A method for preparing a copper-based catalyst

Abstract

This invention discloses a method for preparing a copper-based catalyst, comprising the following steps: (1) placing the material into a processing tank and adding deionized water to the processing tank; (2) sealing the processing tank, introducing carbon dioxide and oxygen-containing gas into the processing tank, and heating and stirring the mixture in the processing tank; after the carbon dioxide in the processing tank is no longer consumed, cooling is started, and solid 1 is obtained after cooling to room temperature; (3) combining the solid 1 with a support to obtain solid 2; (4) drying and calcining the solid 2, then flaking, crushing, and reducing it to obtain a copper-based catalyst. The material in step (1) includes metallic copper, zinc, and magnesium acetate. Since this invention does not add nitrates and sodium salts, the production process does not generate NOx or leave sodium ions, thus effectively avoiding the problem of high preparation costs of copper-based catalysts due to the need for secondary treatment of NOx and sodium ions.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of catalyst preparation, and particularly relates to a preparation method of a copper-based catalyst. BACKGROUND

[0002] The copper-based catalyst is a catalyst commonly used in the fields of petroleum chemical industry and coal chemical industry, and is widely applied due to its superior catalytic performance and low price. At present, the copper-based catalyst has an irreplaceable role in the reactions of methanol synthesis, organic hydrogenation and dehydrogenation, and oxidation. The production method of the copper-based catalyst commonly used in the prior art is a coprecipitation method, which mostly uses copper nitrate as a raw material and a carbonate (mainly sodium carbonate or sodium bicarbonate) as a precipitant, so that a large amount of NOx is generated in the production process, and therefore the tail gas needs to be further treated to meet the emission standard of the tail gas, thereby greatly increasing the production cost of the catalyst. Meanwhile, since sodium carbonate or sodium bicarbonate is mainly used as the precipitant in the prior art, a large amount of sodium ions is also left in the preparation process, and therefore a large amount of water needs to be used for washing to remove the residual sodium ions, thereby further increasing the production cost of the catalyst. SUMMARY

[0003] The application is proposed to solve the technical problems that a large amount of sodium ions is left and a large amount of NOx is generated in the preparation process of the copper-based catalyst in the prior art, and to achieve the technical effect that the preparation process of the copper-based catalyst is free of NOx generation and free of sodium ion residue.

[0004] To achieve the above object, the application adopts the following technical scheme:

[0005] The application provides a preparation method of a copper-based catalyst, which comprises the following steps:

[0006] (1) putting materials into a treatment tank, and adding deionized water into the treatment tank;

[0007] (2) sealing the treatment tank, introducing carbon dioxide and an oxygen-containing gas into the treatment tank, and heating and stirring the mixture in the treatment tank; after the carbon dioxide in the treatment tank is no longer consumed, cooling is started, and solid 1 is obtained after the temperature is reduced to room temperature;

[0008] (3) compounding the solid 1 with a carrier to obtain solid 2;

[0009] (4) drying, calcining, tabletting, crushing and reducing the solid 2 to obtain the copper-based catalyst.

[0010] In the step (1), the materials comprise copper, zinc and magnesium acetate.

[0011] Further, the mass ratio of the copper and the zinc is (0.1-10):1, and the mass of the magnesium acetate accounts for 2%-10% of the total mass of the copper and the zinc.

[0012] Further, the pressure in the treatment tank after the carbon dioxide and the oxygen-containing gas are introduced is 1-3 MPa, and the partial pressure ratio of the carbon dioxide and the oxygen-containing gas is 1:(5-10).

[0013] Further, the oxygen-containing gas is any one of oxygen and air.

[0014] Further, the liquid level of the deionized water in the treatment tank is higher than the height of the material.

[0015] Further, the conductivity of the deionized water is less than 1 μs / cm.

[0016] Further, the heating temperature in the step (2) is 120-300 ℃, and the stirring rate is 2000-5000 r / min.

[0017] Further, the carrier in the step (3) is any one of alumina, zirconia, silica and molecular sieve, and the mass of the carrier is 20%-150% of the mass of the solid.

[0018] Further, the drying temperature in the step (4) is 90-120 ℃, and the drying time is 4-8 h.

[0019] Further, the calcination temperature in the step (4) is 250-350 ℃, and the calcination time is 1-3 h.

