This is consistent with the temperature-programmed reduction diagram of tungsten oxide. Figure 5The results were consistent; the formation of discrete tungsten oxides was due to the decomposition of the tungsten oxide cluster precursor at 200℃, with some depositing onto the surface of the nickel-based catalyst, while the remaining portion spontaneously aggregated to form discrete tungsten oxides. Figure 4 It can be seen that the use of a large amount of tungsten oxide did not effectively increase the amount of tungsten oxide on the surface of the nickel-based catalyst. Instead, it quenched the tungsten oxide adsorbed on the surface of the nickel-based catalyst, causing it to aggregate and form more discrete tungsten oxide. Therefore, the use of a large amount of tungsten oxide leads to a reduction in the amount of tungsten oxide deposited on the surface of the nickel-based catalyst, thereby reducing the catalyst activity. This result also explains why the activity of solid-phase deposited nickel / carbon supported catalysts exhibits a volcano-shaped curve with the amount of tungsten oxide clusters. It also demonstrates that solid-phase deposition is a powerful method for efficiently modifying the reductive amination catalytic performance of nickel-based catalysts. For nickel powder, only 5 wt% of tungsten oxide clusters can significantly improve catalyst performance, which is very useful for the commercialization of catalysts.

[0153] Meanwhile, the temperature reduction results showed that the reduction temperature of nickel oxide on the surface of nickel powder decreased from 150℃ before modification to 90℃ after modification. This indicates that the surface and interface modification of tungsten oxide effectively inhibited the formation of dense nickel oxide on the surface. Furthermore, even if the catalyst is exposed to air and slightly oxidized, the non-dense trace amount of nickel oxide on its surface can be reduced under mild conditions (90℃), thus giving the catalyst a certain degree of stability.

[0154] Example 15

[0155] The preparation steps in Example 15 are the same as in Example 11, except that the deposition temperature in Example 15 is 120℃, and Ni@WO is prepared. x -5%-120-2h catalyst.

[0156] Hydrogenation catalytic efficiency

[0157] The performance of the catalyst prepared in Example 15 was evaluated. The catalytic reaction conditions were the same as in Example 10, except that 6 mg of Ni@WO3 was used in Example 15. x The catalyst was 5%-120-2h, and the product amine yield was 84% ​​according to gas chromatography analysis.

[0158] Example 16

[0159] The preparation steps in Example 16 are the same as in Example 11, except that the deposition temperature in Example 16 is 160℃, and Ni@WO is prepared. x -5%-160-2h catalyst.

[0160] Hydrogenation catalytic efficiency

[0161] The performance of the catalyst prepared in Example 16 was evaluated. The catalytic reaction conditions were the same as in Example 10, except that 6 mg of Ni@WO3 was used in Example 16. x The catalyst was 5%-160-2h, and the amine yield was 97% according to gas chromatography analysis.

[0162] Example 17

[0163] The preparation steps in Example 17 are the same as in Example 11, except that the deposition temperature in Example 17 is 240℃, and Ni@WO is prepared. x -5%-240-2h catalyst.

[0164] Hydrogenation catalytic efficiency

[0165] The performance of the catalyst prepared in Example 17 was evaluated. The catalytic reaction conditions were the same as in Example 1, except that 6 mg of Ni@WO3 was used in Example 17. x The catalyst was 5%-240-2h, and the amine yield was 91% according to gas chromatography analysis.

[0166] Example 18

[0167] The preparation steps in Example 18 are the same as in Example 11, except that the deposition time in Example 18 is 6 hours, resulting in the preparation of Ni@WO x -5%-200-6h catalyst.

[0168] Hydrogenation catalytic efficiency

[0169] The performance of the catalyst prepared in Example 18 was evaluated. The catalytic reaction conditions were the same as in Example 1, except that 6 mg of Ni@WO3 was used in Example 18. x The catalyst, with a yield of -5%-200-6h, showed an amine yield of 92% according to gas chromatography analysis.

[0170] Example 19

[0171] The preparation steps in Example 19 are the same as in Example 11, except that the deposition time in Example 19 is 12 hours, and Ni@WO is obtained. x -5%-200-12h catalyst.

