Synthesis method of phosphorus-doped copper oxide, catalyst and preparation method and application of catalyst

Abstract

The invention relates to a synthesis method of novel energy-saving phosphorus-doped copper oxide, a catalyst as well as a preparation method and application of the catalyst. The synthesis method comprises the following steps: S100, obtaining copper oxide nanoparticles; s200, obtaining a black phosphorus nanosheet; s300, the copper oxide nanoparticles and the black phosphorus nanosheets are mixed and then subjected to ultrasonic treatment, and phosphorus-doped copper oxide is obtained.According to the method, the phosphorus-doped copper oxide nanoparticle catalyst can be synthesized under the mild condition, and very high methanol oxidation reaction activity and formate selectivity are achieved.

Description

Technical Field

[0001] This invention relates to the fields of nanomaterials and catalysis, and in particular to a novel energy-saving method for synthesizing phosphorus-doped copper oxide, a catalyst thereof, its preparation method, and its application. Background Technology

[0002] Methanol, as an important chemical raw material, produces formate, an oxidation product that plays a vital role in various fields such as chemical industry, agriculture, environmental protection, and medicine. Currently, industrial formate production typically requires the introduction of carbon monoxide under high temperature and pressure conditions. This process is not only energy-intensive but also poses safety hazards due to the toxicity and flammability of carbon monoxide, as well as the high temperature and pressure conditions. In contrast, the electrocatalytic oxidation of methanol to formate has attracted significant attention due to its milder conditions and lower standard potential (0.103 V relative to the reversible hydrogen electrode potential). Furthermore, the anolyte reaction can serve as a half-reaction in the overall water splitting process, effectively enhancing the economic value of the anolyte reaction.

[0003] Traditional electrocatalytic oxidation of methanol to formate mainly relies on noble metal catalysts, such as platinum and palladium. These catalysts are expensive and susceptible to catalyst poisoning. In recent years, non-noble metal-based catalysts have shown great potential in the field of catalysis due to their unique electronic structure and tunable physicochemical properties. However, non-noble metal-based catalysts typically exhibit poor catalytic activity and selectivity. Summary of the Invention

[0004] To address the aforementioned shortcomings, this invention proposes a method for synthesizing phosphorus-doped copper oxide, a catalyst, its preparation method, and its application. This invention addresses the high cost and high energy consumption issues of catalysts in existing methanol-to-formate technology by providing a green and efficient method for synthesizing a non-precious metal catalyst and its application in the electrocatalytic oxidation of methanol to formate. This method can synthesize phosphorus-doped copper oxide nanoparticle catalysts under mild conditions, exhibiting very high methanol oxidation reactivity and formate selectivity.

[0005] The technical solution adopted in this invention is a method for synthesizing phosphorus-doped copper oxide, comprising the following steps:

[0006] S100, obtaining copper oxide nanoparticles;

[0007] S200, obtaining black phosphorus nanosheets;

[0008] S300: After mixing the copper oxide nanoparticles and black phosphorus nanosheets, ultrasonic treatment is performed to obtain phosphorus-doped copper oxide.

[0009] Preferably, the temperature of S300 is controlled between 0 and 60°C, and the mass ratio of copper oxide nanoparticles to black phosphorus nanosheets is 5:1 to 1:5.

[0010] Preferably, S100 specifically includes:

[0011] S110. Dissolve Ag copper salt in B mL of deionized water, add C mL of acid, heat and stir to obtain solution one;

[0012] S120. Add alkaline solution dropwise to the first solution until the pH = 6-10 to obtain the second solution;

[0013] S130. After cooling the solution, centrifuge and wash to obtain the copper oxide nanoparticles.

[0014] Preferably, the heating temperature in S110 is between 25 and 100°C, the alkali solution temperature in S120 is between 25 and 100°C, and the ratio of A:B:C in S110 is (0.1 to 10):(10 to 1000):(1 to 100).

[0015] Preferably, S200 specifically includes:

[0016] S210. Dilute D mg of black phosphorus to a suspension with a total volume of E mL;

[0017] S220. The suspension is ultrasonically stripped to obtain mixture one;

[0018] S230. Wash the mixture to obtain the black phosphorus nanosheets.

