A porous Pt-CuOx catalyst with high hydrogen evolution activity, its preparation method and application

Abstract

The application discloses a porous Pt-CuO x catalyst with high hydrogen evolution activity and a preparation method and application thereof. The porous Pt-CuO x catalyst has micro-nano hierarchical pores and an antenna-like surface structure. The preparation method comprises the following steps: uniformly mixing copper powder and aluminum powder according to a proportion, performing compression molding on the mixed powder, performing powder sintering to obtain a CuAl intermetallic compound, and placing the sintered product into a NaOH solution to perform corrosion to obtain micro-nano porous CuO x , uniformly stirring the dry powder and PVP in a solution, removing supernatant by centrifugation, adding a platinum metal salt solution to perform stirring and evaporation, and drying to obtain a Pt-CuO x material. The Pt-CuO x catalyst loads Pt nanoclusters by using a two-step dealloying-impregnation method, constructs a micro-nano hierarchical pore structure and has an antenna-like surface distribution, and in a hydrogen evolution reaction, the Pt-CuO ‑1 catalyst has a low hydrogen evolution overpotential of 150 mV and a low Tafel slope of 125 mV dec, and compared with an un-loaded Cu-based material, the overpotential is increased by 80 mV, and the special surface structure improves the accessibility of active sites.

Description

Technical Field

[0001] This invention relates to the field of metal catalysts, specifically to a porous Pt-CuO catalyst with high hydrogen evolution activity. x Catalysts, their preparation methods, and applications. Background Technology

[0002] Hydrogen energy, due to its high energy density, abundant sources, and pollution-free combustion products, is considered one of the most promising clean energy sources to replace traditional fossil fuels. Hydrogen production methods mainly include water electrolysis and fossil fuel reforming. Among these, the electrocatalytic hydrogen evolution reaction (HER), as a key step in the electrochemical splitting of water, plays a crucial role in the production and utilization of hydrogen energy. To improve the efficiency of the HER, the selection of the electrocatalyst is critical, and the surface structure (pore structure and surface morphology, etc.) of the electrocatalyst substrate / matrix has a significant impact on the transport of substances such as water and hydrogen during the HER process.

[0003] Compared to dense oxides, porous metal oxides possess high specific surface area and large pore size, and some even exhibit unique morphological and structural characteristics. These properties enable porous metal oxides to provide more active sites in catalytic reactions, facilitating the diffusion, adsorption, and activation of reactant molecules, thereby enhancing catalytic efficiency. However, the surface structure of porous metal oxides prepared using traditional methods is relatively simple (CN116422335A). CN107398554A discloses a dealloying method for preparing metallic copper, but the dealloying precursor exhibits a single phase distribution, and the dealloying product does not display a hierarchical pore structure, nor does it show the growth of nanoscale microstructures on its surface. In practical applications, their catalytic activity may still be relatively low, requiring further optimization of the preparation scheme to address the issue of their simple surface / pore structure.

[0004] Another important indicator affecting electrocatalytic performance is the degree of exposure and / or dispersion of active sites. Copper oxides (CuO) x CuO, as a low-cost and environmentally friendly material, has been widely studied in recent years as a candidate support material for electrocatalytic reactions. x Its unique structure and excellent electrocatalytic properties make it a potential candidate for hydrogen evolution reactions; however, a single CuO... x Typically, these catalysts exhibit low catalytic activity and poor stability. On the other hand, noble metal catalysts (mainly Pt) are widely used in hydrogen evolution reactions due to their excellent catalytic performance, but the limited resources and high prices of noble metals restrict their large-scale application. Summary of the Invention

[0005] One of the objectives of this invention is to provide a method for preparing a Pt-CuOx catalyst with high hydrogen evolution activity, in order to solve the problems of the simple surface structure of dealloyed products and the low catalytic rate of copper-based oxides in the HER reaction.

