A nano-porous bifunctional overall water-splitting electrocatalyst, a preparation method and application thereof

Abstract

The application discloses a kind of nano-porous bifunctional full water-splitting electrocatalysts, the chemical formula of the nano-porous bifunctional full water-splitting electrocatalyst is:Fe a Co b Ni c Zr d P e Wherein, 10≤a≤15, 20≤b≤30, 10≤c≤15, 20≤d≤25, 15≤e≤20, a+c=b, a+b+c+d+e=100, micro-morphology structure is honeycomb-like multi-level nano-porous structure.The nano-porous bifunctional full water-splitting electrocatalyst has excellent electrocatalytic hydrogen production and oxygen production performance, and can realize efficient and stable full water-splitting in the same alkaline electrolyte.The application also discloses a preparation method of the nano-porous bifunctional full water-splitting electrocatalyst.The preparation method can obtain higher catalytic performance using less phosphorus.The application also discloses the application of the nano-porous bifunctional full water-splitting electrocatalyst in alkaline electrolytic cell.

Description

Technical Field

[0001] This invention belongs to the field of water electrolysis catalysts, specifically relating to a nanoporous bifunctional total water electrolysis catalyst, its preparation method, and its application. Background Technology

[0002] Currently, the massive combustion of non-renewable fossil fuels such as oil and coal produces byproducts like carbon oxides and nitrogen oxides, causing serious environmental problems such as the greenhouse effect, acid rain, and global warming, and inevitably leading to the predicament of energy depletion. Therefore, developing renewable, green, pollution-free, and sustainable new energy sources is particularly important at this stage.

[0003] Hydrogen energy is considered one of the most promising clean energy sources for the future. Compared to hydrogen production from fossil fuels, hydrogen production through water electrolysis has gained widespread attention due to its advantages such as renewability and high gas purity. The water electrolysis process involves the hydrogen evolution reaction (HER) at the cathode and the oxygen evolution reaction (OER) at the anode, both of which have a significant impact on the overall water splitting efficiency. The theoretical minimum voltage required for water electrolysis is 1.23V; however, commercial water electrolysis devices often require a higher operating voltage of 1.8–2.0V. Suitable and effective electrocatalysts are typically used to reduce overpotential and decrease energy consumption during the reaction process.

[0004] Currently, the most active HER and OER catalysts are platinum-based and ruthenium / iridium-based catalysts, respectively. However, the scarcity and high cost of precious metals limit the large-scale application of water electrolysis for hydrogen production. Therefore, preparing bifunctional catalysts with both high HER and OER activity remains a significant challenge.

[0005] Transition metal phosphides (TMPs) have been widely developed and applied in the field of bifunctional electrocatalytic water splitting due to their platinum-like and tunable d-band electronic structure and inherently high HER catalytic activity. The negatively charged phosphorus atoms can effectively capture H*, enhancing HER catalytic activity and exhibiting excellent conductivity. Simultaneously, phosphorus doping / phosphating modification can suppress catalyst dissolution in the electrolyte, resulting in good catalytic stability and corrosion resistance. However, the use of large amounts of phosphorus can cause serious damage to the environment and organisms; therefore, the preparation of highly efficient bifunctional catalysts containing small amounts of phosphorus is particularly important.

[0006] The preparation of nanoporous structures with large specific surface areas is crucial for achieving rapid water splitting reactions and for utilizing and improving the catalytic activity of catalysts. However, nanoporous structures obtained through dealloying methods, i.e., selectively dissolving active elements, suffer from poor mechanical stability and low electron transport efficiency, which severely hinders their industrial application as long-term stable and durable water electrolysis catalysts.

[0007] Therefore, it is very attractive to prepare nanoporous bifunctional electrolytic water catalysts that can be used efficiently and stably in strong alkaline media, as this can simplify the system and reduce costs. Summary of the Invention

[0008] This invention provides a nanoporous bifunctional water electrocatalyst, its preparation method, and its application. The nanoporous bifunctional water electrocatalyst provided by this invention has excellent electrocatalytic hydrogen and oxygen production performance, and can achieve efficient and stable water electrolysis in the same alkaline electrolyte.

