A copper-bismuth catalyst with activity and wear resistance, and a preparation method and application thereof

Abstract

This invention provides a copper-bismuth catalyst with both high activity and wear resistance, its preparation method, and its application, belonging to the field of catalyst material technology. The invention first prepares a copper-bismuth precursor I and a second precipitate, which are then mixed with trace amounts of inorganic seeds and subjected to a second aging process. The inorganic seeds serve as anchoring points for crosslinking, guiding the selective binding of subsequent inorganic composite crosslinking agents. This facilitates the formation of a three-dimensional structure—a core-shell structure, inorganic seeds, and a crosslinking network—as a support system, improving the mechanical stability of the prepared copper-bismuth catalyst, resulting in copper-bismuth precursor II. This precursor is then mixed with deionized water, followed by slurrying and spray granulation to obtain the initial catalyst product. This product is then impregnated in an inorganic composite crosslinking agent solution and subjected to low-temperature crosslinking, resulting in a solidification reaction. This constructs the copper-bismuth catalyst with a gradient structure of "dense surface + porous interior," ensuring high activity while further improving wear resistance.

Description

Technical Field

[0001] This invention relates to the field of catalyst materials technology, and in particular to a copper-bismuth catalyst with both activity and wear resistance, its preparation method, and its application. Background Technology

[0002] The acetylation-aldehyde process is the mainstream technology for producing 1,4-butanediol, consisting of two core reactions: The first step (main reaction) involves the acetylene and formaldehyde undergoing an acetylation reaction under the action of a catalyst to produce 1,4-butynediol (BYD), a crucial step in BDO synthesis. The reaction conditions are 80–110 °C and 0.1–0.3 MPa, with a liquid-phase formaldehyde aqueous solution as the reaction medium. The catalyst must be in a solid-phase suspension state, highly compatible with the liquid-solid suspension system of the slurry bed. The second step (hydrogenation reaction) involves the liquid-phase hydrogenation of 1,4-butynediol to 1,4-butanediol. This step can share a slurry bed with the acetylation reaction (or be connected in series with it). The activated copper-bismuth catalyst possesses dual catalytic activity for both acetylation and hydrogenation. Both core reactions are completed in a slurry bed reactor. A carrierless basic copper carbonate type copper-bismuth catalyst is commonly used in slurry bed reactors. The carrierless basic copper carbonate type copper-bismuth catalyst does not directly participate in the reaction with basic copper carbonate. Instead, it uses basic copper carbonate as a precursor, which is activated on-site to generate active copper-based species. Bismuth is used as a co-catalyst for modification. The carrierless design is its core industrial advantage.

[0003] While existing copper-bismuth catalysts offer advantages such as high selectivity and conversion rates, they suffer from insufficient mechanical wear resistance. During activation and reaction stirring, particle fragmentation easily occurs, and the resulting fine particles clog the candle filter in the slurry bed reactor, leading to reduced equipment lifespan and increased production costs. Current improvement methods often involve adjusting the precipitation method or adding organic additives to increase catalyst particle size. However, residual organic matter can affect reaction efficiency, and simply increasing particle size does not fundamentally solve the problem of insufficient mechanical stability. Therefore, developing a copper-bismuth catalyst that combines uniform particle size, high activity, and excellent fragmentation resistance is of great significance for the industrial production of 1,4-butynediol. Summary of the Invention

[0004] The purpose of this invention is to provide a copper-bismuth catalyst with both high activity and wear resistance, as well as its preparation method and application. The copper-bismuth catalyst provided by this invention has uniform particle size and excellent anti-fragmentation performance, ensuring high activity while further improving wear resistance.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] This invention provides a method for preparing a copper-bismuth catalyst that combines activity and wear resistance, comprising the following steps:

[0007] (1) Mix soluble copper salt, soluble bismuth salt and acid solution to obtain mixed salt solution;

[0008] A portion of the mixed salt solution is added dropwise to a portion of the alkaline solution, and then the remaining alkaline solution and the remaining mixed salt solution are added dropwise simultaneously to carry out the first precipitation reaction, thereby obtaining the first precipitate;

[0009] (2) The first precipitate obtained in step (1) is subjected to a first aging and a first post-treatment in sequence to obtain copper bismuth precursor I;

[0010] (3) Following the same operation as in step (1), a second precipitate is prepared, and then the copper bismuth precursor I and inorganic seeds obtained in step (2) are added. The second aging and the second post-treatment are carried out in sequence to obtain copper bismuth precursor II.

