A platinum-cobalt bimetallic catalyst, a preparation method and application thereof
By preparing a core-shell carbon-coated platinum-cobalt bimetallic catalyst, the problems of insufficient stability and selectivity of existing catalysts in the hydrogenation of C4 dicarboxylic acids to 1,4-butanediol were solved, realizing efficient and environmentally friendly BDO production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- DALIAN INSTITUTE OF CHEMICAL PHYSICS CHINESE ACADEMY OF SCIENCES
- Filing Date
- 2026-04-02
- Publication Date
- 2026-07-14
AI Technical Summary
Existing catalysts for the hydrogenation of C4 dicarboxylic acids or their anhydrides to prepare 1,4-butanediol (BDO) suffer from problems such as complex reaction pathways, difficulty in controlling product selectivity, poor catalyst stability, and high costs, making it difficult to meet the requirements for long-term stable industrial operation.
The core-shell carbon-coated platinum-cobalt bimetallic catalyst utilizes the synergistic effect of Pt and Co nanoparticles within a porous carbon layer to enhance catalytic activity and stability. This preparation method is simple and environmentally friendly.
The efficient conversion of C4 dicarboxylic acids and their anhydrides to BDO in the aqueous phase was achieved. The catalyst exhibited good stability, and the BDO selectivity reached as high as 82.3%. Furthermore, the preparation method was simple and low in cost.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of butanediol preparation technology, specifically relating to a platinum-cobalt bimetallic catalyst, its preparation method, and its application in the aqueous hydrogenation of C4 dicarboxylic acids and their anhydrides to produce 1,4-butanediol. Background Technology
[0002] 1,4-Butanediol (BDO) is an important basic chemical raw material, its core value lying in its wide application in high-value-added chemicals and green chemistry. BDO serves as a raw material for the synthesis of polytetramethylene ether glycol (PTMEG), used in the production of polyurethane elastomers (TPU). It is also a monomer for the synthesis of various important polymers, including biodegradable plastics such as polybutylene succinate (PBS) and polybutylene terephthalate (PBT). In recent years, driven by global "dual carbon" goals, the market demand for BDO has continued to grow. However, traditional production processes have significant shortcomings, necessitating the development of more efficient and green synthetic routes.
[0003] Currently, industrial BDO production mainly relies on petrochemical-based routes, including the following processes: the Reppe method (acetylene-aldehyde method), the maleic anhydride method, and the propylene oxide method. The Reppe method uses formaldehyde and acetylene as raw materials, which are catalytically synthesized into butynediol and then hydrogenated to produce BDO (Biofuel. Bioprod. Bior. 2008, 2 (6), 505-529.); the maleic anhydride method uses maleic anhydride obtained from the oxidation of n-butane as raw material, which is then esterified and hydrogenated or directly hydrogenated to produce BDO (Modern Chemical Research, 2022(1): 48-50.); the propylene oxide method uses propylene as raw material to produce BDO through multiple steps of reaction (Coal and Chemical Industry, 2019, 42(10): 123-128.).
