NiFeMo-based spherical porous composite catalytic material, and preparation method and application thereof

Abstract

The present application relates to a kind of NiFeMo-based spherical porous composite catalytic material and its preparation method and application, belong to electrocatalytic material technical field.The present application is aimed at solving the problems of complex preparation process of existing material, powder is easy to agglomerate, insufficient controllability of morphology and limited continuous preparation capacity.A kind of NiFeMo-based spherical porous composite catalytic material is provided, it is the composite powder containing Ni, Fe, Mo element, presents monodisperse spherical particle, with multi-level porous structure, Ni, Fe, Mo molar ratio is 10:10:(0.5~2);It is prepared by ultrasonic spray pyrolysis one-step method.The electrochemical active surface area of the material of the present application reaches 0.6303 cm 2 , higher than NiFeV (0.3360 cm 2 ) And NiMo (0.1485 cm 2 ) ; Hydrogen evolution driving potential is smaller, charge transfer resistance is lower, and it is suitable for alkaline electrolytic water cathode hydrogen evolution catalyst.

Description

Technical Field

[0001] This invention belongs to the field of electrocatalytic materials technology, and relates to a NiFeMo-based spherical porous composite catalytic material, its preparation method and application. Background Technology

[0002] Hydrogen energy boasts advantages such as wide availability, clean combustion products, and high energy density, making it a crucial secondary energy carrier for achieving a low-carbon energy system. Hydrogen production through water electrolysis is considered a key technological route for producing green hydrogen due to its clean process, high product purity, and compatibility with renewable energy sources. Among these processes, the cathode hydrogen evolution reaction is one of the key half-reactions determining the energy consumption and efficiency of water electrolysis.

[0003] Currently, Pt-based noble metal catalysts remain the best-performing materials for hydrogen evolution reactions, but their scarcity and high cost limit their large-scale industrial application. Therefore, developing low-cost, highly active, and highly stable non-noble metal hydrogen evolution catalysts is of great significance.

[0004] Ni-based composite catalysts exhibit good water molecule dissociation capabilities in alkaline media, making them important non-noble metal HER candidate systems. Existing methods for preparing these materials typically employ hydrothermal, sol-gel, and co-precipitation methods, which often suffer from long process flows, powder agglomeration, difficulty in controlling morphological consistency, and insufficient continuous production capabilities, thus limiting their further application in the field of water electrolysis for hydrogen production. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a NiFeMo-based spherical porous composite catalytic material, its preparation method, and its application in hydrogen production by water electrolysis, so as to solve the problems of complex process, easy agglomeration of powder, insufficient morphology controllability, and limited continuous preparation capability of existing NiFeMo materials, and to improve the exposure degree of active sites and interfacial charge transfer capability of the material in alkaline hydrogen evolution reaction.

[0006] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a NiFeMo-based spherical porous composite catalytic material, wherein the NiFeMo-based spherical porous composite catalytic material is a nickel-iron-molybdenum ternary composite metal compound powder, wherein the NiFeMo-based spherical porous composite catalytic material consists of monodisperse spherical particles with a multi-level porous structure on the surface, and the particle size is 0.5μm-3μm; the molar ratio of Ni, Fe, and Mo in the NiFeMo-based spherical porous composite catalytic material is 10:10:(0.5~2); Preferably, the molar ratio of the three metallic elements Ni, Fe, and Mo is 10:10:1; Preferably, the porous structure of the spherical particles includes mesopores and micropores; Furthermore, the preparation method of the NiFeMo-based spherical porous composite catalytic material includes the following steps: S1: Preparation of precursor solution: Weigh out nickel source, iron source and molybdenum source, dissolve in deionized water, and stir to obtain precursor solution; S2: Ultrasonic spray pyrolysis reaction: The precursor solution is transferred to an ultrasonic spray device, and high-purity nitrogen is used as the carrier gas to send the atomized droplets of the precursor solution into a tubular reactor. The continuous pyrolysis reaction is carried out under an inert atmosphere to obtain the solid product as the NiFeMo-based spherical porous composite catalyst material. Preferably, in step S1, the molar ratio of the nickel source, iron source and molybdenum source is 10:10:1; Preferably, in step S1, the total metal ion concentration of the precursor solution is 1.05 mol / L; Preferably, in step S2, the atomization frequency of the ultrasonic spray device is 1.7 MHz, and the carrier gas flow rate is 0.2~3 L / min; Preferably, in step S2, the heating zone length of the tubular reactor is 50~100 cm, and the precursor solution feed rate is 12~36 mL / h; Preferably, in step S2, the pyrolysis reaction temperature is 800 °C; Furthermore, the NiFeMo-based spherical porous composite catalytic material is used in the electrocatalytic water splitting for hydrogen production, to prepare an alkaline water electrolysis cathode catalytic layer.