[0009] To achieve the above objectives, on the one hand, the present invention provides a nanoporous bifunctional total water electrolysis catalyst, wherein the chemical formula of the nanoporous bifunctional total water electrolysis catalyst is: Fe a Co b Ni c Zr d P e , where 10≤a≤13, 22≤b≤25, 20≤c≤23, 24≤d≤28, 11≤e≤24, d+e≥35, a+b+c+d+e=100, and the microstructure is a honeycomb-like multi-level nanoporous structure.

[0010] Furthermore, the multi-level nanoporous structure is composed of transition metal phosphide TMZrP nanocrystals.

[0011] The phosphide nanocrystals in the nanoporous bifunctional electrocatalyst for total water splitting provided by this invention are directly exposed on the surface of a multi-level nanoporous structure, allowing the phosphorus element to fully serve as an active site for the catalytic reaction, thus achieving more efficient electrocatalytic total water splitting. Compared with the existing technologies that use vapor deposition or phosphating methods, more active sites on the crystal facets are exposed, resulting in better catalytic performance.

[0012] The Fe, Ni, Co, and Zr elements provided by this invention contribute a large number of electrons to the P element. Therefore, compared with the prior art, the P element in this invention can obtain more electrons to perform total water splitting, thus enabling more efficient total water splitting and improving the electrocatalytic hydrogen and oxygen production performance.

[0013] The Zr and P provided by this invention can form a stable transition metal phosphide TMZrP nanocrystalline phase, thus maintaining good catalytic performance even after multiple, long-term catalytic reactions.

[0014] Furthermore, the specific surface area of ​​the nanoporous bifunctional hydrolytic catalyst is 15–25 cm². 2 / mg.

[0015] On the other hand, the present invention also provides a method for preparing a nanoporous bifunctional hydrolytic catalyst, comprising:

[0016] Step 1: Prepare the raw materials according to the chemical formula of the precursor, melt them evenly, and make a master alloy. The chemical formula of the precursor is: [(FeNiCo)]. 0.6 Cu 0.3 Zr 0.1 ] 100-x P x Where 0 at.% < x ≤ 10 at.%;

[0017] Step 2: After melting the master alloy, spray it onto the surface of a rotating copper roller to obtain the alloy strip precursor;

[0018] Step 3: Add the alloy strip precursor to an etching solution for treatment to obtain a nanoporous bifunctional hydrolytic catalyst.

[0019] This invention uses an etching solution to completely etch away Cu and partially etch away Fe, Ni, and Co, thereby forming a porous structure. This porous structure consists of stable transition metal phosphide (TMZrP) nanocrystals. Due to the stability of the nanocrystal structure, the prepared catalyst exhibits high stability. Since the etching solution does not corrode Zr and P, but does corrode Cu, Fe, Ni, and Co, Zr and P are exposed on the outer surface, thus improving the efficiency of P in the catalyst for complete water splitting. Furthermore, the etching action of the etching solution rearranges the electronic structure of each element, promoting the transfer of electrons from Fe, Ni, Co, and Zr to P. The higher electronegativity of P accelerates the catalytic reaction kinetics, providing higher intrinsic catalytic activity and resulting in excellent complete water splitting performance.

[0020] Furthermore, the volume / mass ratio of the etching solution to the precursor is 0.05–0.15 mL / g.

[0021] Furthermore, in this embodiment of the invention, the alloy strip precursor is added to an etching solution for etching, and the etching time is 8 to 12 minutes.

[0022] Furthermore, the etching solution is prepared by mixing concentrated hydrochloric acid and concentrated nitric acid at a volume ratio of 2.5 to 3.5:1.

[0023] Furthermore, the ingredients are formulated according to the chemical formula of the precursor, and the percentage purity of the raw materials used in the formulation is not less than 99%.

[0024] Furthermore, the ingredients are smelted, and the smelting process is carried out under vacuum, with a vacuum degree of not less than 5 × 10⁻⁶. -3 Pa.

