A synthesis method of a bifunctional PdCu catalyst for electrocatalytic HMF hydrogenation coupling oxidation
The preparation of Pd-supported Cu nanowire catalysts by cation exchange method solves the problem of insufficient H* generation in high-concentration HMF solutions, and realizes efficient electrocatalytic hydrogenation and oxidation of HMF, producing BHMF and FDCA with high selectivity and high conversion rate.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- FUZHOU UNIV
- Filing Date
- 2026-03-17
- Publication Date
- 2026-06-09
Smart Images
Figure CN122169147A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a method for synthesizing a bifunctional PdCu catalyst for electrocatalytic hydrogen-coupled oxidation of HMF and its application, belonging to the field of chemical engineering. Background Technology
[0002] The environmental pollution caused by the overexploitation of fossil fuels is becoming increasingly severe. Finding and developing renewable energy sources is crucial for achieving both environmental protection and sustainable economic development. The conversion of widely distributed and inexpensive biomass feedstocks into value-added fuels and chemicals provides a clean option for upgrading traditional fossil fuels. Among these, 5-hydroxymethylfurfural (HMF), as an important biomass-based platform compound, can be used to produce fuels and various derivative chemical feedstocks through hydrogenation or oxidation reactions. The HMF electrocatalytic hydrogenation product, 2,5-furandiethanol (BHMF), has a furan ring and two hydroxymethyl groups, allowing it to be used directly as a monomer in the synthesis of bio-based polyesters and polyurethanes, as well as pharmaceutical intermediates, crown ethers, and other fine chemicals. The HMF electrocatalytic oxidation product, 2,5-furandicarboxylic acid (FDCA), has a furan ring and two carboxyl groups, and can be used to replace terephthalic acid in the synthesis of green biodegradable plastics. It has been listed by the U.S. Department of Energy as one of the ten most important bio-platform chemicals.
[0003] In recent years, bimetallic electrocatalysts have been widely used in the field of HMF electrocatalytic hydrogenation due to their synergistic effect and tandem catalytic mechanism. A published paper (Angew. Chem. Int. Ed. 2022, 61, 2-10) discloses a synthetic method for introducing Ru single atoms into Cu nanowires (CuNWs) via electrosubstitution. By introducing Ru single atoms to promote the dissociation of water to generate active hydrogen (H*), Cu nanowires provide abundant reaction sites and increase the hydrogen evolution reaction (HER) overpotential to suppress side reactions. The bimetallic synergistic reaction achieves a Faraday efficiency (85.6%), high HMF conversion (87.3%), and high BHMF selectivity (97.5%) at a 20 mM concentration. A published paper (Sci. Bull., 68, 2023, 2190-2199) discloses a synthetic method for loading Rh nanoparticles onto Cu nanowires via cation exchange. Rh nanoparticles modified Cu nanowires altered the water structure at the electrode interface, creating an environment rich in ordered, weakly H-bonded water molecules. This facilitated the dissociation of water molecules, promoting H* generation and thus inducing further hydrogenation of the HMF reaction intermediate to BHMF. Ultimately, this method achieved a high Faradaic efficiency (92.6%) in an electrolyte with a 50 mM HMF concentration. However, most current reports focus on the hydrogenation of low-concentration (<50 mM), small-volume (10 ml) HMF to BHMF in H-type electrolyzers. Furthermore, the anode is typically coupled with the oxygen evolution reaction (OER) of water electrolysis, resulting in slow kinetics and the economically unviable product O2. In industrial production processes, high-concentration HMF solutions are commonly used in thermocatalysis to improve efficiency. The aim is to achieve high-concentration HMF conversion during electrocatalytic hydrogenation and effectively utilize the anode's half-reaction to produce high-value-added chemicals.