[0172] Hydrogenation catalytic efficiency

[0173] The performance of the catalyst prepared in Example 19 was evaluated. The catalytic reaction conditions were the same as in Example 1, except that 6 mg of Ni@WO3 was used in Example 19. x The catalyst was 5%-200-12h, and the amine yield was 88% according to gas chromatography analysis.

[0174] Summary of reaction data for the reductive amination of benzaldehyde with dimethylamine in Examples 7 to 19: see Table 2.

[0175] Table 2: Reaction data for the reductive amination of benzaldehyde with dimethylamine in Examples 7 to 19

[0176]

[0177] Results analysis: From Examples 11, 15, 16, 17, 18, and 19, it can be concluded that the catalysts obtained with a deposition temperature of 160℃-200℃ have the best activity.

[0178] As can be seen from the results of Examples 7-9, when the catalyst of the present invention is prepared by using a carbon-supported nickel catalyst as the metal-based active component, the catalyst has high activity when the weight ratio of ammonium metatungstate to nickel in the carbon-supported nickel catalyst is 20wt%-40wt%, and the preferred weight ratio of ammonium metatungstate to nickel in the carbon-supported nickel catalyst is 30wt%.

[0179] As can be seen from the results of Examples 10-13, when nickel powder is used as the metal-based active component to prepare the catalyst of the present invention, the catalyst has high activity when the weight ratio of ammonium metatungstate to nickel powder is 2.5wt%-10wt%, and the preferred weight ratio of ammonium metatungstate to nickel powder is 5wt%.

[0180] Example 20: The carrier is alumina

[0181] The preparation steps and material selection for Example 20 are the same as in Example 8. The difference is that in Example 20, alumina is used as the support, and the reduction temperature for preparing the carbon-supported nickel catalyst (i.e., the reduction temperature under a 5% hydrogen-argon mixed atmosphere in step (2) of Example 1) is 500°C, thus obtaining Ni@WO x / Al2O3-30%-200-2h catalyst.

[0182] Hydrogenation catalytic efficiency

[0183] The catalyst prepared in Example 20 was evaluated for performance. The catalytic reaction conditions were the same as in Example 1, and the reaction time was 20 minutes. According to the gas chromatography analysis, the amine yield of the product was 99%.

[0184] Example 21: The carrier is silicon dioxide

[0185] The preparation steps and material selection in Example 21 are the same as in Example 8. The difference is that in Example 21, silica is used as the support, and the reduction temperature (i.e., the reduction temperature under a 5% hydrogen-argon mixed atmosphere in step (2) of Example 1) is 500°C to prepare Ni@WO x / SiO2-30%-200-2h catalyst.

[0186] Hydrogenation catalytic efficiency

[0187] The performance of the catalyst prepared in Example 21 was evaluated. The catalytic reaction conditions were the same as in Example 1, and the reaction time was 20 minutes. According to the gas chromatography analysis, the yield of the product amine was 99%.

[0188] Example 22: The carrier is magnesium oxide

[0189] The preparation steps and material selection in Example 22 are the same as in Example 8. The difference is that in Example 22, magnesium oxide is used as the support, and the reduction temperature for preparing the carbon-supported nickel catalyst (i.e., the reduction temperature under a 5% hydrogen-argon mixed atmosphere in step (2) of Example 1) is 500°C, thus obtaining Ni@WO x / SiO2-30%-200-2h catalyst.

[0190] Hydrogenation catalytic efficiency

[0191] The performance of the catalyst prepared in Example 22 was evaluated. The catalytic reaction conditions were the same as in Example 1, and the reaction time was 20 minutes. According to the gas chromatography analysis, the yield of the product amine was 99%.

[0192] Example 23: Using Raney nickel catalyst as the metal-based active component

[0193] The preparation steps and material selection in Example 23 are the same as in Example 11, except that Raney nickel catalyst is used instead of nickel powder in Example 23 to prepare Raney Ni@WO. x -5%-200-2h catalyst.

[0194] Hydrogenation catalytic efficiency

[0195] The catalyst prepared in Example 23 was evaluated for performance. The catalytic reaction conditions were the same as in Example 11. According to gas chromatography analysis, the yield of the product amine was 99%.

[0196] Example 24

[0197] The preparation steps and material selection in Example 24 are the same as in Example 11, except that Raney cobalt catalyst is used instead of nickel powder in Example 24 to prepare Raney Co@WO x-5%-200-2h catalyst.

