A noble metal active site enriched nanoporous amorphous alloy electrode material and its water electrolysis catalytic application

Abstract

The application relates to a noble metal active site enriched nanoporous amorphous alloy electrode material and electrolytic water catalytic application thereof. x Nb y N z The amorphous alloy thin strip is a precursor (wherein M is one or more than one of 3d transition metal elements Ni, Fe or Co, and N is one or more than one of noble metal elements Pt, Ir or Os), M and Nb elements are selectively removed by dealloying to obtain a nanoporous amorphous alloy electrode material composed of a surface nanometer noble metal enrichment layer, a middle nanoporous amorphous transition layer and an internal amorphous matrix layer, the electrode material has good mechanical bending flexibility, can be bent by 180 degrees at will without breaking, and is easy to prepare a self-supporting electrode device. The nanometer noble metal enrichment layer on the surface of the electrode material presents a multi-level pore structure composed of submicron 0.3-0.5 mu m honeycomb-shaped channels and superfine sponge-like 20-50 nm nanometer through holes, provides rich active sites, and exhibits excellent electrocatalytic performance: the hydrogen evolution overpotential is 17-30 mV at a current density of 10 mA / cm 2 The Tafel slope is 24-43 mV / dec, and the stable operation time can be more than 1000 hours under the condition of a current density of 500 mA / cm 2 The electrode material can be applied to the field of new energy such as electrolytic water catalytic hydrogen production.

Description

Technical Field

[0001] This invention belongs to the field of clean and sustainable energy preparation and application, and specifically relates to a nanoporous amorphous alloy electrode material with noble metal active sites enriched for efficient water electrolysis to produce hydrogen. Background Technology

[0002] The development and utilization of hydrogen energy can alleviate the energy crisis and environmental pollution problems facing the international community today. Compared with other technologies, water electrolysis is the most promising method for hydrogen production due to its advantages such as abundant water resources, no greenhouse gas emissions, and high hydrogen purity. The hydrogen evolution reaction (HER) is one of the key reactions in water electrolysis, but because the HER requires a large overpotential, it means that greater electrical energy consumption is needed. To solve this problem, it is necessary to prepare excellent catalysts to improve catalytic performance.

[0003] The current catalysts also face the following challenges: (1) The mass transfer of industrial electrode materials is slow and the hydrogen production efficiency is low, making it difficult to increase the working current density. (2) Although the catalytic activity of laboratory-prepared catalysts has been improved, their preparation process is complicated and requires high preparation conditions, which is not conducive to industrial production. (3) Most laboratory-prepared catalysts are particulate and require binders to load them onto other supports, which is not conducive to industrial application. (4) Laboratory-prepared catalysts are often tested at relatively low current densities, which are quite different from the conditions required by industry, and their service stability is poor, which cannot meet the requirements for long-term operation.

[0004] Numerous studies have demonstrated that noble metals such as Pt, Ir, and Os possess excellent HER catalytic activity, exhibiting characteristics such as fast reaction kinetics and low overpotential. However, the scarcity of noble metals leads to prohibitively high costs, severely limiting their application in water electrolysis. Reducing the content of noble metals while further improving their catalytic activity and stability remains a key international challenge. Therefore, alloying with transition metals can not only reduce the amount of noble metals used but also achieve suitable metal-hydrogen bond energies, thereby enhancing HER performance.

[0005] Besides compositional regulation, increasing the number of active sites by constructing structures with large specific surface areas is also a strategy to improve electrocatalytic activity. Nanoporous metals prepared by dealloying are a new type of macroscopic nanostructured materials. Their high specific surface area, low density, high permeability, high electrical and thermal conductivity, and flexible and tunable structure make them widely applicable in electrocatalysis-related fields. Although nanoporous metal materials have broad application prospects in electrocatalysis, currently common nanoporous metal materials are mainly prepared by dealloying crystalline alloys. Due to the inhomogeneous composition of the crystalline precursor alloy, the material inevitably contains inherent defects such as grain boundaries and dislocations, resulting in a large number of defects inside the porous structure after dealloying, making it impossible to prepare a uniform nanoporous structure. At the same time, nanoporous metal catalysts are relatively brittle and easily break during the dealloying process. These factors severely limit the practical application of nanoporous metals in electrocatalytic electrode devices.