[0004] Based on the research and conclusions provided in the published literature (Adv. Energy Mater. 2025, 8-11), the main challenges in the electrocatalytic hydrogenation of high-concentration HMF are as follows: In high-concentration HMF solutions (>100 mM), a large amount of HMF reaction intermediates lack sufficient H*, making them highly susceptible to dimerization to form 5,5-bis(hydroxymethyl)hydrofuran (BHH). This leads to reduced selectivity and yield of the target product, and an increase in hydrogen evolution side reactions. Therefore, accelerating the H* generation rate and selectively utilizing it for HMF hydrogenation is crucial for achieving high-concentration HMF electrocatalytic hydrogenation. Simultaneously, the coupled reaction requires potential matching between the anode and cathode. Since the theoretical potential of HMF electrocatalytic hydrogenation (ECH) (0.1 V vs. RHE) is close to that of the hydrogen evolution reaction (HER), it is difficult to efficiently achieve simultaneous electrocatalytic oxidation of HMF at the anode and electrocatalytic reduction at the cathode. Therefore, it is necessary to develop bifunctional catalysts to balance the requirements of both reactions, thereby achieving efficient production of BHMF and FDCA at both ends under mild conditions.
[0005] Based on this, the present invention provides a method for synthesizing a bifunctional PdCu catalyst for electrocatalytic HMF hydrogenation coupled oxidation. Cu has a high HER overpotential, which can effectively suppress the occurrence of hydrogen evolution side reactions. The in-situ growth of nanowire structures on the foamed copper framework is beneficial to the exposure of active sites and electron transport. The introduction of Pd clusters promotes water dissociation to generate H*, which is transported to the Cu surface through hydrogen overflow to achieve high HMF concentration hydrogenation in series catalysis. Summary of the Invention
[0006] This invention utilizes a cation exchange method to prepare a Pd-supported Cu nanowire catalyst, a simple and convenient preparation method. By adjusting the amount of Pd introduced, the loading form of Pd on the Cu nanowire surface can be controlled. When the cluster form exists, the amount of H* provided is adapted to the requirements of HMF hydrogenation reaction, and it exhibits high selectivity and conversion rate for HMF oxidation, achieving optimal performance. In a 300 mM HMF / 0.5 M PBS||100 mM HMF / 1 M KOH coupling system, a total FE of 180.1% (FDCA 91% + DHMF 89.1%) can be achieved, with an anode HMF conversion rate of 98.0%, close to 100%, and a cathode HMF conversion rate of 93.9%. After eight consecutive reactions in an H-type electrolytic cell or 100 h in a continuous flow electrochemical reactor, the catalyst showed no significant deactivation. This successfully achieved high conversion rate, Faraday efficiency, and high selectivity for BHMF and FDCA in a high-concentration HMF hydrogenation coupled HMF oxidation system.
[0007] The purpose of this invention is to overcome the shortcomings of low hydrogen concentration in HMF electrocatalytic oxidation, slow kinetics of the anodic oxygen evolution reaction, and low economic value of the products, and to propose a method for synthesizing a bifunctional PdCu catalyst for electrocatalytic HMF hydrogenation coupled oxidation.
[0008] The Pd-based Cu nanowire electrocatalytic material provided by this invention has Cu nanowires growing randomly on the surface of a foamed copper framework. The diameter of the Cu nanowires is about 300 nm and the length is about 10 μm. The surface of the nanowires is loaded with a large number of Pd clusters, and the particle size of the individual Pd clusters is between 3 and 5 nm. This structure provides a sufficient number of active sites and realizes efficient tandem catalysis, thereby enabling the conversion of higher concentrations of HMF hydrogenation.
[0009] One aspect of this application provides a method for preparing a bifunctional Pd-based Cu nanowire catalyst that is simple to prepare, has strong catalytic performance, long service life, high economic benefits, and is grown in situ on the surface of copper foam, comprising the following steps: (1) Dissolve ammonium persulfate in deionized water to obtain solution A; dissolve sodium hydroxide in deionized water to obtain solution B; add solution A to solution B to obtain a mixed solution; immerse pretreated copper foam in the solution for oxidation reaction; wash and dry the product to obtain copper foam nanowire precursor. (2) The soluble palladium salt was completely dissolved in deionized water by ultrasound to obtain solution C; the copper nanowire foam precursor was immersed in solution C to carry out ion exchange reaction, and the product was washed, dried and then calcined in a muffle furnace at 200 °C for 2 h to obtain Pd-based Cu nanowire catalyst.