[0020] Further, the atmosphere used in the reduction in the step (4) is hydrogen-nitrogen mixed gas with a hydrogen content of 10%-50%, the final temperature of the reduction is 210-250 ℃, and the total volume concentration of carbon dioxide and carbon monoxide in the tail gas at the end of the reduction is less than 0.001%.

[0021] The present application has the following beneficial effects:

[0022] The present invention provides a method for preparing a copper-based catalyst using metallic copper, zinc, and magnesium acetate. During the preparation process, the reaction rate of metallic copper and zinc with CO2 and oxygen is accelerated by the promoting effect of magnesium acetate, forming a copper-zinc basic carbonate precursor. Finally, the copper-based catalyst is obtained through further processing of this precursor. Since the entire preparation process does not involve the addition of nitrates and does not require carbonates or sodium salts as precipitants, no NOx is generated during production, and no sodium ions remain. This effectively avoids the problem of high preparation costs for copper-based catalysts caused by the need for secondary treatment of generated NOx and residual sodium ions. Detailed Implementation

[0023] This invention provides a method for preparing a copper-based catalyst to solve the technical problem in the prior art where a large amount of sodium ions remain and a large amount of NOx is generated during the preparation of copper-based catalysts.

[0024] The overall concept adopted in this invention is as follows:

[0025] The present invention discloses a method for preparing a copper-based catalyst, comprising the following steps:

[0026] (1) Put the material into the treatment tank and add deionized water to the treatment tank;

[0027] (2) Seal the processing tank, introduce carbon dioxide and oxygen-containing gas into the processing tank, and heat and stir the mixture in the processing tank; after the carbon dioxide in the processing tank is no longer consumed, start cooling, and after cooling to room temperature, solid 1 can be obtained;

[0028] (3) The solid 1 is combined with the carrier to obtain solid 2;

[0029] (4) After drying and calcining the solid 2, it is granulated, crushed and reduced to obtain a copper-based catalyst.

[0030] The materials mentioned in step (1) include metallic copper, zinc, and magnesium acetate. The mass ratio of metallic copper to zinc is (0.1-10):1, and the mass of magnesium acetate accounts for 2%-10% of the sum of the masses of metallic copper and zinc. The pressure after introducing carbon dioxide and oxygen-containing gas into the treatment tank is 1-3 MPa, and the partial pressure ratio of carbon dioxide and oxygen-containing gas is 1:(5-10). The oxygen-containing gas is any one of oxygen or air. The level of deionized water in the treatment tank is higher than the height of the material, i.e., the amount of deionized water added should be such that the material is completely submerged in the deionized water. The conductivity of the deionized water is less than 1 μS / cm.

[0031] The reason that the prior art preparation of copper-based catalyst produces a large amount of NOx and a large amount of residual sodium ions is that the raw material contains nitrate and sodium salt. The present application starts from the source, and the materials used are metallic copper, zinc and magnesium acetate. In the preparation process, the promotion of magnesium acetate accelerates the reaction rate of metallic copper, zinc, CO2 and oxygen, forming a copper-zinc basic carbonate precursor. Finally, the copper-based catalyst is obtained by further processing the precursor. The entire preparation process does not produce NOx and does not leave sodium ions because no nitrate is added and no carbonate or sodium salt is needed as a precipitant.

[0032] To make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the embodiments of the present application will be described more clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the described embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without any creative effort belong to the scope of protection of the present application. Unless otherwise defined, the technical terms or scientific terms used herein should have the usual meanings understood by those of ordinary skill in the art to which the present application belongs.

[0033] The terms "first", "second", and similar terms used in the patent application specification and claims of the present application do not represent any order, quantity or importance, but are only used to distinguish different components. Similarly, unless the context clearly indicates otherwise, the singular form "one", "an" or "the" and the like do not represent a quantity limitation, but represent the existence of at least one. The terms "include" or "contain" and the like mean that the elements or objects appearing before "include" or "contain" cover the features, whole, steps, operations, elements and / or components listed after "include" or "contain", and do not exclude the existence or addition of one or more other features, whole, steps, operations, elements, components and / or their collections. "Up", "down", "left", "right" and the like are only used to represent relative positional relationships, and when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0034] Embodiment 1

[0035] A preparation method of a copper-based catalyst, comprising the following steps:

[0036] (1) Put 1 g of metallic copper particles and 10 g of metallic zinc particles together with 1.1 g of magnesium acetate into a treatment tank, add 500 mL of deionized water with an electrical conductivity less than 1 μs / cm to the treatment tank, stir the magnesium acetate solvent in the deionized water, and ensure that the deionized water can completely immerse the metallic copper and zinc.

