A copper-based catalyst and preparation method thereof

Abstract

The present invention relates to the technical field of copper-based catalysts, specifically a copper-based catalyst and a preparation method thereof, comprising: using a pore-expanding agent to expand alumina to obtain an expanded alumina carrier; using deionized water to fully dissolve copper chloride, samarium chloride and lanthanum chloride, immersing the expanded alumina carrier in the obtained solution, standing and filtering to obtain filter material and filtrate; steam explosion treatment of the filter material, then immersing it in the filtrate, standing and filtering to obtain a load material; high-temperature roasting of the load material to obtain a copper-based catalyst. The present invention combines starch or methylcellulose / ammonium bicarbonate as a pore-expanding agent, which can greatly improve the effect of pore expansion, and steam explosion treatment, which can drive the solution to fully enter the pores of the carrier under high pressure, and in the subsequent vaporization flow, can drive copper, samarium and lanthanum to be evenly distributed on the surface of the pores and the carrier, thereby improving the quality of the copper-based catalyst.

Description

Technical Field

[0001] The invention relates to the technical field of copper-based catalysts, in particular to a copper-based catalyst and a preparation method thereof. Background Art

[0002] Methanol is one of the important raw materials for producing other organic chemical products and synthetic fuels. Coal-based slurry bed methanol synthesis technology is one of the most dynamic directions for the development of modern coal chemical industry in the 21st century, and it is also one of the most promising ways to efficiently and cleanly convert coal. Catalysts are crucial to the reaction of CO and H2 to synthesize methanol. Studies have shown that in the absence of catalysts, the CO conversion rate is almost zero; but when a catalyst is present, its conversion rate currently exceeds 37%.

[0003] There are two main types of catalysts used for methanol reforming to produce hydrogen: copper catalysts and precious metal catalysts. Among them, the disadvantage of precious metal catalysts is that they are expensive and difficult to promote and use; copper-based catalysts are low-cost and widely used in the reaction of carbon dioxide hydrogenation to produce methanol. Due to the limited loading amount of the catalytic carrier in the copper-based catalyst and the difficulty in achieving uniform distribution of the catalyst, the catalytic performance of the copper-based catalyst will be affected. Based on this, a copper-based catalyst and a preparation method thereof are proposed. Summary of the invention

[0004] In order to address the deficiencies of the prior art, the present invention provides a copper-based catalyst and a method for preparing the same. The pores of the carrier are expanded by using a pore-expanding agent and the copper samarium lanthanum is evenly distributed inside and outside the carrier by steam explosion treatment, thereby improving the catalytic performance of the copper-based catalyst.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for preparing a copper-based catalyst, comprising the following steps:

[0006] (1) using a pore-enlarging agent to perform pore-enlarging treatment on alumina to obtain a pore-enlarged alumina carrier;

[0007] (2) using deionized water to fully dissolve copper chloride, samarium chloride and lanthanum chloride, immersing the expanded pore alumina support in the obtained solution, allowing it to stand for treatment and filtering to obtain a filter material and a filtrate;

[0008] (3) steam explosion the filter material, then immerse it in a filtrate, allow it to stand for treatment and filter it to obtain a loaded material;

[0009] (4) The supported material is calcined at high temperature to obtain a copper-based catalyst.

[0010] Preferably, the pore-enlarging treatment method is as follows: uniformly mix the pore-enlarging agent and alumina, drop deionized water, and knead while dropping until it becomes a plastic body, and then cut, roast, and grind to obtain the product.

[0011] Preferably, the pore enlarging agent is composed of an organic pore enlarging agent and an inorganic pore enlarging agent, wherein the mass ratio of the organic pore enlarging agent to the inorganic pore enlarging agent is 1:(1-5).

[0012] Preferably, the organic pore enlarging agent is any one of starch and methyl cellulose or a combination of two thereof; the inorganic pore enlarging agent is ammonium bicarbonate.

[0013] Preferably, the pore expanding agent accounts for 2-10% of the mass of the alumina.

[0014] Preferably, in step (2), the mass ratio of copper chloride, samarium chloride, lanthanum chloride and expanded pore alumina carrier is (3-5):(1-2):(1-2):(12-15).

[0015] Preferably, in steps (2)-(3), the standing treatment time is 3-5 hours.

[0016] Preferably, in step (3), the process of steam explosion treatment is: steam pressure is 1.2-2.5 MPa, and pressure maintenance time is 100-200 s.

[0017] Preferably, the high temperature calcination is performed at 400-600° C. for 2-6 hours.

[0018] The present invention also provides a copper-based catalyst prepared by the preparation method.

[0019] The present invention provides a copper-based catalyst and a preparation method thereof, which has the following advantages compared with the prior art:

[0020] Beneficial effects:

[0021] The present invention combines starch or methyl cellulose / ammonium bicarbonate as a pore expanding agent, which can greatly improve the pore expanding effect. Because during the roasting process, the starch or methyl cellulose will burn and generate gas to escape for pore expansion, and the decomposition of ammonium bicarbonate will help the combustion of starch or methyl cellulose, further improving the pore expanding effect, so that the pore-expanding alumina carrier has abundant pores to increase the loading amount, thereby improving the catalytic performance of the copper-based catalyst.