[0025] Furthermore, the rotational speed of the copper roller is 25–35 m / s.

[0026] The present invention provides a method for adding the alloy strip precursor to an etching solution for etching treatment, followed by washing and drying of the obtained nanoporous bifunctional hydrolytic catalyst.

[0027] Furthermore, the nanoporous bifunctional hydrolytic catalyst is washed, and the specific washing steps are as follows: the nanoporous bifunctional hydrolytic catalyst is rinsed sequentially with acetone, ethanol and deionized water.

[0028] Furthermore, the nanoporous bifunctional hydrolysis catalyst is dried at a temperature of 20–30°C for 1–1.5 h.

[0029] On the other hand, this invention also provides the application of the aforementioned nanoporous bifunctional water electrolytic catalyst in an alkaline electrolyzer, whereby the nanoporous bifunctional water electrolytic catalyst is simultaneously used as the cathode and / or anode of the alkaline electrolyzer. Both exhibit good hydrogen evolution and oxygen evolution reaction activity and good stability; that is, the nanoporous electrocatalyst prepared by this invention can effectively achieve stable and efficient water electrolysis. The high-efficiency nanoporous bifunctional water electrolytic catalyst prepared in this invention has self-supporting properties and can be directly used as the working electrode.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0031] (1) The present invention utilizes the large amount of exposed P element in the nanoporous bifunctional water electrolytic catalyst, and the fact that Fe, Ni, Co, and Zr provide more electrons for P element, so that the P element in the catalyst provided by the present invention can serve as a large amount and efficient reaction active site, thus giving the nanoporous bifunctional water electrolytic catalyst excellent electrocatalytic hydrogen and oxygen production performance; since the transition metal phosphide TMZrP nanocrystals in the nanoporous bifunctional water electrolytic catalyst are relatively stable, the nanoporous bifunctional water electrolytic catalyst can perform water electrolysis relatively stably.

[0032] (2) The efficient nanoporous bifunctional water electrolytic catalyst provided by the present invention has a multi-level distribution of pore size in its nanoporous structure, a large specific surface area, and an increased number of active reaction sites. Its catalytic activity is superior to that of the dual-electrode water electrolytic system composed of noble metals such as Pt / C||IrO2.

[0033] (3) The preparation method provided by the present invention uses an acidic etching solution to corrode the metal elements, so that as much P as possible is exposed to the outside world, thereby achieving better catalytic performance with less P. Attached Figure Description

[0034] Figure 1This is a SEM image of the nanoporous bifunctional hydrolytic catalyst prepared in Example 1 of this invention.

[0035] Figure 2 These are TEM morphology comparison images of the alloy strip precursor and the nanoporous bifunctional hydrolytic catalyst prepared in Example 1 of this invention.

[0036] Figure 3 The photoelectron spectroscopy characterization diagram of the nanoporous bifunctional hydrolytic catalyst prepared in Example 1 of this invention is shown.

[0037] Figure 4 The results are the test results of the hydrogen evolution performance of the electrocatalysts prepared in Example 1, Comparative Example 1 and Comparative Example 2 of this invention.

[0038] Figure 5 The results are the water electrolysis oxygen evolution performance test results of the electrocatalysts prepared in Example 1, Comparative Example 1 and Comparative Example 3 of the present invention.

[0039] Figure 6 The results of the total water splitting performance tests of Embodiment 1, Comparative Example 1, Comparative Example 2, and Comparative Example 3 of the present invention are as the two electrodes.

[0040] Figure 7 The results are the hydrogen evolution stability test results of the highly efficient nanoporous bifunctional water electrolytic catalyst prepared in Example 1 of this invention;

[0041] Figure 8 The results are the oxygen evolution stability test results of the highly efficient nanoporous bifunctional total water electrolytic catalyst prepared in Example 1 of this invention;

[0042] Figure 9 The results show the stability test results of the high-efficiency nanoporous bifunctional electrocatalyst for water electrolysis prepared in Example 1 of this invention. Detailed Implementation

[0043] The present invention will be further described below with reference to the accompanying drawings and embodiments. It should be noted that the embodiments described below are intended to facilitate the understanding of the present invention, but are not intended to limit the scope of protection of the present invention.