[0011] (4) After mixing the copper-bismuth precursor II obtained in step (3) with deionized water, the mixture is then subjected to slurrying and spray granulation to obtain the initial catalyst product.

[0012] (5) The catalyst sample obtained in step (4) is immersed in an inorganic composite crosslinking agent solution for impregnation treatment to obtain the impregnated catalyst;

[0013] The impregnated catalyst is subjected to low-temperature crosslinking to obtain a copper-bismuth catalyst that combines activity and wear resistance.

[0014] Preferably, the soluble copper salt in step (1) is at least one of copper nitrate, copper sulfate, copper acetate, and copper chloride; and the soluble bismuth salt is at least one of bismuth nitrate, bismuth sulfate, bismuth oxide (Bi2O3), and bismuth phosphate (BiPO4).

[0015] Preferably, the temperature of the first aging process in step (2) is 60℃~100℃; the aging time is 2~8h.

[0016] Preferably, in step (3), the inorganic seed is at least one of nano Al2O3, nano ZrO2, and nano SiO2; the average particle size of the inorganic seed is 20~100nm; and the mass of the inorganic seed is 0.08%~2.4% of the mass of the second precipitate.

[0017] Preferably, in step (4), the mass ratio of copper bismuth precursor II to deionized water is (1~11):(3~9).

[0018] Preferably, in step (5), the concentration of the inorganic composite crosslinking agent in the inorganic composite crosslinking agent solution is 0.08~1.4 mol / L; the inorganic composite crosslinking agent is composed of silane coupling agent and aluminum phosphate, or titanate coupling agent and zinc borate.

[0019] Preferably, the impregnation treatment in step (5) is carried out in a nitrogen / argon atmosphere with a stirring speed of 100 rpm to 300 rpm; the temperature of the impregnation treatment is 38℃ to 90℃ and the time of the impregnation treatment is 1 to 6 hours.

[0020] Preferably, the low-temperature crosslinking in step (5) includes: heating to 70℃~120℃ at a rate of 1~6℃ / min and holding for 2~8h in an inert atmosphere.

[0021] The present invention also provides a copper-bismuth catalyst with both activity and wear resistance prepared by the preparation method described above.

[0022] The present invention also provides the application of the copper bismuth catalyst with both activity and wear resistance described in the above technical solution in the synthesis of 1,4-butynediol.

[0023] This invention provides a method for preparing a copper-bismuth catalyst with both activity and wear resistance. First, a copper-bismuth precursor I and a second precipitate are prepared. These are then mixed with trace amounts of inorganic seeds and subjected to a second aging process. The inorganic seeds serve as anchor points for crosslinking sites, guiding the selective binding of subsequent inorganic composite crosslinking agents. This facilitates the formation of a three-dimensional structure—a core-shell structure, inorganic seeds, and a crosslinking network—as a support system, improving the mechanical stability of the prepared copper-bismuth catalyst. This yields a copper-bismuth precursor II, which is then mixed with water, slurried, and spray-granulated to obtain a primary catalyst product. This product is then impregnated in an inorganic composite crosslinking agent solution, allowing the agent to fully penetrate the product. After low-temperature crosslinking, the inorganic composite crosslinking agent and inorganic seeds undergo a synergistic curing reaction, constructing a copper-bismuth catalyst with a "dense surface + porous interior" gradient structure. The dense surface further enhances wear resistance, while the porous interior retains active centers, ensuring that the prepared copper-bismuth catalyst possesses both activity and wear resistance. Attached Figure Description

[0024] Figure 1 This is a SEM image of the copper-bismuth catalyst with both activity and wear resistance prepared in Example 1 of the present invention. Detailed Implementation

