A layered hydrogenation catalyst and its preparation method and application

Abstract

This invention discloses a layered hydrogenation catalyst, its preparation method, and its application. The layered hydrogenation catalyst has a layered thin film structure and its chemical formula is: A-(M-N). x / Y, where M-N are active components, A is a nitrogen-containing organic polymer, M is a metal compound, N is an auxiliary agent, x is the number of film layers, and Y is a support. The nitrogen-containing organic polymer, metal compound, and auxiliary agent are uniformly distributed on the surface of the support. The layered hydrogenation catalyst of this invention utilizes the coordination effect of metal compounds and heteroatoms to self-assemble layer by layer, forming a sheet-like layered structure. In the hydrogenation reaction, the catalyst is slowly released into the reaction system, exhibiting excellent catalytic activity for the hydrogenation reaction.

Description

Technical Field

[0001] The invention relates to a layered hydrogenation catalyst, in particular to a supported layered hydrogenation catalyst for preparing 1,3-propylene glycol by hydrogenating 3-hydroxypropionaldehyde and a preparation method thereof, as well as application of the catalyst in preparing 1,3-propylene glycol by hydrogenating 3-hydroxypropionaldehyde, belonging to the technical field of catalyst preparation and application. Background Art

[0002] 1,3-propylene glycol (1,3-PDO for short) is an important organic chemical raw material, widely used in the synthesis of plasticizers, detergents, preservatives, emulsifiers, and can also be used in food, cosmetics, pharmaceuticals and other industries, but its most important use is to replace ethylene glycol and butanediol to produce polyol polyesters and prepare poly(1,3-propylene terephthalate) fibers (PTT for short), which are then used in clothing, carpets, electronics, automobiles and other markets. Benefiting from the growth of the PTT market size, the global 1,3-propylene glycol market size reached US$402 million in 2020, and is expected to reach US$691 million in 2025, with a CAGR of 11.4%. Therefore, the technical development of 1,3-propylene glycol has received widespread attention.

[0003] At present, the production technology of 1,3-PDO mainly includes chemical method and biological fermentation method. However, both preparation methods produce the intermediate product 3-hydroxypropanal (3-HPA). 3-HPA can be converted into 1,3-propylene glycol by biological enzymes or hydrogenation catalysts. The catalysts reported for hydrogenating 3-hydroxypropanal to 1,3-propylene glycol mainly include the following three types: (1) Raney-type catalysts; (2) supported catalysts with platinum, palladium and nickel as active components; (3) biological enzymes. The main problems currently exist are: (1) The chemical properties of 3-HPA are unstable and it is very easy to polymerize, resulting in the intensification of side reactions as the temperature rises during the hydrogenation process; (2) The existing Raney-type catalysts and supported catalysts with platinum, palladium and nickel as active components cannot be recycled in the autoclave reaction; therefore, the selection of highly active, highly selective, mild and recyclable hydrogenation catalysts has become an urgent problem to be solved. Summary of the invention

[0004] The main purpose of the present invention is to provide a layered hydrogenation catalyst and a preparation method and application thereof, so as to overcome the deficiencies existing in the prior art.

[0005] To achieve the aforementioned object of the invention, the technical solution adopted by the embodiment of the present invention includes:

[0006] The present invention provides a layered hydrogenation catalyst, which has a layered film structure and a chemical formula of: A-(MN) x / Y, wherein MN is the active component, A is a nitrogen-containing organic polymer, M is a metal compound, N is an additive, x is the number of layers of the film, and Y is a carrier, and the nitrogen-containing organic polymer, metal compound and additive are uniformly distributed on the surface of the carrier.

[0007] Furthermore, the metal content in the active component is greater than 5 μg.

[0008] Furthermore, the metal elements contained in the metal compound include any one or a combination of two or more of group VII, IB, and IIB metal elements; preferably, the metal elements include any one or a combination of two or more of Pd, Pt, Ru, Rh, Os, Au, Ni, Fe, Co, Ir, Cu, and Zn.

[0009] Furthermore, the metal compound includes metal chloride and / or metal nitrate.

