CN116575045A

CN116575045A - MEA water splitting device applied to water splitting catalysis and preparation method thereof

Info

Publication number: CN116575045A
Application number: CN202310860946.4A
Authority: CN
Inventors: 孙立成; 丁仕文
Original assignee: Westlake University
Current assignee: Westlake University
Priority date: 2023-07-14
Filing date: 2023-07-14
Publication date: 2023-08-11
Anticipated expiration: 2043-07-14
Also published as: CN116575045B

Abstract

The application discloses an MEA water splitting device applied to water splitting catalysis and a preparation method thereof, wherein the water splitting device comprises a nickel screen lamination and MEA equipment, and the nickel screen lamination is placed in the MEA equipment; the nickel screen is laminated with 2 layers, one layer is a 60-mesh nickel screen, and the other layer is a 300-mesh nickel screen; the preparation method comprises the following steps: putting a nickel screen into a beaker; pouring pure HCl solution, completely immersing a nickel screen, covering a sealing film, and putting the nickel screen into an ultrasonic cleaner for cleaning until the color of the solution changes from colorless to blue-green; the acid treated web is then washed with water and ethanol to remove any unwanted debris and grease; secondly, completely aligning the two nickel screens after treatment, and then placing the nickel screens into a tablet press to make nickel screen lamination; finally, the nickel mesh stack was placed into an MEA apparatus. Based on the design, the application realizes the technical effect of promoting water decomposition while protecting the anion exchange membrane in the assembly process of the MEA water decomposition device.

Description

MEA water splitting device applied to water splitting catalysis and preparation method thereof

Technical Field

The application relates to the field of water splitting, in particular to an MEA water splitting device applied to water splitting catalysis and a preparation method thereof.

Background

Water splitting catalysts are materials that can facilitate the water splitting process to produce oxygen and hydrogen, membrane electrode assembly MEA is a key component of many electrochemical devices, and mass transfer limitations are key factors affecting the performance and efficiency of MEA water splitting devices that use OER catalysts to produce hydrogen and oxygen from water. Existing OER catalysts, while better promoting water decomposition, are mostly rare and expensive elements such as iridium, platinum and ruthenium, which also results in higher production costs of OER catalysts and limits their scalability in large-scale commercial applications.

Researchers have found and synthesized a range of new materials for OER catalysts, such as metal oxides, perovskites, and metal-organic frameworks, which have high catalytic activity, stability, and selectivity, and can be tuned by doping, surface modification, and other methods to further enhance their performance.

The preparation method of the porous nickel screen electrolytic water catalytic material comprises the following steps: step 1, in a two-electrode system, an electrolyte is arranged in an electrolytic tank, a pretreated commercial nickel screen is used as a working electrode, a platinum sheet is used as a counter electrode, and after current is applied, a nickel nano particle layer is loaded on the commercial nickel screen by using an electrodeposition method, so that the commercial nickel screen with the nickel nano particle layer is obtained; and 2, taking the commercial nickel screen loaded with the nickel nanoparticle layer in the step 1 out of the electrolytic tank, and washing and naturally drying to obtain the porous nickel screen electrolytic water catalytic material. The porous nickel screen electrolytic water catalytic material prepared by the method has higher catalytic activity, can effectively improve the electrolytic water efficiency and reduce the energy consumption, thereby greatly reducing the cost of hydrogen production by water electrolysis, but can reduce the mechanical property of the anion exchange membrane due to higher surface roughness of the nickel screen.

Efficient water splitting requires rapid transport of reactant, product and electrolyte ions between the various components of the MEA, mass transfer limitations can result in poor performance and reduced efficiency of the water splitting process, and OER catalyst activity and effectiveness can also be limited due to poor mass transfer. For example, if the reactants do not reach the catalyst surface fast enough, the OER reaction may not proceed efficiently, resulting in lower hydrogen production rates. Secondly the membrane properties in the MEA are also affected by mass transfer limitations. For example, if the reactants and products do not diffuse through the membrane fast enough, this can impair the membrane performance and reduce the efficiency of the water splitting process. Finally, mass transfer limitations can also lead to localized concentration gradients and uneven current densities, which in turn can lead to uneven wear of the MEA components, ultimately leading to reduced durability and service life of the device.

A preparation method of a self-supporting three-dimensional porous structure bifunctional catalytic electrode, as disclosed in Chinese patent CN 110205636A. The preparation of the dual-function catalytic electrode is to prepare three-dimensional porous nickel by electro-deposition in aqueous solution of nickel chloride and ammonium chloride under normal temperature and normal pressure by taking nickel screen as a cathode and inert conductor as an anode; then taking the obtained nickel screen as an electrodeposited cathode, using an inert conductor as an anode, immersing the nickel screen into an aqueous solution containing nickel nitrate, ferrous sulfate and ethylene glycol, and performing electrodepositing treatment under normal temperature and normal pressure conditions to obtain a nickel-iron/nickel catalytic electrode with a porous hierarchical structure; the electrode with large effective active area, bubble precipitation channel and excellent conductivity is obtained through two-step electrodeposition, and excellent electrochemical hydrogen evolution and oxygen evolution performance is shown under alkaline conditions, but the surface roughness of the nickel-iron/nickel catalytic electrode is reduced on the contrary due to the porous hierarchical structure.