[0006] The second objective of this invention is to provide a Pt-CuOx catalyst with high hydrogen evolution activity prepared by the above-described method, exhibiting high catalytic activity.

[0007] A third objective of this invention is to provide applications of the aforementioned Pt-CuOx catalyst with high hydrogen evolution activity.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] In a first aspect, the present invention provides a method for preparing a Pt-CuOx catalyst with high hydrogen evolution activity, employing a two-step exothermic / dealloying-impregnation method to prepare the desired catalyst. Firstly, a porous CuO catalyst is prepared via the exothermic / dealloying method. x The matrix was then impregnated onto CuO. x Nanoclusters of Pt are grown on the substrate, eventually forming tentacle-like micro-nanoporous Pt-CuO. x Specifically, it includes the following steps:

[0010] Step 1: Mix Cu powder and Al powder evenly at a copper-aluminum atomic ratio of 17:83, press the mixed powder to obtain a green body; sinter the green body under an argon atmosphere to obtain the sintered product CuAl intermetallic compound.

[0011] Step 2: Place the sintered product prepared in Step 1 into a 10wt.%–30wt.% NaOH solution and perform chemical dealloying at 30–50℃ until no more bubbles are generated. Then, perform drying treatment. The dried product is micro / nano porous CuO. x Powder; the mass ratio of the sintered product to the volume of NaOH solution is 60 mg: 10 mL to 30 mL;

[0012] Step 3: Take the CuO prepared in Step 2 x The powder and PVP were mixed evenly in high-purity water, and the supernatant was removed after centrifugation to obtain the centrifuged precipitate.

[0013] Step 4: Prepare a 0.025 mol / L platinum salt solution and add it to the centrifuged precipitate obtained in Step 3. Stir and evaporate the mixture in a water bath. The dried product is porous Pt-CuO. x Material.

[0014] This invention first uses copper powder and aluminum powder as raw powders, which are uniformly mixed and cold-pressed into discs using a pressing mold. The discs are then sintered under an argon atmosphere, resulting in an exothermic reaction. The sintered blanks are then chemically dealloyed in a NaOH alkaline solution until the bubbles disappear. The vacuum-dried product is porous CuO. x CuO x The powder was ultrasonically immersed in high-purity water, PVP was added and stirred until thoroughly mixed; the supernatant was removed by centrifugation, platinum salt solution was added, and the mixture was stirred at a certain temperature and then evaporated to dryness, finally yielding tentacle-shaped micro / nanoporous Pt-CuO. x Material.

[0015] Preferably, the Cu powder particle size in step one is 35-45 μm, and the Al powder particle size is 38-74 μm; the sintering temperature is 600℃, followed by immediate cooling.

[0016] Preferably, the drying process in step two is: vacuum drying at 60-80°C for 10-24 hours.

[0017] Preferably, the CuO mentioned in step three x The powder to PVP mass ratio is 3:2; the CuO x The powder mass to high-purity water volume ratio is 60mg:5-50mL; the stirring time is 1-2h, and the stirring speed is 300-400rpm.

[0018] Preferably, the centrifugation process in step three is as follows: rotation speed 4500-5500 rpm, time 1-10 min.

[0019] Preferably, the platinum metal salt mentioned in step four is selected from any one of platinum acetylacetonate, chloroplatinic acid, potassium chloroplatinate, ammonium chloroplatinate, and dichlorotetramineplatinum, and the volume of the platinum metal salt solution added is 300 μL to 2000 μL.

[0020] Preferably, the water bath heating temperature in step four is 60-100℃, and the mixture is stirred at a magnetic stirring speed of 300-400 rpm for 2-4 hours.

[0021] Secondly, the present invention provides Pt-CuO with high hydrogen evolution activity prepared by the above preparation method. x catalyst.

[0022] The Pt-CuO x The catalyst has a complex, tentacled hierarchical porous structure with micron-sized pores of 10–30 μm and nano-sized pores of 35–75 nm.