[0004] With the maturation of bio-fermentation technology, the industrial production scale of bio-based succinic acid has been continuously expanding, leading to a sustained reduction in production costs and providing a solid raw material foundation for the industrialization of the SA-to-BDO route. Furthermore, aqueous hydrogenation technology has attracted widespread attention due to its environmental friendliness (using water as a solvent, avoiding the use of organic solvents) and potential energy-saving advantages. Meanwhile, besides SA, other C4 dicarboxylic acids or their anhydrides (including maleic acid, fumaric acid, and maleic anhydride) can also be used in BDO production, but many challenges remain in practical applications. Firstly, the reaction pathway is complex, and product selectivity is difficult to control. The hydrogenation of C4 dicarboxylic acids such as SA or their anhydrides is a series of reactions. First, hydrogenation produces γ-butyrolactone (GBL), which is further hydrogenated to produce BDO, accompanied by the formation of tetrahydrofuran (THF) and side reactions of C-C bond cleavage caused by excessive hydrogenation (producing propanol, butanol, etc.) (Chem. Commun., 2009, 35, 5305-5307.). Therefore, achieving high selectivity for the target product BDO while ensuring complete conversion of C4 dicarboxylic acids such as SA or their anhydrides is the core technical challenge. Secondly, catalyst performance needs improvement. Single-metal catalysts (such as Ru and Pd) exhibit high activity but low BDO selectivity; while Re-based bimetallic catalysts (Re-Pd and Re-Ru) can improve BDO selectivity, they suffer from problems such as easy loss of Re species, poor catalyst stability, complex preparation processes, and high costs (Top. Catal., 2012, 55, 466-473; ChemSusChem, 2013, 6, 2388-2395). Furthermore, existing catalysts are prone to sintering and carbon deposition deactivation during long-term operation, making it difficult to meet the requirements for long-term stable industrial operation (J. Chem. Technol. Biotechnol., 2025, 100, 545-554). Summary of the Invention
[0005] This invention provides a core-shell carbon-coated platinum-cobalt bimetallic catalyst, its preparation method, and its application in the aqueous hydrogenation of C4 dicarboxylic acids and their anhydrides to BDO. This catalyst, under the synergistic effect of Pt and Co bimetals, exhibits both high activity and high BDO selectivity. Furthermore, the PtCo@C catalyst demonstrates good stability, achieving complete conversion of C4 dicarboxylic acids or their anhydrides after five cycles. The preparation method is simple, inexpensive, and easy to operate.
[0006] To achieve the above objectives, the technical solution of the present invention is as follows:
[0007] The first aspect of this invention provides a method for preparing a platinum-cobalt bimetallic catalyst, comprising the following steps: (1) Dissolve the Pt precursor, Co precursor and carbon precursor in water to obtain a mixture; (2) Heat and stir the mixture to obtain a gel; (3) The gel is dried, ground, then carbonized, and finally reduced to obtain a platinum-cobalt bimetallic catalyst.
[0008] Furthermore, the ratio of the total molar amount of the Pt precursor and Co metal precursor to the molar amount of the carbon precursor is 1:2-8, preferably 1:6.
[0009] Furthermore, the Pt precursor includes one or more of tetraammineplatinum nitrate, chloroplatinic acid, platinum nitrate, and platinum tetrachloride; The Co precursor includes one or more of cobalt nitrate and cobalt chloride; The carbon precursor includes one or more of citric acid, sodium citrate, tartaric acid, ethylenediaminetetraacetic acid, and polyvinyl alcohol.
[0010] Furthermore, the heating and stirring time is 5-15 h, and the heating temperature is 60-120 ℃.
[0011] Furthermore, the drying temperature is 60-120 ℃, and the drying time is 12-24 h; The carbonization process is carried out in an inert gas atmosphere at a temperature of 600-900 ℃ for 2-6 hours; the inert gas includes one of N2, Ar, and He. The reduction process is carried out in a hydrogen atmosphere at a temperature of 400-600 °C for 0.5-5 h.
[0012] Another aspect of the present invention provides a platinum-cobalt bimetallic catalyst prepared by the above-described preparation method, wherein the platinum-cobalt bimetallic catalyst comprises an active component and a support coated on the outside of the active component; the active component is composed of Pt nanoparticles and Co nanoparticles, and the support is porous carbon.
[0013] Furthermore, in the platinum-cobalt bimetallic catalyst, the loading of metal Pt is 0.02-10 wt.%, and the loading of metal Co is 10-60 wt.%.
[0014] The present invention also provides an application of the above-mentioned platinum-cobalt bimetallic catalyst in the aqueous hydrogenation reaction of C4 dicarboxylic acids and their anhydrides to produce butanediol; the reactants are aqueous solutions of C4 dicarboxylic acids and their anhydrides, wherein the C4 dicarboxylic acids and their anhydrides include one of succinic acid, maleic acid, fumaric acid, and maleic anhydride.