[0006] Amorphous alloys have been proven to have good electrocatalytic performance due to their unique electronic structure. Compared with crystalline alloys, amorphous alloys have significant advantages as precursors for the preparation of nanoporous metals: (1) Amorphous alloys have a simple phase structure and no defects such as grain boundaries and dislocations, which is conducive to the formation of a uniform nanoporous structure during dealloying; (2) Amorphous alloys have a wide range of compositions and adjustable components, which makes it easy to control the nanoporous microstructure through alloy composition design; (3) Amorphous alloys have diverse preparation methods. In addition to particle and thin film materials, amorphous alloy strips can be self-supporting and have good mechanical bending flexibility.

[0007] Therefore, compared with crystalline alloys, amorphous alloys with good mechanical bending flexibility were selected as precursors to prepare a nanoporous amorphous alloy electrode material enriched with noble metal active sites via dealloying. This electrode material not only inherits the excellent mechanical properties of amorphous alloys, but also increases the active area and provides abundant active sites due to the nanoporous structure on its surface, significantly improving electrocatalytic activity. Furthermore, alloying with trace amounts of noble metals and transition metals reduces costs while maintaining both activity and stability, representing an effective solution to the current limitations of nanostructured electrocatalyst applications. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of existing hydrogen evolution electrode materials and provide a nanoporous amorphous alloy electrode material enriched with noble metal active sites and its catalytic application in water electrolysis. This material combines activity and stability while reducing the amount of noble metal used, and also possesses good mechanical flexibility, allowing it to be used directly as a catalytic electrode. Using an amorphous alloy as a precursor, a self-supporting nanoporous amorphous alloy electrode material enriched with surface noble metal active sites is obtained through chemical dealloying. This material consists of a surface nano-noble metal enrichment layer, an intermediate nanoporous amorphous transition layer, and an internal amorphous matrix layer. The surface nano-noble metal enrichment layer exhibits a hierarchical porous structure composed of submicron-sized 0.3-0.5 μm honeycomb channels and ultrafine sponge-like 20-50 nm nanopores. The noble metal content and the thickness of the nanoporous layer can be controlled by adjusting the concentration of the etching solution, the dealloying time, and the temperature. This nanoporous amorphous alloy electrode material, enriched with precious metal active sites, meets the requirements of large specific surface area, high catalytic activity, simple production process, self-supporting structure, and strong service stability, and has important practical application value in the field of water electrolysis catalysis.

[0009] The technical solution of the present invention is as follows:

[0010] A nanoporous amorphous alloy electrode material enriched with noble metal active sites is provided. The electrode material is a nanoporous amorphous alloy thin strip composed of a surface nano-noble metal enrichment layer, an intermediate nanoporous amorphous transition layer and an inner amorphous matrix layer. It has good mechanical bending flexibility, can be bent arbitrarily at 180° without breaking, and is easy to fabricate self-supporting electrode devices.

[0011] Furthermore, the electrode material is composed of trace amounts of noble metal elements (Pt, Ir, or Os), 3d transition metal elements (Ni, Fe, or Co), and Nb.

[0012] Furthermore, the surface nano-noble metal enrichment layer of the electrode material exhibits a multi-level porous structure composed of submicron-sized honeycomb channels of 0.3-0.5 μm and ultrafine sponge-like nanopores of 20-50 nm, and the thickness of the multi-level porous structure is controllable in the range of 100-500 nm.

[0013] Furthermore, the noble metals (Pt, Ir, or Os) on the surface of the electrode material are enriched on the pore edges of the honeycomb channels, with an atomic percentage of 50-70%.