[0198] Hydrogenation catalytic efficiency

[0199] The catalyst prepared in Example 24 was evaluated for performance. The catalytic reaction conditions were the same as in Example 11. According to gas chromatography analysis, the yield of the product amine was 99%.

[0200] Example 25

[0201] The preparation steps and material selection in Example 25 are the same as in Example 1, except that in Example 24, cobalt nitrate is used as a precursor to prepare Co@WO x / C-30%-200-2h catalyst.

[0202] Hydrogenation catalytic efficiency

[0203] The catalyst prepared in Example 25 was evaluated for performance. The catalytic reaction conditions were the same as in Example 11. According to gas chromatography analysis, the yield of the product amine was 99%.

[0204] Example 26: Using phosphotungstic acid

[0205] The preparation steps and material selection in Example 26 are the same as in Example 8, except that in Example 26, 18 mg of phosphotungstic acid is used to replace ammonium metatungstate to prepare Ni@WO x / C-30%-200-2h-P catalyst.

[0206] Hydrogenation catalytic efficiency

[0207] The catalyst prepared in Example 26 was evaluated for performance. The catalytic reaction conditions were the same as in Example 1, and the reaction time was 20 minutes. According to the gas chromatography analysis, the amine yield of the product was 99%.

[0208] Example 27: Using silicotungstic acid

[0209] The preparation steps and material selection in Example 27 are the same as in Example 8, except that in Example 27, 18 mg of silicotungstic acid is used to replace ammonium metatungstate to prepare Ni@WO x / C-30%-200-2h-Si catalyst.

[0210] Hydrogenation catalytic efficiency

[0211] The performance of the catalyst prepared in Example 27 was evaluated. The catalytic reaction conditions were the same as in Example 1, and the reaction time was 20 minutes. According to the gas chromatography analysis, the yield of the product amine was 99%.

[0212] Example 28: Using ammonium molybdate

[0213] The preparation steps and material selection in Example 28 are the same as in Example 8, except that in Example 28, 18 mg of ammonium molybdate is used to replace ammonium metatungstate to prepare Ni@MO. x / C-30%-200-2h catalyst.

[0214] Hydrogenation catalytic efficiency

[0215] The performance of the catalyst prepared in Example 28 was evaluated. The catalytic reaction conditions were the same as in Example 1, and the reaction time was 20 minutes. According to the gas chromatography analysis, the yield of the product amine was 99%.

[0216] Summary of reaction data for the reductive amination of benzaldehyde with dimethylamine in Examples 20 to 28: see Table 3.

[0217] Table 3: Reaction data for the reductive amination of benzaldehyde with dimethylamine in Examples 20 to 28

[0218]

[0219] Results Analysis: As can be seen from the results of Examples 20-28, the catalysts obtained by using alumina, silica or magnesium oxide as supports, or by using Raney nickel or Raney cobalt as metal-based active components, or by using phosphotungstic acid, silicotungstic acid or ammonium molybdate, all have excellent activity.

[0220] Examples 29-47

[0221] The preparation steps and material selection of the catalysts in Examples 29-47 are the same as in Example 8. The only difference from Example 8 is the substrate used for catalyst performance evaluation. In Examples 29-47, 4-methylbenzaldehyde, 3-methylbenzaldehyde, 2-methylbenzaldehyde, 4-chlorobenzaldehyde, 3-chlorobenzaldehyde, 2-chlorobenzaldehyde, 4-fluorobenzaldehyde, 3-fluorobenzaldehyde, 2-fluorobenzaldehyde, 4-methoxybenzaldehyde, 3-methoxybenzaldehyde, 2-methoxybenzaldehyde, 3,5-dimethylbenzaldehyde, 4-trifluoromethylbenzaldehyde, 2-trifluoromethylbenzaldehyde, 4-phenylbenzaldehyde, 3-phenylbenzaldehyde, n-octanal, 2-octanone, and cyclohexanone were used to replace benzaldehyde in Example 1. The reaction time was 30 minutes. The remaining preparation steps and material selection were the same as in Example 1. Meanwhile, the performance of the catalysts prepared in Examples 29-47 was evaluated. The catalytic reaction conditions were the same as in Example 1. The results of gas chromatography analysis are shown in Table 4.