[0015] Furthermore, the reaction is carried out in a high-pressure reactor at a temperature of 160-240 °C, preferably 180-220 °C, with a hydrogen pressure of 1-12 MPa, preferably 2-8 MPa, a reactant concentration of 1-30 wt.%, and a catalyst dosage of 0.5-30% of the reactant mass.
[0016] Furthermore, the reaction is carried out in a fixed-bed reactor at a temperature of 180-220 °C, a hydrogen pressure of 2-8 MPa, and a WHSV of 0.5-5 h⁻¹ for C₄ dicarboxylic acids and their anhydrides. -1 The hydrogen space velocity (GHSV) is 100-1000 h⁻¹. -1 The concentration of reactants is 1-30 wt.%, and the amount of catalyst is 0.5-30% of the mass of reactants.
[0017] The beneficial effects of this invention are: (1) Encapsulating Pt and Co active metal nanoparticles in a C layer can improve the acid resistance and metal dispersion of the catalyst. Not only do the C layer and metal species have a synergistic effect, but the C layer can also promote the adsorption of substrate (SA), thereby improving catalytic activity and stability.
[0018] (2) The catalyst is easy to prepare. The operating conditions for the aqueous hydrogenation reaction of C4 dicarboxylic acids and their anhydrides are relatively mild and water is used as a solvent, which is environmentally friendly.
[0019] (3) There is a synergistic effect between the active components Pt and Co. The PtCo@C catalyst can catalyze the hydrogenation of C4 dicarboxylic acids and their anhydrides into BDO in the aqueous phase, with a yield of up to 82.3%.
[0020] (4) The catalyst has good stability. After five cycles, SA can still be fully converted.
[0021] Considering all the above factors, the present invention has good application prospects. Attached Figure Description
[0022] Figure 1 For Co@C, Pt 0.8 Co@C、Pt 0.8 Co-A and Pt 0.8 XRD pattern of Co / C catalyst; Figure 2 For Co@C, Pt 0.8 Co@C and Pt 0.8 Adsorption isotherms and pore size distribution of Co-A catalyst, a is the adsorption isotherm, b is the pore size distribution; Figure 3 For Co@C and Pt 0.8TEM and HRTEM images of Co@C catalysts and statistical diagrams of metal nanoparticle size distribution. a) TEM image of Co@C, b) HRTEM image of Co@C, c) statistical diagram of metal particle size distribution of Co@C, d) Pt 0.8 TEM image of Co@C, e is Pt 0.8 HRTEM image of Co@C, f is Pt 0.8 Statistical diagram of particle size distribution of Co@C metal particles; Figure 4 The sample Pt after the reaction 0.8 TEM images, HRTEM images, and a statistical graph of metal particle size distribution for Co@C-used. a is a TEM image, b is an HRTEM image, and c is a statistical graph of metal particle size distribution. Figure 5 For Pt 0.8 Co-A and Pt 0.8 Stability evaluation of Co@C catalyst, where a is Pt 0.8 Co-A, b is Pt 0.8 Co@C. Detailed Implementation
[0023] The following examples are intended to enable those skilled in the art to more fully understand the present invention, but do not limit the invention in any way.
[0024] Unless otherwise specified, the materials used in the embodiments of the present invention can be obtained commercially or prepared according to conventional methods known to those skilled in the art.