[0025] This invention provides a method for preparing a copper-bismuth catalyst that combines activity and wear resistance, comprising the following steps:

[0026] (1) Mix soluble copper salt, soluble bismuth salt and acid solution to obtain mixed salt solution;

[0027] A portion of the mixed salt solution is added dropwise to a portion of the alkaline solution, and then the remaining alkaline solution and the remaining mixed salt solution are added dropwise simultaneously to carry out the first precipitation reaction, thereby obtaining the first precipitate;

[0028] (2) The first precipitate obtained in step (1) is subjected to a first aging and a first post-treatment in sequence to obtain copper bismuth precursor I;

[0029] (3) Following the same operation as in step (1), a second precipitate is prepared, and then the copper bismuth precursor I and inorganic seeds obtained in step (2) are added. The second aging and the second post-treatment are carried out in sequence to obtain copper bismuth precursor II.

[0030] (4) After mixing the copper-bismuth precursor II obtained in step (3) with deionized water, the mixture is then subjected to slurrying and spray granulation to obtain the initial catalyst product.

[0031] (5) The catalyst sample obtained in step (4) is immersed in an inorganic composite crosslinking agent solution for impregnation treatment to obtain the impregnated catalyst;

[0032] The impregnated catalyst is subjected to low-temperature crosslinking to obtain a copper-bismuth catalyst that combines activity and wear resistance.

[0033] Unless otherwise specified, all raw materials used in this invention are commercially available products in the art.

[0034] This invention involves mixing a soluble copper salt, a soluble bismuth salt, and an acid solution to obtain a mixed salt solution;

[0035] A portion of the mixed salt solution is added dropwise to a portion of the alkaline solution, and then the remaining alkaline solution and the remaining mixed salt solution are added dropwise simultaneously to carry out the first precipitation reaction, thereby obtaining the first precipitate.

[0036] In this invention, the soluble copper salt is preferably at least one of copper nitrate, copper sulfate, copper acetate, and copper chloride; the soluble bismuth salt is preferably at least one of bismuth nitrate, bismuth sulfate, bismuth oxide (Bi₂O₃), and bismuth phosphate (BiPO₄). In this invention, the acid in the acid solution is preferably at least one of nitric acid and sulfuric acid. In this invention, the total molar concentration of copper and bismuth metal ions in the mixed salt solution is preferably 0.5 mol / L to 2.0 mol / L. In this invention, the alkali in the alkaline solution is preferably at least one of sodium carbonate, sodium hydroxide, ammonium carbonate, urea, and sodium bicarbonate; the concentration of the alkali in the alkaline solution is preferably 0.5 mol / L to 2.0 mol / L. This invention controls the concentration of the alkali in the first alkaline solution within the above range to promote the full progress of the subsequent first precipitation reaction. In this invention, the first precipitation reaction is preferably carried out under stirring conditions of 10℃ to 80℃ and a stirring speed of 250 rpm to 500 rpm. In this invention, the pH of the system for the first precipitation reaction is preferably 6 to 7. The present invention performs the first precipitation reaction under the above conditions to ensure that the obtained first precipitate has a uniform particle size distribution, thereby facilitating the acquisition of copper bismuth precursor I with a uniform particle size distribution.

[0037] After obtaining the first precipitate, the present invention performs a first aging and a first post-treatment on the first precipitate to obtain copper bismuth precursor I.

[0038] In this invention, the preferred temperature for the first aging is 60℃~100℃, more preferably 70~90℃; the preferred aging time is 2~8 hours, more preferably 2~6 hours. This invention promotes sufficient crystal growth in the first precipitate through the above conditions for the first aging. In this invention, the first post-processing preferably includes: sequentially filtering, washing, and drying the product of the first aging to obtain copper-bismuth precursor I. This invention does not impose any special limitations on the methods of filtration, washing, and drying; any technical solution well-known in the art can be used.

[0039] After obtaining copper-bismuth precursor I, the present invention prepares a second precipitate by following the same operation as the preparation of the first precipitate described above. Then, copper-bismuth precursor I and inorganic seeds are added, and the second aging and second post-treatment are carried out in sequence to obtain copper-bismuth precursor II.