[0222] Table 4: Reaction data for different substrates in Examples 29 to 47

[0223]

[0224]

[0225] As can be seen from Table 4, the catalyst provided by this invention has excellent catalytic effect on the catalytic reduction amination reaction of aldehydes and ketones when using different aldehydes or ketones as substrates.

[0226] Examples 48-54

[0227] The preparation steps and material selection of the catalysts in Examples 478-54 are the same as in Example 8. The only difference is the organic amine used in the performance evaluation of the catalysts. In Examples 48-54, 4-methylaniline, 4-chloroaniline, 4-fluoroaniline, 4-methoxyaniline, n-butylamine, and isopropylamine were used to replace the dimethylamine in Example 1, respectively. The reaction time was 60 minutes. The remaining preparation steps and material selection were the same as in Example 1. The performance of the catalysts prepared in Examples 48-54 was evaluated under the same catalytic reaction conditions as in Example 1. The results of gas chromatography analysis are shown in Table 5.

[0228] Table 5: Reaction data for different substrates in Examples 48 to 54

[0229]

[0230]

[0231] Results Analysis: As can be seen from Table 4, the catalyst provided by this invention has excellent catalytic activity for the catalytic reduction amination of aldehydes and ketones using different types of amine sources.

[0232] Comparative Example 1

[0233] Comparative Example 1 prepared a 20 wt% carbon-supported nickel catalyst using the same preparation conditions as Example 1, except that no tungsten oxide surface modification was performed, and the catalytic conditions were the same as in Example 1.

[0234] Comparative Example 2

[0235] Comparative Example 2 prepared a 20 wt% carbon-supported nickel catalyst using the same preparation conditions as Example 8, except that no tungsten oxide surface modification was performed, and the catalytic conditions were the same as in Example 8.

[0236] Comparative Example 3

[0237] Comparative Example 3 used the same nickel powder as Example 10, except that no tungsten oxide surface modification was performed.

[0238] Comparative Example 4

[0239] Comparative Example 4 prepared a 20 wt% Al2O3 supported nickel catalyst using the same preparation conditions as Example 20, except that no tungsten oxide surface or interface modification was performed.

[0240] Comparative Example 5

[0241] Comparative Example 5 prepared a 20 wt% SiO2-supported nickel catalyst using the same preparation conditions as Example 21, except that no tungsten oxide surface or interface modification was performed.

[0242] Comparative Example 6

[0243] Comparative Example 6 prepared a 20 wt% MgO-supported nickel catalyst using the same preparation conditions as Example 22, except that no tungsten oxide surface or interface modification was performed.

[0244] Comparative Example 7

[0245] Comparative Example 7 used the same Raney nickel catalyst as Example 23, except that no tungsten oxide surface modification was performed.

[0246] Comparative Example 8

[0247] Comparative Example 8 used the same Raney cobalt catalyst as Example 24, except that no tungsten oxide surface modification was performed.

[0248] Comparative Example 9

[0249] Comparative Example 9 prepared a 20 wt% carbon-supported cobalt catalyst using the same preparation conditions as Example 25, except that no tungsten oxide surface modification was performed, and the catalytic conditions were the same as in Example 8.

[0250] Comparative Example 10

[0251] Comparative Example 10 used tungsten oxide as a catalyst, and the catalytic conditions were the same as in Example 8, using 10 mg of tungsten oxide as a catalyst.

[0252] Comparative Example 11

[0253] Comparative Example 11 used molybdenum oxide as a catalyst. The catalytic conditions were the same as in Example 8, using 8 mg of molybdenum oxide as the catalyst.

[0254] Comparative Example 12

[0255] Comparative Example 12 used the same carbon-supported nickel catalyst as Example 8, with the same catalytic conditions as Example 8, except that 10 mg of tungsten oxide was added.

[0256] Comparative Example 13

[0257] Comparative Example 13 used the same carbon-supported nickel catalyst as Example 8, with the same catalytic conditions as Example 8, except that 8 mg of molybdenum oxide was added.

[0258] Comparative Example 14

[0259] Comparative Example 13 used the same carbon-supported cobalt catalyst as Example 25, and the catalytic conditions were the same as in Example 8, except that 10 mg of tungsten oxide was added.

