Preparation method of nitrogen-doped carbon-supported bimetallic carbide material and application thereof

Abstract

The application provides a preparation method of a nitrogen-doped carbon-supported bimetallic carbide material, which comprises the following steps: at 0 DEG C, adding a metal salt, a transition metal oxide and a nitrogen-containing polymer monomer into a 0.1 mol / L hydrochloric acid aqueous solution, and performing ultrasonic dispersion to obtain a mixed solution A; at 0 DEG C, adding an initiator aqueous solution into the mixed solution A drop by drop, and performing reaction stirring; collecting solid substances, washing, and performing air blowing drying to obtain a reaction precursor; under a nitrogen atmosphere, performing high-temperature calcination treatment on the reaction precursor to obtain a calcined product; the high-temperature calcination treatment is performed at a temperature increasing rate of 1-10 DEG C / min from room temperature to 50-1000 DEG C, and the temperature is kept constant for 1-8 h, and then the temperature is naturally cooled to room temperature; after washing, the calcined product is subjected to air blowing drying for 12 h to obtain the nitrogen-doped carbon-supported bimetallic carbide material. The application also provides an application of the material in cathode deuterium evolution, anode oxygen evolution and total decomposition of heavy water. The material prepared by the application can be used for electrocatalytic water / heavy water decomposition.

Description

Technical Field

[0001] This invention belongs to the field of electrocatalysis technology, specifically relating to a method for preparing nitrogen-doped carbon-supported bimetallic carbide materials and their applications. Background Technology

[0002] Sustainable energy is a crucial tool for eliminating society's over-reliance on fossil fuels and the excessive carbon emissions resulting from their consumption. However, there is still significant room for improvement in the storage, utilization, and conversion technologies for sustainable energy. Hydrogen, with its ultra-high energy density and zero pollution, has long been widely considered an ideal energy carrier. Producing high-purity green hydrogen through water splitting via electrochemical means is an effective way to convert sustainable energy into clean chemical energy, but this process is limited by the high overpotential in actual reactions and the high cost of commercial catalysts (ruthenium dioxide, iridium dioxide, and platinum).

[0003] In addition, deuterium, as an isotope of hydrogen, has the same properties as hydrogen, but its abundance in the ocean is only 0.0156%. High-purity deuterium gas is usually prepared by electrochemical heavy water decomposition, which is similar to electrochemical water decomposition. It has extremely important applications in industrial and scientific research fields, such as bombarding ions in nuclear accelerators, electronic gas for integrated circuit manufacturing, and tracer for hydrogen reaction mechanisms.

[0004] Ideally, integrating the advantages of both anionic (hydrogen evolution / deuterium evolution reaction) and cation (oxygen evolution reaction) electrocatalysts to design and construct low-cost, high-efficiency bifunctional electrocatalysts for the decomposition of water and heavy water can not only improve system performance but also simplify the system and reduce overall cost. Transition metal-based materials, due to their abundant reserves on Earth and their potential to catalyze hydrogen evolution / deuterium evolution and oxygen evolution reactions, hold promise as alternatives to noble metal catalysts; however, many problems, such as high overpotential and low stability, still need to be addressed. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for preparing nitrogen-doped carbon-supported bimetallic carbide materials and their applications, which address the shortcomings of the prior art. The nitrogen-doped carbon-supported bimetallic carbide materials prepared by this method can be used for electrocatalytic water / heavy water splitting.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for preparing nitrogen-doped carbon-supported bimetallic carbide materials, the method being as follows:

[0007] S1. Under ice bath conditions at 0℃, metal salts, transition metal oxides and nitrogen-containing polymer monomers are added to a 0.1 mol / L hydrochloric acid aqueous solution and ultrasonically dispersed to obtain mixture A.

[0008] S2. Under ice bath conditions at 0℃, the initiator aqueous solution is added dropwise to the mixture A obtained in S1. The reaction is stirred for 12h to 14h. The solid substance is collected, washed successively with deionized water, ethanol, methanol and deionized water, and then dried by blowing air at 40℃ to 80℃ for 6h to obtain the reaction precursor.