[0025] Example 1 Pt 0.8 Preparation of Co@C catalyst: (1) Dissolve 0.1 mmol H2PtCl6·6H2O and 20 mmol Co(NO3)2·6H2O in 50 mL of deionized water, and then add 120.6 mmol of anhydrous citric acid to form a homogeneous mixture; (2) The mixture was heated and stirred in an 80 ℃ water bath to obtain a red gel; (3) The gel was transferred to a 100 °C oven and dried for 12 h to obtain an orange-red "foamed" solid. After grinding, it was placed in a quartz boat and calcined in a tube furnace at 700 °C for 4 h under a N2 atmosphere to carbonize it. Finally, it was transferred to a reduction furnace and reduced at 400 °C for 2 h under a mixed atmosphere of H2 and N2 with 5 vol% H2 to obtain a black powder, which is the catalyst. ICP-OES results showed that the loading of Pt was 0.84 wt.% and the loading of Co was 53.36 wt.%. Based on the actual loading of Pt, it was named Pt. 0.8 Co@C.
[0026] Example 2 The amount of H2PtCl6·6H2O in Example 1 was replaced with 0.05 mmol, and the amount of anhydrous citric acid was replaced with 120.3 mmol. The amount of Co(NO3)2·6H2O remained unchanged. The preparation method was the same as in Example 1, and a catalyst with a Pt loading of 0.44 wt.% was obtained, named Pt. 0.4 Co@C.
[0027] Example 3 The amount of H2PtCl6·6H2O in Example 1 was replaced with 0.2 mmol, and the amount of anhydrous citric acid was replaced with 121.2 mmol. The amount of Co(NO3)2·6H2O remained unchanged. The preparation method was the same as in Example 1, and a catalyst with a Pt loading of 1.75 wt.% was obtained, named Pt. 1.7 Co@C.
[0028] Example 4 The amount of H2PtCl6·6H2O in Example 1 was replaced with 0.5 mmol, and the amount of anhydrous citric acid was replaced with 123 mmol. The amount of Co(NO3)2·6H2O remained unchanged. The synthesis method was the same as in Example 1, and a catalyst with a Pt loading of 3.50 wt.% was obtained, named Pt. 3.5 Co@C.
[0029] Comparative Example 1 Preparation of Co@C catalyst: The preparation method was the same as in Example 1, except that H2PtCl6·6H2O was not added in step (1), but only 20 mmol Co(NO3)2·6H2O and 120 mmol anhydrous citric acid were added. The remaining steps were the same as in Example 1, and a single metal catalyst was obtained, named Co@C. ICP-OES results showed that the Co loading was 59.19%.
[0030] Comparative Example 2 Pt preparation by equal volume impregnation method 0.8 / C catalyst: Weigh 0.0223 g of H₂PtCl₆·6H₂O, dissolve it in 0.8 g of deionized water, and add it dropwise to 1 g of coconut shell carbon powder treated with nitric acid. Stir well, let stand for 12 h, dry at 80 ℃ for 12 h, grind into powder, transfer to a reduction furnace, and reduce at 400 ℃ for 2 h under a hydrogen atmosphere. The obtained catalyst is named Pt. 0.8 / C.
[0031] Comparative Example 3 Pt preparation by impregnation method 0.8 Co / C catalyst: 0.0345 g of H₂PtCl₆·6H₂O and 5.6974 g of Co(NO₃)₂·6H₂O were weighed and dissolved in 10 g of deionized water. 1 g of carbon powder was added, and the mixture was stirred for 12 h. After drying at 80 °C for 12 h, the powder was ground into a fine powder and transferred to a reduction furnace. The powder was then reduced at 400 °C for 2 h under a hydrogen atmosphere. The resulting catalyst was named Pt. 0.8 Co / C.
[0032] Comparative Example 4 Pt 0.8 Preparation of Co-A catalyst: The preparation method is the same as in Example 1, except that in step (3), the carbonization process in the tube furnace is replaced by calcination at 700 °C for 4 h in an air atmosphere in a muffle furnace. The remaining steps are the same as in Example 1. The resulting catalyst is named Pt. 0.8 Co-A.
[0033] Comparative Example 5 Ru 0.8 Preparation of Co@C catalyst: The preparation method is the same as in Example 1, except that in step (1), H2PtCl6·6H2O is replaced with RuCl3·3H2O, and the remaining steps are the same as in Example 1. The resulting catalyst is named Ru. 0.8 Co@C.
