A copper catalyst, its preparation method and use

Abstract

The application relates to a copper catalyst and a preparation method and application thereof, and relates to a Cu-ALPO4-5 molecular sieve prepared from CuNO3.3H2O, Al2O3, P2O5, Et3N, HF, H2O and the like as raw materials in a proper proportion at a certain temperature, which is used to catalyze the oxidation reaction of isoneral, and the catalytic effect is tested. Compared with the prior art, the copper catalyst prepared by the method has the advantages of simple preparation method, and the catalyst has good conversion rate and selectivity in the oxidation reaction of isoneral.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of catalyst preparation, in particular to a copper catalyst and a preparation method and application thereof. BACKGROUND

[0002] Isornic acid is an important chemical intermediate and is widely used. It can be used as a raw material for synthesizing lubricants, a medical intermediate, a raw material for metal soaps and metal processing fluids, and is also suitable for modifying alkyd resins to improve the resistance and impact resistance of the resins. It can also be used to produce various isornic acid esters, which can be used in the field of cosmetics. Its metal salt can be used as a catalyst for paint, a vinyl stabilizer, a polyvinyl chloride stabilizer, and a corrosion inhibitor, a tire adhesion aid, and other different purposes.

[0003] The preparation of isornic acid by aldehyde oxidation is the main production process in the industry, and the raw material is isornic aldehyde (3, 5, 5-trimethyl hexanal). It reacts with oxygen to obtain the corresponding acid, and the raw material isornic aldehyde is mainly prepared by olefin hydroformylation process. Generally, metal salts are used as catalysts to promote the decomposition of peroxo acid in the process of aldehyde oxidation to acid. Mostly Co, Mn, Cu and other salt types, such as acetate or naphthenate, which mainly promote the generation of peracid and its rapid decomposition. For example, in the process of producing acetic acid by oxidation of acetaldehyde, manganese acetate is used as a catalyst to make the peracetic acid generated during the oxidation of acetaldehyde decompose in time, preventing the accumulation, decomposition and explosion of peracetic acid.

[0004] However, at the same time, metal salts can promote the generation of free radicals, accelerate the initiation reaction of the chain, shorten the induction period of the reaction, and significantly shorten the reaction time. But with the rapid progress of the exothermic reaction, the reaction is difficult to control, and the selectivity is reduced. For example, in the process of producing propionic acid by oxidation of propyl aldehyde, when manganese acetate, cobalt acetate, iron acetate, copper nitrate and other catalysts are used, the selectivity of the products is greatly affected by the three catalysts, which is 5%-10% lower than that without catalyst. At the same time, during the reaction process, the reactor and pipeline of metal material will have Fe and other metal ions accumulated in the material after several cycles, which will promote the initiation of the reaction, make the reaction too fast, increase the heat release rate, and the temperature is not easy to control, especially it will lead to the increase of by-products and the decrease of isornic acid selectivity.

[0005] In summary, it is necessary to develop a stable catalyst with high activity and high selectivity for efficient preparation of isornic acid to meet the needs of industrial production. SUMMARY

[0006] The purpose of the present application is to overcome the defects of the prior art and provide a copper catalyst and a preparation method and application thereof. The prepared copper catalyst is a stable supported copper catalyst with high activity and high selectivity, which can be used in the process of producing isornic acid by oxidation of isornic aldehyde.

[0007] The object of the present application can be achieved by the following technical solutions.

[0008] The first aspect of the present application provides a preparation method of a copper catalyst, which comprises the following steps:

[0009] 1) preparing the catalyst precursor, the specific steps are as follows:

[0010] 1.1) adding an appropriate amount of 85 wt% phosphoric acid (H3PO4) into water, stirring at room temperature to obtain a slurry mixture;

[0011] 1.2) adding an appropriate amount of aqueous sodium tungstate (Na2WO4) solution into the slurry mixture in step 1.1), stirring at room temperature to obtain a slurry mixture;

[0012] 1.3) adding an appropriate amount of triethylamine (Et3N) solution into the slurry mixture in step 1.2), stirring at room temperature to obtain a slurry mixture;