[0010] Furthermore, the pretreatment described in step (1) includes: sequentially placing the copper foam into dilute hydrochloric acid, acetone, and deionized water and sonicating for 10-30 min respectively.
[0011] Furthermore, the reaction time of the oxidation reaction in step (1) is 10-60 min.
[0012] Furthermore, the soluble palladium salt mentioned in step (2) is any one of palladium chloride, palladium nitrate and palladium sulfate, and the concentration of the soluble palladium salt is 5-20 mM.
[0013] Another aspect of this application provides an application of electrocatalytic HMF hydrogenation coupled with HMF oxidation to prepare BHMF and FDCA. This method has mild reaction conditions, high selectivity, high economic efficiency, and high stability of the two-stage catalysts for HMF.
[0014] The application of the Pd-based Cu nanowire catalyst in the electrocatalytic hydrogenation coupled with HMF oxidation to prepare BHMF and FDCA specifically includes the following steps: (1) Using the Pd-based Cu nanowire catalyst as the working electrode and the counter electrode, the Ag / AgCl electrode as the reference electrode, the alkaline solution as the anolyte, and the neutral solution as the catholyte, a three-electrode system was prepared in an H-type electrolytic cell. (2) Alternatively, the Pd-based Cu nanowire catalyst can be used as the working electrode and the counter electrode, with an alkaline solution as the anolyte and a neutral solution as the catholyte, to create a two-electrode system in a continuous flow electrochemical reactor. (3) 5-hydroxymethylfurfural is dissolved in the cathode and anolyte electrolytes, and electrochemical catalytic hydrogenation coupled with electrochemical catalytic oxidation reaction is carried out in the three-electrode system and the two-electrode system respectively in the H-type electrolytic cell and the continuous flow electrochemical reactor with applied voltage.
[0015] Furthermore, the alkaline electrolyte in step (1) is an aqueous solution of potassium hydroxide with a concentration of 0.1-1 mol / L.
[0016] Furthermore, the cathode neutral electrolyte in step (1) is a phosphate buffer solution with a concentration of 0.1-1 mol / L.
[0017] Furthermore, in step (3), the concentration of 5-hydroxymethylfurfural in the anolyte is 10-100 mmol / L; and the concentration of 5-hydroxymethylfurfural in the catholyte is 10-300 mmol / L.
[0018] Furthermore, in step (3), the conditions in the H-type electrolytic cell are set primarily with the cathode, and a constant current is used for the electrochemical reduction reaction. The constant current is 20-180 mA·cm⁻¹. -2 The reaction time is 10-180 min; in the continuous flow electrochemical reactor, the conditions are set with the cathode as the main component and a constant current is used for the electrochemical reduction reaction, wherein the constant current is 20-250 mA·cm. -2 The flow rate is 0.01-0.5 mL / min. -1 The reaction time is 1-100 h.
[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The Pd-based Cu nanowire catalyst has a three-dimensional nanowire structure, which increases the number of active centers participating in the catalytic reaction. The Pd clusters regulate the H* coverage on the catalyst surface, thereby selectively promoting the HMF electrocatalytic hydrogenation reaction.
[0020] 2. The synthesis method of the Pd-based Cu nanowire catalyst is simple and easy to implement.
[0021] 3. The Pd-based Cu nanowire catalyst has bifunctional catalytic characteristics and can be used simultaneously in two reaction systems: HMF electrocatalytic hydrogenation and HMF electrocatalytic oxidation. The coupled system has high electron utilization.
[0022] 4. The Pd-based Cu nanowire catalyst exhibits excellent HMF hydrogenation and HMF oxidation performance, and can achieve complete conversion of high-concentration HMF. In 300 mM HMF / 0.5 M PBS||100 mM HMF / 1 M KOH, the total FE can reach 180.1% (FDCA 91%+DHMF 89.1%), with a conversion rate of over 90%.
[0023] 5. The Pd-based Cu nanowire catalyst showed no significant deactivation after being reacted 8 times in an H-type electrolytic cell or 100 h in a continuous flow electrochemical reactor, indicating high catalyst stability.