[0023] The Pt-CuO x The Pt in the catalyst is supported in the form of nanoclusters, and the actual Pt loading is 0.94–1.3 wt.%.

[0024] Thirdly, the present invention also provides the above-mentioned Pt-CuO with high hydrogen evolution activity. x Application of catalysts in the HER reaction of water electrolysis.

[0025] The Pt-CuO x The catalyst exhibits high hydrogen evolution activity at 10 mA cm⁻¹ -2 The hydrogen evolution overpotential is 150 mV and the Tafel slope is low at 125 mV. -1 The Pt-CuO x The catalyst overpotential is increased by 80 mV compared to the unsupported copper-based catalyst.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. This invention employs direct pressing and sintering of Cu and Al powders without a heat preservation process. A stable, intersecting Al and CuAl2 phases are obtained through a eutectic reaction, resulting in stable phases and rapid sintering. Further treatment using dealloying overcomes problems such as low porosity in the Cu-Al eutectic composition and irregular shape of the sintered blank during heat absorption and release, producing micro / nano porous structures and micro / nano-scale bicontinuous ligament structures. Combined with impregnation, the surface structure uniformity is improved based on the hierarchical porous structure. By changing the loading amount to adjust the oxide ratio, surface micromorphology, and Pt presence form, porous Pt-CuO with a surface nano-tentacled distribution is prepared. x Material.

[0028] 2. This invention is the first to combine the self-exothermic / dealloying method and the impregnation method to precisely control the Pt loading, thus preparing Pt nanoclusters-loaded surface tentacle-like micro / nanoporous Pt-CuO. x The catalyst, with its refined and controllable composition and structure, enhances the catalyst's electrical conductivity and catalytic performance in HER, showing a significant increase in activity compared to unsupported copper-based catalysts. Furthermore, Pt-CuO... x The catalyst can also be used as a negative electrode material for secondary batteries and as a photocatalyst. Thanks to its hierarchical porous structure, it is beneficial to expose more reaction sites and improve the storage efficiency and kinetic performance of secondary batteries.

[0029] 3. This invention utilizes trace amounts of Pt and CuO. x The composite and porous structure design can reduce the amount of Pt used to some extent, thereby lowering the cost of the catalyst. The preparation process is relatively simple and controllable, which is conducive to the large-scale production and application of the catalyst, and generates less environmental pollution, meeting the requirements of green chemistry and sustainable development. Attached Figure Description

[0030] Figure 1 The present invention is Pt-CuO x Material preparation roadmap.

[0031] Figure 2 For CuO at different dealloying temperatures in this invention x Material SEM images: (a) 10℃, (b) 40℃, (c) 80℃.

[0032] Figure 3 This invention provides CuO with different corrosion solution concentrations. x Material SEM images: (a) 10 wt.%, (b) 20 wt.%, (c) 30 wt.%.

[0033] Figure 4 Pt-CuO in Example 3 of this invention x Material SEM image: (ac) 0.94 wt.% Pt-CuO x (a) 100 times, (b) 30 times, (c) 10 times; (df) 1.20 wt.% Pt-CuO x (d) 100 times, (e) 30 times, (f) 10 times; (gi) 1.30 wt.% Pt-CuO x :(g) 100 times, (h) 30 times, (i) 10 times.

[0034] Figure 5 Pt-CuO in Example 3 of this invention x TEM images of materials: (a) 100 nm, (b) 50 nm, (c) 10 nm, (d) 5 nm.

[0035] Figure 6 CuO in Example 3 of the present invention x With Pt-CuO x Material WAXS diagram.