[0014] To better achieve the objectives of this invention, the present invention further provides a method for preparing a nanoporous amorphous alloy electrode material enriched with noble metal active sites, the key points of which include:

[0015] (1) Amorphous alloy precursor composition: The precursor alloy composition is expressed by the following formula: Mx Nb y N z Where M is one or more of the 3d transition metal elements Ni, Fe or Co, and N is one or more of the noble metal elements Pt, Ir or Os, 55≤x≤65, 35≤y≤45, 0≤z≤5, x+y+z=100, and the indicated components are atomic percentages.

[0016] (2) Vacuum spin quenching and strip spinning process: The linear speed of the copper roller is controlled at 20-35m / s, the thickness of the amorphous alloy strip is 25-50μm, and the width is 2-3mm.

[0017] (3) Dealloying parameters: Hydrofluoric acid is used as the etching solution with a concentration of 0.1-1 mol / L, the dealloying time is 2-9 h, and the dealloying temperature is 0-25℃.

[0018] Furthermore, the electrode material possesses a three-dimensional self-supporting electrode structure and can be directly used as a hydrogen evolution electrode in water electrolysis, exhibiting excellent electrocatalytic activity: 10 mA / cm². 2 The hydrogen evolution overpotential at current density is 17-30 mV, and the Tafel slope is 24-43 mV / dec.

[0019] Furthermore, the electrode material exhibits excellent stability under high current density conditions, at 500 mA / cm². 2 It can operate stably for more than 1,000 hours under current density conditions.

[0020] The beneficial effects of this invention are as follows:

[0021] (1) The nanoporous amorphous alloy electrode material enriched with noble metal active sites can overcome the defects such as insufficient performance caused by the low specific surface area of ​​traditional amorphous ribbons. At the same time, the nanoporous structure enriched with noble metal active sites also increases the active sites of the reaction, improves the ion transport capacity, and significantly improves the electrocatalytic activity of HER.

[0022] (2) The nanoporous amorphous alloy electrode material enriched with noble metal active sites has a three-dimensional self-supporting structure and can be directly used as an electrocatalytic hydrogen evolution electrode without modification. This electrode material is easy to device and suitable for large-scale industrial production.

[0023] (3) A nanoporous amorphous alloy electrode material with rich noble metal active sites for hydrogen production by direct chemical dealloying is obtained. The process is simple and fast, and its multi-level pore structure is flexible and adjustable, making it easy to control the performance.

[0024] (4) The nanoporous amorphous alloy electrode material enriched with noble metal active sites has both a high specific surface area and a double continuous nanoporous structure and a flexible amorphous alloy matrix, exhibiting excellent activity and stability, which can effectively solve the limitation problem of insufficient stability of water electrolysis catalysts under high current density. Attached Figure Description

[0025] Figure 1 For Ni 60 Nb 40 、(Ni 60 Nb 40 ) 99 Ir1,(Ni 60 Nb 40 ) 99 Pt1, (Ni 60 Nb 40 ) 99 Os1, (Ni 60 Nb 40 ) 99 X-ray diffraction pattern of (IrPt)1 alloy thin strip.

[0026] Figure 2 For (Ni) 60 Nb 40 ) 99 Optical image of nanoporous amorphous alloy electrode material obtained by dealloying (IrPt)1 amorphous alloy thin strips.

[0027] Figure 3 For Ni 60 Nb 40 Scanning electron microscope images of the surface morphology of nanoporous materials prepared by chemical dealloying with amorphous alloy ribbons as precursors.

[0028] Figure 4 For (Ni) 60 Nb 40 ) 99.5 Ir 0.5 Scanning electron microscope images of the surface morphology of nanoporous materials prepared by chemical dealloying with amorphous alloy ribbons as precursors.

[0029] Figure 5 For (Ni) 60 Nb 40 ) 99.5 Ir 0.5 Scanning electron microscope image of a cross-section of a nanoporous amorphous alloy prepared by chemical dealloying using amorphous alloy ribbon as a precursor.

[0030] Figure 6 For (Ni) 60 Nb 40 )99.5 Os 0.5 Scanning electron microscope images and X-ray energy dispersive spectroscopy of nanoporous surface morphology prepared by chemical dealloying method using amorphous alloy thin strips as precursors.