[0024] 6. The electrocatalytic high-concentration HMF hydrogenation coupled HMF oxidation method using the Pd-based Cu nanowire catalyst is simple, has mild conditions, and is conducive to industrial production.
[0025] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description
[0026] Figure 1 The images show the XRD patterns of the PdCuNWs catalyst before and after electroreduction obtained in Example 1.
[0027] Figure 2 The images show scanning electron microscope (SEM) images, HRTEM images, and EDS spectra of the Cu nanowire catalyst and PdCuNWs catalyst obtained in Example 1.
[0028] Figure 3 The reduction reaction polarization curves are shown for the PdCuNWs catalyst obtained in Example 1 and the CuNWs catalyst obtained in Comparative Example 1.
[0029] Figure 4 The oxidation reaction polarization curves are shown for the PdCuNWs catalyst obtained in Example 1 and the CuNWs catalyst obtained in Comparative Example 1.
[0030] Figure 5 The graph shows a comparison of the HMF conversion (Con.), BHMF selectivity (Sel.), and Faraday efficiency (FE) of the PdCuNWs catalyst obtained in Example 1 and the CuNWs catalyst obtained in Comparative Example 1 in 150 mM HMF / 0.5 M PBS at the cathode.
[0031] Figure 6 The graph shows a comparison of the HMF conversion (Con.), FDCA selectivity (Sel.), and Faraday efficiency (FE) of the PdCuNWs catalyst obtained in Example 1 and the CuNWs catalyst obtained in Comparative Example 1 in 50 mM HMF / 1.0 M KOH at the anode.
[0032] Figure 7 The graph shows the cathode BHMF yield and anode FDCA yield-time of the PdCuNWs catalyst obtained in Example 1 in a two-electrode system of a continuous flow electrochemical reactor. Detailed Implementation
[0033] To make the above features and advantages of the present invention more apparent and understandable, specific embodiments are provided below for detailed description. Unless otherwise specified, the methods of the present invention are conventional methods in the art. Example 1
[0034] (1) Pretreatment of copper foam: Cut the copper foam into 1×2 cm pieces. 2The rectangular pieces were immersed in dilute hydrochloric acid and ultrasonically treated for 30 minutes to remove surface oxides; then immersed in acetone and ultrasonically treated for 30 minutes to remove surface organic matter; finally immersed in deionized water and ultrasonically treated for 30 minutes to clean surface dust, and dried in a vacuum oven at 60 ℃.
[0035] (2) Weigh 2.282 g of ammonium persulfate ((NH4)2S2O8) and dissolve it in 100 ml of deionized water to obtain solution A; weigh 4 g of sodium hydroxide (NaOH) and dissolve it in 100 ml of deionized water to obtain solution B; add solution A to solution B and mix well; immerse the pretreated copper foam in the mixed solution and let it stand for 1 h to obtain copper foam nanowire precursor.
[0036] (3) 17.73 mg of palladium chloride (PdCl2) was accurately weighed and completely dissolved in 10 ml of deionized water by ultrasonication to obtain solution C; the Cu nanowire precursor was immersed in solution C for ion exchange for 12 h, then washed, dried, and calcined in a muffle furnace at 200 °C for 2 h to obtain the PdCuONWs catalyst. The obtained PdCuONWs catalyst was further subjected to constant -40 mAcm on an electrochemical workstation. -2 The PdCuNWs catalyst was obtained by in-situ reduction at the current density for 1 h.
[0037] The XRD patterns of the prepared PdCuONWs catalyst and the reduced PdCuNWs using an electrochemical workstation are shown below. Figure 1 As shown.
[0038] The catalyst prepared in this embodiment was used in the electrocatalytic HMF hydrogenation reaction coupled with the electrocatalytic HMF oxidation reaction, and its electrocatalytic performance was measured. The specific implementation steps are as follows: (1) Preparation of working electrode: The catalyst obtained in Example 1 was fixed by Pt electrode clamp to prepare a working electrode.
[0039] (2) Assembly of the three-electrode system: The working electrodes are used as the cathode and anode respectively, and the Ag / AgCl electrode is fixed at the cathode end of the H-type electrolytic cell as the reference electrode. The volume of the electrolytic cell is more than 30 mL.