Because the nickel screen in the existing OER catalyst has a rough surface, the mechanical property of the anion exchange membrane can be reduced, the function of protecting the anion exchange membrane can not be achieved in the assembly of the MEA water splitting device, and at the moment, a new water splitting device and a preparation method thereof are urgently needed to be designed so as to solve the problem of mass transfer under high current and realize the effect of protecting the anion exchange membrane.

Disclosure of Invention

Aiming at the problem that the surface of a nickel screen in an OER catalyst is rough, so that the mechanical property of an anion exchange membrane is reduced, the application designs an MEA water splitting device applied to water splitting catalysis and a preparation method thereof, so as to realize the effect of protecting the anion exchange membrane and promoting water splitting in the assembly process of the MEA water splitting device.

An MEA water splitting device applied to water splitting catalysis comprises a nickel screen lamination and an MEA device, wherein the nickel screen lamination is placed in the MEA device;

the nickel screen lamination comprises two layers of nickel screens with different pores.

Preferably, the nickel mesh stack comprises 60 mesh nickel mesh and 300 mesh nickel mesh.

Preferably, the length of the two layers of nickel screens is 0.5-2 cm, and the width of the two layers of nickel screens is 0.5-2 cm.

Preferably, the area of the nickel screen lamination is 1 cm ² 。

The preparation method of the MEA water splitting device applied to water splitting catalysis comprises the following steps:

s1, placing an industrial pure nickel screen with the mesh number of 60 and an industrial pure nickel screen with the mesh number of 300 into a beaker;

s2, pouring the pure HCl solution into a beaker to fully submerge the nickel screen;

step S3, covering a sealing film on the beaker to prevent evaporation or overflow of the HCl solution, and then putting the beaker into an ultrasonic cleaner for cleaning until the color of the solution changes from colorless to blue-green;

step S4, washing the acid treated web with water and ethanol to remove any unwanted debris and grease;

and S5, completely aligning the two processed nickel screens, and then placing the nickel screens into a tablet press to make nickel screen lamination.

Step S6, placing the nickel screen lamination into an MEA device.

Preferably, the pure HCl solution in step S2 is a 3 mol HCl solution.

Preferably, in the step S3, the cleaning time is 1-3 hours.

Preferably, in the step S5, the pressure applied by the tablet press is 10 MPa.

Preferably, in the step S5, both nickel screens have a length of 1 cm and a width of 1 cm.

Preferably, a film is further arranged on the outer side of the 300-mesh nickel screen.

The beneficial effects obtained by the application are as follows:

1. due to the unique pointed surface structure of nickel foam, such surface perforations weaken the anion exchange membrane, and breakage of the anion exchange membrane is a very common problem during conventional MEA assembly, which severely reduces MEA stability, thereby impeding the industrialization of water electrolysis using MEA. The application designs an MEA water splitting device applied to water splitting catalysis, which designs a nickel screen lamination, namely a double-layer nickel screen for physical high-pressure treatment, wherein the nickel screen lamination has a smooth plane, and the problem of membrane breakage of the MEA in the installation process is avoided.

2. The application relates to an MEA water splitting device applied to water splitting catalysis, wherein a membrane|300|60 anode catalyst is selected and placed in the MEA water splitting device, and the membrane|300|60 anode catalyst has the most excellent water splitting catalysis performance.

3. The nickel screen stack designed according to the present application may also be used as a substrate where the growing nickel iron catalyst may increase the performance of the hydrolysis by modifying mass transfer.

The foregoing description is only an overview of the present application, and is intended to provide a better understanding of the technical means of the present application, so that the present application may be practiced according to the teachings of the present specification, and so that the above-mentioned and other objects, features and advantages of the present application may be better understood, and the following detailed description of the preferred embodiments of the present application will be presented in conjunction with the accompanying drawings.

The above and other objects, advantages and features of the present application will become more apparent to those skilled in the art from the following detailed description of the specific embodiments of the present application when taken in conjunction with the accompanying drawings.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art. Like elements or portions are generally identified by like reference numerals throughout the several figures. In the drawings, elements or portions thereof are not necessarily drawn to scale.

FIG. 1 is a side view of a nickel screen stack provided by the present application;

FIG. 2 is a diagram showing the comparison of mass transfer effects of a monocular nickel screen provided by the application;

FIG. 3 is a front SEM image of 300 mesh and 60 mesh nickel screen stacks provided by the present application;

FIG. 4 is a reverse side SEM image of 300 mesh and 60 mesh nickel screen stacks provided by the present application;

FIG. 5 is a graph showing the performance of different types of nickel screens provided by the application;

FIG. 6 is a graph showing the comparison of the effects of 300 mesh nickel screen, 60 mesh nickel screen and combinations thereof;

FIG. 7 is a graph showing the distribution time of bubbles generated by different types of nickel screens according to the present application;

FIG. 8 is a comparative graph of the literature provided by the present application;

FIG. 9 is a graph illustrating the performance of the nickel screen 300|60 under various pressures provided by the present application;

FIG. 10 is a SEM image of 300|60 of a nickel screen under various pressures provided by the present application.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application. In the following description, specific details such as specific configurations and components are provided merely to facilitate a thorough understanding of embodiments of the application. It will therefore be apparent to those skilled in the art that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the application. In addition, descriptions of well-known functions and constructions are omitted in the embodiments for clarity and conciseness.