[0031] Figure 7 For (Ni) 60 Nb 40 ) 99 Scanning electron microscope (SEM) image of the surface morphology of nanoporous materials prepared by chemical dealloying using Pt1 amorphous alloy thin strips as precursors.

[0032] Figure 8 For (Ni) 60 Nb 40 ) 99 Scanning electron microscope image of the surface morphology of nanoporous materials prepared by chemical dealloying using (IrPt)1 amorphous alloy thin strips as precursors.

[0033] Figure 9 For Ni 60 Nb 40 Linear voltammetric scan curves of nanoporous / amorphous composite electrode materials obtained by dealloying amorphous alloy strips under different conditions in 1 mol / L KOH electrolyte.

[0034] Figure 10 For Ni 60 Nb 40 、(Ni 60 Nb 40 ) 99 Ir1,(Ni 60 Nb 40 ) 99 Pt1, (Ni 60 Nb 40 ) 99 Os1, (Ni 60 Nb 40 ) 99 Linear voltammetry curves of nanoporous amorphous alloy electrode materials obtained by dealloying (IrPt)1 amorphous alloy strips in 1 mol / L KOH.

[0035] Figure 11 For Ni 60 Nb 40 、(Ni 60 Nb 40 ) 99 Ir1,(Ni 60 Nb 40 ) 99 Pt1, (Ni 60 Nb 40 )99 Os1, (Ni 60 Nb 40 ) 99 The Tafel slope of the nanoporous amorphous alloy electrode material obtained by dealloying (IrPt)1 amorphous alloy strip in 1 mol / L KOH was measured.

[0036] Figure 12 For (Ni) 60 Nb 40 ) 99 The nanoporous amorphous alloy electrode material obtained by dealloying (IrPt)1 amorphous alloy strips in 1 mol / L KOH has a current of 500 mA / cm². 2 Voltage-time curves under current density conditions. Specific Implementation

[0037] Figure 1 The image shows the prepared Ni. 60 Nb 40 、(Ni 60 Nb 40 ) 99 Ir1,(Ni 60 Nb 40 ) 99 Pt1, (Ni 60 Nb 40 ) 99 Os1, (Ni 60 Nb 40 ) 99 X-ray diffraction patterns of (IrPt)1 alloy ribbons showed that the alloy ribbons prepared by the melt casting method only had diffuse scattering peaks and no sharp crystallization peaks, indicating that they were all amorphous structures.

[0038] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0039] Example 1:

[0040] Take Ni 60 Nb 40 As the nominal composition of the precursor alloy, the required elements are weighed and proportioned. The pure elements required for the precursor alloy (Ni 99.99wt%, Nb 99.99wt%) are converted into mass (10g) according to the atomic percentage of the alloy. Then, the master alloy button ingot is obtained by vacuum arc melting in a high-purity argon atmosphere. The melting is carried out more than four times to ensure that the composition of the master alloy ingot is uniform.

[0041] Using a vacuum spinning device, the master alloy ingot is remelted by induction heating and continuously and rapidly sprayed onto a water-cooled rotating copper roller under the action of high-purity argon gas at a pressure of approximately 0.2 MPa. The linear velocity of the copper roller is 20-30 m / s, thus producing Ni. 60 Nb 40 Alloy strips, with a thickness of 35-50μm and a width of 2-3mm.

[0042] Example 2:

[0043] With (Ni 60 Nb 40 ) 99 Ir1,(Ni 60 Nb 40 ) 99.5 Ir 0.5 As the nominal composition of the precursor alloy, the required elements are weighed and proportioned. The pure elements required for the precursor alloy (Ni 99.99wt%, Nb 99.99wt%, Ir 99.99wt%) are converted into mass (10g) according to the atomic percentage of the alloy. Then, the master alloy button ingot is obtained by vacuum arc melting in a high-purity argon atmosphere. The melting is carried out more than four times to ensure that the composition of the master alloy ingot is uniform.