[0009] S3. Under a nitrogen atmosphere, the reaction precursor obtained in S2 is subjected to high-temperature calcination to obtain the calcined product. The conditions for the high-temperature calcination are as follows: the temperature is raised from room temperature to 500℃ to 1000℃ at a heating rate of 1℃ / min to 10℃ / min, then kept at a constant temperature for 1h to 8h, and then naturally cooled to room temperature.

[0010] S4. The calcined product obtained in S3 is washed sequentially with deionized water, ethanol, methanol, and deionized water, and then dried by blowing air at a temperature of 40℃~80℃ for 12h to obtain nitrogen-doped carbon-supported bimetallic carbide material.

[0011] Preferably, the ultrasonic dispersion time in S1 is 10 min to 20 min.

[0012] Preferably, the metal salt in S1 is (NH4)6Mo7O 24 ·4H2O, wherein the transition metal oxide is cobalt tetroxide; and the nitrogen-containing polymer monomer is aniline.

[0013] Preferably, the ratio of the metal salt, transition metal oxide and nitrogen-containing polymer monomer is 2.3 mmol: (90-150) mg: 5 mmol.

[0014] Preferably, the initiator aqueous solution in S2 is a 0.6 mol / L ammonium persulfate aqueous solution.

[0015] Preferably, the particle size of the nitrogen-doped carbon-supported bimetallic carbide material in S4 is 2 nm to 8 nm.

[0016] Preferably, the carrier of the nitrogen-doped carbon-supported bimetallic carbide material in S4 is nitrogen-doped carbon, the surface of the nitrogen-doped carbon has a local small spherical morphology, and the interior of the nitrogen-doped carbon is uniformly coated with bimetallic carbide particles with a diameter of 1 nm to 15 nm.

[0017] The present invention also provides the application of the nitrogen-doped carbon-supported bimetallic carbide material prepared by the above preparation method, characterized in that the nitrogen-doped carbon-supported bimetallic carbide material is used in the cathode deuteration, anode oxygen evolution and total decomposition of heavy water reactions.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] 1. This invention provides a method for synthesizing ultra-small, uniformly dispersed homogeneous bimetallic carbide materials on nitrogen-doped carbon supports. On the one hand, it utilizes transition metal oxides and metal salts to prepare highly dispersed active sites to enhance the electrocatalytic activity of hydrogen / deuterium evolution and oxygen evolution reactions. On the other hand, it protects the reactive active sites by using nitrogen-doped carbon supports to reduce the corrosion of the catalyst by the electrolyte and thus enhance stability.

[0020] 2. The nitrogen-doped carbon-supported bimetallic carbide material prepared in this invention has highly dispersed ultra-small bimetallic carbide nanoparticles that increase the electrochemical active area and enhance the electrocatalytic hydrogen / deuterium evolution and oxygen evolution reaction activities; the nitrogen-doped carbon support encapsulates the bimetallic carbide nanoparticles to protect the active sites and increase the stability of the catalytic material in the electrochemical process; compared with heterogeneous bimetallic carbide catalysts, homogeneous bimetallic carbide catalysts are free from unfavorable phase separation, which is more conducive to charge transfer and effective regulation of 3d electronic structure.

[0021] 3. The nitrogen-doped carbon-supported ultra-small bimetallic carbide material prepared in this invention exhibits an overpotential of 220 mV that can reach 50 mA cm⁻¹ during the catalytic electrolysis of water for hydrogen evolution. -2 The current density; during the catalytic oxygen evolution reaction, the overpotential can reach 50 mA cm⁻¹ at 319 mV. -2 The material can achieve a current density of 50 mA / cm² in the catalytic electrolysis of deuterium from heavy water with only 235 mV. -2 The current density is such that only 327mV is needed to achieve 50mA / cm² in the oxygen evolution reaction. -2 The current density is higher than that of most transition metal-based electrolytic water / heavy water catalysts, and the above performance is superior to that of most transition metal-based electrolytic water / heavy water catalysts. It also has the potential for large-scale production and good application prospects.

[0022] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. Attached Figure Description

[0023] Figure 1 This is a scanning electron microscope image of the nitrogen-doped carbon-supported ultra-small bimetallic carbide material obtained in Example 1.