[0013] 1.4) adding an appropriate amount of solid phosphorus pentoxide (P2O5) into the slurry mixture in step 1.3), stirring at room temperature to obtain a slurry mixture;

[0014] 1.5) adding an appropriate amount of solid aluminum trioxide (Al2O3) into the slurry mixture in step 1.4), stirring at room temperature to obtain a slurry mixture;

[0015] 1.6) adding an appropriate amount of hydrofluoric acid (HF) solution into the slurry mixture in step 1.5), stirring at room temperature to obtain a slurry mixture;

[0016] 1.7) adding an appropriate amount of solid copper nitrate trihydrate (CuNO3·3H2O) into the slurry mixture in step 1.6), and adding an appropriate amount of distilled water into the slurry mixture, stirring at room temperature to obtain the catalyst precursor;

[0017] 2) placing the catalyst precursor in a polytetrafluoroethylene liner, crystallizing at high temperature, and then placing the product after suction filtration in a vacuum dryer at high temperature to obtain a solid powder, and then placing the powder in a muffle furnace for high-temperature calcination to obtain the catalyst.

[0018] Further, the mass ratio of each raw material of the catalyst precursor is H3PO4: Na2WO4: CuNO3·3H2O: Al2O3: P2O5: Et3N: HF: H2O = 0.1-0.15: 0.3-2.0: 0.01-0.1: 0.1-2.0: 0.1-2.0: 0.1-2.5: 0.1-2.0: 300-600.

[0019] Preferably, H3PO4:Na2WO4:CuNO3.3H2O:Al2O3:P2O5:Et3N:HF:H2O = 0.12:1.0:0.05:1.0:1.5:1.7:1.4:400.

[0020] Further, in steps 1.1) to 1.6), the room temperature stirring time is 5-30 minutes, and in step 1.7), the room temperature stirring time is 2-5 hours.

[0021] Preferably, in steps 1.1) to 1.6), the room temperature stirring time is 15 minutes, and in step 1.7), the room temperature stirring time is 3h.

[0022] Further, in step 2), the high-temperature crystallization temperature is 100-300℃, and the crystallization time is 12-48 hours.

[0023] Preferably, in step 2), the high-temperature crystallization temperature is 200℃, and the crystallization time is 24 hours.

[0024] Further, in step 2), the product vacuum drying temperature is 100-150℃, and the drying time is 6-12 hours.

[0025] Preferably, in step 2), the product vacuum drying temperature is 120℃, and the drying time is 8 hours.

[0026] Further, in step 2), the high-temperature calcination temperature is 400-1000℃, and the calcination time is 3-12 hours.

[0027] Preferably, in step 2), the high-temperature calcination temperature is 700℃, and the calcination time is 6 hours.

[0028] The second aspect of the present application provides a copper catalyst prepared by the above preparation method.

[0029] Further, the copper catalyst comprises active center copper and its carrier; the content of the active center in the copper catalyst by mass percentage comprises: Cu 2%-5%; and the carrier is amphoteric Al2O3 carrier.

[0030] The third aspect of the present application provides an application of a copper catalyst, which is prepared by the above preparation method, and the copper catalyst is used for isononyl aldehyde oxidation catalysis.

[0031] Compared with the prior art, the present application has the following beneficial effects:

[0032] 1) The copper catalyst prepared by the present application can provide the conversion rate and selectivity of isononyl aldehyde oxidation reaction.

[0033] 2) The copper catalyst of the present application is simple to prepare and is a stable catalyst with high activity and selectivity. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 Scanning electron microscope image of the copper catalyst prepared in Example 1 of the present application. DETAILED DESCRIPTION

[0035] The present application will be described in detail below with reference to the accompanying drawings and specific examples. The following examples will help those skilled in the art to further understand the present application, but do not limit the present application in any form. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present application. These are within the scope of protection of the present application.

[0036] If the preparation means, materials, structures or composition ratio of the features are not explicitly stated in the technical solution, they are considered as common technical features disclosed in the prior art.

[0037] The present technical solution uses CuNO3·3H2O, Al2O3, P2O5, Et3N, HF, H2O, etc. as raw materials, and Cu-AlPO4-5 molecular sieve is prepared in a proper proportion at a certain temperature. The catalytic effect of the catalyst is tested in the oxidation reaction of isoneryl aldehyde. The experimental results show that the catalyst has good conversion rate and selectivity in the oxidation reaction of isoneryl aldehyde.