[0044] Using a vacuum spinning device, the master alloy ingot is remelted by induction heating and continuously and rapidly sprayed onto a water-cooled rotating copper roller under the action of high-purity argon gas at a pressure of approximately 0.2 MPa. The linear velocity of the copper roller is 25-35 m / s, thus preparing (Ni) alloy. 60 Nb 40 ) 99 Ir1,(Ni 60 Nb 40 ) 99.5 Ir 0.5 Alloy strips, with a thickness of 25-40μm and a width of 2-3mm.

[0045] Example 3:

[0046] With (Ni 60 Nb 40 ) 99 Os1, (Ni 60 Nb 40 ) 99.5 Os 0.5As the nominal composition of the precursor alloy, the required elements are weighed and proportioned. The pure elements required for the precursor alloy (Ni 99.99wt%, Nb 99.99wt%, Os 99.99wt%) are converted into mass (10g) according to the atomic percentage of the alloy. Then, the master alloy button ingot is obtained by vacuum arc melting in a high-purity argon atmosphere. The melting is carried out more than four times to ensure that the composition of the master alloy ingot is uniform.

[0047] Using a vacuum spinning device, the master alloy ingot is remelted by induction heating and continuously and rapidly sprayed onto a water-cooled rotating copper roller under the action of high-purity argon gas at a pressure of approximately 0.2 MPa. The linear velocity of the copper roller is 25-35 m / s, thus preparing (Ni) alloy. 60 Nb 40 ) 99 Os1, (Ni 60 Nb 40 ) 99.5 Os 0.5 Alloy strips, with a thickness of 25-40μm and a width of 2-3mm.

[0048] Example 4:

[0049] With (Ni 60 Nb 40 ) 99 Pt1 is used as the nominal composition of the precursor alloy. The required elements are weighed and proportioned. The pure elements required for the precursor alloy (Ni 99.99wt%, Nb 99.99wt%, Pt 99.99wt%) are converted into mass (10g) according to the atomic percentage of the alloy. Then, the master alloy button ingot is obtained by vacuum arc melting in a high-purity argon atmosphere. The melting is carried out more than four times to ensure that the composition of the master alloy ingot is uniform.

[0050] Using a vacuum spinning device, the master alloy ingot is remelted by induction heating and continuously and rapidly sprayed onto a water-cooled rotating copper roller under the action of high-purity argon gas at a pressure of approximately 0.2 MPa. The linear velocity of the copper roller is 25-35 m / s, thus preparing (Ni) alloy. 60 Nb 40 ) 99 Pt1 alloy thin strips, with a thickness of 25-40μm and a width of 2-3mm.

[0051] Example 5:

[0052] With (Ni 60 Nb 40 ) 99(IrPt)1 is used as the nominal composition of the precursor alloy. The required elements are weighed and proportioned. The pure elements required for the precursor alloy (Ni 99.99wt%, Nb 99.99wt%, Ir 99.99wt%, Pt 99.99wt%) are converted into mass (10g) according to the atomic percentage of the alloy. Then, the master alloy button ingot is obtained by vacuum arc melting in a high-purity argon atmosphere. The melting is carried out more than four times to ensure that the composition of the master alloy ingot is uniform.

[0053] Using a vacuum spinning device, the master alloy ingot is remelted by induction heating and continuously and rapidly sprayed onto a water-cooled rotating copper roller under the action of high-purity argon gas at a pressure of approximately 0.2 MPa. The linear velocity of the copper roller is 30-35 m / s, thus preparing (Ni) alloy. 60 Nb 40 ) 99 (IrPt)1 alloy thin strip, with a thickness of 20-35μm and a width of 2-3mm.

[0054] Example 6:

[0055] The Ni prepared in Example 1 60 Nb 40 Using amorphous alloy thin strips as precursors and 0.5 mol / L HF solution as etching solution, chemical dealloying was carried out at room temperature for 9 hours. The strips were then removed and washed repeatedly with ultrapure water and anhydrous alcohol to remove residual chemical substances in the pores. After drying, nanoporous amorphous alloy electrode materials were obtained.