[0024] Figure 2 This is a transmission electron microscope (TEM) image of the nitrogen-doped carbon-supported ultra-small bimetallic carbide material obtained in Example 1.

[0025] Figure 3 The images show the XRD patterns of the nitrogen-doped carbon-supported ultra-small bimetallic carbide materials obtained in Examples 1-3 and the nitrogen-doped carbon-supported ultra-small molybdenum carbide and nitrogen-doped carbon-supported cobalt elemental materials prepared in Comparative Examples 1-2.

[0026] Figure 4The linear sweep voltammetry curves of the nitrogen-doped carbon-supported ultra-small bimetallic carbide materials obtained in Examples 1-3 and the nitrogen-doped carbon-supported ultra-small molybdenum carbide materials and nitrogen-doped carbon-supported cobalt elemental materials prepared in Comparative Examples 1-2 during the hydrogen evolution reaction in water electrolysis are shown.

[0027] Figure 5 The linear sweep voltammetry curves of the nitrogen-doped carbon-supported ultra-small bimetallic carbide materials obtained in Examples 1-3 and the nitrogen-doped carbon-supported ultra-small molybdenum carbide materials and nitrogen-doped carbon-supported cobalt elemental materials prepared in Comparative Examples 1-2 during the oxygen evolution reaction in water electrolysis are shown.

[0028] Figure 6 The linear sweep voltammetry curves of the nitrogen-doped carbon-supported ultra-small bimetallic carbide materials obtained in Examples 1-3 and the nitrogen-doped carbon-supported ultra-small molybdenum carbide materials and nitrogen-doped carbon-supported cobalt elemental materials prepared in Comparative Examples 1-2 during the deuterium precipitation reaction in electrolytic heavy water are shown.

[0029] Figure 7 Linear sweep voltammetry measurement curves of nitrogen-doped carbon-supported ultra-small bimetallic carbide materials obtained in Examples 1-3 and nitrogen-doped carbon-supported ultra-small molybdenum carbide materials and nitrogen-doped carbon-supported cobalt elemental materials prepared in Comparative Examples 1-2 during the oxygen evolution reaction of electrolytic heavy water.

[0030] Figure 8 The linear sweep voltammetry curves of nitrogen-doped carbon-supported ultra-small bimetallic carbide materials obtained in Examples 1-3 and nitrogen-doped carbon-supported ultra-small molybdenum carbide materials and nitrogen-doped carbon-supported cobalt elemental materials prepared in Comparative Examples 1-2 are obtained in water.

[0031] Figure 9 The linear sweep voltammetry curves of nitrogen-doped carbon-supported ultra-small bimetallic carbide materials obtained in Examples 1-3 and nitrogen-doped carbon-supported ultra-small molybdenum carbide materials and nitrogen-doped carbon-supported cobalt elemental materials prepared in Comparative Examples 1-2 in decomposed heavy water are shown. Detailed Implementation

[0032] Example 1

[0033] The method for preparing nitrogen-doped carbon-supported ultrasmall bimetallic carbide materials in this embodiment is as follows:

[0034] S1. Under ice bath conditions at 0℃, 2.3 mmol of metal salt ((NH4)6Mo7O) was added. 24·4H2O (2.84 g), 0.500 mol transition metal oxide (cobalt tetroxide, 120 mg) and nitrogen-containing polymer monomer (aniline, 5 mmol) were added to 300 mL of 0.1 mol / L hydrochloric acid aqueous solution and ultrasonically dispersed for 15 min until uniform dispersion was obtained to obtain mixture A.

[0035] S2. Under ice bath conditions at 0℃, 10 mL of initiator aqueous solution (0.6 mol / L ammonium persulfate aqueous solution) was added dropwise to the mixture A obtained in S1. The reaction was stirred for 12 h, the solid substance was collected, and washed successively with deionized water, ethanol, methanol and deionized water. Then, it was dried by blowing air at 60℃ for 6 h to obtain the reaction precursor.

[0036] S3. Under a nitrogen atmosphere, the reaction precursor obtained in S2 is subjected to high-temperature calcination to obtain the calcined product. The conditions for the high-temperature calcination are as follows: the temperature is raised from room temperature to 750°C at a heating rate of 5°C / min, then kept at a constant temperature for 2 hours, and then naturally cooled to room temperature.