[0007] The beneficial effects of this invention are as follows: This invention provides a spherical NiFeMo-based porous composite catalytic material prepared by ultrasonic spray pyrolysis. The ultrasonic spray pyrolysis method has the characteristics of continuous powder preparation, adjustable composition and controllable morphology, and is suitable for the preparation of multi-metal compound powder materials.

[0008] (1) The present invention takes elemental composition, spherical particle morphology and multi-level porous structure as the core protection points. Compared with limiting the material to a single chemical phase, it is more conducive to improving the stability and coverage of the claims.

[0009] (2) The NiFeMo-based spherical porous composite catalytic material provided by the present invention has a spherical morphology and a multi-level porous structure, which is beneficial to increasing the contact interface between the electrolyte and the material, exposing more surface active sites, and helping the desorption and mass transfer of bubbles during hydrogen evolution.

[0010] (3) By introducing three metal elements, Ni, Fe and Mo, this invention constructs a composite system, which is conducive to achieving synergistic control of material composition and structure, improving interfacial charge transfer characteristics and optimizing hydrogen evolution reaction kinetics.

[0011] (4) The present invention uses ultrasonic spray pyrolysis one-step method to prepare target materials. The process is relatively simple and suitable for continuous preparation of powder materials. It has good potential for engineering scale-up.

[0012] (5) Compared with the NiMo and NiFeV comparative materials prepared using the same process, the NiFeMo material of the present invention exhibits a higher electrochemically active surface area (0.6303 cm²). 2 It also exhibits superior overall electrocatalytic performance in hydrogen evolution polarization curves and impedance tests.

[0013] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0014] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein: Figure 1 The image shown is a SEM image of the NiFeMo-based spherical porous composite catalyst prepared in Example 1 of this invention at a magnification of 10,000x, with a scale bar of 10 μm. It is used to demonstrate the overall morphological uniformity and lack of agglomeration of the products prepared in large batches, and to verify the batch stability of the preparation method of this invention.

[0015] Figure 2 This is a SEM image of the NiFeMo-based spherical porous composite catalytic material prepared in Example 1 of the present invention at a magnification of 15,000x, with a scale bar of 5 μm, used to show the overall morphology, monodispersity and particle size distribution range of the material.

[0016] Figure 3 This is a SEM image of the NiFeMo-based spherical porous composite catalytic material prepared in Example 1 of the present invention at a magnification of 50,000x, with a scale bar of 2μm, used to show the complete morphology, particle size uniformity and multi-level porous structure of the spherical particles.

[0017] Figure 4This is a SEM image of the NiFeMo-based spherical porous composite catalytic material prepared in Example 1 of the present invention at a magnification of 60,000x, with a scale bar of 1 μm, used to show the spherical structure, surface nanocrystal arrangement, and mesoporous characteristics of the spherical particles.

[0018] Figure 5 This is a SEM image of the NiFeMo-based spherical porous composite catalytic material prepared in Example 1 of the present invention at a magnification of 80,000x, with a scale bar of 1 μm, used to show the internal porous channels, hierarchical pore structure and mesoporous morphology of the spherical structure of the material.