[0037] (2) Seal the treatment tank and heat it to 120°C. Introduce carbon dioxide and air into the treatment tank to maintain the total pressure inside the treatment tank at 2 MPa and the partial pressure ratio of the air to the carbon dioxide at 7:1. Adjust the stirring speed inside the treatment tank to 3000 r / min and start the reaction. When the pressure inside the treatment tank no longer changes within 1 hour and the carbon dioxide gas on the surface is no longer consumed, start cooling. After cooling to room temperature, solid 1 can be obtained by filtration.

[0038] (3) The solid 1 and the carrier alumina are dispersed together in deionized water at 60°C and pulped for 30 minutes, and then filtered to obtain solid 2; wherein the mass of the carrier is 40% of the mass of the solid 1.

[0039] (4) The solid 2 was placed in a forced-air drying oven and dried at 90°C for 8 hours, and then calcined at 250°C for 3 hours in an air atmosphere. It was then flaked and crushed to a particle size of 20-40 mesh. 2 mL of the small particle size catalyst was packed into the constant temperature section of the fixed bed reactor and reduced with a hydrogen-nitrogen mixture containing 50% hydrogen. The heating rate was 2°C / min, and the temperature was raised to 210°C and maintained. When the total concentration of CO and CO2 in the reduction tail gas was less than 0.001%, the reduction was stopped. The copper-based catalyst was obtained and named cat1.

[0040] Example 2

[0041] A method for preparing a copper-based catalyst includes the following steps:

[0042] (1) Place 4g of copper particles and 10g of zinc particles together with 1.12g of magnesium acetate into a treatment tank. Add 500mL of deionized water with a conductivity of less than 1μs / cm to the treatment tank and stir to ensure that the magnesium acetate solvent is in the deionized water and that the deionized water can completely immerse the copper and zinc.

[0043] (2) Seal the treatment tank and heat it to 150°C. Introduce carbon dioxide and air into the treatment tank to maintain the total pressure inside the treatment tank at 1.5 MPa and the partial pressure ratio of the air to the carbon dioxide at 6:1. Adjust the stirring speed inside the treatment tank to 4000 r / min and start the reaction. When the pressure inside the treatment tank no longer changes within 1 hour and the carbon dioxide gas on the surface is no longer consumed, start cooling. After cooling to room temperature, solid 1 can be obtained by filtration.

[0044] (3) The solid 1 and the carrier alumina are dispersed together in deionized water at 60°C and pulped for 30 minutes, and then filtered to obtain solid 2; wherein the mass of the carrier is 40% of the mass of the solid 1.

[0045] (4) The solid 2 was placed in a forced-air drying oven and dried at 100°C for 7 hours. It was then calcined at 280°C for 2.5 hours in an air atmosphere. The solid was then flaked and crushed to a particle size of 20-40 mesh. 2 mL of the small particle size catalyst was packed into the constant temperature section of the fixed-bed reactor and reduced with a hydrogen-nitrogen mixture containing 50% hydrogen. The heating rate was 2°C / min. The temperature was raised to 230°C and maintained. When the total concentration of CO and CO2 in the reduction tail gas was less than 0.001%, the reduction was stopped. The copper-based catalyst was obtained and named cat2.

[0046] Example 3

[0047] A method for preparing a copper-based catalyst includes the following steps:

[0048] (1) Place 5g of copper particles and 10g of zinc particles together with 1.5g of magnesium acetate into a treatment tank, add 500mL of deionized water with a conductivity of less than 1μs / cm into the treatment tank, stir to make the magnesium acetate solvent in the deionized water, and ensure that the deionized water can completely immerse the copper and zinc.

[0049] (2) Seal the treatment tank and heat it to 200°C. Introduce carbon dioxide and air into the treatment tank, maintain the total pressure in the treatment tank at 2 MPa, and the partial pressure ratio of the air to the carbon dioxide at 7:1. Adjust the stirring speed in the treatment tank to 3000 r / min and start the reaction. When the pressure in the treatment tank no longer changes within 1 hour and the carbon dioxide gas on the surface is no longer consumed, start cooling. After cooling to room temperature, solid 1 can be obtained by filtration.