[0037] S4. The calcined product obtained in S3 was washed sequentially with deionized water, ethanol, methanol, and deionized water, and then dried in a forced-air dryer at 60°C for 12 hours to obtain a nitrogen-doped carbon-supported bimetallic carbide material with a particle size of 2nm to 8nm (containing 120mg of cobalt, denoted as CoMoC-120).

[0038] This embodiment also provides the application of the nitrogen-doped carbon-supported ultra-small bimetallic carbide material prepared by the above preparation method, and the application of the nitrogen-doped carbon-supported ultra-small bimetallic carbide material in the cathode deuteration, anode oxygen evolution and total decomposition of heavy water reactions.

[0039] Example 2

[0040] The method for preparing nitrogen-doped carbon-supported ultrasmall bimetallic carbide materials in this embodiment is as follows:

[0041] S1. Under ice bath conditions at 0℃, 2.3 mmol of metal salt ((NH4)6Mo7O) was added. 24 ·4H2O (2.84 g), 0.375 mol of transition metal oxide (cobalt tetroxide, 90 mg) and nitrogen-containing polymer monomer (aniline, 5 mmol) were added to 300 mL of 0.1 mol / L hydrochloric acid aqueous solution and ultrasonically dispersed for 15 min until uniformly dispersed to obtain mixture A.

[0042] S2. Under ice bath conditions at 0℃, 10 mL of initiator aqueous solution (0.6 mol / L ammonium persulfate aqueous solution) was added dropwise to the mixture A obtained in S1. The reaction was stirred for 13 h, the solid substance was collected, and washed successively with deionized water, ethanol, methanol and deionized water. Then, it was dried by blowing air at 80℃ for 6 h to obtain the reaction precursor.

[0043] S3. Under a nitrogen atmosphere, the reaction precursor obtained in S2 is subjected to high-temperature calcination to obtain the calcined product. The conditions for the high-temperature calcination are as follows: the temperature is raised from room temperature to 500℃ at a heating rate of 1℃ / min, then kept at a constant temperature for 8 hours, and then naturally cooled to room temperature.

[0044] S4. The calcined product obtained in S3 is washed sequentially with deionized water, ethanol, methanol, and deionized water, and then dried in a forced-air dryer at 80℃ for 12 hours to obtain a nitrogen-doped carbon-supported bimetallic carbide material with a particle size of 2nm to 8nm (containing 90mg of cobalt, denoted as CoMoC-90).

[0045] This embodiment also provides the application of the nitrogen-doped carbon-supported ultra-small bimetallic carbide material prepared by the above preparation method, and the application of the nitrogen-doped carbon-supported ultra-small bimetallic carbide material in the cathode deuteration, anode oxygen evolution and total decomposition of heavy water reactions.

[0046] Example 3

[0047] The method for preparing nitrogen-doped carbon-supported ultrasmall bimetallic carbide materials in this embodiment is as follows:

[0048] S1. Under ice bath conditions at 0℃, 2.3 mmol of metal salt ((NH4)6Mo7O) was added. 24 ·4H2O (2.84 g), 0.625 mol of transition metal oxide (cobalt tetroxide, 150 mg) and nitrogen-containing polymer monomer (aniline, 5 mmol) were added to 300 mL of 0.1 mol / L hydrochloric acid aqueous solution and ultrasonically dispersed for 15 min until uniform dispersion was obtained to obtain mixture A.

[0049] S2. Under ice bath conditions at 0℃, 10 mL of initiator aqueous solution (0.6 mol / L ammonium persulfate aqueous solution) was added dropwise to the mixture A obtained in S1. The reaction was stirred for 14 h, the solid substance was collected, and washed successively with deionized water, ethanol, methanol and deionized water. Then, it was dried by blowing air at 40℃ for 6 h to obtain the reaction precursor.

[0050] S3. Under a nitrogen atmosphere, the reaction precursor obtained in S2 is subjected to high-temperature calcination to obtain the calcined product. The conditions for the high-temperature calcination are as follows: the temperature is raised from room temperature to 1000℃ at a heating rate of 10℃ / min, then kept at a constant temperature for 1 hour, and then naturally cooled to room temperature.