[0019] Figure 6 This is a SEM image of the NiFeMo-based spherical porous composite catalytic material prepared in Example 1 of the present invention at a magnification of 100,000x, with a scale bar of 1 μm. It is used to show the microstructure of individual spherical particles, the surface rough nanocrystal stacking structure, and the porous characteristics.

[0020] Figure 7 The results show the comparison of the electrochemically active surface area of ​​the materials in Example 1 and Comparative Examples 1-2.

[0021] Figure 8 The results show the comparison of hydrogen evolution polarization curves of the materials in Example 1 and Comparative Examples 1-2.

[0022] Figure 9 The electrochemical impedance spectroscopy comparison results are shown for the materials in Example 1 and Comparative Examples 1-2. Detailed Implementation

[0023] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0024] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0025] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0026] Example 1 The preparation method of NiFeMo-based spherical porous composite catalytic materials includes the following specific steps: (1) Preparation of precursor solution: Accurately weigh the nickel source, iron source and molybdenum source, dissolve them in 180 mL of deionized water, stir until completely dissolved, and then make up to 200 mL with deionized water. Continue stirring for 30 min to obtain a clear and transparent precursor solution, in which the molar ratio of Ni, Fe and Mo is 10:10:1 and the total metal ion concentration is 1.05 mol / L.

[0027] (2) Ultrasonic spray pyrolysis reaction: The above precursor solution was transferred to an ultrasonic spray device, the atomization frequency was set to 1.7 MHz, high-purity nitrogen was used as the carrier gas, and the carrier gas flow rate was set to 0.2 L / min; the atomized droplets were fed into the tubular reactor at a uniform speed, the heating zone of the tubular reactor was 80 cm long, the pyrolysis reaction temperature was 800 ℃, and the precursor solution feed rate was 12 mL / h.

[0028] (3) Product collection: Collect the solid products at the outlet of the reactor to obtain NiFeMo-based spherical porous composite catalyst.

[0029] The morphology of the product prepared in this embodiment was characterized, and the SEM results are as follows: Figures 1 to 6 As shown in the figure. The results indicate that the obtained product is mainly monodisperse spherical particles with no obvious agglomeration; the surface of the spherical particles is rough, formed by the accumulation of nanoscale primary particles, and has a multi-level porous structure. The particle size is consistent with the range of 0.5 μm to 3 μm defined in the claims.

[0030] Comparative Example 1 The NiMo comparative material was prepared using the same ultrasonic spray pyrolysis process as in Example 1, except that the precursor composition was adjusted to a Ni-Mo binary system, and all other process parameters remained the same.

[0031] Comparative Example 2 The NiFeV comparative material was prepared using the same ultrasonic spray pyrolysis process as in Example 1, except that the precursor composition was adjusted to a Ni-Fe-V ternary system, and all other process parameters remained the same.

[0032] Example 2 Electrocatalysis Test and Result Analysis The powdered catalysts obtained in Example 1, Comparative Example 1, and Example 2 were mixed with a conductive agent and a binder, respectively, and an appropriate amount of dispersion medium was added to prepare a uniform catalyst slurry. The slurry was coated onto a nickel foam substrate and dried to obtain a working electrode. Cyclic voltammetry, linear sweep voltammetry, and electrochemical impedance spectroscopy were performed using an alkaline three-electrode system to evaluate the electrochemical active surface area, hydrogen evolution activity, and interfacial charge transfer characteristics of the catalyst.

[0033] Figure 7 The results comparing the electrochemically active surface areas of the three materials are presented. Figure 7 It can be seen that the ECSA of the NiFeMo material is 0.6303 cm⁻¹. 2 This is significantly higher than the 0.3360 cm⁻¹ of NiFeV material. 2 and 0.1485 cm of NiMo material 2 The values ​​are approximately 1.88 times and 4.24 times that of the latter two, respectively. This indicates that NiFeMo materials can expose more surface active sites that can participate in the reaction, and its spherical porous structure and the synergistic effect of the Ni, Fe, and Mo ternary elements are beneficial to increasing the effective reaction area at the electrode / electrolyte interface.