[0056] Figure 3 The image shows Ni 60 Nb 40 The surface morphology of the amorphous alloy strip after chemical dealloying for 9 hours shows that a three-dimensional double-continuous nanoporous structure has formed on its surface.

[0057] Example 7:

[0058] The (Ni) prepared in Example 2 60 Nb 40 ) 99.5 Ir 0.5 Amorphous alloy ribbons were used as precursors, and 0.5 mol / L HF solution was used as etching solution. After chemical dealloying at room temperature for 2-9 hours, the ribbons were taken out and washed repeatedly with ultrapure water and anhydrous alcohol to remove residual chemical substances in the pores. After drying, nanoporous amorphous alloy ribbons doped with noble metal Ir were prepared.

[0059] Figure 4 The figure shown is (Ni) 60 Nb 40 ) 99.5 Ir0.5 The surface morphology of the amorphous alloy strip after dealloying for 2 hours shows that a three-dimensional bicontinuous nanoporous structure has also been formed on its surface. At the same time, due to the addition of Ir, a honeycomb-like noble metal enriched network structure has been formed on its surface, which increases the specific surface area and provides abundant active sites. The interconnected network structure is also conducive to material transport and full contact between active sites and electrolyte. Figure 5 The figure shown is (Ni) 60 Nb 40 ) 99.5 Ir 0.5 Scanning electron microscope images of the cross-section of the nanoporous amorphous alloy strip after dealloying for 6 hours show that it consists of a high specific surface area double continuous nanoporous layer, a transition layer, and an amorphous matrix layer, forming a nanocomposite structure in which a nanoporous active layer covers the amorphous matrix, with a porous layer thickness of about 200 nm.

[0060] Example 8:

[0061] The (Ni) prepared in Example 3 60 Nb 40 ) 99.5 Os 0.5 Amorphous alloy ribbon was used as a precursor, and 0.5 mol / L HF solution was used as an etchant. After chemical dealloying at room temperature for 2 hours, the ribbon was taken out and washed repeatedly with ultrapure water and anhydrous alcohol to remove residual chemical substances in the pores. After drying, a nanoporous amorphous alloy ribbon doped with noble metal Os was prepared.

[0062] Figure 6 The figure shown is (Ni) 60 Nb 40 ) 99.5 Os 0.5 The surface morphology of the amorphous alloy strip after dealloying for 2 hours revealed the formation of a three-dimensional bicontinuous nanoporous structure. Simultaneously, the addition of Os resulted in a honeycomb-like macroporous structure, increasing the specific surface area and providing abundant active sites. The interconnected network structure also facilitated mass transport and sufficient contact between the active sites and the electrolyte. Furthermore, EDS results showed that Os was enriched in the honeycomb structure, with an atomic percentage of ~50%.

[0063] Example 9:

[0064] The (Ni) prepared in Example 4 60 Nb 40 ) 99Using Pt1 amorphous alloy ribbon as a precursor, and 0.5 mol / L HF solution as an etchant, chemical dealloying was performed at room temperature for 9 hours. The ribbon was then removed and repeatedly washed with ultrapure water and anhydrous alcohol to remove residual chemical substances from the pores. After drying, Pt-doped nanoporous amorphous alloy ribbon was obtained.

[0065] Figure 7 The figure shown is (Ni) 60 Nb 40 ) 99 The surface morphology of Pt1 amorphous alloy strip after dealloying for 9 hours shows that a three-dimensional bicontinuous nanoporous structure has also been formed on its surface. At the same time, due to the addition of Pt, a honeycomb-like noble metal enriched network structure has also been formed on its surface. EDS results show that the atomic percentage of Pt element at the edges of the honeycomb pores is ~70%.