[0034] Test Example 1 The structural characteristics of the catalyst were analyzed using methods such as N2 physical adsorption, X-ray diffraction (XRD), and transmission electron microscopy (TEM).
[0035] Figure 1 Pt prepared for Example 1 and Comparative Examples 1, 3, and 4 0.8 Co@C, Co@C, Pt 0.8 Co / C and Pt 0.8 The XRD pattern of the Co-A catalyst indicates that Co@C and Pt... 0.8 Co@C and Pt 0.8 In both Co / C catalysts, only diffraction peaks attributable to elemental Co were detected, while Pt... 0.8 In addition to the diffraction peaks of elemental Co, diffraction peaks belonging to CoO were also detected in the Co-A catalyst. Co@C and Pt 0.8 The detection of C diffraction peaks in the Co@C catalyst indicates that anhydrous citric acid can form C species after calcination at 700 ℃ for 4 h in a N2 atmosphere. No obvious characteristic diffraction peaks attributable to Pt were observed, possibly due to the uniform distribution of Pt particles or a low Pt content.
[0036] Figure 2Pt prepared for Example 1 and Comparative Examples 1 and 4 0.8 Co@C, Co@C and Pt 0.8 The adsorption isotherm and pore size distribution of the Co-A catalyst indicate that the presence of porous carbon facilitates the adsorption of Pt calcined in air. 0.8 Compared to Co-A, Co@C and Pt calcined in nitrogen... 0.8 The specific surface area, pore size and pore volume of the Co@C catalyst are greatly improved, and it has a large specific surface area and both microporous and mesoporous structures.
[0037] Figure 3 The Pt synthesized in Example 1 and Comparative Example 1 0.8 TEM and HRTEM images of Co@C and Co@C catalysts, along with a particle size distribution of metal nanoparticles, show that the particle size distribution of Co@C and Pt catalysts is significant. 0.8 In Co@C catalysts, the metal particles are clearly coated with several layers of carbon, while in bimetallic Pt catalysts... 0.8 The metal nanoparticles in the Co@C catalyst are smaller and better dispersed. (Co@C, Pt) 0.8 The average particle sizes of the metal particles in the Co@C catalyst are 4.0 nm and 2.1 nm, respectively.
[0038] Figure 4 Pt as described in Example 1 0.8 Co@C catalyst after 5 cycles Pt 0.8 TEM images and particle size distribution of metal nanoparticles in the Co@C-used sample. The metal nanoparticles in the sample remained uniformly distributed after the reaction, with an average particle size of 2.8 nm, not significantly different from the initial 2.1 nm, indicating a stable catalyst structure.
[0039] Test Example 2 The aqueous hydrogenation of succinic acid (SA) to 1,4-butanediol (BDO) was carried out in a 50 mL high-pressure reactor at 200 °C, a hydrogen pressure of 5 MPa, and a reaction time of 4 h. The concentration of the succinic acid aqueous solution was 1 wt.%, the reaction volume was 10 mL, and the catalyst mass was 0.2 g. The liquid products were collected, and the conversion rate of SA was analyzed by liquid chromatography, while the product selectivity was analyzed by gas chromatography. The products included γ-butyrolactone (GBL), 1,4-butanediol (BDO), tetrahydrofuran (THF), n-butanol (NBA), and n-propanol (NPA).