[0010] Furthermore, the auxiliary agent includes a compound combination containing any one or two of dinitrogen / oxygen or polynitrogen / oxygen organic compounds, preferably including any one or a combination of two or more of pyridine organic compounds, imidazole organic compounds, and thiazole organic compounds, and is particularly preferably any one or a combination of two or more of dipyridine, quadrapyridine, spiropyridine, imidazole or thiazole.

[0011] Furthermore, x>5 layers, preferably 10-50 layers.

[0012] The present invention also provides a method for preparing the aforementioned layered hydrogenation catalyst, comprising:

[0013] The carrier is immersed in a nitrogen-containing organic polymer solution to form an organic polymer / carrier complex; the organic polymer / carrier complex is immersed in a metal compound solution to form an organic polymer-metal compound / carrier complex;

[0014] The organic polymer-metal compound / carrier complex is immersed in an additive solution to form an organic polymer-metal compound-additive / carrier complex;

[0015] The above steps are repeated for multiple times to obtain a layered hydrogenation catalyst having a plurality of layered film structures through self-assembly.

[0016] Furthermore, the preparation method of the layered hydrogenation catalyst also includes a carrier pretreatment, specifically: heating the carrier in a mixed solution of concentrated sulfuric acid and hydrogen peroxide for a first time; after completing the first heating, heating the carrier in a mixed solution of water, hydrogen peroxide and ammonia water for a second time; wherein the mass ratio of concentrated sulfuric acid to hydrogen peroxide in the first heating is 1:1-20:1, preferably 1:1-10:1; the heating temperature is 30-80°C, preferably 50-80°C; the heating time is 10-160min, preferably 10-80min; the mass ratio of water, hydrogen peroxide and ammonia water in the second heating is 1:1:1-20:1:1, preferably 1:1:1-10:1:1; the heating temperature is 30-80°C, preferably 50-80°C; the heating time is 10-160min, preferably 10-80min.

[0017] The present invention also provides the use of the aforementioned layered hydrogenation catalyst in the preparation of 1,3-propylene glycol by hydrogenation of 3-hydroxypropanal.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) The layered hydrogenation catalyst for preparing 1,3-propylene glycol by hydrogenation of 3-hydroxypropionaldehyde provided by the present invention is innovative in the structure of the catalyst. The metal active component is loaded on the carrier through the coordination effect with the organic polymer, and then the metal active component and the auxiliary agent are evenly distributed on the carrier surface in layers through the coordination effect between the metal and the auxiliary agent, thereby avoiding the agglomeration of the metal. The synthesized catalyst has uniform size and is evenly distributed on the carrier surface in layers in the form of sheets.

[0020] (2) The main function of the carrier pretreatment in the preparation method of the layered hydrogenation catalyst of the present invention is to generate hydroxyl groups on the carrier surface, so that the organic polymer and the hydroxyl groups on the carrier are stably coated on the carrier surface through cross-linking.

[0021] (3) The layered hydrogenation catalyst prepared by the present invention has a low metal loading (taking 10 layers as an example, the metal content is at the ppm level) and a controllable content of active components. The content of active components can be controlled by the number of loaded layers, and the size of the carrier can be adjusted according to the size of the reactor, which is flexible and controllable.

[0022] (4) Benefiting from the structural characteristics of the layered hydrogenation catalyst of the present invention, in the reaction of hydrogenating 3-HPA to 1,3-PDO, the metal active components are uniformly released from the carrier into the system in the form of nanoparticles, which promotes the hydrogenation conversion of 3-HPA, improves the selectivity of the hydrogenation reaction of 3-hydroxypropanal, reduces the occurrence of side reactions, and achieves high selectivity of the product; in addition, the layered hydrogenation catalyst of the present invention can be recycled, and the catalyst participates in the reaction by converting different valence states of the metal, and the catalyst does not need to be reduced and is easy to store. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 In one embodiment of the present application, PEI-[Ni(NO 3 ) 2 -Bpy] 10 / SEM scan of quartz multilayer thin film catalyst.