[0040] In this invention, the inorganic seeds are preferably at least one of nano-Al2O3, nano-ZrO2, and nano-SiO2; the average particle size of the inorganic seeds is preferably 20-100 nm; and the mass of the inorganic seeds is preferably 0.08%-2.4% of the mass of the second precipitate. This invention, by controlling the type, average particle size, and amount of inorganic seeds within the above ranges, ensures uniform dispersion of the seeds in the copper-bismuth precipitation system, maximizing the exposure of surface active sites (such as hydroxyl groups), while avoiding seed aggregation or excessive coverage of copper-bismuth active centers. This enhances the efficiency of the specific interaction between the seeds and the crosslinking agent, thereby enabling the inorganic seeds to act as anchor points for crosslinking sites, guiding the selective binding of the crosslinking agent to form a uniform three-dimensional support network. In this invention, the second aging temperature is preferably 60℃-100℃, more preferably 70-90℃; and the second aging time is preferably 2-8 h, more preferably 2-6 h. This invention employs a second aging process under the aforementioned conditions to promote the directional growth of copper-bismuth crystals along the surface of the copper-bismuth precursor I, forming a well-structured multi-layered core-shell structure. Simultaneously, it promotes the uniform dispersion and firm embedding of inorganic seeds within the shell matrix, fully exposing surface-active anchoring sites (such as hydroxyl groups). This avoids structural defects caused by excessive crystal aggregation or insufficient growth, ensuring both the porosity of the shell to maintain the exposure of copper-bismuth active centers and the increased shell density to strengthen the basic mechanical strength. This provides a solid foundation for the specific binding of the crosslinking agent and seeds, ensuring the integrity and stability of the three-dimensional support network. In this invention, the second post-processing preferably includes: sequentially filtering and washing the product of the second aging process to obtain the copper-bismuth precursor I. This invention does not impose any particular limitations on the filtering and washing methods; any technical solutions well-known in the art can be used.

[0041] After obtaining copper-bismuth precursor II, the present invention mixes copper-bismuth precursor II with deionized water, and then performs slurrying and spray granulation sequentially to obtain the initial catalyst product.

[0042] In this invention, the preferred mass ratio of the copper-bismuth precursor II to deionized water is (1~11):(3~9). This invention controls the mass ratio of the copper-bismuth precursor II to deionized water within the above range to form a slurry of suitable concentration, ensuring the effectiveness of subsequent spray granulation.

[0043] After obtaining the initial catalyst, the present invention immerses the initial catalyst in an inorganic composite crosslinking agent solution for impregnation treatment to obtain the impregnated catalyst.

[0044] The impregnated catalyst is subjected to low-temperature crosslinking to obtain a copper-bismuth catalyst that combines activity and wear resistance.

[0045] In this invention, the concentration of the inorganic composite crosslinking agent in the inorganic composite crosslinking agent solution is preferably 0.8~1.4 mol / L; the inorganic composite crosslinking agent is preferably composed of a silane coupling agent and aluminum phosphate, or a titanate coupling agent and zinc borate. In this invention, the molar ratio of the silane coupling agent to aluminum phosphate is preferably 1:(0.2~0.8); the molar ratio of the titanate coupling agent to zinc borate is preferably 1:(0.2~0.8). In this invention, the solvent in the inorganic composite crosslinking agent solution is an ethanol-water or propanol-water mixture; the water volume percentage in the solvent is 30%~70%. This invention controls the concentration and composition of the inorganic composite crosslinking agent solution within the above ranges to balance the solubility and penetration ability of the inorganic composite crosslinking agent, ensuring that the crosslinking agent is uniformly dispersed and fully penetrates into the catalyst substrate, precisely binding to the active anchoring sites (such as hydroxyl groups) on the inorganic seed surface. In this invention, the impregnation treatment is preferably carried out in a nitrogen / argon atmosphere with stirring at a speed of 100 rpm to 300 rpm; the temperature of the impregnation treatment is preferably 38℃ to 90℃, more preferably 40℃ to 80℃; and the time of the impregnation treatment is preferably 1 to 6 hours, more preferably 1 to 4 hours. This invention controls the conditions, temperature, and time of the impregnation treatment within the above ranges to regulate the molecular motion rate and reactivity of the crosslinking agent, ensuring that it fully penetrates into the internal pores of the catalyst and efficiently and specifically binds to the active anchoring sites on the surface of the inorganic seeds. In this invention, the low-temperature crosslinking preferably includes: heating to 70℃ to 120℃ at a rate of 1 to 6℃ / min and holding for 2 to 8 hours in an inert atmosphere, more preferably: heating to 80℃ to 110℃ at a rate of 2 to 5℃ / min and holding for 3 to 6 hours in an inert atmosphere. This invention controls the conditions, temperature, and time of the low-temperature crosslinking within the above ranges to ensure that the crosslinking agent and inorganic seeds are fully and uniformly cured, forming a stable three-dimensional support network. It avoids thermal stress cracking and active center blockage under mild conditions, is suitable for low-temperature use and leaves no residue, and balances mechanical wear resistance and catalytic activity.