[0050] (3) The solid 1 and the carrier alumina are dispersed together in deionized water at 60°C and pulped for 30 minutes, and then filtered to obtain solid 2; wherein the mass of the carrier is 60% of the mass of the solid 1.

[0051] (4) The solid 2 was placed in a forced-air drying oven and dried at 120°C for 4 hours, and then calcined at 300°C for 1 hour in an air atmosphere. It was then flaked and crushed to a particle size of 20-40 mesh. 2 mL of the small particle size catalyst was packed into the constant temperature section of the fixed bed reactor and reduced with a hydrogen-nitrogen mixture containing 30% hydrogen. The heating rate was 2°C / min, and the temperature was maintained at 240°C. When the total concentration of CO and CO2 in the reduction tail gas was less than 0.001%, the reduction was stopped. The copper-based catalyst was obtained and named cat3.

[0052] Example 4

[0053] A method for preparing a copper-based catalyst includes the following steps:

[0054] (1) Place 8g of copper particles and 10g of zinc particles together with 2g of magnesium acetate into a treatment tank. Add 800mL of deionized water with a conductivity of less than 1μs / cm to the treatment tank and stir to ensure that the magnesium acetate solvent is in the deionized water and that the deionized water can completely immerse the copper and zinc particles.

[0055] (2) Seal the treatment tank and heat it to 270°C. Introduce carbon dioxide and air into the treatment tank to maintain the total pressure inside the treatment tank at 3.0 MPa and the partial pressure ratio of the air to the carbon dioxide at 10:1. Adjust the stirring speed inside the treatment tank to 2000 r / min and start the reaction. When the pressure inside the treatment tank no longer changes within 1 hour and the carbon dioxide gas on the surface is no longer consumed, start cooling. After cooling to room temperature, solid 1 can be obtained by filtration.

[0056] (3) The solid 1 and the carrier alumina are dispersed together in deionized water at 60°C and pulped for 30 minutes, and then filtered to obtain solid 2; wherein the mass of the carrier is 80% of the mass of the solid 1.

[0057] (4) The solid 2 was placed in a forced-air drying oven and dried at 120°C for 7 hours, and then calcined at 350°C for 1 hour in an air atmosphere. It was then flaked and crushed to a particle size of 20-40 mesh. 2 mL of the small particle size catalyst was packed into the constant temperature section of the fixed bed reactor and reduced with a hydrogen-nitrogen mixture containing 20% ​​hydrogen. The heating rate was 2°C / min, and the temperature was maintained at 250°C. When the total concentration of CO and CO2 in the reduction tail gas was less than 0.001%, the reduction was stopped. The copper-based catalyst was obtained and named cat4.

[0058] Example 5

[0059] A method for preparing a copper-based catalyst includes the following steps:

[0060] (1) Place 10g of copper particles and 10g of zinc particles together with 2g of magnesium acetate into a treatment tank. Add 800mL of deionized water with a conductivity of less than 1μs / cm to the treatment tank and stir to ensure that the magnesium acetate solvent is in the deionized water and that the deionized water can completely submerge the copper and zinc.

[0061] (2) Seal the treatment tank and heat it to 270°C. Introduce carbon dioxide and air into the treatment tank to maintain the total pressure inside the treatment tank at 3 MPa and the partial pressure ratio of the air to the carbon dioxide at 10:1. Adjust the stirring speed inside the treatment tank to 1000 r / min and start the reaction. When the pressure inside the treatment tank no longer changes within 1 hour and the carbon dioxide gas on the surface is no longer consumed, start cooling. After cooling to room temperature, solid 1 can be obtained by filtration.

[0062] (3) The solid 1 and the carrier ZSM-5 molecular sieve powder are dispersed together in deionized water at 60°C and pulped for 30 min, and then filtered to obtain solid 2; wherein the mass of the carrier is 100% of the mass of the solid 1.

[0063] (4) The solid 2 was placed in a forced-air drying oven and dried at 120°C for 4 hours, and then calcined at 350°C for 1 hour in an air atmosphere. It was then flaked and crushed to a particle size of 20-40 mesh. 2 mL of the small particle size catalyst was packed into the constant temperature section of the fixed bed reactor and reduced with a hydrogen-nitrogen mixture containing 10% hydrogen. The heating rate was 2°C / min, and the temperature was maintained at 230°C. When the total concentration of CO and CO2 in the reduction tail gas was less than 0.001%, the reduction was stopped. The copper-based catalyst was obtained and named cat5.