[0038] In the following examples, the raw materials used can be commercially purchased. Among them, 30wt% phosphoric acid aqueous solution is commercially available 85wt% phosphoric acid diluted in water. 40g of 85wt% phosphoric acid is added to a beaker, 66ml of water is added, and diluted to prepare.

[0039] Example 1

[0040] The present embodiment provides a preparation method of a copper catalyst, comprising the following steps:

[0041] Step 1, in 100g of 30wt% phosphoric acid aqueous solution, 1.0g of sodium tungstate aqueous solution is added dropwise, 1.7g of triethylamine, 1.4g of hydrofluoric acid, 1.5g of solid phosphorus pentoxide, and 1.0g of aluminum oxide are added, and each compound is stirred at room temperature for 15 minutes after dropwise addition.

[0042] Step 2, 0.05g of copper nitrate trihydrate is added to the solution obtained in step 1, 300g of distilled water is added, and stirred at room temperature for 3 hours.

[0043] Step 3, the solution obtained in step 2 is transferred to a polytetrafluoroethylene lined container, and crystallized at 200°C for 24 hours.

[0044] Step 4, the solution obtained in step 3 is filtered, vacuum dried at 120°C for 8 hours to obtain a solid powder.

[0045] Step 5, the solid powder obtained in step 4 is placed in a muffle furnace and calcined at 700°C for 6 hours to obtain a copper catalyst.

[0046] Figure 1 A scanning electron microscope picture of the copper catalyst prepared in Example 1 is provided. The obtained copper catalyst has a single crystal phase, good crystallinity, and a particle size of 40-50 nm.

[0047] Example 2

[0048] The present embodiment provides a method for preparing a copper catalyst, comprising the following steps:

[0049] Step 1, in 100g of a 30wt% aqueous phosphoric acid solution, 0.8g of a sodium tungstate aqueous solution is added dropwise, followed by the addition of 2.0g of triethylamine, 1.5g of hydrofluoric acid, 1.7g of solid phosphorus pentoxide, and 1.2g of aluminum oxide. Each compound is stirred at room temperature for 15 minutes after being added dropwise.

[0050] Step 2, 0.04g of copper nitrate trihydrate is added to the solution obtained in step 1, followed by the addition of 400g of distilled water. The mixture is stirred at room temperature for 3 hours.

[0051] Step 3, the solution obtained in step 2 is transferred to a polytetrafluoroethylene-lined container and crystallized at 200°C for 24 hours.

[0052] Step 4, the solution obtained in step 3 is filtered, vacuum dried at 120°C for 8 hours to obtain a solid powder.

[0053] Step 5, the solid powder obtained in step 4 is placed in a muffle furnace and calcined at 700°C for 6 hours to obtain a copper catalyst.

[0054] Example 3

[0055] The present embodiment provides a method for preparing a copper catalyst, comprising the following steps:

[0056] Step 1, in 100g of a 30wt% aqueous phosphoric acid solution, 0.8g of a sodium tungstate aqueous solution is added dropwise, followed by the addition of 2.0g of triethylamine, 1.5g of hydrofluoric acid, 1.7g of solid phosphorus pentoxide, and 1.2g of aluminum oxide. Each compound is stirred at room temperature for 15 minutes after being added dropwise.

[0057] Step 2, 0.04g of copper nitrate trihydrate is added to the solution obtained in step 1, followed by the addition of 400g of distilled water. The mixture is stirred at room temperature for 3 hours.

[0058] Step 3, the solution obtained in step 2 is transferred to a polytetrafluoroethylene-lined container and crystallized at 200°C for 24 hours.

[0059] Step 4, the solution obtained in Step 3 was suction filtered and vacuum dried at 120 °C for 8 hours to obtain a solid powder.

[0060] Step 5, the solid powder obtained in Step 4 was placed in a muffle furnace and calcined at 700 °C for 6 hours to obtain a copper catalyst.