[0044] Example 1

[0045] This embodiment provides the preparation of a highly efficient nanoporous bifunctional hydrolytic water electrolysis catalyst, comprising:

[0046] (1) Select Fe, Co, Ni, Cu, Zr, and P elements with a purity greater than 99.9 wt%, according to [(FeNiCo)] 0.6 Cu 0.3 Zr 0.1 ] 95P5 (x = 5 at.%) is proportioned, and the alloying elements in the above proportion are subjected to arc melting in an Ar protective atmosphere. The mixture is stirred evenly at least four times, and after cooling, a master alloy ingot is obtained.

[0047] (2) Then, using a vacuum strip spinning device, the master alloy ingot is induction remelted in a quartz tube, and then sprayed onto a copper roller with a linear velocity of 30 m / s through an instantaneous pressure difference of 0.04 MPa, forming an alloy strip precursor. The strip has a thickness of 35-45 μm, a width of 1-2 mm, and a metallic luster.

[0048] (3) The alloy strip precursor was immersed in a fresh etching solution prepared with concentrated hydrochloric acid and concentrated nitric acid (volume ratio 3:1) for 10 min at room temperature. After etching, the obtained alloy electrocatalyst was rinsed repeatedly with acetone, ethanol and deionized water at least three times, and then dried in an oven at 30°C for 1 h. The highly efficient nanoporous bifunctional water electrocatalyst was obtained.

[0049] Example 2

[0050] This embodiment provides the preparation of a highly efficient nanoporous bifunctional hydrolytic water electrolysis catalyst, comprising:

[0051] (1) Select Fe, Co, Ni, Cu, Zr, and P elements with a purity greater than 99.9 wt%, according to [(FeNiCo)] 0.6 Cu 0.3 Zr 0.1 ] 93 P7 (x = 7 at.%) is proportioned, and the alloying elements in the above proportion are subjected to arc melting in an Ar protective atmosphere. The mixture is melted at least four times to ensure uniformity, and the master alloy ingot is obtained after cooling.

[0052] (2) Then, using a vacuum strip spinning device, the master alloy ingot is induction remelted in a quartz tube and then sprayed onto a copper roller with a linear velocity of 25 m / s through an instantaneous pressure difference of 0.04 MPa to form an alloy strip precursor.

[0053] (3) The alloy strip precursor was immersed in a fresh etching solution prepared with concentrated hydrochloric acid and concentrated nitric acid (volume ratio 2.5:1) for 8 min at room temperature. After etching, the obtained alloy electrocatalyst was rinsed repeatedly with acetone, ethanol and deionized water at least three times, and then dried in an oven at 30°C for 1 h. The highly efficient nanoporous bifunctional water-splitting electrocatalyst was obtained.

[0054] Comparative Example 1

[0055] This embodiment provides the preparation of a highly efficient nanoporous bifunctional hydrolytic water electrolysis catalyst, comprising:

[0056] (1) Select Fe, Co, Ni, Cu, Zr, and P elements with a purity greater than 99.9 wt%, according to [(FeNiCo)] 0.6 Cu 0.3 Zr 0.1 ] 95 P5 (x = 5 at.%) is proportioned, and the alloying elements in the above proportion are subjected to arc melting in an Ar protective atmosphere. The mixture is stirred evenly at least four times, and after cooling, a master alloy ingot is obtained.

[0057] (2) Then, using a vacuum strip spinning device, the master alloy ingot is induction remelted in a quartz tube, and then sprayed onto a copper roller with a linear velocity of 30 m / s through an instantaneous pressure difference of 0.04 MPa, forming an alloy strip precursor. The strip has a thickness of 35–45 μm and a width of 1–2 mm, and has a metallic luster. The alloy strip precursor is used as a catalyst.