[0064] Example 6

[0065] A method for preparing a copper-based catalyst includes the following steps:

[0066] (1) Place 10g of copper particles and 6g of zinc particles together with 1.6g of magnesium acetate into a treatment tank, add 500mL of deionized water with a conductivity of less than 1μs / cm into the treatment tank, stir to make the magnesium acetate solvent in the deionized water, and ensure that the deionized water can completely immerse the copper and zinc.

[0067] (2) Seal the treatment tank and heat it to 300°C. Introduce carbon dioxide and air into the treatment tank to maintain the total pressure inside the treatment tank at 3 MPa and the partial pressure ratio of the air to the carbon dioxide at 8:1. Adjust the stirring speed inside the treatment tank to 3000 r / min and start the reaction. When the pressure inside the treatment tank no longer changes within 1 hour and the carbon dioxide gas on the surface is no longer consumed, start cooling. After cooling to room temperature, solid 1 can be obtained by filtration.

[0068] (3) The solid 1 and the carrier alumina are dispersed together in deionized water at 60°C and pulped for 30 minutes, and then filtered to obtain solid 2; wherein the mass of the carrier is 120% of the mass of the solid 1.

[0069] (4) The solid 2 was placed in a forced-air drying oven and dried at 120°C for 4 hours, and then calcined at 350°C for 1 hour in an air atmosphere. It was then flaked and crushed to a particle size of 20-40 mesh. 2 mL of the small particle size catalyst was packed into the constant temperature section of the fixed bed reactor and reduced with a hydrogen-nitrogen mixture containing 20% ​​hydrogen. The heating rate was 2°C / min, and the temperature was maintained at 240°C. When the total concentration of CO and CO2 in the reduction tail gas was less than 0.001%, the reduction was stopped. The copper-based catalyst was obtained and named cat6.

[0070] Example 7

[0071] A method for preparing a copper-based catalyst includes the following steps:

[0072] (1) Place 10g of copper particles and 1g of zinc particles together with 1.1g of magnesium acetate into a treatment tank, add 500mL of deionized water with a conductivity of less than 1μs / cm into the treatment tank, stir to make the magnesium acetate solvent in the deionized water, and ensure that the deionized water can completely immerse the copper and zinc.

[0073] (2) Seal the treatment tank and heat it to 300°C. Introduce carbon dioxide and air into the treatment tank to maintain the total pressure inside the treatment tank at 3.0 MPa and the partial pressure ratio of the air to the carbon dioxide at 8:1. Adjust the stirring speed inside the treatment tank to 3000 r / min and start the reaction. When the pressure inside the treatment tank no longer changes within 1 hour and the carbon dioxide gas on the surface is no longer consumed, start cooling. After cooling to room temperature, solid 1 can be obtained by filtration.

[0074] (3) The solid 1 and the carrier alumina are dispersed together in deionized water at 60°C and pulped for 30 minutes, and then filtered to obtain solid 2; wherein the mass of the carrier is 80% of the mass of the solid 1.

[0075] (4) The solid 2 was placed in a forced-air drying oven and dried at 120°C for 4 hours, and then calcined at 350°C for 1 hour in an air atmosphere. It was then flaked and crushed to a particle size of 20-40 mesh. 2 mL of the small particle size catalyst was packed into the constant temperature section of the fixed bed reactor and reduced with a hydrogen-nitrogen mixture containing 20% ​​hydrogen. The heating rate was 2°C / min, and the temperature was maintained at 250°C. When the total concentration of CO and CO2 in the reduction tail gas was less than 0.001%, the reduction was stopped. The copper-based catalyst was obtained and named cat7.

[0076] Application Example 1

[0077] The sodium content in the copper-based catalysts obtained in Examples 1-7 was determined using ICP-AES. The copper-based catalysts prepared in Examples 1-7 were then used in the CO2 hydrogenation to methanol reaction to assess their catalytic effect. The conditions for the CO2 hydrogenation to methanol reaction were: a feed gas composition of H2 / CO2 molar ratio of 3 and a gas hourly space velocity of 10000 h⁻¹. -1 The reaction temperature was 240℃ and the pressure was 5MPa. The final test and application results are shown in Table 1 below.