[0051] S4. The calcined product obtained in S3 is washed sequentially with deionized water, ethanol, methanol, and deionized water, and then dried in a forced-air dryer at 40°C for 12 hours to obtain a nitrogen-doped carbon-supported bimetallic carbide material with a particle size of 2nm to 8nm (containing 150mg of cobalt, denoted as CoMoC-150).

[0052] This embodiment also provides the application of the nitrogen-doped carbon-supported ultra-small bimetallic carbide material prepared by the above preparation method, and the application of the nitrogen-doped carbon-supported ultra-small bimetallic carbide material in the cathode deuteration, anode oxygen evolution and total decomposition of heavy water reactions.

[0053] Comparative Example 1

[0054] The comparative example demonstrates a method for preparing nitrogen-doped carbon-supported ultrasmall molybdenum carbide materials, which is as follows:

[0055] S1. Under ice bath conditions at 0℃, 2.3 mmol of metal salt ((NH4)6Mo7O) was added. 24 ·4H2O (2.84 g) and nitrogen-containing polymer monomer (aniline, 5 mmol) were added to 300 mL of 0.1 mol / L hydrochloric acid aqueous solution and ultrasonically dispersed for 15 min until uniform dispersion was obtained to obtain mixture A;

[0056] S2. Under ice bath conditions at 0℃, 10 mL of initiator aqueous solution (0.6 mol / L ammonium persulfate aqueous solution) was added dropwise to the mixture A obtained in S1. The reaction was stirred for 12 h, the solid substance was collected, and washed successively with deionized water, ethanol, methanol and deionized water. Then, it was dried by blowing air at 60℃ for 6 h to obtain the reaction precursor.

[0057] S3. Under a nitrogen atmosphere, the reaction precursor obtained in S2 is subjected to high-temperature calcination to obtain the calcined product. The conditions for the high-temperature calcination are as follows: the temperature is raised from room temperature to 750°C at a heating rate of 5°C / min, then kept at a constant temperature for 2 hours, and then naturally cooled to room temperature.

[0058] S4. The calcined product obtained in S3 is washed sequentially with deionized water, ethanol, methanol, and deionized water, and then dried in a forced-air dryer at 60°C for 12 hours to obtain a nitrogen-doped carbon-supported bimetallic carbide material with a particle size of 2nm to 8nm (denoted as Mo2C).

[0059] Comparative Example 2

[0060] The preparation method of the nitrogen-doped carbon-supported cobalt elemental material in this comparative example is as follows:

[0061] S1. Under ice bath conditions at 0℃, 0.500 mol of transition metal oxide (cobalt tetroxide, 120 mg) and nitrogen-containing polymer monomer (aniline, 5 mmol) were added to 300 mL of 0.1 mol / L hydrochloric acid aqueous solution and ultrasonically dispersed for 15 min until uniformly dispersed to obtain mixture A.

[0062] S2. Under ice bath conditions at 0℃, 10 mL of initiator aqueous solution (0.6 mol / L ammonium persulfate aqueous solution) was added dropwise to the mixture A obtained in S1. The reaction was stirred for 12 h, the solid substance was collected, and washed successively with deionized water, ethanol, methanol and deionized water. Then, it was dried by blowing air at 60℃ for 6 h to obtain the reaction precursor.

[0063] S3. Under a nitrogen atmosphere, the reaction precursor obtained in S2 is subjected to high-temperature calcination to obtain the calcined product. The conditions for the high-temperature calcination are as follows: the temperature is raised from room temperature to 750°C at a heating rate of 5°C / min, then kept at a constant temperature for 2 hours, and then naturally cooled to room temperature.

[0064] S4. The calcined product obtained in S3 is washed sequentially with deionized water, ethanol, methanol, and deionized water, and then dried in a forced-air dryer at 60°C for 12 hours to obtain nitrogen-doped carbon-supported cobalt particles with a particle size of 2nm to 8nm (denoted as Co).