[0019] Preferably, in S210, D:E = (1~1000):(50~5000).

[0020] Preferably, the concentration of the alkali solution in S120 is between 0.1 and 10 mol / L, and / or

[0021] The ultrasonic power in S220 is between 800-2000W, the ultrasonic processing time in S220 is between 10-40 hours, and / or

[0022] The ultrasound time in the S300 is between 5 and 60 minutes.

[0023] This invention also provides a method for preparing a catalyst, comprising the following steps:

[0024] S410. Carbon black is added to ethanol and then ultrasonically dispersed to obtain a dispersion.

[0025] S420. The dispersion is mixed with the phosphorus-doped copper oxide synthesized by the above synthesis method, and then ultrasonically treated to obtain the catalyst.

[0026] The present invention also provides a catalyst, which is prepared by the above-described preparation method.

[0027] The present invention also provides an application of the phosphorus-doped copper oxide synthesized by the above-described synthesis method in electrocatalytic methanol oxidation to formate or in direct methanol fuel cells.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The synthesis method used in this invention does not require high-temperature and high-pressure conditions, which greatly reduces energy consumption and production costs. It also avoids the safety hazards that may occur in traditional methods and is in line with the principles of green chemistry.

[0030] 2. By precisely controlling the reaction conditions, phosphorus-doped copper oxide with a uniform morphology and a particle size of approximately 4.5 nm can be obtained. This precise control is crucial for improving the activity and selectivity of the catalyst.

[0031] 3. By precisely controlling the proportion of copper-phosphorus bonds in phosphorus doping through the control of black phosphorus addition, the prepared phosphorus-doped copper oxide exhibits excellent performance in the catalytic field and can effectively promote the methanol oxidation reaction.

[0032] 4. The catalyst prepared in this invention exhibits a selectivity of 96.4% in the oxidation of methanol to formic acid. Phosphorus doping reduces the adsorption of formic acid on the catalyst surface, which helps to reduce the formation of by-products and improve the yield of the target product. Attached Figure Description

[0033] The present invention will now be described in detail with reference to the embodiments and accompanying drawings, wherein:

[0034] Figure 1 This is a flowchart of the synthesis method of phosphorus-doped copper oxide;

[0035] Figure 2 This is a schematic diagram of black phosphorus nanosheets analyzed using high-resolution TEM;

[0036] Figure 3 This is an atomic force microscope image of black phosphorus nanosheets;

[0037] Figure 4 This is a schematic diagram of CuO1BP2 analysis using TEM, high-angle annular dark-field scanning TEM (HAADF-STEM), high-resolution TEM (HR-TEM), and energy-dispersive X-ray spectroscopy (EDS).

[0038] Figure 5 These are the XRD patterns of BP, CuO1BP2, and CuO;

[0039] Figure 6 These are the Cu2p XPS spectra of CuO1BP2 and CuO;

[0040] Figure 7 These are Cu LMM XPS spectra of CuO1BP2 and CuO;

[0041] Figure 8 The CV curve of electrocatalytic methanol oxidation of CuO1BP2 is shown.

[0042] Figure 9 This is a schematic diagram of the Faraday efficiency of CuO1BP2 and CuO at 20 and 100 mA.

[0043] Figure 10 This is a schematic diagram of the stability test of the electrocatalytic methanol oxidation reaction of CuO1BP2;

[0044] Figure 11 These are TEM images, aberration-corrected HAADF-STEM (AC-HAADF-STEM) images, and STEM-EDS elemental distribution maps of CuO nanorods.

[0045] Figure 12 This is a schematic diagram of the polarization curve of a direct methanol fuel cell with a membrane electrode assembly. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0047] In one embodiment, a method for synthesizing phosphorus-doped copper oxide is described in [reference needed]. Figure 1 This includes the following steps:

[0048] S100, obtaining copper oxide nanoparticles;

[0049] S200, obtaining black phosphorus nanosheets;

[0050] S300: After mixing the copper oxide nanoparticles and black phosphorus nanosheets, ultrasonic treatment is performed to obtain phosphorus-doped copper oxide.