[0058] Comparative Example 2

[0059] The catalyst provided in this embodiment is an existing Pt / C catalyst, and the method for preparing the working electrode of this Pt / C catalyst is as follows:

[0060] 5 mg of commercial Pt / C powdered catalyst was dispersed in a mixture of 1,000 μL ethanol and 50 μL Nafion, and then sonicated for 30 min to form a homogeneous catalyst suspension. 10 μL of the catalyst suspension was transferred to a pre-treated L-shaped glassy carbon (GC) electrode (0.0707 cm⁻¹). 2 The Pt / C working electrode was obtained by loading the material onto a substrate and then drying it at room temperature, with a loading of 0.674 mg / cm³. 2 .

[0061] Comparative Example 3

[0062] The catalyst provided in this embodiment is an existing IrO2 catalyst. Unlike the preparation method in Comparative Example 2, the commercially available powdered catalyst used is commercially available IrO2.

[0063] Performance Analysis

[0064] like Figure 1 As shown, the nanoporous bifunctional hydrolytic catalyst prepared in Example 1 exhibits a honeycomb-like morphology, with micropores and macropores arranged in a multi-level distribution, a pore size of 80–200 nm, and a specific surface area of ​​15–25 cm². 2 / mg.

[0065] In Example 1, as Figure 2 As shown in a, before the etching solution was added, pure Cu and TMZrP nanocrystalline phases were present, such as Figure 2As shown in b, after treatment with etching solution, the Cu-rich region is completely etched by the etching solution, forming a nanoporous structure. The remaining small portion of etched Fe, Ni, and Co, and the unetched Zr and P still form a stable transition metal phosphide TMZrP nanocrystalline phase. Therefore, the obtained nanoporous bifunctional water electrolytic catalyst has a large amount of exposed P element on its surface, resulting in more active sites and faster electron transport speed, which can provide highly efficient nanoporous bifunctional water electrolytic reaction activity.

[0066] In Example 1, as Figure 3 As shown, the 2p spectra of Fe, Co, Ni, and Zr before and after etching, obtained by photoelectron spectroscopy, show that the electron orbitals shifted towards higher binding energies by 0.26, 0.24, 0.53, and 0.13 eV, respectively, indicating that electrons transferred outwards. In contrast, the 2p spectra of P before and after etching show that the electron orbitals shifted towards lower binding energies by 0.08 eV, indicating that electrons transferred towards P. This suggests that P has more electrons, which improves the efficiency of total hydrolysis.

[0067] This invention utilizes a Zahner Zennium electrochemical workstation with a three-electrode system: samples prepared in Example 1 and Comparative Examples 1 and 2 are used as working electrodes, Ag / AgCl as a reference electrode, and a carbon rod as an auxiliary electrode. Linear sweep voltammetry (LSV) tests are performed in a 1 mol / L KOH electrolyte. Hydrogen evolution performance is tested within the test potential window of 0 to -0.9 V (corresponding to a reversible hydrogen electrode) at a scan rate of 3 mV / s, and the current is converted to current density. The test results are as follows: Figure 4 As shown, the experimental data were compensated by iR. Hydrogen evolution activity was analyzed using the relationship between current density and overpotential; a higher absolute value of current density and a lower overpotential indicate better catalytic performance. Compared to the alloy strip precursor (FeCoNi)CuZrP, the nanoporous bifunctional hydrolytic catalyst, i.e., the etched (FeCoNi)CuZrP, exhibits a lower overpotential. (Driven by 10 mA / cm²) 2 At current density, the overpotential is approximately 82mV, with a drive current of 100mA / cm. 2 The overpotential at current density is approximately 136 mV, which is close to the performance of commercially available Pt / C electrocatalysts.

[0068] The oxygen evolution performance test provided in this embodiment of the invention is consistent with the hydrogen evolution test method described above. Samples prepared in Example 1 and Comparative Examples 1 and 3 are used as the working electrode with a test window of 0–0.6 V (corresponding to the reversible hydrogen electrode). Oxygen evolution activity is analyzed using the relationship between current density and overpotential. A higher absolute value of current density and a lower overpotential indicate better oxygen evolution catalytic reaction performance. The test results are as follows: Figure 5As shown, compared with the alloy strip precursor (FeCoNi)CuZrP and commercial IrO2 catalysts, the nanoporous bifunctional total water electrolysis catalyst, i.e., the etched (FeCoNi)CuZrP, exhibits a low overpotential. The current density is 10 mA / cm². 2 The overpotential at that time is approximately 270 mV, and the current density is 100 mA / cm². 2 The overpotential at that time is approximately 316mV.