[0065] In this invention, highly dispersed ultra-small bimetallic carbide nanoparticles increase the electrochemical active area, enhancing the electrocatalytic activity of hydrogen / deuterium evolution and oxygen evolution reactions. Nitrogen-doped carbon supports encapsulate the bimetallic carbide nanoparticles, protecting the active sites and increasing the stability of the catalytic material during electrochemical processes. Compared to heterogeneous bimetallic carbide catalysts (where the two metal elements exist as different substances), homogeneous bimetallic carbide catalysts (where the two metal elements exist as the same substance) are free from unfavorable phase separation, making them more conducive to charge transfer and effective regulation of the 3d electronic structure. The product of this invention, cobalt-molybdenum carbide Co6Mo6C2, is a homogeneous bimetallic carbide.

[0066] The nitrogen-doped carbon-supported ultra-small bimetallic carbide materials (CoMoC-120, CoMoC-90, CoMoC-150) prepared in Examples 1-3 of this invention, and the nitrogen-doped carbon-supported ultra-small molybdenum carbide material (Mo2C) and nitrogen-doped carbon-supported cobalt elemental material (Co) prepared in Comparative Examples 1-2 were used as catalysts for the electrochemical water splitting cathode (hydrogen evolution) and anodic (oxygen evolution) reactions, and the heavy water splitting cathode (deuterium evolution) and anodic (oxygen evolution) reactions. The testing system was a three-electrode system, with an Hg / HgO electrode as the reference electrode, a graphite rod as the counter electrode, and a rotating disk electrode as the working electrode (material loading of 0.10 mg / cm³). -2 The electrolyte was 1.0 M KOH solution; the reaction temperature was 20℃.

[0067] Figure 1 The image shown is a scanning electron microscope (SEM) image of the nitrogen-doped carbon-supported ultrasmall bimetallic carbide material obtained in Example 1. Figure 1 It can be seen that the prepared catalyst has an irregular, tightly packed spherical structure.

[0068] Figure 2 The image shown is a transmission electron microscope (TEM) image of the nitrogen-doped carbon-supported ultrasmall bimetallic carbide material obtained in Example 1. Figure 2 It is known that the particle diameter of the nitrogen-doped carbon-supported bimetallic carbide catalyst is 2nm to 8nm, with an average diameter of 4.6nm.

[0069] Figure 3 The XRD patterns of the nitrogen-doped carbon-supported ultrasmall bimetallic carbide materials obtained in Examples 1-3, and the nitrogen-doped carbon-supported ultrasmall molybdenum carbide and nitrogen-doped carbon-supported cobalt elemental materials prepared in Comparative Examples 1-2 are shown below. Figure 3 It is known that the characteristic peaks at 42.4°, 39.9°, and 46.4° appearing in CoMoC-120, CoMoC-90, and CoMoC-150 correspond to the (511), (422), and (440) crystal planes of Co6Mo6C2 (JCPDS No. 80-0339). In the results for Mo2C, the characteristic peaks at 39.5°, 38.1°, and 34.5° correspond to the (121), (200), and (021) crystal planes of Mo2C (JCPDS No. 72-1683). In the sample Co, the peak intensities at 44.2°, 51.5°, and 75.9° belong to the (111), (200), and (220) crystal planes of Co (JCPDS No. 15-0806). The phase compositions of the examples and comparative examples were determined.

[0070] Figure 4The linear sweep voltammetry curves of the nitrogen-doped carbon-supported ultrasmall bimetallic carbide materials obtained in Examples 1-3 and the nitrogen-doped carbon-supported ultrasmall molybdenum carbide and nitrogen-doped carbon-supported cobalt elemental materials prepared in Comparative Examples 1-2 during the hydrogen evolution reaction in water electrolysis are shown below. Figure 4 It can be seen that when Co and Mo exist alone to form a Co and Mo2C catalyst, the catalyst reaches 10 mAcm. -2 The required overpotentials for the current are 234 mV and 235 mV, respectively. When Co and Mo form the bimetallic carbide Co6Mo6C2, CoMoC-90 reaches 10 mAcm. -2 The required overpotential during current transfer is reduced to 205mV. Furthermore, CoMoC-120 achieves 10mAcm. -2 The required overpotential during current flow is further reduced to 138mV. Meanwhile, in CoMoC-150, 10mAcm is achieved. -2 The required overpotential for current is 172mV.