[0066] Example 10:

[0067] The (Ni) prepared in Example 5 60 Nb 40 ) 99 Using (IrPt)1 amorphous alloy ribbon as a precursor, and 0.5 mol / L HF solution as an etchant, chemically dealloying was performed at room temperature for 9 hours. The ribbon was then removed and repeatedly washed with ultrapure water and anhydrous alcohol to remove residual chemical substances from the pores. After drying, nanoporous amorphous alloy ribbons doped with noble metals Pt and Ir were obtained. Figure 2 The figure shown is (Ni) 60 Nb 40 ) 99 Optical images of nanoporous amorphous alloy electrode materials obtained by dealloying (IrPt)1 amorphous alloy strips show that they have good mechanical bending flexibility and can be bent arbitrarily at 180° without breaking.

[0068] Figure 8 The figure shown is (Ni) 60 Nb 40 ) 99 The surface morphology of the (IrPt)1 amorphous alloy strip after dealloying for 9 hours shows that a three-dimensional bicontinuous nanoporous structure has also formed on its surface. At the same time, due to the addition of Pt and Ir, a honeycomb-like noble metal enrichment network structure has also formed on its surface. Moreover, its network structure is finer, which can obtain a relatively larger specific surface area and provide more active sites. The interconnected network structure is also conducive to material transport and sufficient contact between active sites and electrolyte.

[0069] Example 11:

[0070] The Ni prepared in Example 6 60 Nb40 A three-electrode system was constructed using an amorphous alloy thin strip as the working electrode, a platinum wire electrode as the auxiliary electrode, and an Ag / AgCl standard electrode as the reference electrode. A linear voltammetric scan was performed in a 1 mol / L KOH solution at a scan rate of 50 mV / s.

[0071] Figure 9 The figure shows Ni after different dealloying times. 60 Nb 40 The polarization curves of the amorphous alloy thin film after conversion to the standard hydrogen electrode potential show that, compared with the pure amorphous alloy material, the nanoporous amorphous alloy electrode material after chemical dealloying has better hydrogen evolution catalytic activity.

[0072] Example 12:

[0073] We used the Ni prepared in Examples 6, 7, 8, 9, and 10 respectively 60 Nb 40 、(Ni 60 Nb 40 ) 99 Ir1,(Ni 60 Nb 40 ) 99 Pt1, (Ni 60 Nb 40 ) 99 Os1, (Ni 60 Nb 40 ) 99 A three-electrode system was constructed using (IrPt)1 nanoporous amorphous alloy electrode material as the working electrode, a platinum wire electrode as the auxiliary electrode, and an Ag / AgCl standard electrode as the reference electrode. A linear voltammetric scan was performed in a 1 mol / L KOH solution at a scan rate of 50 mV / s.

[0074] Figure 10 The figure shows the polarization curves of different nanoporous amorphous alloy electrode materials after conversion to standard hydrogen electrode potential. Figure 11 The Tafel slope of the nanoporous amorphous alloy electrode material is shown. As can be seen from the figure, relative to Ni... 60 Nb 40 Nanoporous amorphous alloy electrode materials doped with trace amounts of noble metal elements exhibit significantly stronger hydrogen evolution catalytic activity. At a current density of 10 mA / cm², 2 The hydrogen evolution potential is only 28 mV, and the Tafel slope is only 24 mV / dec.

[0075] Example 13:

[0076] The (Ni) prepared in Example 10 60 Nb 40 )99 A three-electrode system was constructed using an (IrPt)1 amorphous alloy thin strip as the working electrode, a platinum wire electrode as the auxiliary electrode, and an Ag / AgCl standard electrode as the reference electrode. Constant current testing was performed in a 1 mol / L KOH solution.

[0077] Figure 12 The image shows (Ni) after dealloying. 60 Nb 40 ) 99 (IrPt)1 amorphous alloy thin strip at a current density of 500 mA / cm² 2 The voltage-time curve under the given conditions, as shown in the figure, is at 500 mA / cm². 2 Under certain current density conditions, the stable operating time exceeds 90 hours, and further stability experiments show that it can operate continuously for 1000 hours without performance degradation. These results demonstrate that the (Ni) prepared in this invention... 60 Nb 40 ) 99 (IrPt)1 nanoporous amorphous alloy electrode material exhibits good stability in alkaline hydrogen evolution reaction.