[0025] Figure 2 In one embodiment of the present application, PEI-[Ni(NO 3 ) 2 -Bpy] 10 / SEM scan of quartz multilayer thin film catalyst after 5 cycles of reaction. DETAILED DESCRIPTION

[0026] In order to overcome the deficiencies of the prior art, the inventors of this case have proposed the technical solution of the present invention after long-term research and extensive practice. The present invention mainly provides a catalyst used in the process of producing 1,3-propylene glycol by hydrogenation of 3-hydroxypropanal, which is a self-assembled composite thin film catalyst, i.e., a layered hydrogenation catalyst. The catalyst is mainly composed of active components (metal compounds and additives) and a carrier. The coordination effect of metal compounds and heteroatoms is utilized to self-assemble layer by layer to form a layered structure with sheet-like distribution. In the hydrogenation reaction, the catalyst is slowly released into the reaction system, and exhibits good catalytic activity for the hydrogenation reaction. The technical solution, its implementation process and principle, etc. will be further explained as follows.

[0027] One aspect of an embodiment of the present invention provides a layered hydrogenation catalyst, wherein the layered hydrogenation catalyst has a layered film structure, and its chemical formula is: A-(MN) x / Y, wherein MN is the active component, A is a nitrogen-containing organic polymer, M is a metal compound, N is an additive, x is the number of layers of the film, and Y is a carrier, and the nitrogen-containing organic polymer, metal compound and additive are uniformly distributed on the surface of the carrier.

[0028] In some preferred embodiments, the nitrogen-containing organic polymer may include any one or a combination of two or more of polypropyleneimine (PPI), polyvinylamide (PEI), polyethylenediamine (PEG), etc., but is not limited thereto.

[0029] In some preferred embodiments, the metal content in the active component is greater than 5 μg.

[0030] In some preferred embodiments, the metal elements contained in the metal compound may include any one or a combination of two or more of group VII, IB, IIB metal elements, etc., but are not limited thereto; preferably, the metal elements may include any one or a combination of two or more of Pd, Pt, Ru, Rh, Os, Au, Ni, Fe, Co, Ir, Cu, Zn, etc., but are not limited thereto.

[0031] In some preferred embodiments, the metal compound may include metal chlorides and / or metal nitrates.

[0032] In some preferred embodiments, the auxiliary agent may include a compound combination containing any one or two of dinitrogen / oxygen or polynitrogen / oxygen organic compounds, preferably including one or a combination of two or more of pyridine organic compounds, imidazole organic compounds, thiazole organic compounds, etc., and particularly preferably any one or a combination of two or more of dipyridine, quadrapyridine, spiropyridine, imidazole, thiazole, etc., but not limited thereto.

[0033] In some preferred embodiments, x>5 layers, preferably 10-50 layers.

[0034] In some preferred embodiments, the carrier may include any one of a quartz substrate, a silicon wafer, a glass slide, etc., but is not limited thereto.

[0035] The layered hydrogenation catalyst for preparing 1,3-propylene glycol by hydrogenating 3-hydroxypropionaldehyde provided in the embodiment of the present invention is innovative in the structure of the catalyst. The metal active component is loaded on the carrier through the coordination effect with the organic polymer, and then the metal active component and the auxiliary agent are evenly distributed on the carrier surface in layers through the coordination effect between the metal and the auxiliary agent, thereby avoiding the agglomeration of the metal. The synthesized catalyst has uniform size and is evenly distributed on the carrier surface in layers in the form of sheets.

[0036] Another aspect of an embodiment of the present invention provides a method for preparing the aforementioned layered hydrogenation catalyst, comprising:

[0037] The carrier is immersed in a nitrogen-containing organic polymer solution to form an organic polymer / carrier complex; the organic polymer / carrier complex is immersed in a metal compound solution to form an organic polymer-metal compound / carrier complex;

[0038] The organic polymer-metal compound / carrier complex is immersed in an additive solution to form an organic polymer-metal compound-additive / carrier complex;

[0039] The above steps are repeated for multiple times to obtain a layered hydrogenation catalyst having a plurality of layered film structures through self-assembly.