[0078] Table 1 shows the sodium content detection results of the catalysts obtained in each example and their performance in the CO2 hydrogenation to methanol reaction.

[0079] Catalyst Sodium content / % CO2 conversion / % Methanol selectivity / % cat1 not detected 28 80 cat2 not detected 30 82 cat3 not detected 27 84 cat4 not detected 25 81 cat5 not detected 32 82 cat6 not detected 34 84 cat7 not detected 31 81

[0080] As can be seen from Table 1, the copper-based catalyst prepared by the method of the present invention has a high CO2 conversion rate and methanol selectivity. This is mainly due to the fact that the copper-based catalyst is free of sodium impurities and has high purity, which makes it have good catalytic effect.

[0081] Application Example 2

[0082] The copper-based catalysts prepared in Examples 1-7 were used in the methanol production reaction from acetylene tail gas. The reaction conditions were as follows: the feed gas composition was 15% CO, 3% CO2, 65% H2, 0.3% ethylene, with the balance being N2, and the gas hourly space velocity was 10000 h⁻¹. -1 The reaction temperature was 230℃ and the pressure was 5MPa. The space-time yield of methanol and the impurity content in crude methanol are shown in Table 2 below.

[0083] Table 2. Performance of the catalyst in the acetylene tail gas to methanol reaction.

[0084]

[0085]

[0086] As can be seen from Table 2, in the reaction of acetylene tail gas containing ethylene to methanol, the copper-based catalyst prepared by the method of the present invention is free of sodium impurities and has high purity. Sodium methoxide (a catalyst for the synthesis of methyl formate and ethanol from syngas) will not be produced during the reaction, thus effectively reducing the content of the main impurities methyl formate and ethanol in crude methanol.

[0087] Finally, it should be noted that these embodiments are for illustrative purposes only and do not limit the scope of the invention. Furthermore, those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all embodiments here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for preparing a copper-based catalyst, characterized by, The method comprises the following steps: (1) placing materials into a treatment tank, and adding deionized water into the treatment tank; (2) sealing the treatment tank, and introducing carbon dioxide and oxygen-containing gas into the treatment tank, and heating and stirring the mixture in the treatment tank; after the carbon dioxide in the treatment tank is no longer consumed, cooling is started, and solid 1 is obtained after the temperature is reduced to room temperature; (3) compounding the solid 1 with a carrier to obtain solid 2; (4) drying, calcining, tabletting, crushing, and reducing the solid 2 to obtain a copper-based catalyst. In the step (1), the materials comprise copper, zinc, and magnesium acetate.

2. A process for the preparation of a copper-based catalyst according to claim 1, characterized in that: The mass ratio of the copper to the zinc is (0.1-10):1, and the mass of the magnesium acetate accounts for 2%-10% of the total mass of the copper and the zinc.

3. The method of making a copper-based catalyst of claim 1, wherein: After the carbon dioxide and the oxygen-containing gas are introduced into the treatment tank, the pressure in the treatment tank is 1-3 MPa, and the partial pressure ratio of the carbon dioxide to the oxygen-containing gas is 1:(5-10).

4. The method of making a copper-based catalyst of claim 1, wherein: The oxygen-containing gas is any one of oxygen and air.

5. The method of making a copper-based catalyst of claim 1, wherein: The liquid level of the deionized water in the treatment tank is higher than the height of the materials.

6. The method of making a copper-based catalyst of claim 1, wherein: The conductivity of the deionized water is less than 1 μs / cm.

7. The method of making a copper-based catalyst of claim 1, wherein: In the step (2), the heating temperature is 120-300 ℃, and the stirring rate is 2000-5000 r / min.

8. The method of making a copper-based catalyst of claim 1, wherein: In the step (3), the carrier is any one of alumina, zirconia, silica, and molecular sieve, and the mass of the carrier is 20%-150% of the mass of the solid 1.

9. The method of making a copper-based catalyst of claim 1, wherein: In the step (4), the drying temperature is 90-120 ℃, and the drying time is 4-8 h; the calcining temperature is 250-350 ℃, and the calcining time is 1-3 h.

10. The method of claim 1, wherein: In the step (4), the reducing atmosphere is hydrogen-nitrogen mixed gas with a hydrogen content of 10%-50%, the final temperature of the reduction is 210-250 ℃, and the total volume concentration of carbon dioxide and carbon monoxide in the tail gas at the end of the reduction is less than 0.001%.

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