[0046] The present invention also provides a copper-bismuth catalyst with both activity and wear resistance prepared by the preparation method described above.

[0047] The present invention also provides the application of the copper bismuth catalyst with both activity and wear resistance described in the above technical solution in the synthesis of 1,4-butynediol.

[0048] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0049] Unless otherwise specified, all experiments were repeated three times, and the results are expressed as averages.

[0050] Example 1

[0051] A method for preparing a copper-bismuth catalyst that combines activity and wear resistance, comprising the following steps:

[0052] (1) Weigh 11.89 kg of copper nitrate trihydrate and 0.39 kg of bismuth nitrate pentahydrate, dissolve them in dilute nitric acid to prepare a mixed salt solution with a total molar concentration of 0.5 mol / L for copper and bismuth metal ions; weigh 7.18 kg of anhydrous sodium carbonate, dissolve it in pure water to prepare an alkaline solution with a concentration of 0.68 mol / L.

[0053] First, add 50L of alkaline solution to the reactor. Then, add an equal volume of mixed salt solution dropwise at 20℃ and 250rpm. Next, add the remaining alkaline solution and the remaining mixed salt solution dropwise at the same time, controlling the pH to 6~7, to carry out the first precipitation reaction and obtain the first precipitate.

[0054] (2) The first precipitate obtained in step (1) is aged at 80°C for 3 hours, and then filtered, washed and dried to obtain copper bismuth precursor I.

[0055] (3) Following the same operation as in step (1), a second precipitate is prepared, and then 4.06 kg of copper bismuth precursor I and 0.08 kg of nano Al2O3 seeds (average particle size of 50 nm) obtained in step (2) are added. The precipitate is aged at 80 °C for 3 h, and then filtered and washed to obtain copper bismuth precursor II.

[0056] (4) The copper bismuth precursor II obtained in step (3) and deionized water are mixed in a mass ratio of 1:3 to form a slurry, and then spray granulation is performed to obtain the initial catalyst product.

[0057] (5) Using silane coupling agent and aluminum phosphate in a molar ratio of 1:0.5 as inorganic composite crosslinking agents, prepare a silane coupling agent-aluminum phosphate composite crosslinking agent solution with a concentration of 0.3 mol / L, and use ethanol-water mixture as solvent (the volume ratio of water in the solvent is 50%).

[0058] The catalyst sample obtained in step (4) was immersed in the silane coupling agent-aluminum phosphate composite crosslinking agent solution and impregnated for 2 hours under nitrogen atmosphere, 50°C and 200 rpm to obtain the impregnated catalyst.

[0059] The impregnated catalyst was placed in a nitrogen atmosphere and heated to 100°C at a rate of 3°C / min, and held at that temperature for 4 hours to complete low-temperature crosslinking, thereby obtaining a copper-bismuth catalyst with both activity and wear resistance.