[0040] In some preferred embodiments, the preparation method of the layered hydrogenation catalyst further includes a carrier pretreatment, specifically: heating the carrier in a mixed solution of concentrated sulfuric acid and hydrogen peroxide for a first time; after completing the first heating, heating the carrier in a mixed solution of water, hydrogen peroxide and ammonia water for a second time; wherein the mass ratio of concentrated sulfuric acid to hydrogen peroxide in the first heating is 1:1-20:1, preferably 1:1-10:1; the heating temperature is 30-80°C, preferably 50-80°C; the heating time is 10-160min, preferably 10-80min; the mass ratio of water, hydrogen peroxide and ammonia water in the second heating is 1:1:1-20:1:1, preferably 1:1:1-10:1:1; the heating temperature is 30-80°C, preferably 50-80°C; the heating time is 10-160min, preferably 10-80min.

[0041] In some preferred embodiments, the concentration of the nitrogen-containing organic polymer solution is 5-500 mg / mL, preferably 5-100 mg / mL, and the infiltration time is 10-180 min, preferably 10-80 min.

[0042] In some preferred embodiments, the concentration of the metal compound solution is 1-500 mmol / L, preferably 1-100 mmol / L, and the immersion time is 10-180 min, preferably 10-80 min.

[0043] In some preferred embodiments, the concentration of the auxiliary agent solution is 1-500 mmol / L, preferably 11100 mmol / L; the infiltration time is 10-180 min, preferably 10-80 min.

[0044] Another aspect of the embodiments of the present invention provides the use of the aforementioned layered hydrogenation catalyst in the hydrogenation of 3-hydroxypropanal to prepare 1,3-propylene glycol.

[0045] In the reaction of hydrogenating 3-HPA to produce 1,3-PDO, the metal active components are uniformly released from the carrier into the system in the form of nanoparticles, which promotes the hydrogenation conversion of 3-HPA, improves the selectivity of the hydrogenation reaction of 3-hydroxypropanal, reduces the occurrence of side reactions, and achieves high selectivity of the product.

[0046] Another aspect of the embodiments of the present invention further provides a method for preparing 1,3-propylene glycol, comprising:

[0047] A reaction system comprising the aforementioned layered hydrogenation catalyst and an aqueous solution of 3-hydroxypropanal is subjected to a hydrogenation reaction in a hydrogen atmosphere to produce 1,3-propylene glycol;

[0048] Wherein, the metal content in the layered hydrogenation catalyst in the reaction system is greater than 5 μg;

[0049] The process conditions of the hydrogenation reaction include: the hydrogenation reaction temperature is 35-80° C., the time is 30-300 min, the hydrogenation reaction pressure is 2-8 MPa, and the concentration of the aqueous solution containing 3-hydroxypropanal is 5-50 wt %.

[0050] In some preferred embodiments, the process conditions of the hydrogenation reaction include: the hydrogenation reaction temperature is 40-70°C, the time is 60-180 min, the hydrogenation reaction pressure is 3-6 MPa, and the concentration of the aqueous solution containing 3-hydroxypropanal is 5-30 wt%.

[0051] The technical solution of the present invention is described below through specific embodiments. It should be understood that one or more method steps mentioned in the present invention do not exclude the existence of other method steps before and after the combination steps or other method steps can be inserted before these explicitly mentioned steps; it should also be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention. Moreover, unless otherwise specified, the numbering of each method step is only a convenient tool for identifying each method step, and is not intended to limit the order of arrangement of each method step or to limit the scope of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the present invention without substantially changing the technical content.

[0052] Examples 1-12 use the method of the present invention to prepare a layered hydrogenation catalyst, which specifically includes the following steps:

[0053] (1) Place the carrier (quartz substrate, silicon wafer, glass slide) in a beaker containing concentrated sulfuric acid and hydrogen peroxide in a mass ratio of 6:5, heat at 60°C for 20 min, take it out, and wash it 5-6 times; then add it to a mixed solution of distilled water, hydrogen peroxide and ammonia in a mass ratio of 6:4:1, wash and dry.