[0022] The present invention performs steam explosion treatment on the loaded filter material, which can drive the surface dissolved liquid to fully enter the pores of the carrier under a high-pressure environment, and in the subsequent vaporization flow, can drive copper, samarium and lanthanum to be evenly distributed on the surface of the pores and the carrier, thereby improving the quality of the copper-based catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0024] Figure 1 The present invention is a flow chart for preparing the copper-based catalyst. DETAILED DESCRIPTION

[0025] The following examples are used to explain the implementation methods of the present application in detail, so that the implementation process of how the present application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0026] Example 1

[0027] The preparation method of the pore-expanded alumina carrier is as follows: uniformly mix the pore-expanding agent (starch and ammonium bicarbonate in a mass ratio of 1:1) and alumina, control the pore-expanding agent to 2% of the mass of alumina, add deionized water dropwise, and knead while adding until it becomes a plastic body, and then cut, roast, and grind to obtain the carrier.

[0028] Example 2

[0029] The preparation method of the pore-expanded alumina carrier is as follows: uniformly mix the pore-expanding agent (starch and ammonium bicarbonate in a mass ratio of 1:3) and alumina, control the pore-expanding agent to 5% of the mass of alumina, add deionized water dropwise, and knead while adding until it becomes a plastic body, and then cut, roast, and grind to obtain the carrier.

[0030] Example 3

[0031] The preparation method of the pore-expanded alumina carrier is as follows: uniformly mix the pore-expanding agent (methyl cellulose and ammonium bicarbonate in a mass ratio of 1:5) and alumina, control the pore-expanding agent to 10% of the mass of alumina, add deionized water dropwise, and knead while adding until it becomes a plastic body, and then cut, roast, and grind to obtain the carrier.

[0032] Example 4

[0033] A method for preparing a copper-based catalyst comprises the following steps:

[0034] (1) The expanded pore alumina carrier prepared in Example 1 was used.

[0035] (2) Fully dissolving copper chloride, samarium chloride and lanthanum chloride with deionized water, immersing the expanded pore alumina carrier in the obtained solution, leaving it to stand for 3 hours and filtering to obtain a filter material and a filtrate; wherein the mass ratio of copper chloride, samarium chloride, lanthanum chloride and the expanded pore alumina carrier is 3:2:1:12.

[0036] (3) The filter material was subjected to steam explosion treatment, with the steam pressure controlled at 1.2 MPa and the pressure maintained for 200 s. It was then immersed in the filtrate, allowed to stand for 3 h and filtered to obtain a loaded material.

[0037] (4) The loaded material was calcined at 400°C for 6 hours to obtain a copper-based catalyst.

[0038] Example 5

[0039] A method for preparing a copper-based catalyst comprises the following steps:

[0040] (1) The expanded pore alumina carrier prepared in Example 2 was used.

[0041] (2) Using deionized water to fully dissolve copper chloride, samarium chloride and lanthanum chloride, immersing the expanded pore alumina carrier in the obtained solution, leaving it to stand for 4 hours and filtering to obtain a filter material and a filtrate; wherein the mass ratio of copper chloride, samarium chloride, lanthanum chloride and the expanded pore alumina carrier is 4:1:2:13.

[0042] (3) The filter material was subjected to steam explosion treatment, with the steam pressure controlled at 2.5 MPa and the pressure maintained for 100 s. It was then immersed in the filtrate, allowed to stand for 4 h and filtered to obtain a loaded material.

[0043] (4) The loaded material was calcined at 600°C for 2 h to obtain a copper-based catalyst.

[0044] Example 6

[0045] A method for preparing a copper-based catalyst comprises the following steps:

[0046] (1) The expanded pore alumina carrier prepared in Example 3 was used.

[0047] (2) Fully dissolving copper chloride, samarium chloride and lanthanum chloride with deionized water, immersing the expanded pore alumina carrier in the obtained solution, allowing it to stand for 5 hours and filtering to obtain a filter material and a filtrate; wherein the mass ratio of copper chloride, samarium chloride, lanthanum chloride and the expanded pore alumina carrier is 5:1:1:15.

[0048] (3) The filter material was subjected to steam explosion treatment, with the steam pressure controlled at 2.0 MPa and the pressure maintained for 150 s. It was then immersed in the filtrate, allowed to stand for 5 h and filtered to obtain a loaded material.

[0049] (4) The loaded material was calcined at 500°C for 3.5 hours to obtain a copper-based catalyst.

[0050] Comparative Example 1

[0051] A method for preparing a copper-based catalyst is basically the same as that of Example 5, except that an ordinary non-pore-expanded alumina carrier is used instead of a pore-expanded alumina carrier.

[0052] Comparative Example 2

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

[0054] (1) Use a pore-expanded alumina carrier.

[0055] (2)-(4) are the same as the corresponding steps in Example 5.