[0071] Figure 5 The linear sweep voltammetry curves of the nitrogen-doped carbon-supported ultrasmall bimetallic carbide materials obtained in Examples 1-3 and the nitrogen-doped carbon-supported ultrasmall molybdenum carbide materials and nitrogen-doped carbon-supported cobalt elemental materials prepared in Comparative Examples 1-2 during the oxygen evolution reaction in water electrolysis are shown below. Figure 5 It can be seen that the catalyst Mo2C reaches 10 mAcm -2 The required overpotential for current is 475mV, while the Co catalyst reaches 10mAcm. -2 The required overpotential at current is 439 mV. Catalysts CoMoC-90 and CoMoC-150 achieve an overpotential of 10 mA cm⁻¹. -2 The required overpotentials for current applications are 348mV and 310mV, respectively. Furthermore, CoMoC-120 performs best, achieving 10mAcm. -2 The required overpotential for current is 266mV.

[0072] Figure 6 The linear sweep voltammetry curves of the nitrogen-doped carbon-supported ultrasmall cobalt-molybdenum bimetallic carbide materials obtained in Examples 1-3, and the nitrogen-doped carbon-supported ultrasmall molybdenum carbide materials and nitrogen-doped carbon-supported cobalt elemental materials prepared in Comparative Examples 1-2, in the deuterium precipitation reaction of electrolytic heavy water are shown below. Figure 6 It can be seen that the performance of each catalyst is related to Figure 4 The behavior is similar; when Co and Mo are present alone to form Co and Mo2C catalysts, the efficiency reaches 10 mA / cm². -2 The required overpotentials for current are 249 mV and 241 mV, respectively. When Co and Mo form the bimetallic carbide Co6Mo6C2, CoMoC-90 reaches 10 mAcm.-2 The required overpotential during current flow is reduced to 218 mV. Furthermore, CoMoC-120 achieves 10 mAcm. -2 The required overpotential during current flow is further reduced to 150mV. Meanwhile, in CoMoC-150, 10mAcm is achieved. -2 The required overpotential for current is 171mV.

[0073] Figure 7 The linear sweep voltammetry curves of the nitrogen-doped carbon-supported ultrasmall bimetallic carbide materials obtained in Examples 1-3 and the nitrogen-doped carbon-supported ultrasmall molybdenum carbide materials and nitrogen-doped carbon-supported cobalt elemental materials prepared in Comparative Examples 1-2 during the oxygen evolution reaction in the electrolysis of heavy water are shown below. Figure 7 It can be seen that the catalyst Mo2C reaches 10 mAcm -2 The required overpotential for current is 475mV, while the Co catalyst reaches 10mAcm. -2 The required overpotential at current is 369 mV. Catalysts CoMoC-90 and CoMoC-150 achieve an overpotential of 10 mA cm⁻¹. -2 The required overpotentials for current applications are 352mV and 316mV, respectively. Furthermore, CoMoC-120 exhibits the best performance, reaching 10mAcm. -2 The required overpotential for current is 273mV.

[0074] Figure 8 The linear sweep voltammetry curves of the nitrogen-doped carbon-supported ultrasmall bimetallic carbide materials obtained in Examples 1-3 and the nitrogen-doped carbon-supported ultrasmall molybdenum carbide and nitrogen-doped carbon-supported cobalt elemental materials prepared in Comparative Examples 1-2 are shown below in the water splitting method. Figure 8 It can be seen that in the process of electrocatalytic water splitting, when the current density reaches 20 mA / cm², -2 At that time, the required voltage is 1.587V (i.e., the overpotential is 357mV), and the current density reaches 50mAcm. -2 At that time, the required voltage is 1.648V (i.e., the overpotential is 418mV).