[0061] Example 4

[0062] The present example provides a method for preparing a copper catalyst, comprising the following steps:

[0063] Step 1, in 100 g of a 30 wt% aqueous phosphoric acid solution, 1.0 g of an aqueous sodium tungstate solution was added dropwise, followed by the dropwise addition of 0.8 g of triethylamine, 1.5 g of hydrofluoric acid, 1.0 g of solid phosphorus pentoxide, and 1.5 g of aluminum oxide. Each compound was stirred at room temperature for 15 minutes after being added dropwise.

[0064] Step 2, 0.05 g of copper nitrate trihydrate was added to the solution obtained in Step 1, and 300 g of distilled water was added. The mixture was stirred at room temperature for 3 hours.

[0065] Step 3, the solution obtained in Step 2 was transferred to a polytetrafluoroethylene-lined container and crystallized at 200 °C for 24 hours.

[0066] Step 4, the solution obtained in Step 3 was suction filtered and vacuum dried at 120 °C for 8 hours to obtain a solid powder.

[0067] Step 5, the solid powder obtained in Step 4 was placed in a muffle furnace and calcined at 700 °C for 6 hours to obtain a copper catalyst.

[0068] Example 5

[0069] The present example provides a method for preparing a copper catalyst, comprising the following steps:

[0070] Step 1, in 100 g of a 30 wt% aqueous phosphoric acid solution, 1.0 g of an aqueous sodium tungstate solution was added dropwise, followed by the dropwise addition of 2.0 g of triethylamine, 1.0 g of hydrofluoric acid, 1.5 g of solid phosphorus pentoxide, and 1.5 g of aluminum oxide. Each compound was stirred at room temperature for 15 minutes after being added dropwise.

[0071] Step 2, 0.04 g of copper nitrate trihydrate was added to the solution obtained in Step 1, and 300 g of distilled water was added. The mixture was stirred at room temperature for 3 hours.

[0072] Step 3, the solution obtained in Step 2 was transferred to a polytetrafluoroethylene-lined container and crystallized at 200 °C for 24 hours.

[0073] Step 4, the solution obtained in Step 3 was suction filtered and vacuum dried at 120 °C for 8 hours to obtain a solid powder.

[0074] Step 5, the solid powder obtained in step 4 was placed in a muffle furnace and calcined at 700℃ for 6 hours to obtain the copper catalyst.

[0075] Test Example

[0076] The test example is used to illustrate the application of the copper catalyst prepared in examples 1-5 in the oxidation catalytic reaction of isononyl aldehyde.

[0077] In a polytetrafluoroethylene liner, 50ml of acetonitrile, 0.25g of the prepared copper catalyst, and 2.8g of isononyl aldehyde were added, and the liner was placed in a high-pressure reaction kettle, 800kPa of oxygen was applied, the temperature was raised at a rate of 5℃ / min to 35℃, 45℃ and 55℃ respectively. The reaction time was 15 minutes, after the reaction, the reaction liquid was centrifuged to separate the catalyst from the reaction liquid, and finally high performance liquid chromatography was used for chromatographic analysis.

[0078] Table 1 results of catalytic oxidation experiment

[0079]

[0080] The catalyst numbers 1-5 correspond to the copper catalysts prepared in examples 1-5 respectively.

[0081] Comparative Test Example

[0082] The comparative test example is used to compare the results of isononyl aldehyde oxidation reaction without catalyst.

[0083] In a polytetrafluoroethylene liner, 50ml of acetonitrile, and 2.8g of isononyl aldehyde were added, and the liner was placed in a high-pressure reaction kettle, 800kPa of oxygen was applied, the temperature was raised at a rate of 5℃ / min to 35℃, 45℃ and 55℃ respectively. The reaction time was 15 minutes, after the reaction, the reaction liquid was centrifuged to separate the catalyst from the reaction liquid, and finally high performance liquid chromatography was used for chromatographic analysis.

[0084] Table 2 results of oxidation experiment without catalyst

[0085]

[0086] From the test example and the comparative test example, it can be seen that the conversion rate and selectivity of the copper catalyst provided by the present application to the isononyl aldehyde oxidation reaction are greatly improved, the conversion rate of the reaction can be increased by 30% under the same reaction temperature; the selectivity is increased by 20% under the same reaction conditions.