[0036] Figure 7 CuO in Example 3 of the present invention x With Pt-CuO x Hydrogen evolution performance of materials: (a) LSV plot, (b) Tafel curve plot, (c) double-layer capacitance C dl picture. Detailed Implementation

[0037] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0038] Example 1

[0039] This embodiment provides a method for preparing a porous Pt-CuOx catalyst with high hydrogen evolution activity, the route of which is as follows: Figure 1 As shown, it includes the following steps:

[0040] Step 1: Mix Cu powder with a particle size of 35-45 μm and Al powder with a particle size of 38-74 μm at a copper-aluminum atomic ratio of 17:83 until homogeneous. Press the mixed powder to obtain a circular green sheet. Sinter the circular green sheet at 600°C under an argon atmosphere, and then immediately cool it down to obtain the sintered product Cu-Al intermetallic compound.

[0041] Step 2: Prepare a 10 wt.% NaOH alkaline solution and place it in a 10℃ oven. Add 60 mg of the sintered product from Step 1 to 5 mL of the alkaline solution for etching until no more bubbles are generated. Then, vacuum dry at 60℃ for 5 hours. The dried product is micro / nano porous CuO. x powder.

[0042] Step 3: Obtain CuO from Step 2 x 60 mg of powder and 40 mg of PVP were added to 5 mL of high-purity water and stirred for 1 hour to achieve uniform distribution. The solution was centrifuged at 5000 rpm for 1 minute, and the supernatant was removed. The centrifuged precipitate was collected for later use.

[0043] Step 4: Add 300 μL of 0.025 mol / L H₂PtCl₆ solution to the centrifuged precipitate from Step 3. Stir the mixture in a water bath at 60°C at 300 rpm for about 2 hours until the solution is completely dry. The resulting product is porous 0.94 wt.% Pt-CuO. x Collect the materials and grind them thoroughly for later use.

[0044] Example 2:

[0045] This embodiment provides a method for preparing a porous Pt-CuOx catalyst with high hydrogen evolution activity, the route of which is as follows: Figure 1 As shown, it includes the following steps:

[0046] Step 1: Mix Cu powder with a particle size of 35-45 μm and Al powder with a particle size of 38-74 μm at a copper-aluminum atomic ratio of 17:83 until homogeneous. Press the mixed powder to obtain a circular green blank. Sinter the circular green blank at 600°C under an argon atmosphere, and then immediately cool it down to obtain the sintered product CuAl intermetallic compound.

[0047] Step 2: Prepare a 10 wt.% NaOH alkaline solution and place it in a 10℃ oven. Add 60 mg of the sintered product from Step 1 to 12 mL of the alkaline solution for etching until no more bubbles are generated. Then, vacuum dry at 60℃ for 10 h. The dried product is a micro / nano porous CuO. x powder.

[0048] Step 3: Obtain CuO from Step 2 x 60 mg of powder and 40 mg of PVP were added to 10 mL of high-purity water and stirred for 1 hour to achieve uniform distribution. The solution was centrifuged at 5000 rpm for 5 minutes, and the supernatant was removed. The centrifuged precipitate was collected for later use.

[0049] Step 4: Add 300 μL of 0.025 mol / L H₂PtCl₆ solution to the centrifuged precipitate from Step 3. Stir the mixture in a water bath at 70°C at 300 rpm for about 3 hours until the solution is completely dry. The resulting product is porous 1.30 wt.% Pt-CuO. x Collect the materials and grind them thoroughly for later use.

[0050] Example 3:

[0051] This embodiment provides a method for preparing a porous Pt-CuOx catalyst with high hydrogen evolution activity, the route of which is as follows: Figure 1 As shown, it includes the following steps:

[0052] Step 1: Mix Cu powder with a particle size of 35-45 μm and Al powder with a particle size of 38-74 μm at a copper-aluminum atomic ratio of 17:83 until homogeneous. Press the mixed powder to obtain a circular green blank. Sinter the circular green blank at 600°C under an argon atmosphere, and then immediately cool it down to obtain the sintered product CuAl intermetallic compound.