[0051] This embodiment utilizes a mixture of black phosphorus and copper oxide to obtain phosphorus-doped copper oxide. Copper-based metal oxide catalysts have advantages such as low cost, high catalytic activity, and strong resistance to poisoning, making them suitable as efficient catalysts for the production of formate from methanol. Phosphorus doping can significantly improve the electronic properties of copper-based oxides, thereby further enhancing catalytic activity and selectivity. Therefore, the phosphorus-doped copper oxide synthesized in this embodiment, as a catalyst for the traditional electrocatalytic oxidation of methanol to formate, has the advantages of low cost, high catalytic activity and selectivity, and strong resistance to poisoning.

[0052] Furthermore, the synthesis method in this embodiment does not require high-temperature treatment or high-pressure reaction. It only requires room-temperature ultrasonic treatment to induce the transfer of phosphorus from black phosphorus nanosheets to copper oxide, thereby regulating the electronic structure of copper oxide, improving catalytic activity, controlling production costs, and making the final performance of phosphorus-doped copper oxide as a catalyst more stable.

[0053] In one specific embodiment, S100 specifically includes:

[0054] S110. Dissolve Ag copper salt in B mL of deionized water, add C mL of acid, heat and stir to obtain solution one. The copper salt can be copper nitrate, copper sulfate, copper chloride, copper acetate, copper acetylacetonate, etc., and the acid can be acetic acid, hydrochloric acid, nitric acid, sulfuric acid, formic acid, etc.

[0055] S120. Add an alkaline solution dropwise to the first solution until the pH reaches 6-10, obtaining the second solution. The alkaline solution can be potassium hydroxide, sodium hydroxide, etc. The pH of the second solution (6-10) directly determines the morphology and particle size of the copper oxide nanoparticles. Spherical nanoparticles (approximately 4.5 nm) are formed at pH 6-8, and nanorods (approximately 10 nm in diameter and 50 nm in length) are formed at pH 9-10.

[0056] S130. After cooling the second solution, centrifuge and wash to obtain the copper oxide nanoparticles. Specifically, transfer the second solution to ice water and cool to room temperature. Centrifuge at 10,000 rpm and wash with ethanol or N-methylpyrrolidone, deionized water, etc., to obtain copper oxide nanoparticles.

[0057] Furthermore, the heating temperature in S110 is between 25 and 100°C, and the stirring time in S110 is between 5 and 60 minutes, which can ensure that the copper salt is fully dissolved.

[0058] Furthermore, the temperature of the alkali solution in S120 is between 25 and 100°C. The synchronous alkali solution temperature can avoid local overcooling or overheating of the solution due to temperature difference, and ensure uniform generation of copper oxide nanoparticles. For example, when both the alkali solution and the solution are at 80°C, the precipitation rate is consistent and the particle size is uniform.

[0059] Furthermore, in S110, A:B:C = (0.1~10):(10~1000):(1~100), and the concentration of copper ions and the amount of acid are controlled within this range. The minimum, maximum and preferred intermediate values ​​of A are 0.1, 10 and 2, respectively; the values ​​of B are 10, 1000 and 100, respectively; and the values ​​of C are 1, 100 and 1, respectively. When A, B and C are preferred values, the concentration of copper ions is moderate, and a stable copper ion solution system can be formed.

[0060] Furthermore, the concentration of the alkali solution in S120 is between 0.1 and 10 mol / L, with the minimum, maximum, and preferred intermediate values ​​being 0.1, 10, and 1 mol / L of potassium hydroxide solution, respectively. This concentration of alkali solution can control the pH rise of solution one to be gradual, facilitating precise control. At the same time, the pH can be adjusted by adding a small amount of solution, making it suitable for large-scale preparation.

[0061] This embodiment can prepare copper oxide nanoparticles with controllable morphology and uniform particle size under mild conditions of 25–100℃, with the minimum, maximum, and preferred intermediate temperatures being 25, 100, and 90℃, respectively. Through the synergistic regulation of the A:B:C ratio, temperature, and pH, precise control of nanomaterial preparation is achieved. This not only solves the problems of high energy consumption and uneven particle size in traditional methods, but also provides an ideal substrate for subsequent phosphorus doping through ultra-small particle size and high purity. Ultimately, the formate Faraday efficiency of the electrocatalytic methanol oxidation reaches 96.4%, laying the foundation for the industrial application of non-precious metal catalysts.