[0075] Figure 9 The linear sweep voltammetry curves of the nitrogen-doped carbon-supported ultrasmall bimetallic carbide materials obtained in Examples 1-3 and the nitrogen-doped carbon-supported ultrasmall molybdenum carbide and nitrogen-doped carbon-supported cobalt elemental materials prepared in Comparative Examples 1-2 in decomposed heavy water are shown below. Figure 9 It can be seen that in the process of electrocatalytic water splitting, when the current density reaches 20 mA / cm², -2 At that time, the required voltage is 1.587V (i.e., the overpotential is 365mV), and the current density reaches 50mAcm. -2 At that time, the required voltage is 1.648V (i.e., the overpotential is 424mV).

[0076] Experimental results show that the nitrogen-doped carbon-supported ultra-small cobalt-molybdenum bimetallic carbide material provided by this invention can achieve an overpotential of 50 mAcm at 220 mV during the catalytic electrolysis of water for hydrogen evolution. -2 The current density; during the catalytic oxygen evolution reaction, the overpotential can reach 50 mA cm⁻¹ at 319 mV. -2 The material can achieve a current density of 50 mA / cm² in the catalytic electrolysis of deuterium from heavy water with only 235 mV. -2 The current density is such that only 327mV is needed to achieve 50mA / cm² in the oxygen evolution reaction. -2 The current density is higher than that of most transition metal-based electrolytic water / heavy water catalysts, and the above performance is superior to that of most transition metal-based electrolytic water / heavy water catalysts. It also has the potential for large-scale production and good application prospects.

[0077] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Any simple modifications, alterations, and equivalent changes made to the above embodiments based on the inventive essence shall still fall within the protection scope of the present invention.

Claims

1. An application of a nitrogen-doped carbon-supported bimetallic carbide material, characterized in that, The application of the nitrogen-doped carbon-supported bimetallic carbide material in the cathode deuteration, anode oxygen evolution, and total heavy water decomposition reactions of electrolytic heavy water, and the preparation method of the nitrogen-doped carbon-supported bimetallic carbide material are as follows: S1. Under ice bath conditions at 0℃, metal salts, transition metal oxides and nitrogen-containing polymer monomers are added to a 0.1 mol / L hydrochloric acid aqueous solution and ultrasonically dispersed to obtain mixture A. The metal salt in S1 is (NH4)6Mo7O 24 ·4H2O; the transition metal oxide is cobalt tetroxide; the nitrogen-containing polymer monomer is aniline; the ratio of the metal salt, transition metal oxide and nitrogen-containing polymer monomer is 2.3 mmol: (90-150) mg: 5 mmol; S2. Under ice bath conditions at 0℃, the initiator aqueous solution is added dropwise to the mixture A obtained in S1. The reaction is stirred for 12-14 hours. The solid substance is collected and washed successively with deionized water, ethanol, methanol and deionized water. Then, it is dried by blowing air at 40℃-80℃ for 6 hours to obtain the reaction precursor. The initiator aqueous solution mentioned in S2 is a 0.6 mol / L ammonium persulfate aqueous solution. S3. Under a nitrogen atmosphere, the reaction precursor obtained in S2 is subjected to high-temperature calcination to obtain the calcined product. The conditions for the high-temperature calcination are as follows: the temperature is raised from room temperature to 500℃ to 1000℃ at a heating rate of 1℃ / min to 10℃ / min, then kept at a constant temperature for 1h to 8h, and then naturally cooled to room temperature. S4. The calcined product obtained in S3 is washed sequentially with deionized water, ethanol, methanol, and deionized water, and then dried by blowing air at a temperature of 40℃~80℃ for 12h to obtain nitrogen-doped carbon-supported bimetallic carbide material; the particle size of the nitrogen-doped carbon-supported bimetallic carbide material in S4 is 2nm~8nm.

2. The application of the nitrogen-doped carbon-supported bimetallic carbide material according to claim 1, characterized in that, The ultrasonic dispersion time in S1 is 10 min to 20 min.

3. The application of the nitrogen-doped carbon-supported bimetallic carbide material according to claim 1, characterized in that, The nitrogen-doped carbon-supported bimetallic carbide material described in S4 is supported by nitrogen-doped carbon. The surface of the nitrogen-doped carbon has a local spherical morphology, and the interior of the nitrogen-doped carbon is uniformly coated with bimetallic carbide particles with a diameter of 1 nm to 15 nm.

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