[0060] The catalytic performance and wear resistance of the catalyst were evaluated using a gas chromatography-titration method for the formaldehyde acetylation reaction. The long-term stability of the catalyst was assessed using a slurry-bed continuous acetylation reaction stability evaluation method. The particle size change of the catalyst was measured using a laser particle size analyzer. The results showed that the average particle size D50 of the copper-bismuth catalyst prepared in Example 1, which combines activity and wear resistance, was 22.3 μm, and the percentage of particles <7 μm was <0.8%. The stirring wear rate of the copper-bismuth catalyst prepared in Example 1, which combines activity and wear resistance, was 0.42%, and the formaldehyde conversion rate was 84.5%. After continuous operation in a slurry-bed reaction at 95℃ for 200 h, the pressure difference of the candle filter did not increase significantly, and there was no clogging.

[0061] Figure 1 This is a SEM image of the copper-bismuth catalyst with both activity and wear resistance prepared in Example 1 of this invention. Figure 1 Based on the above tests, it can be seen that in Example 1, ellipsoidal particles are formed by spray granulation followed by impregnation and calcination. The particles are then separated by cyclone separation in a flash dryer to remove small particles, thereby increasing the proportion of large particles in the prepared copper-bismuth catalyst that has both activity and wear resistance.

[0062] Example 2

[0063] A method for preparing a copper-bismuth catalyst that combines activity and wear resistance, comprising the following steps:

[0064] (1) Weigh 21.42 kg of copper nitrate trihydrate and 0.66 kg of bismuth nitrate pentahydrate, dissolve them in dilute nitric acid to prepare a 1.4 mol / L mixed salt solution; weigh 12.16 kg of anhydrous sodium carbonate, dissolve it in pure water to prepare a 1.7 mol / L alkaline solution;

[0065] First, add 25L of alkaline solution to the reactor. Then, add an equal volume of mixed salt solution dropwise at 45℃ and 300rpm. Next, add the remaining alkaline solution and the remaining mixed salt solution dropwise at the same time, controlling the pH to 6~7, to carry out the first precipitation reaction and obtain the first precipitate.

[0066] (2) The first precipitate obtained in step (1) is aged at 75°C for 5 hours, and then filtered, washed and dried to obtain copper bismuth precursor I.

[0067] (3) Following the same operation as in step (1), a second precipitate is prepared, and then 5.08 kg of copper bismuth precursor I and 0.12 kg of nano ZrO2 seeds (particle size 80 nm) obtained in step (2) are added. The mixture is aged at 75°C for 5 h, and then filtered and washed to obtain copper bismuth precursor II.

[0068] (4) The copper bismuth precursor II obtained in step (3) and deionized water are mixed in a mass ratio of 1:1 to form a slurry, which is then spray-granulated to obtain the initial catalyst product.

[0069] (5) Using titanate coupling agent and zinc borate in a molar ratio of 1:0.6 as inorganic composite crosslinking agent, prepare a titanate coupling agent-zinc borate composite crosslinking agent solution with a concentration of 0.5 mol / L, with propanol-water mixture as solvent (water volume ratio of 40% in the solvent), to obtain titanate coupling agent-zinc borate composite crosslinking agent solution;

[0070] The catalyst sample was immersed in a solution of titanate coupling agent-zinc borate composite crosslinking agent and impregnated for 3 hours under argon atmosphere, 60°C and 250 rpm to obtain the impregnated catalyst.

[0071] The impregnated catalyst was placed in an argon atmosphere and heated to 105°C at a rate of 4°C / min, and held at that temperature for 3.5 hours to complete low-temperature crosslinking, thereby obtaining a copper-bismuth catalyst with both activity and wear resistance.

[0072] The catalyst prepared in Example 2 was tested using the same method as in Example 1. The average particle size D50 was 22.8 μm, and the percentage of particles <7 μm was <0.7%. The agitation wear rate of the catalyst prepared in Example 2 was 0.38%, the formaldehyde conversion rate was 85.2%, and after continuous operation in a slurry bed reaction at 98°C for 200 h, the filter pressure difference was stable and there was no clogging.