[0054] (2) placing the carrier obtained in (1) into a 20 mg / mL nitrogen-containing organic polymer (PEI, PPI, PEG) solution, soaking for 10 min, rinsing, and drying;

[0055] (3) The support obtained in (2) was placed in a 5.0 mmol / L metal compound solution (IrCl 3 Aqueous solution, PdCl 2 Aqueous solution, FeCl 3 Aqueous solution, Ni(NO 3 ) 2 Aqueous solution, RuCl 2 Aqueous solution, Cu(NO 3 ) 2Aqueous solution, Co(NO 3 ) 2 aqueous solution), soak for 40 min, rinse, and dry;

[0056] (4) The carrier obtained in (3) was placed in a 5.0 mmol / L auxiliary agent solution (bipyridine (Bpy) ethanol solution, tetrapyridine (Bp) ethanol solution, spirofluorene pyridine (psf) ethanol solution, imidazole (Im) ethanol solution, thiazole (Thi) ethanol solution), soaked for 40 min, taken out, rinsed, and dried;

[0057] (5) Repeat (3) and (4) to form a layered hydrogenation catalyst having a multi-layered thin film structure.

[0058] Examples 1 to 12 are catalysts prepared by the method, and Comparative Examples 1 to 5 are commercial catalysts purchased on the market, and they are applied to the reaction of hydrogenating 3-hydroxypropanal to 1,3-propylene glycol, specifically as follows: the catalyst is placed in a 50ml high-pressure reactor, 10g of a 10% 3-HPA aqueous solution is added, nitrogen is repeatedly passed through 3 times to exhaust the air, and then hydrogen is flushed into 6Mpa, heated to 60°C, and reacted for 3h under stirring. The reaction results of Examples 1 to 10 and Comparative Examples 1 to 5 are shown in Table 1 (if it is a layered catalyst of Examples 1-10, one piece is placed in the system, and if it is a supported catalyst, the amount placed is 0.1g).

[0059] Table 1 Composition of different catalysts and their application in hydrogenation of 3-hydroxypropanal to 1,3-PDO

[0060]

[0061] As can be seen from Table 1, although the catalytic activities of Examples 1-12 and Comparative Examples 1-5 in the reaction are not much different, the content of metal active components in Examples 1-10 is much lower than that in Comparative Examples 1-5, which greatly reduces the cost of the catalyst.

[0062] In the experiment of hydrogenation of 3-hydroxypropanal to 1,3-PDO, PEI-[Ni(NO 3 ) 2 -Bpy] 10 / Quartz,Ni / Al 2 O 3 , Raney nickel, and Pd / C were used as catalysts for a cyclic reaction and the cyclic performance of the catalyst was tested, as shown in Table 2.

[0063] Table 2 Cyclic performance experiments of different catalysts in hydrogenation of 3-hydroxypropanal to 1,3-PDO

[0064]

[0065] It can be seen from Table 2 that PEI-[Ni(NO 3 ) 2 -Bpy] 10 / quartz multilayer film catalysts showed excellent catalytic activity in the cyclic reaction, while the supported and Raney catalysts had significantly reduced activity in the second round of reaction; in addition, Figure 1 and Figure 2 PEI-[Ni(NO 3 ) 2 -Bpy] 10 / SEM scans of the quartz multilayer film catalyst before reaction and after 5 cycles of reaction. It can be seen from the figure that there is no obvious change in the morphology of the catalyst after 5 cycles of reaction.

[0066] In addition, the inventors of this case also referred to the aforementioned embodiments and conducted experiments with other raw materials, process operations, and process conditions described in this specification, and obtained relatively ideal results.

[0067] Although the present invention has been described with reference to illustrative embodiments, it will be appreciated by those skilled in the art that various other changes, omissions and / or additions may be made without departing from the spirit and scope of the present invention and that the elements of the embodiments may be replaced by substantial equivalents. In addition, many modifications may be made without departing from the scope of the present invention to adapt specific circumstances or materials to the teachings of the present invention. Therefore, it is not intended herein to limit the present invention to the disclosed specific embodiments for performing the present invention, but it is intended that the present invention will include all embodiments within the scope of the appended claims. In addition, unless specifically stated, any use of the terms first, second, etc. does not indicate any order or importance, but rather uses the terms first, second, etc. to distinguish one element from another.