[0062] In one specific embodiment, S200 specifically includes:

[0063] S210. Dilute D mg of black phosphorus to a suspension with a total volume of E mL. Specifically, add D mg of block black phosphorus to ethanol (or N-methylpyrrolidone) and grind for 0.5–4 hours. Subsequently, dilute the mixture with ethanol (or N-methylpyrrolidone) to a total volume of E mL.

[0064] S220. The suspension is ultrasonically stripped to obtain mixture one.

[0065] S230. Wash the mixture to obtain the black phosphorus nanosheets. Specifically, after peeling, the mixture is washed several times with ethanol (or N-methylpyrrolidone). The concentration of the black phosphorus sheets is determined based on the absorbance at 808 nm.

[0066] Furthermore, in S210, D:E = (1~1000):(50~5000). The minimum, maximum, and preferred intermediate values ​​of D are 1, 1000, and 500, respectively, and the values ​​of D'' are 50, 5000, and 100, respectively. This preferred concentration results in high ultrasonic exfoliation efficiency; excessively high concentrations can lead to agglomeration, while excessively low concentrations waste solvent. For example, when D = 500 mg and E = 100 mL, the black phosphorus concentration is 5 mg / mL, at which point the ultrasonic exfoliation efficiency is highest.

[0067] Furthermore, the ultrasonic power in S220 is between 800-2000W, with a minimum, maximum, and preferred intermediate value of 800, 2000, and 1200W, respectively. For example, as... Figure 2 As shown, 1200W ultrasound for 15 hours can peel off bulk black phosphorus into nanosheets with an average thickness of about 12 nanometers.

[0068] Furthermore, the ultrasonic treatment time in S220 is between 10 and 40 hours, with a minimum, maximum, and preferred intermediate value of 10, 40, and 20 hours, respectively. The long treatment time (10-40 hours) ensures sufficient dissociation of the layered structure; for example, after 20 hours of ultrasonic treatment, as... Figure 3 As shown, the lateral dimensions of black phosphorus nanosheets can reach 100-500 nm.

[0069] In one specific embodiment, the temperature of S300 is controlled between 0 and 60°C, with a minimum, maximum, and preferred intermediate value of 0, 60, and 20°C, respectively. This suppresses black phosphorus oxidation and ensures that phosphorus substitutes for lattice oxygen in copper oxide doping. The mass ratio of copper oxide nanoparticles to black phosphorus nanosheets is 5:1 to 1:5. Excess copper oxide (>5:1) results in low phosphorus doping; excess black phosphorus (<1:5) affects electrochemical performance. Furthermore, the ultrasonic time in S300 is between 5 and 60 minutes, which increases the density of catalytic active sites as black phosphorus is doped into copper oxide.

[0070] By using high-power ultrasonic stripping of black phosphorus and room-temperature ultrasonic doping of copper oxide, copper oxide nanoparticles were transformed into a highly efficient phosphorus-doped copper oxide catalyst under mild conditions. This catalyst exhibited high activity, high selectivity, and high stability in the electro-oxidation of methanol to formate, providing a low-cost, high-performance catalyst solution for green chemistry and fuel cell fields.

[0071] In one embodiment, a method for preparing a catalyst includes the following steps:

[0072] S410. Add F mg of carbon black to G μL of ethanol and then disperse by ultrasonication to obtain a dispersion.

[0073] S420. The dispersion is mixed with phosphorus-doped copper oxide synthesized by the above synthesis method, and then ultrasonically treated to obtain the catalyst.

[0074] Secondary ultrasonic mixing ensures full contact between carbon black and phosphorus-doped copper oxide nanoparticles, improving the catalyst's dispersibility and conductivity.

[0075] Furthermore, in S410, F:G = (0.1-10):(50-5000), where the minimum, maximum, and preferred intermediate values ​​of F are 0.1, 10, and 2, respectively, and the values ​​of G are 50, 5000, and 2000, respectively. The carbon dispersion exhibits optimal dispersibility at a concentration of 1 mg / mL. If the concentration is too high, the carbon black is prone to agglomeration, making ultrasonic dispersion difficult.