[0040] (3) Under normal temperature and pressure conditions, using the assembled three-electrode system, 0.5 M PBS + 150 mM HMF solution and 1 M KOH + 50 mM HMF solution were used as the anode and cathode electrolytes, respectively. The constant current density during the reaction was 100 mA / cm². -2 The reaction time was 3.5 h, and electrocatalytic performance was tested. After the reaction, the reaction solution was filtered and analyzed using an Agilent high-performance liquid chromatograph to determine the conversion rate of cathode HMF, the selectivity of BHMF, and the Faraday efficiency. Figure 5The conversion rates of HMF at the anode, the selectivity of FDCA, and the Faraday efficiency ( ) Figure 6 The results are shown in Table 1. Example 2
[0041] In this embodiment, the same three-electrode system and reaction conditions as in Example 1 were used, except that the HMF concentration at the cathode was changed to 300 mM and the HMF concentration at the anode to 100 mM. The conversion rate, Faraday efficiency, BHMF selectivity, and FDCA selectivity of the two electrodes were measured, and the results are shown in Table 1. Example 3
[0042] In this embodiment, the same three-electrode system and reaction conditions as in Example 1 are used, only the magnitude of the reaction current is changed from 100 mA / cm². -2 Change to 80mA cm -2 The conversion rate, Faraday efficiency, BHMF selectivity, and FDCA selectivity of the two electrodes were determined, and the results are shown in Table 1. Example 4
[0043] The catalyst prepared in Example 1 was used in a continuous flow electrochemical reactor for the electrocatalytic hydrogenation-coupled oxidation of 5-hydroxymethylfurfural, and its electrocatalytic performance was determined. The specific implementation steps are as follows: 1) Preparation of working electrode: Cut copper foam into 3×2 cm pieces. 2 Rectangular sheets of the same size were prepared using the same pretreatment steps as in Example 1 to obtain Cu nanowire precursors. 26.6 mg of palladium chloride (PdCl2) was weighed and completely dissolved in 10 ml of deionized water by ultrasonication to obtain solution C. The Cu nanowire precursors were immersed in solution C for ion exchange for 12 h, then washed, dried, and calcined in a muffle furnace at 200 °C for 2 h to obtain PdCuONWs catalysts, which were used as the working electrodes of the anode and cathode.
[0044] 2) Under ambient temperature and pressure conditions, using an assembled two-electrode system, the KOH and HMF solutions at the anode were stored separately and then mixed in a three-way valve before being pumped into the continuous flow electrochemical reactor. This setup allows the reactants to be rapidly converted into the target product within the flow electrochemical reactor, effectively preventing the degradation of HMF in the KOH solution. The PBS and HMF solutions at the cathode were also stored separately and mixed in a three-way valve before flowing into the continuous flow electrochemical reactor. During the reaction, a constant current of 150 mA was maintained. -2 The reaction temperature was 25 °C, and the reaction time was 100 h. Figure 7 Electrochemical tests were conducted.
[0045] Comparative Example 1
[0046] Pretreatment of copper foam: Cut the copper foam into 2×3 cm pieces.2 The rectangular piece of the same size is used, and the rest of the operation is the same as in Example 1.
[0047] 2.282 g of ammonium persulfate ((NH4)2S2O8) was dissolved in 100 ml of deionized water to obtain solution A; 4 g of sodium hydroxide (NaOH) was dissolved in 100 ml of deionized water to obtain solution B; solution A was added to solution B and mixed thoroughly; the pretreated copper foam was then immersed in the mixed solution and allowed to stand for 1 h to obtain the copper foam nanowire precursor. This precursor was then directly calcined in a muffle furnace at 200°C for 2 h and reduced to obtain the CuNWs catalyst.
[0048] In this comparative example, the same three-electrode system and the same reaction conditions as in Example 1 were used, and the results are shown in Table 1.
[0049] Table 1 Evaluation of the hydrogenation-coupled HMF oxidation performance of the catalysts in the examples and comparative examples
[0050] Note: The current is the current density set when the cathode is used as the working electrode.