[0078] The remaining embodiments can be prepared using the same method as this embodiment, with the only difference being the change in the nominal composition of the raw materials to obtain amorphous alloy thin strips with different compositions and the control of dealloying parameters. After characterization and analysis, these nanoporous amorphous alloy electrode materials all exhibit good electrocatalytic activity and stability.

[0079] The embodiments described above provide a detailed explanation of the technical solution of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, additions, or similar substitutions made within the scope of the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A nanoporous amorphous alloy electrode material enriched with noble metal active sites, characterized in that, The precursor alloy of the electrode material is composed of noble metal element N, 3d transition metal element M, and Nb element, and the composition formula is M. x Nb y N z , where M is one or more of Ni, Fe or Co, N is one or more of Pt, Ir or Os, 55≤x≤65, 35≤y≤45, 0<z≤5, x+y+z=100, and x, y and z are atomic percentages; The electrode material is obtained by preparing an amorphous alloy strip by melting and vacuum spin-quenching the precursor alloy, and then placing the amorphous alloy strip in a hydrofluoric acid solution for dealloying.

2. The nanoporous amorphous alloy electrode material according to claim 1, characterized in that, The electrode material consists of a surface nano-noble metal enrichment layer, a middle nanoporous amorphous transition layer, and an inner amorphous matrix layer.

3. The nanoporous amorphous alloy electrode material according to claim 2, characterized in that, The surface nano-noble metal enrichment layer exhibits a multi-level porous structure composed of submicron-sized honeycomb channels of 0.3-0.5μm and ultrafine sponge-like nanopores of 20-50nm. The thickness of this multi-level porous structure is controllable in the range of 100-500nm.

4. The nanoporous amorphous alloy electrode material according to claim 2, characterized in that, The noble metal elements in the surface nano-noble metal enrichment layer are enriched on the pore edges of the honeycomb channels, with an atomic percentage of 50-70%.

5. A method for preparing a nanoporous amorphous alloy electrode material according to any one of claims 1-4, characterized in that, The method includes: (1) Raw material preparation: Weigh and proportion the required elements according to the composition of the precursor alloy; the composition of the precursor alloy is expressed by the following formula: M x Nb y N z , where M is one or more of the 3d transition metal elements Ni, Fe or Co, N is one or more of the noble metal elements Pt, Ir or Os, 55≤x≤65, 35≤y≤45, 0<z≤5, x+y+z=100, and x, y and z are atomic percentages; (2) Melting: The raw materials obtained in step (1) are melted in a vacuum arc under a high-purity argon atmosphere to obtain master alloy button ingots; (3) Vacuum spin quenching and strip spinning process: The master alloy ingot obtained in step (2) is remelted by induction heating using a vacuum strip spinning equipment to obtain an amorphous alloy strip; wherein, the linear speed of the copper roller is controlled at 20-35m / s, the thickness of the amorphous alloy strip is controlled at 20-50μm, and the width is 2-3mm. (4) Dealloying: Hydrofluoric acid is used as the etching solution to dealloy the amorphous alloy strip obtained in step (3) at room temperature and then take it out to obtain the electrode material. The concentration of the etching solution is 0.1-1 mol / L, the dealloying time is 2-9 h, and the dealloying temperature is 0-25℃.

6. The application of the nanoporous amorphous alloy electrode material according to any one of claims 1-4 in water electrolysis catalysis, characterized in that, The electrode material has a three-dimensional self-supporting structure and, as a hydrogen evolution electrode for water electrolysis, exhibits the following electrocatalytic activity: 10 mA / cm². 2 The hydrogen evolution overpotential at current density is 17-30 mV, and the Tafel slope is 24-43 mV / dec.

7. The application of the nanoporous amorphous alloy electrode material according to any one of claims 1-4 in water electrolysis catalysis, characterized in that, The electrode material is at 500 mA / cm 2 It can operate stably for more than 1,000 hours under current density conditions.

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