[0076] Furthermore, the ultrasonic treatment time in S420 is between 5 and 60 minutes, preferably 30 minutes, so that phosphorus-doped copper oxide is uniformly loaded on carbon.

[0077] In one embodiment, a catalyst is prepared using the preparation method described in the above embodiments.

[0078] In one embodiment, the phosphorus-doped copper oxide synthesized by the synthesis method described in the above embodiments is used in the electrocatalytic oxidation of methanol to formate or in direct methanol fuel cells. Therefore, this invention aims to provide a novel energy-saving method for synthesizing phosphorus-doped copper oxide nanoparticles, which is simple to operate, low in cost, and easy to industrialize. Simultaneously, this invention also provides an application for the highly efficient electrocatalytic oxidation of methanol to formate, aiming to solve the problems of low catalyst activity, poor selectivity, and poor stability in existing technologies.

[0079] In a more specific embodiment, the preparation of phosphorus-doped copper oxide.

[0080] Dissolve 2g of copper nitrate in 100mL of deionized water, add 1mL of acetic acid, heat the solution to 80℃ and stir for 30 minutes. Heat 1mol / L potassium hydroxide to 80℃ and add it dropwise to the copper nitrate solution while stirring vigorously until the pH reaches 8. Then transfer the solution to ice water and cool to room temperature. Centrifuge at 10000rpm, wash twice with ethanol, then add an appropriate amount of deionized water and centrifuge again. Collect the supernatant to obtain copper oxide nanoparticles.

[0081] Copper oxide nanoparticles and black phosphorus nanosheets were mixed at a mass ratio of 1:2, and ethanol was added to adjust the concentration of copper oxide nanoparticles to 0.1 mg / mL. The dispersion was then thoroughly dispersed and subjected to ultrasonic treatment for 30 minutes.

[0082] 1 mg of carbon black was added to 500 μL of ethanol and sonicated to achieve uniform dispersion. This dispersion was then mixed with 1 mL of copper oxide-black phosphorus dispersion and sonicated for 30 minutes to obtain carbon-loaded phosphorus-doped copper oxide. Highly dispersed copper oxide nanoparticles with an ultra-small particle size (approximately 4.5 nm) were synthesized at a lower temperature via a simple one-step reaction, and phosphorus doping was completed by sonication with black phosphorus at room temperature.

[0083] Phosphorus-doped copper oxide was characterized using scanning transmission electron microscopy, such as... Figure 4 As shown, CuO1BP2 was analyzed using TEM, high-angle annular dark-field scanning TEM (HAADF-STEM), high-resolution TEM (HR-TEM), and energy-dispersive X-ray spectroscopy (EDS). In a and b, CuO nanoparticles are uniformly dispersed on BP sheets with an average size of approximately 4.5 nm, and the addition of BP does not affect their size distribution and uniformity. In c, the edges of the CuO1BP2 nanoparticles show a less distinct lattice, and the arrangement of Cu atoms becomes less linear, with the spacing widening to approximately [missing value]. The presence of copper oxide nanoparticles and black phosphorus was confirmed by STEM-EDS images (df). Specifically, the lattice of phosphorus-doped copper oxide exhibited distortion and widening in some regions, and the interlattice spacing in some areas was also affected. Energy-dispersive X-ray spectroscopy (EDS) revealed the doping of phosphorus.

[0084] XRD patterns confirmed the synthesis of copper oxide nanoparticles. Figure 5 The lattice spacing of CuO1BP2 is broadened, and compared with CuO, the XRD spectrum of CuO1BP2 shows a blue shift of 0.22 on the {111} plane reflection peak.

[0085] The effect of BP doping on the electronic structure of CuO1BP2 was investigated using X-ray photoelectron spectroscopy (XPS). The doping ratio was controlled by varying the amount of BP nanosheets added during fabrication. Figure 6 As shown, the increase in BP content leads to a gradual decrease in the area of ​​the 2p peak of Cu(II) (divalent copper) at 934.5 eV. Conversely, the area of ​​the 2p peak of Cu(I) (monovalent copper) (933.2 eV) increases proportionally, indicating the conversion of Cu(II) to Cu(I).