[0056] The preparation method of the pore-expanded alumina carrier is as follows: uniformly mix the pore-expanding agent (starch) and alumina, control the pore-expanding agent to 5% of the mass of alumina, add deionized water, and knead while adding until it becomes a plastic body, and then cut, roast, and grind to obtain the product.

[0057] Comparative Example 3

[0058] A method for preparing a copper-based catalyst comprises the following steps:

[0059] (1) Use a pore-expanded alumina carrier.

[0060] (2)-(4) are the same as the corresponding steps in Example 5.

[0061] The preparation method of the pore-expanded alumina carrier is as follows: uniformly mix the pore-expanding agent (ammonium bicarbonate) and alumina, control the pore-expanding agent to 5% of the alumina mass, add deionized water, and knead while adding until it becomes a plastic body, and then cut, roast, and grind to obtain the carrier.

[0062] Comparative Example 4

[0063] A method for preparing a copper-based catalyst comprises the following steps:

[0064] (1) The expanded pore alumina carrier prepared in Example 2 was used.

[0065] (2) Using deionized water to fully dissolve copper chloride, samarium chloride and lanthanum chloride, immersing the expanded pore alumina carrier in the obtained solution, leaving it to stand for 4 hours and filtering to obtain a filter material and a filtrate; wherein the mass ratio of copper chloride, samarium chloride, lanthanum chloride and the expanded pore alumina carrier is 4:1:2:13.

[0066] (3) The filter material is immersed in the filtrate for a second time, left to stand for 4 hours and filtered to obtain a loaded material.

[0067] (4) The loaded material was calcined at 600°C for 2 h to obtain a copper-based catalyst.

[0068] Performance Testing

[0069] 1. The copper-based catalysts in Examples 4-6 and Comparative Examples 1-4 were used as samples, and 1.0 g of each sample was used as a catalyst for hydrogenation of carbon dioxide to methanol. The specific reaction conditions were as follows: the volume ratio of the reaction gas H2 / CO2 / Ar was 70:23:7, the contact time W / F was 10 g·h / mol, the reaction pressure was 3.0 MPa, the reaction temperature was 200°C, and the catalytic effects of each sample were shown in the following table.

[0070] Table 1 Catalytic effect

[0071] category <![CDATA[CO2 conversion rate, %]]> <![CDATA[CH3OH yield, %]]> Example 4 9.5 7.3 Example 5 10.2 7.9 Example 6 10.0 7.6 Comparative Example 1 7.2 5.5 Comparative Example 2 8.8 6.6 Comparative Example 3 8.6 6.4 Comparative Example 4 7.8 6.0

[0072] From the above table we can know:

[0073] (1) Compared with Example 5, the catalytic effect of the samples in Comparative Examples 1-3 deviates, indicating that the combined use of starch / ammonium bicarbonate or methyl cellulose / ammonium bicarbonate pore-enlarging agent can significantly improve the catalytic effect of the copper-based catalyst compared with no use or use alone.

[0074] (2) The catalytic effect of the sample in Comparative Example 4 is not as good as that in Example 5, indicating that steam explosion treatment can ultimately improve the catalytic performance of the copper-based catalyst.

[0075] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a copper-based catalyst, characterized in that: The following steps are involved: (1) using a pore-enlarging agent to perform pore-enlarging treatment on alumina to obtain a pore-enlarged alumina carrier; (2) using deionized water to fully dissolve copper chloride, samarium chloride and lanthanum chloride, immersing the expanded pore alumina support in the obtained solution, allowing it to stand for treatment and filtering to obtain a filter material and a filtrate; (3) steam explosion the filter material, then immerse it in a filtrate, allow it to stand for treatment and filter it to obtain a loaded material; (4) calcining the supported material at high temperature to obtain a copper-based catalyst; In step (1), the pore-enlarging treatment method is as follows: uniformly mix the pore-enlarging agent and alumina, dropwise add deionized water, and knead while dropping until a plastic body is obtained, and then cut, roast, and grind to obtain; The pore expanding agent is composed of an organic pore expanding agent and an inorganic pore expanding agent, wherein the mass ratio of the organic pore expanding agent to the inorganic pore expanding agent is 1:(1-5); The organic pore-enlarging agent is any one of starch and methyl cellulose or a combination of the two; the inorganic pore-enlarging agent is ammonium bicarbonate; In step (3), the process of steam explosion treatment is: steam pressure is 1.2-2.5MPa, and pressure maintenance time is 100-200s.

2. The method for preparing a copper-based catalyst according to claim 1, characterized in that: The pore expanding agent accounts for 2-10% of the mass of the alumina.

3. The method for preparing a copper-based catalyst according to claim 1, characterized in that: In step (2), the mass ratio of the copper chloride, samarium chloride, lanthanum chloride and expanded pore alumina carrier is (3-5):(1-2):(1-2):(12-15).

4. The method for preparing a copper-based catalyst according to claim 1, characterized in that: In steps (2)-(3), the standing treatment time is 3-5 hours.

5. The method for preparing a copper-based catalyst according to claim 1, characterized in that: In step (4), the high temperature calcination is carried out at 400-600°C for 2-6h.

6. A copper-based catalyst obtained by the preparation method according to any one of claims 1 to 5.

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