[0051] As shown in Table 1, the performance of both the HMF hydrogenation end and the HMF oxidation end of the PdCuNWs electrode material prepared by this method in Example 1 is superior to that of the CuNWs electrode material in Comparative Example 1. The coupled system achieved an anode HMF conversion rate of 99.8%, an FDCA selectivity of 94.2%, and a Faradaic efficiency of 95.1%; and a cathode HMF conversion rate of 92.7%, a BHMF selectivity of 88.9%, and a Faradaic efficiency of 89.3%. In contrast, the coupled system of the unloaded CuNWs electrode material achieved an anode HMF conversion rate of 99.4%, an FDCA selectivity of 64.7%, and a Faradaic efficiency of 74.9%; and a cathode HMF conversion rate of 73%, a BHMF selectivity of 77.3%, and a Faradaic efficiency of 56.6%. When the HMF concentration was increased (300 mM at the cathode and 100 mM at the anode), the PdCuNWs electrode material still maintained a 98% conversion, 91.1% selectivity, and 91% Faradaic efficiency at the anode in the coupled system; and a 93.9% conversion, 89.7% selectivity, and 89.1% Faradaic efficiency at the cathode. Electrochemical testing was conducted in the continuous flow reactor in Example 4 for 100 h, and the PdCuNWs maintained excellent stability, with a total yield of 174.7% (83.3% BHMF + 91.4% FDCA) in the coupled system. This indicates that the catalyst possesses excellent bifunctional catalytic properties and demonstrates broad application prospects in industrial production.
[0052] The above results demonstrate that the PdCuNWs electrode material has higher catalytic hydrogenation and catalytic oxidation activities for HMF, and can effectively pair up the electrosynthesis of HMF hydrogenation and HMF oxidation, making it a high-performance bifunctional electrocatalytic material.
[0053] Depend on Figure 1 It can be seen that PdCuONWs contains diffraction peaks of Cu substrate and a small amount of diffraction peaks of CuO. After reduction, it only contains diffraction peaks of Cu. The loading of Pd is too low to be directly observed from XRD.
[0054] Depend on Figure 2 As can be seen, CuNWs are smooth and slender Cu nanowire structures with a diameter of about 300 nm and a length of about 10 μm. The surface of PdCuNWs has a large number of protrusions supported by Pd clusters. The particle size of a single Pd cluster is about 3 to 5 nm as observed by TEM.
[0055] Depend on Figure 3 It can be seen at -20 mA cm -2 The HMFRR overpotentials of CuNWs obtained in Comparative Example 1 and PdCuNWs obtained in Example 1 were both lower than the corresponding HER, indicating that the Cu nanowire structure can effectively promote the HMF reduction reaction and inhibit the competing hydrogen evolution reaction. Furthermore, the overpotential of PdCuNWs in the HMFRR process was much lower than that of CuNWs, indicating that PdCuNWs has the best HMF reduction reaction kinetics.
[0056] Depend on Figure 4 It can be seen that at a current density of 10 mA cm⁻¹ -2 At that time, the PdCuNWs obtained in Example 1 had the lowest HMF oxidation potential compared to the CuNWs obtained in Comparative Example 1, indicating that PdCuNWs can effectively catalyze the HMF oxidation reaction and have good HMF oxidation reaction kinetics.
[0057] Depend on Figure 5 As can be seen, the PdCuNWs obtained in Example 1 achieved a 92.7% HMF conversion, 88.9% BHMF selectivity, and 89.3% Faradaic efficiency at the hydrogenation end of the coupled reaction. This is in contrast to the CuNWs obtained in Comparative Example 1, which only achieved a 73% HMF conversion, 77.3% BHMF selectivity, and 56.6% Faradaic efficiency. This indicates that the PdCuNWs at the hydrogenation end of the coupled reaction exhibit superior selectivity for HMF reduction, and that the electricity consumed in the reaction system is primarily used for HMF reduction at the cathode.
[0058] Depend on Figure 6As can be seen, the PdCuNWs obtained in Example 1 achieved a 99.8% HMF conversion, 94.2% FDCA selectivity, and 95.1% Faradaic efficiency at the oxidation end of the coupled reaction. This is in contrast to the CuNWs obtained in Comparative Example 1, which only achieved a 99.4% HMF conversion, 64.7% FDCA selectivity, and 74.9% Faradaic efficiency. This indicates that the PdCuNWs at the oxidation end of the coupled reaction exhibit superior selectivity for HMF oxidation, and that the electricity consumed in the reaction system is primarily used for the HMF oxidation reaction.