[0086] To distinguish between the Cu(II) and Cu(I) states in CuO and CuO1BP2, the CuLMM spectrum was analyzed. With increasing BP content, the CuLMM peak shifted from 917.8 eV to 916.6 eV, confirming the transformation from Cu(II) to Cu(I). Figure 7 The presence of phosphorus indicates the presence of phosphorus doping.

[0087] In a more specific embodiment, the electrochemical performance of the phosphorus-doped copper oxide catalyst for methanol oxidation was characterized.

[0088] The CV curves of the methanol oxidation reaction of carbon-supported phosphorus-doped copper oxide in the aforementioned examples in 1 mol / L potassium hydroxide and 1 mol / L methanol were measured, as shown below. Figure 8 As shown, the current density of the catalyst at a potential of 1.65 V vs RHE is 1.011 Acm. -2 It has high activity in methanol oxidation.

[0089] Figure 9 The current densities shown are 20 and 100 mA / cm. -2 The Faraday efficiency of CuO1BP2 and CuO at current densities of 20 and 100 mA / cm² is calculated. In a three-electrode system, CuO1BP2 exhibits efficiency at current densities of 20 and 100 mA / cm². -2 At these times, the Faraday efficiencies for formic acid were 96.4% and 92.8%, respectively. In contrast, CuO showed significantly higher Faraday efficiencies at 20 and 100 mA / cm². -2 The Faraday efficiencies under the given conditions were 54.8% and 58.9%, respectively. Gas phase collection and gas chromatography analysis of the anode and cathode products in the Faraday efficiency experiment showed that CuO1BP2 and CuO mainly produced hydrogen gas, while a large amount of excessively oxidized carbon monoxide (CO) byproducts were detected in CuO.

[0090] Stability test of CuO1BP2 in electrocatalytic methanol oxidation reaction, with 1 mol / L KOH solution and 1 mol / L methanol solution as electrolyte. Figure 10 The sample showed a decrease in current density of approximately 14% after 24 hours and approximately 19% after 48 hours.

[0091] In a more specific embodiment, the preparation of copper oxide nanorods with larger particle sizes.

[0092] Dissolve 2 g of copper nitrate in 100 mL of deionized water, add 1 mL of acetic acid, heat the solution to 80 °C and stir for 30 minutes. Heat 2 mmol / L potassium hydroxide to 80 °C and add it dropwise to the copper acetate solution while stirring vigorously until the pH reaches 9–10. Then transfer the solution to ice water and cool to room temperature. Centrifuge at 10,000 rpm, wash twice with ethanol, then add an appropriate amount of deionized water and centrifuge again. Collect the supernatant to obtain copper oxide nanoparticles. Figure 11 TEM images show the morphology of the copper oxide nanorods, which are approximately 10 nm in diameter and 50 nm in length. EDS images show the elemental distribution. This confirms that the particle size of the copper oxide nanoparticles can be controlled by adjusting the pH.

[0093] In a more specific embodiment, the performance of a direct methanol fuel cell was tested using a membrane electrode assembly (MEA) method. Specifically, CuO1BP2 was used as the anode, Pt / C as the cathode, 1 mol / L potassium hydroxide solution + 2 mol / L methanol solution as the electrolyte, and the electrode area was 5 cm². 2 The electrolyte flow rate was 2 mL / min, and the air flow rate was 50 mL / min. The results showed that the peak power density of the CuO1BP2 direct methanol fuel cell was 3.2 times that of CuO. Figure 12 This significant improvement highlights the potential of CuO1BP2 in practical direct methanol fuel cell applications.

[0094] This invention introduces a simple and effective strategy for using phosphorus-doped metal oxides to optimize the electrochemical activity and selectivity of the electrocatalytic oxidation reaction of methanol to formate (methanol oxidation). By adjusting the amount of black phosphorus (BP) to control the phosphorus doping ratio, the optimal active catalyst CuO1BP2 exhibits superior activity in the methanol oxidation reaction, achieving 0.910 Acm at only 1.5 V (compared to a reversible hydrogen electrode) without a naphthol (NAFion) membrane as a separator. -2 and at 20mAcm -2 It exhibits a high formate Faradaic efficiency of 96.4% at a given current density, and good durability exceeding 48 hours in alkaline media. Phosphorus doping on the metal oxide effectively reduces formate adsorption and avoids the formation of the byproduct carbon monoxide, which increases the activity and long-term durability of copper oxide (CuO) in the methanol oxidation reaction.