[0073] Example 3

[0074] A method for preparing a copper-bismuth catalyst that combines activity and wear resistance, comprising the following steps:

[0075] (1) Weigh 21.37 kg of copper nitrate trihydrate and 0.76 kg of bismuth nitrate pentahydrate, and dissolve them in dilute nitric acid to prepare a 1.5 mol / L copper and bismuth mixed salt solution; weigh 12.91 kg of anhydrous sodium carbonate, and dissolve it in pure water to prepare a 2.0 mol / L alkaline solution.

[0076] First, add 15L of alkaline solution to the reaction vessel, and then add an equal volume of mixed salt solution dropwise at 50℃ and 250rpm. Then, add the remaining alkaline solution and the remaining mixed salt solution dropwise at the same time, controlling the pH to 6~7, to carry out the first precipitation reaction and obtain the first precipitate.

[0077] (2) The first precipitate obtained in step (1) is aged at 75°C for 6 hours, and then filtered, washed and dried in sequence to obtain copper bismuth precursor I;

[0078] (3) Following the same operation as in step (1), a second precipitate was prepared, and then 2.54 kg of copper bismuth precursor I and 0.06 kg of nano TiO2 seeds (particle size 30 nm) obtained in step (2) were added. The mixture was aged at 75 °C for 6 h, and then filtered and washed sequentially to obtain copper bismuth precursor II.

[0079] (4) The copper-bismuth precursor II obtained in step (3) and deionized water are mixed in a mass ratio of 11:9 to form a slurry, which is then spray-granulated to obtain the initial catalyst product.

[0080] (5) Using silane coupling agent and aluminum phosphate in a molar ratio of 1:0.4 as inorganic composite crosslinking agents, prepare a silane coupling agent-aluminum phosphate composite crosslinking agent solution with a concentration of 0.4 mol / L, with ethanol-water mixture as the solvent (water volume ratio of the solvent is 60%), to obtain the silane coupling agent-aluminum phosphate composite crosslinking agent solution.

[0081] The catalyst sample obtained in step (4) was immersed in a silane coupling agent-aluminum phosphate composite crosslinking agent solution and impregnated for 2.5 h under nitrogen atmosphere, 70 °C and 150 rpm to obtain the impregnated catalyst.

[0082] The impregnated catalyst was placed in a nitrogen atmosphere and heated to 95°C at a rate of 2.5°C / min, and held at that temperature for 4 hours to complete low-temperature crosslinking, thereby obtaining a copper-bismuth catalyst with both activity and wear resistance.

[0083] The catalyst prepared in Example 3 was tested using the same method as in Example 1. The average particle size D50 was 21.9 μm, and the percentage of particles <7 μm was <0.9%. The agitation wear rate of the catalyst prepared in Example 3 was 0.45%, the formaldehyde conversion rate was 83.8%, and after continuous operation in a slurry bed reaction at 92°C for 200 h, the filter pressure difference showed no significant fluctuation and no clogging was observed.

[0084] Comparative Example 1 (No inorganic seeds + high-temperature cross-linking)

[0085] A method for preparing a copper-bismuth catalyst, comprising the following steps:

[0086] The catalyst precursor prepared in Example 1 was directly impregnated with a single silane coupling agent and then crosslinked and cured at 180°C, with the remaining conditions the same as in Example 1.

[0087] The catalyst prepared in Comparative Example 1 was tested using the same method as in Example 1. The catalyst structure showed slight sintering, the agitation wear rate was 1.3%, the formaldehyde conversion rate was 80.8%, and the filter pressure difference increased after continuous operation in a slurry bed reaction at 95°C for 200 hours.

[0088] Comparative Example 2 (No inorganic seeds + low-temperature cross-linking)

[0089] A method for preparing a copper-bismuth catalyst, comprising the following steps:

[0090] The preparation method differs from that in Example 1 in that nano-Al2O3 seeds were not added, while the other conditions were the same as in Example 1.

[0091] The catalyst prepared in Comparative Example 2 was tested using the same method as in Example 1. The agitation wear rate was 0.85%, the formaldehyde conversion rate was 83.1%, and the filter pressure difference increased slightly after continuous operation in a slurry bed reaction at 95°C for 200 hours.