[0053] Step 2: Prepare a 20 wt.% NaOH alkaline solution and place it in a 40℃ oven. Add 60 mg of the sintered product from Step 1 to 20 mL of the alkaline solution for etching until no more bubbles are generated. Then, vacuum dry at 60℃ for 12 hours. The dried product is micro / nano porous CuO. x powder.

[0054] Step 3: Obtain CuO from Step 2 x 60 mg of powder and 40 mg of PVP were placed in 20 mL of high-purity water and stirred for 1 hour to achieve uniform distribution. The solution was centrifuged at 5000 rpm for 5 minutes, and the supernatant was removed. The centrifuged precipitate was collected for later use.

[0055] Step 4: Add 1000 μL of 0.025 mol / L H₂PtCl₆ solution to the centrifuged precipitate from Step 3. Stir the mixture in an 80°C water bath at 300 rpm for approximately 4 hours until the solution is completely dry. The resulting product is porous 1.20 wt.% Pt-CuO. x Collect the materials and grind them thoroughly for later use.

[0056] Example 4:

[0057] This embodiment provides a method for preparing a porous Pt-CuOx catalyst with high hydrogen evolution activity, the route of which is as follows: Figure 1 As shown, it includes the following steps:

[0058] Step 1: Mix Cu powder with a particle size of 35-45 μm and Al powder with a particle size of 38-74 μm at a copper-aluminum atomic ratio of 17:83 until homogeneous. Press the mixed powder to obtain a circular green blank. Sinter the circular green blank at 600°C under an argon atmosphere, and then immediately cool it down to obtain the sintered product CuAl intermetallic compound.

[0059] Step 2: Prepare a 30 wt.% NaOH alkaline solution and place it in an 80℃ oven. Add 60 mg of the sintered product from Step 1 to 30 mL of the alkaline solution for etching until no more bubbles are generated. Then, vacuum dry at 70℃ for 15 h. The dried product is a micro / nano porous CuO. x powder.

[0060] Step 3: Obtain CuO from Step 2 x 60 mg of powder and 40 mg of PVP were placed in 30 mL of high-purity water and stirred for 1 hour to achieve uniform distribution. The solution was centrifuged at 5000 rpm for 10 minutes, and the supernatant was removed. The centrifuged precipitate was collected for later use.

[0061] Step 4: Add 2000 μL of 0.025 mol / L H2PtCl6 solution to the centrifuged precipitate from Step 3. Stir the mixture in a water bath at 300 rpm for about 5 hours at 90°C until the solution is completely dry. Collect the material and grind it thoroughly for later use.

[0062] Example 5:

[0063] This embodiment provides a method for preparing a porous Pt-CuOx catalyst with high hydrogen evolution activity, the route of which is as follows: Figure 1 As shown, it includes the following steps:

[0064] Step 1: Mix Cu powder with a particle size of 35-45 μm and Al powder with a particle size of 38-74 μm at a copper-aluminum atomic ratio of 17:83 until homogeneous. Press the mixed powder to obtain a circular green blank. Sinter the circular green blank at 600°C under an argon atmosphere, and then immediately cool it down to obtain the sintered product CuAl intermetallic compound.

[0065] Step 2: Prepare a 20 wt.% NaOH alkaline solution and place it in a 40℃ oven. Add 60 mg of the sintered product from Step 1 to 20 mL of the alkaline solution for etching until no more bubbles are generated. Then, vacuum dry at 80℃ for 20 h. The dried product is micro / nano porous CuO. x powder.

[0066] Step 3: Obtain CuO from Step 2 x 60 mg of powder and 40 mg of PVP were placed in 40 mL of high-purity water and stirred for 1 hour to achieve uniform distribution. The solution was centrifuged at 5000 rpm for 10 minutes, and the supernatant was removed. The centrifuged precipitate was collected for later use.