[0069] (2) Testing of the water-splitting performance of nanoporous bifunctional water electrocatalyst

[0070] This invention utilizes a Zahner Zennium electrochemical workstation and a two-electrode system: two samples prepared in Example 1 were selected as the cathode and anode, respectively; two samples prepared in Comparative Example 1 were selected as the cathode and anode; and Comparative Example 2 was selected as the cathode and Comparative Example 3 as the anode. Linear sweep voltammetry (LSV) tests were performed in a 1 mol / L KOH electrolyte. The test potential window was 1.0–2.2 V, and the scan rate was 3 mV / s. The current was converted to current density. The test results are as follows: Figure 6 As shown, in the total water splitting reaction, the nanoporous bifunctional total water splitting electrocatalyst, namely the etched (FeCoNi)CuZrP, at 10 mA / cm², exhibits high efficiency. 2 It exhibits a low voltage of 1.51V at a current density, which is better than the 1.95V of the unetched alloy strip precursor (FeCoNi)CuZrP and the 1.70V of the two-electrode total water splitting system composed of noble metal Pt / C||IrO2.

[0071] (3) Stability test of hydrogen and oxygen evolution of nanoporous bifunctional water electrolysis catalyst

[0072] Using a Zahner Zennium electrochemical workstation and the same three-electrode testing system as in (1), the hydrogen evolution and oxygen evolution stability of the nanoporous bifunctional water electrocatalyst were tested in 1 mol / L KOH electrolyte by cyclic voltammetry (CV) and chronoamperometry (It curve). 10,000 cyclic voltammetry tests were performed under a voltage range of 0–0.6 V (relative to the reversible hydrogen electrode) to characterize the durability of the electrocatalyst. The scan rate was 50 mV / s. After 10,000 scans, the polarization curves for hydrogen evolution and oxygen evolution were tested again at a scan rate of 3 mV / s. The results were compared with the polarization curves before 10,000 scans, as shown below. Figure 7 and Figure 8 As shown. The long-term stability test curve of the nanoporous bifunctional water electrolysis catalyst was tested using the chronoamperometry at a constant potential of -1.12V for hydrogen evolution. The long-term stability test method for oxygen evolution was the same as that for hydrogen evolution, with a constant potential of 0.47V, and the results are shown. Figure 7 and Figure 8 As shown in the figure.

[0073] The nanoporous bifunctional water splitting electrode exhibits stable hydrogen evolution operation, maintaining stable performance after 10,000 cycles at a current density of 10 mA / cm². 2 The potential rise at the point is less than 4mV; and the electrode current density remains almost constant over 24 hours under constant voltage, with a very small decrease (e.g., Figure 7 (As shown). The oxygen evolution reaction of the nanoporous bifunctional water-splitting electrode is stable. After 10,000 cycles of CV durability testing, the results of two polarization curve tests largely overlap, indicating no performance degradation. Meanwhile, the 24-hour It curve test results show only a slight potential increase (e.g., ...). Figure 8 (As shown). The above demonstrates the excellent hydrogen evolution and oxygen evolution stability of the nanoporous bifunctional total water electrolytic catalyst.

[0074] (4) Stability test of nanoporous bifunctional water electrolytic catalyst for water electrolysis

[0075] Using a Zahner Zennium electrochemical workstation and the same two-electrode testing system as in (2), the water-splitting stability of the nanoporous bifunctional water-splitting electrocatalyst was tested in 1 mol / L KOH electrolyte. Chronopotentiometry (Et curves) was used, with values ​​of 10, 30, 50, and 100 mA / cm². 2 A 24-hour test was conducted using multiple current densities, and the test results are as follows: Figure 9 As shown, the continuous and stable curves during the 24-hour Et test reflect the excellent catalytic stability of the nanoporous bifunctional water electrolytic catalyst.