[0040] SA conversion, product selectivity, and BDO yield are calculated based on the molar amounts of feed and product:
[0041] Table 1 shows the Pt prepared in Example 1 and Comparative Examples 1, 2, 3, 4, and 5. 0.8 Co@C, Co@C, Pt 0.8 / C、Pt 0.8 Co / C, Pt 0.8 Co-A, Ru 0.8 Evaluation of the catalytic performance of Co@C catalyst. Table 1 shows that, compared with the single-metal catalyst Pt... 0.8 Compared to / C and Co@C, the bimetallic catalyst Pt 0.8 Co@C activity and BDO selectivity were significantly enhanced. Furthermore, Ru... 0.8 Although Co@C catalysts exhibit high activity, they show poor selectivity for single products and contain significant amounts of GBL and NPA. This indicates that only the synergistic effect between Pt and Co can promote the conversion of SA and the formation of BDO. Furthermore, Pt without carbon coating... 0.8 Co-A and Pt 0.8 The BDO yields of Co / C catalysts are significantly lower than those of Pt catalysts. 0.8 The Co@C catalyst demonstrates the crucial role of the carbon coating layer, whose interaction with the metal effectively promotes the conversion of SA and the formation of BDO.
[0042] Table 1 Catalytic performance of different catalysts in aqueous hydrogenation of succinic acid in a high-pressure reactor
[0043] Test Example 3 The aqueous hydrogenation of succinic acid (SA) to 1,4-butanediol (BDO) was carried out in a high-pressure fixed-bed reactor at a reaction temperature of 200 °C, a hydrogen pressure of 5 MPa, an aqueous succinic acid concentration of 1 wt.%, and a catalyst mass of 0.2 g. The WHSV of succinic acid was 4 h⁻¹. -1 The hydrogen space velocity (GHSV) is 500 h⁻¹. -1 The product analysis method is the same as in Test Example 1.
[0044] Table 2 shows the Pt prepared in Example 1 and Comparative Examples 1, 2, 3, 4, and 5. 0.8 Co@C, Co@C, Pt 0.8 Co / C, Pt 0.8 Co-A, Ru 0.8 The reaction results of Co@C catalyst in a fixed-bed reactor. The evaluation results of different catalysts in the fixed-bed reactor show a similar trend to those in the high-pressure reactor. As can be seen from Table 2, Pt 0.8 The Co@C catalyst exhibited the highest BDO yield, attributed to the synergistic effect between Pt and Co, as well as the interaction between the carbon coating and the metal.
[0045] Table 2 Catalytic performance of different catalysts for aqueous hydrogenation of succinic acid in a fixed-bed reactor
[0046] Test Example 4 The aqueous-phase hydrogenation of different substrates—maleic acid (MA), fumaric acid (FA), and maleic anhydride (MAH)—to produce 1,4-butanediol (BDO) was conducted in a 50 mL high-pressure reactor at 200 °C, a hydrogen pressure of 5 MPa, and a reaction time of 4 h. The aqueous solutions of maleic acid, fumaric acid, and maleic anhydride were 1 wt.%, the reaction volume was 10 mL, and the catalyst mass was 0.2 g. The product analysis method was the same as in Test Example 1.
[0047] Table 3 shows the Pt prepared in Example 1. 0.8 The Co@C catalyst was used in a high-pressure reactor for aqueous-phase hydrogenation of different substrates (maleic acid, fumaric acid, and maleic anhydride) to synthesize 1,4-butanediol, under the same reaction conditions as in Test Example 1. The results showed that Pt... 0.8 Co@C catalysts can also achieve complete conversion of maleic acid, fumaric acid, and maleic anhydride through hydrogenation in aqueous phase, with BDO yields all greater than 78%.
[0048] Table 3 Pt 0.8 Performance of Co@C catalyst in aqueous phase hydrogenation with different substrates in a high-pressure reactor
[0049] Test Example 5 Figure 5 Pt for Example 1 and Comparative Example 4 0.8 Co-A and Pt 0.8 The stability of the Co@C catalyst was evaluated under the same reaction conditions as in Test Example 1. The results showed that the uncoated C Pt... 0.8 The Co-A catalyst exhibits poor stability; after three cycles, the SA conversion rate decreased from 100.0% to 26.9%, and the main product remained GBL, suggesting that it may lack sufficient active sites to convert more SA and GBL to BDO. It is worth noting that the C-coated Pt... 0.8 The Co@C catalyst exhibits good stability, and SA can still be fully converted after 5 cycles, although the BDO selectivity decreases from 82.3% to 68.8%.