[0067] Step 4: Add 2000 μL of 0.025 mol / L H2PtCl6 solution to the centrifuged precipitate from Step 3. Stir the mixture in a water bath at 100°C at 300 rpm for about 3 hours until the solution is completely dry. Collect the material and grind it thoroughly for later use.

[0068] Example 6:

[0069] This embodiment provides a method for preparing a porous Pt-CuOx catalyst with high hydrogen evolution activity, the route of which is as follows: Figure 1 As shown, it includes the following steps:

[0070] Step 1: Mix Cu powder with a particle size of 35-45 μm and Al powder with a particle size of 38-74 μm at a copper-aluminum atomic ratio of 17:83 until homogeneous. Press the mixed powder to obtain a circular green blank. Sinter the circular green blank at 600°C under an argon atmosphere, and then immediately cool it down to obtain the sintered product CuAl intermetallic compound.

[0071] Step 2: Prepare a 20 wt.% NaOH alkaline solution and place it in a 40℃ oven. Add 60 mg of the sintered product from Step 1 to 20 mL of the alkaline solution for etching until no more bubbles are generated. Then, vacuum dry at 80℃ for 24 h. The dried product is micro / nano porous CuO. x powder.

[0072] Step 3: Obtain CuO from Step 2 x 60 mg of powder and 40 mg of PVP were placed in 50 mL of high-purity water and stirred for 2 h to achieve uniform distribution. The solution was centrifuged at 5000 rpm for 20 min, the supernatant was removed, and the centrifuged precipitate was collected for later use.

[0073] Step 4: Add 2000 μL of 0.025 mol / L H2PtCl6 solution to the centrifuged precipitate from Step 3. Stir the mixture in a water bath at 300 rpm for about 1 hour at 90°C until the solution is completely dry. Collect the material and grind it thoroughly for later use.

[0074] Example 3 represents the optimal experimental conditions.

[0075] like Figure 2 As shown, the CuO product is obtained under different etchant concentrations. x Appearance. For example... Figure 2 As shown in (a), when the concentration of the corrosive solution is 10 wt.%, the corrosion rate is low, the corrosion is incomplete, and the structure is not intact; as... Figure 2 As shown in (b), when the concentration of the corrosive solution is 20 wt.%, the ligaments are uniform in size and have a complete structural morphology; Figure 2 As shown in (c), when the concentration of the corrosive solution is 30 wt.%, the corrosion rate is fast, the ligaments coarse, and the violent reaction leads to the damage of some structures.

[0076] like Figure 3 As shown, the CuO products at different dealloying temperatures are illustrated. x Appearance. For example... Figure 3 As shown in (a), at a corrosion temperature of 10℃, the temperature is relatively low, the corrosion time is short, and there are unreacted impurities on the ligament surface; Figure 3 As shown in (b), at a corrosion temperature of 40℃, the ligament surface is smooth and the structure is uniform; Figure 3 As shown in (c), when the corrosion temperature is 80℃, the temperature increases, the Al element dissolves rapidly and the Cu element rearranges rapidly, the ligament growth rate accelerates, and the ligament coarsens severely.

[0077] like Figure 4 As shown, the effect of different Pt loading on the product Pt-CuO is illustrated. x The influence of morphology. For example... Figure 4 As shown in (ac), the Pt-CuO prepared in this invention... x When the material loading is 0.94 wt.%, the low loading is not conducive to the uniform growth of hierarchical porous ligaments, and some cubic cuprous oxide is unevenly attached to the skeleton; for example... Figure 4 As shown in (df), the Pt-CuO prepared in this invention... x When the material has a Pt loading of 1.20 wt.%, it exhibits a complex hierarchical porous structure with micron-sized pores (10–30 μm) and nano-sized pores (35–75 nm). The surface possesses abundant, unique tentacled structures. This provides essential conditions for rapid water / hydrogen mass transport and uniform Pt dispersion and exposure within the HER (hydrogen etherification) process. Figure 4 As shown in (gi), the Pt-CuO prepared in this invention... x When the material loading is 1.30 wt.%, the excessive Pt loading increases the formation of irregular cubic / octahedral cuprous oxide, which adheres to the ligament surface and accumulates in the micro- and nano-pores.