[0087] The foregoing description of the embodiments has been presented for the purpose of illustration and description. It is not intended to be exhaustive or to limit the application to the precise form disclosed. Modifications and variations are possible in light of the above teachings or can be acquired from practice of the application. As well, the description is presented in the context of the preferred embodiments as a number of alternatives. It is not intended to limit the application to the precise form described.

Claims

1. Use of a copper catalyst, characterized in that, The copper catalyst is used for oxidation catalysis of isoneraldehyde; The preparation method of the copper catalyst comprises the following steps: 1) adding 85 wt% phosphoric acid, sodium tungstate solution, triethylamine solution, solid phosphorus pentoxide, solid aluminum oxide, hydrofluoric acid solution, solid copper nitrate trihydrate and distilled water in water in sequence to prepare a catalyst precursor at room temperature; 2) placing the catalyst precursor obtained in step 1) in a polytetrafluoroethylene liner, crystallizing at high temperature, vacuum drying the product after suction filtration at high temperature, obtaining a solid powder, and then calcining the powder in a muffle furnace at high temperature to obtain the copper catalyst.

2. Use of a copper catalyst according to claim 1, characterized in that, The specific process of step 1) is as follows: 1.1) adding an appropriate amount of 85 wt% phosphoric acid in water, stirring at room temperature to obtain a slurry mixture; 1.2) adding an appropriate amount of sodium tungstate solution to the slurry mixture in step 1.1), stirring at room temperature to obtain a slurry mixture; 1.3) adding an appropriate amount of triethylamine solution to the slurry mixture in step 1.2), stirring at room temperature to obtain a slurry mixture; 1.4) adding an appropriate amount of solid phosphorus pentoxide to the slurry mixture in step 1.3), stirring at room temperature to obtain a slurry mixture; 1.5) adding an appropriate amount of solid aluminum oxide to the slurry mixture in step 1.4), stirring at room temperature to obtain a slurry mixture; 1.6) adding an appropriate amount of hydrofluoric acid solution to the slurry mixture in step 1.5), stirring at room temperature to obtain a slurry mixture; 1.7) adding an appropriate amount of solid copper nitrate trihydrate to the slurry mixture in step 1.6) to obtain a slurry mixture, adding an appropriate amount of distilled water to the slurry mixture, stirring at room temperature to obtain a catalyst precursor.

3. Use of a copper catalyst according to claim 2, characterized in that, The mass ratio of each raw material of the catalyst precursor is phosphoric acid: sodium tungstate: copper nitrate trihydrate: aluminum oxide: phosphorus pentoxide: triethylamine: hydrofluoric acid: water = 0.1-0.15: 0.3-2.0: 0.01-0.1: 0.1-2.0: 0.1-2.0: 0.1-2.5: 0.1-2.0: 300-600.

4. Use of a copper catalyst according to claim 3, characterized in that, The mass ratio of each raw material of the catalyst precursor is phosphoric acid: sodium tungstate: copper nitrate trihydrate: aluminum oxide: phosphorus pentoxide: triethylamine: hydrofluoric acid: water = 0.12: 1.0: 0.05: 1.0: 1.5: 1.7: 1.4:

400.

5. Use of a copper catalyst according to claim 2, characterized in that, In steps 1.1) to 1.6), the stirring time at room temperature is 5-30 minutes; In step 1.7), the stirring time at room temperature is 1-5 hours.

6. Use of a copper catalyst according to claim 1, characterized in that, In step 2), the high-temperature crystallization temperature is 100-300°C, and the crystallization time is 12-48 hours; The vacuum drying temperature of the product is 100-150°C, and the drying time is 6-12 hours; The high-temperature calcination temperature is 400-1000°C, and the calcination time is 3-12 hours.

7. Use of a copper catalyst according to claim 6, characterized in that, In step 2), the high-temperature crystallization temperature is 200°C, and the crystallization time is 24 hours; The vacuum drying temperature of the product is 120°C, and the drying time is 8 hours; The high-temperature calcination temperature is 700°C, and the calcination time is 6 hours.

8. Use of a copper catalyst according to claim 1, characterized in that, The copper catalyst comprises active center copper and its carrier.

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