Claims

1. Use of a layered hydrogenation catalyst in the hydrogenation of 3-hydroxypropanal to produce 1,3-propylene glycol, characterized in that: The layered hydrogenation catalyst has a layered film structure, and its chemical formula is: A-(MN) x / Y, wherein MN is the active component, A is a nitrogen-containing organic polymer, M is a metal compound, N is an additive, x is the number of layers of the film and x>5, and Y is a carrier; The nitrogen-containing organic polymer, the metal compound and the auxiliary agent are uniformly distributed on the surface of the carrier; wherein the metal element in the metal compound is loaded on the carrier through coordination with the nitrogen-containing organic polymer, and the metal compound and the auxiliary agent are uniformly distributed on the surface of the carrier in layers through the coordination effect between the metal element in the metal compound and the auxiliary agent; Wherein, the nitrogen-containing organic polymer is selected from any one of polypropylene imine, polyvinyl amide, and polyethylene diamine, or a combination of two or more thereof; the metal element contained in the metal compound is selected from at least one of Pd, Pt, Ru, Rh, Os, Au, Ni, Fe, Co, Ir, Cu, and Zn; the auxiliary agent is selected from any one of dipyridine, quadrapyridine, spirofluorene pyridine, imidazole, and thiazole, or a combination of two or more thereof; The preparation method of the layered hydrogenation catalyst comprises: impregnating a carrier in a nitrogen-containing organic polymer solution to form an organic polymer / carrier composite; impregnating the organic polymer / carrier composite in a metal compound solution to form an organic polymer-metal compound / carrier composite; impregnating the organic polymer-metal compound / carrier composite in an additive solution to form an organic polymer-metal compound-additive / carrier composite; and repeating the above steps for more than 5 times to obtain a layered hydrogenation catalyst having a plurality of layered film structures by self-assembly.

2. The use according to claim 1, characterized in that: The metal content in the active component is >5 μg.

3. The use according to claim 1, characterized in that: The metal compound includes metal chloride and / or metal nitrate.

4. The use according to claim 1, characterized in that: x is 10-50.

5. The use according to claim 1, characterized in that: The carrier includes any one of a quartz substrate, a silicon wafer or a glass slide.

6. The use according to claim 1, characterized in that: The preparation method further includes a carrier pretreatment, specifically: heating the carrier once in a mixed solution of concentrated sulfuric acid and hydrogen peroxide; after the first heating is completed, heating the carrier twice in a mixed solution of water, hydrogen peroxide and ammonia water; Wherein, the mass ratio of concentrated sulfuric acid to hydrogen peroxide in the primary heating is 1:1-20:1, the heating temperature is 30-80°C, and the heating time is 10-160min; In the secondary heating, the mass ratio of water, hydrogen peroxide and ammonia water is 1:1:1-20:1:1, the heating temperature is 30-80°C, and the heating time is 10-160min.

7. The use according to claim 6, characterized in that: The mass ratio of concentrated sulfuric acid to hydrogen peroxide in the primary heating is 1:1-10:1, the heating temperature is 50-80°C, and the heating time is 10-80min.

8. The use according to claim 6, characterized in that: In the secondary heating, the mass ratio of water, hydrogen peroxide and ammonia water is 1:1:1-10:1:1, the heating temperature is 50-80°C, and the heating time is 10-80min.

9. The use according to claim 1, characterized in that: The concentration of the nitrogen-containing organic polymer solution is 5-500 mg / mL, and the infiltration time is 10-180 min.

10. The use according to claim 9, characterized in that: The concentration of the nitrogen-containing organic polymer solution is 5-100 mg / mL, and the infiltration time is 10-80 min.

11. The use according to claim 1, characterized in that: The concentration of the metal compound solution is 1-500 mmol / L, and the infiltration time is 10-180 min.

12. The use according to claim 11, characterized in that: The concentration of the metal compound solution is 1-100 mmol / L, and the infiltration time is 10-80 min.

13. The use according to claim 1, characterized in that: The concentration of the auxiliary agent solution is 1-500 mmol / L, and the infiltration time is 10-180 min.

14. The use according to claim 13, characterized in that: The concentration of the auxiliary agent solution is 1-100 mmol / L, and the infiltration time is 10-80 min.

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