[0076] As can be seen from the above embodiments, the highly efficient nanoporous bifunctional water electrolytic catalyst prepared by this invention exhibits high hydrogen and oxygen evolution activity and good stability. When used as the cathode and anode of an electrocatalytic water electrolysis cell, it can achieve stable and efficient complete water electrolysis in an alkaline electrolyte. The method for preparing this catalytic electrode is simple, effective, low-cost, and scalable. The resulting nanoporous structure has a large specific surface area, an increased number of active sites, a regular morphology, stable structure, and excellent performance.

[0077] It should be noted that the above description is only a preferred embodiment of the present invention. The present invention may also have many other specific implementation methods. Those skilled in the art can make various corresponding changes and modifications according to the present invention, and these changes and modifications should also be considered within the scope of protection of the present invention.

[0078] The hydrogen evolution, oxygen evolution, and water electrolysis performance and specific surface area of ​​the nanoporous bifunctional water electrocatalysts prepared in Examples 1 and 2 are shown in Table 1.

[0079] Table 1. Performance parameters of nanoporous bifunctional hydrolysis catalysts prepared with different phosphorus contents.

[0080]

[0081] Note: All data in the table are 10 mA / cm 2 Overpotential at current density.

[0082] As can be seen from Table 1, the nanoporous bifunctional electrocatalysts prepared from alloy strip precursors with different phosphorus contents all have good water-splitting performance and large specific surface area, which proves the universality of the above-mentioned bifunctional catalyst preparation method.

Claims

1. A nanoporous bifunctional total water electrolysis catalyst, characterized in that, The chemical composition of the nanoporous bifunctional total water electrolysis catalyst is: Fe a Co b Ni c Zr d P e , Among them, 10≤a≤13, 22≤b≤25, 20≤c≤23, 24≤d≤28, 11≤e≤24, d+e≥35, a+b+c+d+e=100, and the microstructure is a honeycomb-like multi-level nanoporous structure. The multi-level nanoporous structure is composed of transition metal phosphide TMZrP nanocrystals; The preparation method of the aforementioned nanoporous bifunctional total water electrolysis catalyst includes: Step 1: Prepare the raw materials according to the chemical formula of the precursor, melt them evenly, and make a master alloy. The chemical formula of the precursor is: [(FeNiCo)]. 0.6 Cu 0.3 Zr 0.1 ] 100-x P x Where 0 at.% < x ≤ 10 at.%; Step 2: After melting the master alloy, spray it onto the surface of a rotating copper roller to obtain the alloy strip precursor; Step 3: Add the alloy strip precursor to the etching solution for etching treatment to obtain a nanoporous bifunctional hydrolytic catalyst. The etching solution is prepared by mixing concentrated hydrochloric acid and concentrated nitric acid at a volume ratio of 2.5 to 3.5:

1. The alloy strip precursor is added to an etching solution for etching treatment, and the etching time is 8 to 12 minutes.

2. The nanoporous bifunctional hydrolytic catalyst according to claim 1, characterized in that, The specific surface area of ​​the nanoporous bifunctional hydrolysis catalyst is 15-25 cm². 2 / mg.

3. The nanoporous bifunctional total water electrolysis catalyst according to claim 1, characterized in that, The volume / mass ratio of the etching solution to the precursor is 0.05-0.15 mL / g.

4. The nanoporous bifunctional hydrolytic catalyst according to claim 1, characterized in that, The materials obtained from the batching process are smelted under vacuum, with a vacuum degree of not less than 5 × 10⁻⁶. -3 Pa.

5. The nanoporous bifunctional total water electrolysis catalyst according to claim 1, characterized in that, The rotational speed of the copper roller is 25-35 m / s.

6. The application of a nanoporous bifunctional water electrolytic catalyst as described in any one of claims 1-5 in an alkaline electrolytic cell, characterized in that, The nanoporous bifunctional hydrolytic catalyst is used as the cathode and / or anode of the alkaline electrolytic cell.

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