[0034] Figure 8 Hydrogen evolution polarization curves for three materials are presented. Figure 8 It can be seen that, under the same cathode current density, the NiFeMo material has the smallest driving potential; when the current density is close to -10 mA / cm², the driving potential is the smallest. 2 At this time, the required potential for NiFeMo is approximately -1.07 V, which is better than that for NiFeV and NiMo materials, indicating that its hydrogen evolution reaction kinetics are faster and its catalytic activity is higher.

[0035] Figure 9 Electrochemical impedance spectroscopy spectra of three materials are presented. Figure 9 The NiFeMo material exhibits a smaller impedance arc and more favorable low-frequency diffusion response, indicating lower interfacial charge transfer resistance and smoother electron / ion transport. This is consistent with its higher ECSA and superior polarization performance.

[0036] In summary, the NiFeMo-based spherical porous composite catalytic material prepared by ultrasonic spray pyrolysis in one step exhibits superior comprehensive electrocatalytic performance compared to the NiMo and NiFeV comparative materials in the alkaline hydrogen evolution reaction. This indicates that the synergistic introduction of Fe and Mo and the spherical porous structure design can effectively increase the number of active sites and improve charge transfer behavior, thereby enhancing hydrogen evolution performance.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A NiFeMo-based spherical porous composite catalytic material, characterized in that, The NiFeMo-based spherical porous composite catalytic material is a nickel-iron-molybdenum ternary composite metal oxide powder. The NiFeMo-based spherical porous composite catalytic material consists of monodisperse spherical particles with a multi-level porous structure on the surface, and the particle size is 0.5μm-3μm. The molar ratio of Ni, Fe, and Mo in the NiFeMo-based spherical porous composite catalytic material is 10:10:(0.5~2).

2. The NiFeMo-based spherical porous composite catalytic material according to claim 1, characterized in that: The molar ratio of the three metallic elements Ni, Fe, and Mo is 10:10:

1.

3. The NiFeMo-based spherical porous composite catalytic material according to claim 1, characterized in that: The porous structure of the spherical particles includes mesopores and micropores.

4. The method for preparing the NiFeMo-based spherical porous composite catalytic material according to any one of claims 1 to 3, characterized in that, Includes the following steps: S1: Preparation of precursor solution: Weigh out nickel source, iron source and molybdenum source, dissolve in deionized water, and stir to obtain precursor solution; S2: Ultrasonic spray pyrolysis reaction: The precursor solution is transferred to an ultrasonic spray device, and high-purity nitrogen is used as the carrier gas to send the atomized droplets of the precursor solution into a tubular reactor. The continuous pyrolysis reaction is carried out under an inert atmosphere to obtain the solid product as the NiFeMo ternary oxide composite catalyst material.

5. The preparation method according to claim 4, characterized in that, In step S1, the molar ratio of the nickel source, iron source and molybdenum source is 10:10:

1.

6. The preparation method according to claim 4, characterized in that, In step S1, the total metal ion concentration of the precursor solution is 1.05 mol / L.

7. The preparation method according to claim 4, characterized in that, In step S2, the atomization frequency of the ultrasonic spray device is 1.7 MHz, and the carrier gas flow rate is 0.2~3 L / min.

8. The preparation method according to claim 4, characterized in that, In step S2, the heating zone of the tubular reactor is 50-100 cm long, and the precursor solution feed rate is 12-36 mL / h.

9. The preparation method according to claim 4, characterized in that, In step S2, the pyrolysis reaction temperature is 800 °C.

10. The application of the NiFeMo-based spherical porous composite catalytic material according to any one of claims 1 to 3 in electrocatalytic water splitting for hydrogen production.

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