[0059] Depend on Figure 7 It is evident that PdCuNWs are suitable for electrocatalytic hydrogenation coupled oxidation systems of HMF, for the continuous production of high-value products BHMF and FDCA.
[0060] The specific embodiments described above can further illustrate the purpose, technical solution and beneficial effects of the present invention. However, it should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A method for synthesizing a bifunctional PdCu catalyst for electrocatalytic hydrogenation coupled oxidation of HMF, characterized in that, Includes the following steps: (1) Dissolve ammonium persulfate in deionized water to obtain solution A; Sodium hydroxide was dissolved in deionized water to obtain solution B; Solution A was added to solution B to obtain a mixed solution. The pretreated copper foam was then immersed in the mixed solution for oxidation. The product was then washed and dried to obtain the copper foam nanowire precursor. (2) The soluble palladium salt was completely dissolved in deionized water by ultrasound to obtain solution C; the copper nanowire foam precursor was immersed in solution C to carry out ion exchange reaction, and the product was washed, dried and then calcined in a muffle furnace at 200 °C for 2 h to obtain Pd-based Cu nanowire catalyst.
2. The method according to claim 1, characterized in that, The pretreatment described in step (1) specifically includes: placing the foamed copper into dilute hydrochloric acid, acetone, and deionized water in sequence and sonicating for 10-30 min respectively.
3. The method according to claim 1, characterized in that, The reaction time for the oxidation reaction in step (1) is 10-60 min.
4. The method according to claim 1, characterized in that, The soluble palladium salt mentioned in step (2) is any one of palladium chloride, palladium nitrate and palladium sulfate, and the concentration of the soluble palladium salt is 5-20 mM.
5. A Pd-based Cu nanowire catalyst prepared by the method according to any one of claims 1-4.
6. The application of the Pd-based Cu nanowire catalyst as described in claim 5 in the electrocatalytic hydrogenation coupled with HMF oxidation to prepare BHMF and FDCA.
7. The application according to claim 6, characterized in that, The specific operations include: using the Pd-based Cu nanowire catalyst as the working electrode and counter electrode, using an Ag / AgCl electrode as the reference electrode, using an alkaline solution as the anolyte, and using a neutral solution as the catholyte, to create a three-electrode system in an H-type electrolytic cell; or using the Pd-based Cu nanowire catalyst as the working electrode and counter electrode, using an alkaline solution as the anolyte, and using a neutral solution as the catholyte, to create a two-electrode system in a continuous flow electrochemical reactor; dissolving 5-hydroxymethylfurfural in the catholy and anolyte solutions, and performing electrochemical catalytic hydrogenation coupled with electrochemical catalytic oxidation reactions on the three-electrode system and the two-electrode system respectively in the H-type electrolytic cell and the continuous flow electrochemical reactor.
8. The application according to claim 7, characterized in that, The alkaline electrolyte at the anode is an aqueous solution of potassium hydroxide with a concentration of 0.1-1 mol / L; the neutral electrolyte at the cathode is a phosphate buffer solution with a concentration of 0.1-1 mol / L.
9. The application according to claim 7, characterized in that, The concentration of 5-hydroxymethylfurfural in the anolyte was 10-100 mmol / L; the concentration of 5-hydroxymethylfurfural in the catholyte was 10-300 mmol / L.
10. The application according to claim 7, characterized in that, In an H-type electrolytic cell, conditions are set primarily at the cathode, and a constant current is used for the electrochemical reduction reaction. The constant current is 20-180 mA·cm⁻¹. -2 The reaction time is 10-180 min; in the continuous flow electrochemical reactor, the conditions are set with the cathode as the main component and a constant current is used for the electrochemical reduction reaction, wherein the constant current is 20-250 mA·cm. -2 The flow rate is 0.01-0.5 mL / min. -1 The reaction time is 1-100 h.