[0078] In Example 3, as Figure 5 As shown, the Pt-CuO prepared in this invention x The material exhibits the following characteristics: a distinct surface tentacled micro / nanoporous structure; and lattice fringes in high-magnification TEM images reveal CuO. xThe formation of nanoscale Pt clusters (approximately 2 nm in size) improves Pt utilization and is beneficial for enhancing HER activity.

[0079] In Example 3, as Figure 6 As shown, the main components of the catalyst are Cu, Cu₂O, CuO, and Pt. The Pt-CuO prepared in this invention... x The material exhibits distinct Pt characteristic peaks (compared to CuO without the second impregnation process to platinum-loaded material). x Materials), combined Figure 2 Medium- and high-magnification TEM images confirmed Pt-CuO x The presence of Pt nanoclusters in the material.

[0080] Pt-CuO prepared in Example 3 x The main steps for testing the electrocatalytic hydrogen evolution performance of the material are as follows:

[0081] In the three-electrode system, a glassy carbon electrode was used as the working electrode, an Hg / HgO electrode as the reference electrode, and a platinum / carbon rod electrode as the counter electrode. The working electrode was prepared by dispersing 4 mg of catalyst in 300 μL of isopropanol, 200 μL of high-purity water, and 20 μL of 5 wt.% Nafion, followed by thorough ultrasonication to achieve uniform dispersion. 5 μL of the catalyst slurry was then drop-coated onto the glassy carbon electrode and allowed to air dry at room temperature. The electrolyte was a 1 M KOH solution. The LSV test potential range was 0.1–0.5 V vs. RHE. Comparative example: Pure CuO without Pt loading via impregnation. x catalyst.

[0082] like Figure 7 As shown, CuO is displayed. x and Pt-CuO x Electrochemical performance. For example... Figure 7 As shown in (a), Pt-CuO was prepared by a two-step self-exothermic / dealloying-impregnation method. x The catalyst exhibits excellent catalytic performance in HER electrocatalysis, at 10 mA cm⁻¹. -2 The hydrogen evolution overpotential is 150 mV, which is higher than that of unsupported platinum CuO. x Increased by one-third (150mV vs. 230mV); such as Figure 7 (b) shows the Pt-CuO prepared by a two-step self-exothermic / dealloying-impregnation method. x The catalyst has a low Tafel slope (125 mV dec). -1 ), namely, rapid transport dynamics; such as Figure 7 As shown in (c), Pt-CuO was prepared by a two-step self-exothermic / dealloying-impregnation method. x The catalyst has a high double-layer capacitance.

[0083] In summary, this invention successfully constructed Pt-CuO with a complex surface structure through a two-step self-exothermic / dealloying-impregnation method. x This catalyst preparation method avoids the traditional CuO x The two-step method overcomes the drawbacks of a simple surface structure and insufficient porosity of the base material, while being relatively simple to operate, with a controllable reaction process, and capable of large-scale production. The catalyst prepared using this method has a hierarchical micro / nanoporous structure with a tentacle-like surface structure. On the one hand, this improves the transport of gas and water; on the other hand, it facilitates the loading and exposure of active sites, greatly enhancing catalytic activity.