[0092] Comparative Example 3 (No inorganic seeds + no impregnation / crosslinking)

[0093] A method for preparing a copper-bismuth catalyst, comprising the following steps:

[0094] The preparation method differs from that in Example 1 in that: no nano-Al2O3 seeds were added when preparing copper-bismuth precursor II. Copper-bismuth precursor II and water were mixed in a mass ratio of 1:3 to form a slurry, which was then spray-granulated and used directly as a copper-bismuth catalyst without subsequent impregnation, crosslinking and low-temperature curing steps.

[0095] The catalyst prepared in Comparative Example 3, tested using the same method as in Example 1, exhibited a stirring attrition rate of 3.5%, a formaldehyde conversion rate of 82.4%, and severe filter clogging after 200 hours of continuous operation in a slurry bed reaction at 95°C.

[0096] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a copper bismuth catalyst having both activity and attrition resistance, characterized by, Includes the following steps: (1) Mix soluble copper salt, soluble bismuth salt and acid solution to obtain mixed salt solution; A portion of the mixed salt solution is added dropwise to a portion of the alkaline solution, and then the remaining alkaline solution and the remaining mixed salt solution are added dropwise simultaneously to carry out the first precipitation reaction, thereby obtaining the first precipitate; (2) The first precipitate obtained in step (1) is subjected to a first aging and a first post-treatment in sequence to obtain copper bismuth precursor I; (3) Following the same operation as in step (1), a second precipitate is prepared, and then the copper bismuth precursor I and inorganic seeds obtained in step (2) are added. The second aging and the second post-treatment are carried out in sequence to obtain copper bismuth precursor II. (4) After mixing the copper-bismuth precursor II obtained in step (3) with deionized water, the mixture is then subjected to slurrying and spray granulation to obtain the initial catalyst product. (5) The catalyst sample obtained in step (4) is immersed in an inorganic composite crosslinking agent solution for impregnation treatment to obtain the impregnated catalyst; The impregnated catalyst is subjected to low-temperature crosslinking to obtain a copper-bismuth catalyst that combines activity and wear resistance.

2. The production method according to claim 1, characterized by, In step (1), the soluble copper salt is at least one of copper nitrate, copper sulfate, copper acetate, and copper chloride; the soluble bismuth salt is at least one of bismuth nitrate, bismuth sulfate, bismuth oxide (Bi2O3), and bismuth phosphate (BiPO4).

3. The preparation method according to claim 1, characterized in that, In step (2), the preferred aging temperature is 60℃~100℃; the aging time is 2~8h.

4. The method of claim 1, wherein, In step (3), the inorganic seeds are at least one of nano Al2O3, nano ZrO2, and nano SiO2; the average particle size of the inorganic seeds is 20~100nm; and the mass of the inorganic seeds is 0.08%~2.4% of the mass of the second precipitate.

5. The preparation method according to claim 1, characterized in that, In step (4), the mass ratio of copper bismuth precursor II to deionized water is (1~11):(3~9).

6. The preparation method according to claim 1, characterized in that, In step (5), the concentration of the inorganic composite crosslinking agent in the inorganic composite crosslinking agent solution is 0.08~1.4 mol / L; the inorganic composite crosslinking agent is composed of silane coupling agent and aluminum phosphate, or titanate coupling agent and zinc borate.

7. The preparation method according to claim 1, characterized in that, In step (5), the impregnation treatment is carried out in a nitrogen / argon atmosphere with a stirring speed of 100 rpm to 300 rpm; the temperature of the impregnation treatment is 38℃ to 90℃ and the time of the impregnation treatment is 1 to 6 hours.

8. The preparation method according to claim 1, characterized in that, The low-temperature crosslinking in step (5) includes: heating to 70℃~120℃ at a rate of 1~6℃ / min in an inert atmosphere and holding for 2~8h.

9. A copper-bismuth catalyst with both activity and wear resistance prepared by the preparation method according to any one of claims 1 to 8.

10. The use of a copper-bismuth catalyst of claim 9, which is both active and wear-resistant, in the synthesis of 1,4-butynediol.

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