[0050] In summary, this invention provides a core-shell carbon-coated platinum-cobalt bimetallic catalyst, its preparation method, and its application in the aqueous hydrogenation of succinic acid to 1,4-butanediol. This catalyst achieves high SA conversion, high BDO selectivity, and high stability, and its preparation method is simple, inexpensive, and easy to operate.
[0051] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the implementation. The scope of protection of the present invention should be determined by the scope defined in the claims. Other variations or modifications can be made based on the above description. Obvious variations or modifications derived therefrom are still within the scope of protection of the present invention.
Claims
1. A method for preparing a platinum-cobalt bimetallic catalyst, characterized in that: Includes the following steps: (1) Dissolve the Pt precursor, Co precursor and carbon precursor in water to obtain a mixture; (2) Heat and stir the mixture to obtain a gel; (3) The gel is dried, ground, then carbonized, and finally reduced to obtain a platinum-cobalt bimetallic catalyst.
2. The preparation method according to claim 1, characterized in that: The ratio of the total molar amount of the Pt precursor and Co metal precursor to the molar amount of the carbon precursor is 1:2-8.
3. The preparation method according to claim 1, characterized in that: The Pt precursor includes one or more of tetraammineplatinum nitrate, chloroplatinic acid, platinum nitrate, and platinum tetrachloride. The Co precursor includes one or more of cobalt nitrate and cobalt chloride; The carbon precursor includes one or more of citric acid, sodium citrate, tartaric acid, ethylenediaminetetraacetic acid, and polyvinyl alcohol.
4. The preparation method according to claim 1, characterized in that: The heating and stirring time is 5-15 h, and the heating temperature is 60-120 ℃.
5. The preparation method according to claim 1, characterized in that: The drying temperature is 60-120 ℃, and the drying time is 12-24 h; The carbonization process is carried out in an inert gas atmosphere, with a carbonization temperature of 600-900 ℃ and a carbonization time of 2-6 h. The reduction process is carried out in a hydrogen atmosphere at a temperature of 400-600 °C for a time of 0.5-5 h.
6. A platinum-cobalt bimetallic catalyst prepared by the method according to any one of claims 1-5, characterized in that: The platinum-cobalt bimetallic catalyst includes an active component and a support coated on the outside of the active component; the active component is composed of Pt nanoparticles and Co nanoparticles, and the support is porous carbon.
7. The platinum-cobalt bimetallic catalyst according to claim 6, characterized in that: In the platinum-cobalt bimetallic catalyst, the loading of metal Pt is 0.02-10 wt.% and the loading of metal Co is 10-60 wt.%.
8. The application of the platinum-cobalt bimetallic catalyst according to any one of claims 6-7, characterized in that: It is applied to the aqueous hydrogenation of C4 dicarboxylic acids and their anhydrides to produce butanediol; the reactants are aqueous solutions of C4 dicarboxylic acids and their anhydrides.
9. The application according to claim 8, characterized in that: The reaction is carried out in a high-pressure reactor at a temperature of 160-240 ℃, preferably 180-220 ℃, with a hydrogen pressure of 1-12 MPa, preferably 2-8 MPa, a reactant concentration of 1-30 wt.%, and a catalyst dosage of 0.5-30% of the reactant mass.
10. The application according to claim 8, characterized in that: The reaction was carried out in a fixed-bed reactor at a temperature of 180-220 °C, a hydrogen pressure of 2-8 MPa, and a WHSV of 0.5-5 h⁻¹ for C₄ dicarboxylic acids and their anhydrides. -1 The hydrogen space velocity (GHSV) is 100-1000 h⁻¹. -1 The concentration of reactants is 1-30 wt.%, and the amount of catalyst is 0.5-30% of the mass of reactants.