[0095] In the description of this specification, the use of terms such as "Embodiment 1," "this embodiment," or "in one embodiment" indicates that the specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example; moreover, the specific features, structures, materials, or characteristics described may be combined in any appropriate manner in one or more embodiments or examples.

[0096] In the description of this specification, the term "having" and similar terms are interpreted broadly. For example, when describing a relationship, "having" can refer to a fixed relationship, a separable relationship, or an integral relationship; it can be a mechanical relationship or an electrical relationship; it can be a direct relationship or an indirect relationship formed through an intermediate medium; it can be a relationship within two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0097] Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0098] In the description of this specification, relational terms such as “first” and “second” are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase “comprising one…” does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0099] The above description of the embodiments is intended to enable those skilled in the art to understand and apply the technology of this invention. Those skilled in the art can easily make various modifications to these examples and apply the general principles described herein to other embodiments without creative effort. Therefore, this invention is not limited to the above embodiments. Modifications in the following situations should be within the scope of protection of this invention: ① New technical solutions implemented based on the technical solution of this invention and combined with existing common knowledge, where the technical effects of the new technical solution do not exceed the technical effects of this invention; ② Equivalent substitutions of some features of the technical solution of this invention using known technology, resulting in the same technical effects as those of this invention; ③ Extendable technical solutions based on the technical solution of this invention, where the substantive content of the extended technical solution does not exceed the technical solution of this invention; ④ Equivalent transformations made using the content of this specification and drawings, directly or indirectly applied to other related technical fields.

Claims

1. A method for synthesizing phosphorus-doped copper oxide, characterized in that, Includes the following steps: S100, obtaining copper oxide nanoparticles; S200, obtaining black phosphorus nanosheets; S300: After mixing the copper oxide nanoparticles and black phosphorus nanosheets, ultrasonic treatment is performed to obtain phosphorus-doped copper oxide.

2. The synthesis method according to claim 1, characterized in that, The temperature of the S300 is controlled between 0 and 60°C, and the mass ratio of the copper oxide nanoparticles to the black phosphorus nanosheets is 5:1 to 1:

5.

3. The synthesis method according to claim 2, characterized in that, Specifically, S100 includes: S110. Dissolve Ag copper salt in B mL of deionized water, add C mL of acid, heat and stir to obtain solution one; S120. Add alkaline solution dropwise to the first solution until the pH = 6-10 to obtain the second solution; S130. After cooling the solution, centrifuge and wash to obtain the copper oxide nanoparticles.

4. The synthesis method according to claim 3, characterized in that, The heating temperature in S110 is between 25 and 100°C, the alkali solution temperature in S120 is between 25 and 100°C, and the ratio of A:B:C in S110 is (0.1 to 10):(10 to 1000):(1 to 100).

5. The synthesis method according to claim 3 or 4, characterized in that, Specifically, S200 includes: S210. Dilute D mg of black phosphorus to a suspension with a total volume of E mL; S220. The suspension is ultrasonically stripped to obtain mixture one; S230. Wash the mixture to obtain the black phosphorus nanosheets.

6. The synthesis method according to claim 5, characterized in that, In S210, D:E = (1~1000):(50~5000).

7. The synthesis method according to claim 6, characterized in that, The concentration of the alkali solution in S120 is between 0.1 and 10 mol / L, and / or The ultrasonic power in S220 is between 800-2000W, the ultrasonic processing time in S220 is between 10-40 hours, and / or The ultrasound time in the S300 is between 5 and 60 minutes.

8. A method for preparing a catalyst, characterized in that, Includes the following steps: S410. Carbon black is added to ethanol and then ultrasonically dispersed to obtain a dispersion. S420. The dispersion is mixed with phosphorus-doped copper oxide synthesized by the synthesis method according to any one of claims 1-7, and then ultrasonically treated to obtain the catalyst.

9. A catalyst, characterized in that, The catalyst was prepared using the preparation method described in claim 8.

10. The application of phosphorus-doped copper oxide synthesized by any one of claims 1-7 in electrocatalytic methanol oxidation to formate or in direct methanol fuel cells.

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