[0260] The catalysts of Comparative Examples 1-14 were evaluated for performance. The catalytic reaction conditions of Comparative Example 1 were the same as those of Example 1; the reaction conditions of Comparative Examples 2, 4, 5, and 6 were the same as those of Example 8; and the reaction conditions of Comparative Examples 3, 7, and 8 were the same as those of Example 10. The results of gas chromatography analysis are shown in Table 6.

[0261] Table 6: Reaction data for the reductive amination of benzaldehyde in Comparative Examples 1-8

[0262]

[0263] Comparing Tables 1-6, it can be seen that, compared with nickel-based or cobalt-based nanocatalysts without surface modification with tungsten oxide or molybdenum oxide (i.e., Comparative Examples 1-9), tungsten oxide (Comparative Example 10), molybdenum oxide (Comparative Example 11), and direct mixtures of molybdenum oxide or tungsten oxide with nickel-based or cobalt-based nanocatalysts (Comparative Examples 12-14), the nickel-based or cobalt-based catalysts modified with tungsten oxide or molybdenum oxide (e.g., Examples 1-54) provided by the present invention exhibit significantly improved catalytic activity in the reductive amination reaction. With a smaller amount of catalyst used, the product amine yield increases from 28.5% before modification to 99.5%, while simultaneously reducing the reduction temperature after catalyst oxidation from 150°C to 90°C, allowing the catalyst to be reduced under mild conditions.

[0264] Furthermore, compared to nickel-based or cobalt-based nanocatalysts without surface modification with tungsten oxide or molybdenum oxide (i.e., Comparative Examples 1-9), tungsten oxide (Comparative Example 10), molybdenum oxide (Comparative Example 11), and direct mixtures of molybdenum oxide or tungsten oxide with nickel-based or cobalt-based nanocatalysts (Comparative Examples 12-14), the catalysts obtained by depositing molybdenum oxide or tungsten oxide on the surface of nickel-based or cobalt-based nanocatalysts (as in Examples 1-54) exhibit a synergistic effect in the catalytic activity of the reductive amination reaction, resulting in unexpected technical effects. Therefore, modifying nickel-based / cobalt-based catalysts through tungsten oxide surface modification is an effective strategy to improve the reductive amination selectivity of the catalyst itself, and a low-cost, high-efficiency, highly selective, and highly antioxidant nickel-based / cobalt-based catalyst has been successfully developed.

[0265] Example 55: Investigation of multiple catalyst reuses

[0266] Under the same conditions as the hydrogenation catalytic efficiency test described in Example 8, catalyst 8 prepared in Example 8 of this invention or the carbon-supported nickel catalyst obtained in Comparative Example 1 were continuously applied, and samples were taken respectively. The selectivity data and changes in reactivity after application are as follows: Figure 1 As shown.

[0267] from Figure 1 As can be seen from the above, the product amine yield of catalyst 8 prepared in Example 8 of the present invention remained at around 99% after repeated use without significant change. However, the product amine yield of carbon-supported nickel catalyst without tungsten oxide modification decreased from the initial 28.5% to 20.1% after repeated use, showing a significant decrease.

[0268] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can make modifications to the above embodiments without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention should be as set forth in the claims.

Claims

1. An application in the preparation of multi-level amines as a catalyst for reductive amination reactions, characterized in that, The catalyst comprises a metal-based active component and a surface metal oxide active component; the metal-based active component comprises at least one of a nickel-based catalyst or a cobalt-based catalyst; the surface metal oxide active component comprises at least one of a tungsten oxide or a molybdenum oxide, and the surface metal oxide active component is deposited on the surface of the metal-based active component. The metal-based active component is a supported nickel-based catalyst or a supported cobalt-based catalyst; the mass ratio of metal atoms to the surface metal oxide active component in the metal-based active component is 1.0:0.3; or The metal-based active component is at least one of Raney nickel catalyst, nickel powder, nickel nanoparticles, cobalt nanoparticles, Raney cobalt catalyst, or cobalt powder; the mass ratio of metal atoms to the surface metal oxide active component in the metal-based active component is 1.000:0.

05.

2. In the application according to claim 1, the 4f orbital binding energy of tungsten in the tungsten oxide is between 30 eV and 42 eV; and / or The 3d binding energy of the molybdenum element is between 228 eV and 239 eV; and / or The deposition includes liquid phase deposition, solid phase deposition, or gas phase deposition.