[0084] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. However, it should be noted that electrocatalysts prepared by simply replacing the precursor Cu metal and / or the supported source Pt metal salt using a similar two-step self-exothermic / dealloying-impregnation method, such as Pt-FeO, can also be used. x Pt-CoO x Pt-NiO x Pt-ZnO x Ir-FeO x Ir-CoO x Ir-NiO x Ir-CuO x Ir-ZnO x Ru-FeO x Ru-CoO x ,Ru-NiO x Ru-CuO x Ru-ZnO x Pd-FeO x Pd-CoO x Pd-NiO x Pd-CuO x Pd-ZnO x Such reactions should also fall within the scope of protection of this invention. Furthermore, the applications of the above-mentioned electrocatalysts in water electrolysis / electrochemical synthesis applications such as the hydrogen evolution reaction (OER), the oxidation of 5-hydroxymethylfurfural (HMFOR), the electrochemical reduction of NO (NORR), and the electrochemical reduction of nitrates (NO3RR), which rely on porous matrices and noble metals to achieve mass transport and catalytic activity, should also fall within the scope of protection of this invention. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in this invention, and within the spirit and principles of this invention, should be included within the scope of protection of this invention.

Claims

1. A method for preparing a Pt-CuOx catalyst with high hydrogen evolution activity, characterized in that, Includes the following steps: Step 1: Mix Cu powder and Al powder evenly at a copper-aluminum atomic ratio of 17:83, press the mixed powder to obtain a green body; sinter the green body under an argon atmosphere to obtain the sintered product CuAl intermetallic compound. Step 2: Place the sintered product prepared in Step 1 into a 10wt.% to 30wt.% NaOH solution and perform chemical dealloying at 30 to 50°C until no more bubbles are generated. Then, dry the product to obtain micro-nano porous CuOx powder. The mass ratio of the sintered product to the volume of the NaOH solution is 60mg:10mL to 30mL. Step 3: Put the CuOx powder prepared in Step 2 and PVP into high-purity water and stir evenly. After centrifugation, remove the supernatant to obtain the centrifuged precipitate. Step 4: Prepare a 0.025 mol / L platinum metal salt solution and add it to the centrifuged precipitate obtained in Step 3. Stir and evaporate the mixed solution in a water bath. The dried product is the porous Pt-CuOx material. The highly active Pt-CuOx catalyst is a highly active Pt-CuOx catalyst with an antenna-like hierarchical porous structure.

2. The method for preparing a Pt-CuOx catalyst with high hydrogen evolution activity according to claim 1, characterized in that, In step one, the Cu powder has a particle size of 35–45 μm and the Al powder has a particle size of 38–74 μm; the sintering temperature is 600 °C, followed by immediate cooling.

3. The method for preparing a Pt-CuOx catalyst with high hydrogen evolution activity according to claim 1, characterized in that, The drying process described in step two is: vacuum drying at 60-80℃ for 10-24 hours.

4. The method for preparing a Pt-CuOx catalyst with high hydrogen evolution activity according to claim 1, characterized in that, In step three, the mass ratio of CuOx powder to PVP is 3:2; the mass ratio of CuOx powder to high-purity water is 60mg:5-50mL; the stirring time is 1-2h, and the stirring speed is 300-400rpm.

5. The method for preparing a Pt-CuOx catalyst with high hydrogen evolution activity according to claim 1, characterized in that, The centrifugation process described in step three is as follows: rotation speed 4500-5500 rpm, time 1-10 min.

6. The method for preparing a Pt-CuOx catalyst with high hydrogen evolution activity according to claim 1, characterized in that, The platinum metal salt mentioned in step four is selected from any one of platinum acetylacetonate, chloroplatinic acid, potassium chloroplatinate, ammonium chloroplatinate, and dichlorotetramineplatinum, and the volume of the platinum metal salt solution added is 300 μL to 2000 μL.

7. The method for preparing a Pt-CuOx catalyst with high hydrogen evolution activity according to claim 1, characterized in that, The water bath heating temperature in step four is 60-100℃, and the mixture is stirred at a stirring speed of 300-400 rpm for 2-4 hours.

8. A Pt-CuOx catalyst with high hydrogen evolution activity prepared by the preparation method according to any one of claims 1 to 7.

9. The application of the Pt-CuOx catalyst with high hydrogen evolution activity as described in claim 8 in the HER reaction of water electrolysis.

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