3. The application according to any one of claims 1-2, wherein the catalyst further comprises a support.

4. The application according to claim 3, wherein the carrier comprises at least one selected from activated carbon, Al2O3, TiO2, ZrO2, CeO2, Fe2O3 and SiO2.

5. The application according to claim 3, wherein the method for preparing the supported nickel-based catalyst comprises: Nickel nitrate or its hydrate is dissolved in ethanol to obtain a nickel nitrate solution. The support is then mixed with ethanol and then mixed with the nickel nitrate solution. The mixture is stirred, dried, and calcined under a hydrogen-argon mixed gas atmosphere to obtain the supported nickel-based catalyst.

6. The application according to any one of claims 1-2, characterized in that, The catalyst preparation method includes: mixing tungsten oxide clusters, molybdenum oxide clusters, sodium tungstate, ammonium molybdate, or sodium molybdate with water to obtain a surface metal oxide active component solution; then impregnating the metal-based active component in the surface metal oxide active component solution; and reacting at a certain temperature under a hydrogen atmosphere to obtain the catalyst.

7. The application according to claim 6, wherein the certain temperature is 80℃-120℃; and / or The reaction time at a certain temperature is 1 hour to 12 hours; and / or The molar ratio of metal atoms in the metal-based active component to the tungsten oxide cluster, molybdenum oxide cluster, sodium tungstate, ammonium molybdate, or sodium molybdate is 1.0:0.1-1.0:4.

0.

8. In the application according to claim 6, the metal-based active component is a supported nickel-based catalyst or a supported cobalt-based catalyst; the mass ratio of metal atoms in the metal-based active component to the tungsten oxide cluster, molybdenum oxide cluster, sodium tungstate, ammonium molybdate or sodium molybdate is 1.0:0.1-1.0:0.

4.

9. In the application according to claim 6, the metal-based active component is at least one of Raney nickel catalyst, nickel powder, nickel nanoparticles, cobalt nanoparticles, Raney cobalt catalyst, or cobalt powder; the mass ratio of metal atoms in the metal-based active component to the tungsten oxide cluster, molybdenum oxide cluster, sodium tungstate, ammonium molybdate, or sodium molybdate is 1.000:0.025-1.000:0.

100.

10. The application according to any one of claims 1-2, characterized in that, The catalyst preparation method includes: mixing a metal-based active component with a tungsten oxide cluster, a molybdenum oxide cluster, sodium tungstate, ammonium molybdate, or sodium molybdate solid phase, and reacting the mixture at a specific temperature under a hydrogen-argon mixed gas atmosphere to obtain the catalyst.

11. The application according to claim 10, wherein the specific temperature is 120°C-240°C; and / or The reaction time at the specific temperature is 1 hour to 12 hours; and / or The tungsten oxide cluster includes at least one of ammonium metatungstate, silicotungstic acid, and phosphotungstic acid; and / or The molybdenum oxide cluster includes at least one of silicomolybdic acid and phosphomolybdic acid; and / or The mass ratio of metal atoms in the metal-based active component to the tungsten oxide cluster, molybdenum oxide cluster, sodium tungstate, ammonium molybdate, or sodium molybdate is 1.000:0.001-1.000:1.

000.

12. The application according to claim 11, wherein the metal-based active component is a supported nickel-based catalyst or a supported cobalt-based catalyst; the mass ratio of metal atoms in the metal-based active component to the tungsten oxide cluster, molybdenum oxide cluster, sodium tungstate, ammonium molybdate or sodium molybdate is 1.0:0.1-1.0:0.

4.

13. The application according to claim 11, wherein the metal-based active component is at least one of Raney nickel catalyst, nickel powder, nickel nanoparticles, cobalt nanoparticles, Raney cobalt catalyst, or cobalt powder; and the mass ratio of the metal atoms in the metal-based active component to the tungsten oxide cluster, molybdenum oxide cluster, sodium tungstate, ammonium molybdate, or sodium molybdate is 1.000:0.025-1.000:0.

100.

14. A method for preparing a multi-level amine, comprising: The catalyst described in any one of claims 1-5 or the catalyst prepared by the preparation method described in any one of claims 6-13, an aldehyde compound or a ketone compound, an amine source and a solvent are mixed and subjected to a reducing amination reaction under certain pressure and temperature conditions in a reducing gas atmosphere to obtain a multi-level amine.

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