It should be appreciated that reference throughout this specification to "one embodiment" or "this embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Thus, the appearances of the "one embodiment" or "this embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

Furthermore, the present application may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.

The term "and/or" is herein merely an association relationship describing an associated object, meaning that there may be three relationships, e.g., a and/or B, may represent: the terms "/and" herein describe another associative object relationship, indicating that there may be two relationships, e.g., a/and B, may indicate that: the character "/" herein generally indicates that the associated object is an "or" relationship.

The term "at least one" is herein merely an association relation describing an associated object, meaning that there may be three kinds of relations, e.g., at least one of a and B may represent: a exists alone, A and B exist together, and B exists alone.

It is further noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprise," "include," or any other variation thereof, are intended to cover a non-exclusive inclusion.

Example 1

Since membrane breakage is a common problem during MEA assembly, this surface perforation weakens the membrane due to the unique sharp surface structure of the nickel foam. This reduces the stability of the MEA, thereby impeding the industrialization of water electrolysis using the MEA.

The present embodiment therefore mainly describes a basic design of an MEA water splitting device applied to water splitting catalysis, and as an alternative structure, specifically includes a nickel screen stack and an MEA device, where the nickel screen stack is placed in the MEA device;

please refer to fig. 1 and fig. 1, which are side views of a nickel screen laminate according to the present application, wherein the nickel screen laminate includes two nickel screens with different apertures.

Further, the nickel screen laminate includes a 60 mesh nickel screen and a 300 mesh nickel screen, please refer to fig. 3 and fig. 4, fig. 3 is a front SEM image of the 300 mesh and 60 mesh nickel screen laminate provided in the present application; FIG. 4 is a reverse SEM image of 300 mesh and 60 mesh nickel screen stacks provided by the present application. Referring specifically to FIG. 10, FIG. 10 is a SEM image of a nickel screen 300|60 under various pressures.

Further, the two layers of nickel screens have a length of 1 cm and a width of 1 cm.

Further, the area of the nickel screen lamination is 1 cm ² 。

The nickel screen lamination designed by the application is nickel screen after physical high pressure treatment, and the nickel screen lamination has a smooth plane so as to avoid film breakage in the installation process.

Example 2

Based on the above embodiment 1, this embodiment mainly describes a method for preparing an MEA water splitting device applied to water splitting catalysis, which includes the following steps:

Step S6, placing the nickel screen lamination into an MEA device.

Further, the pure HCl solution in step S2 is a 3 mol HCl solution.

Further, in the step S3, the cleaning time is 1 to 3 hours.

Further, in the step S5, the application pressure of the tablet press is 10 MPa.

Further, in the step S5, the length of both nickel screens is 1 cm and the width is 1 cm.

Furthermore, a film is arranged on the outer side of the 300-mesh nickel screen.

The application relates to a preparation method of an MEA water splitting device applied to water splitting catalysis, which is compared with a traditional complex composite catalyst preparation method, the combination method and materials can reach and are superior to the catalyst performance of more complex preparation reported in the literature, the catalyst grown on the system of the method has improved performance, and through simulation by using COMSOL, the assembly method can solve the mass transfer problem, and can realize more uniform current and voltage density distribution, which is consistent with the test result.

Example 3

Based on the above-described embodiments 1-2, this embodiment mainly describes an effect verification applied to an MEA water splitting device for water splitting catalysis.

The research of mass transfer is obviously reflected from a single sheet, please refer to fig. 2, fig. 2 is a comparison chart of the mass transfer effect of the monocular nickel screen provided by the application; monolayers of different mesh numbers at 60, 100, 300, 400 were used as water electrolysis catalysts with significant differences in performance; from the figure it can be seen that 300 mesh has the best performance and 100 mesh the worst performance, which also indicates that the transfer plays an important role in the MEA system. The highest number will have the best performance if only the active sites of the surface are considered. However, the results do not support the assumption that: referring to fig. 5, at 2.0A and 2.4V, the anode catalyst with 300 mesh size had 20.23% and 14.55% better performance than the anode catalyst with 400 mesh size, and the anode catalyst with 60 mesh size had 19.76% and 35.78% better performance than 100.

As the surface area increases, the active sites where the reaction occurs increase. This basic knowledge led to further research to test the performance of double nickel screens. In view of the results shown in fig. 2, performance could not be predicted at all by screening. Thus, considering all possible combinations of different sieves, please refer to FIG. 5, the average mesh number of membranes |300|60 and membrane|60|300 prepared in accordance with the present application perform best at 80 oC.

Referring to FIG. 6, it can be seen from the single grid results that the highest performance at 2.4V was 3.81A cm for 300 and 60 screen counts, respectively ^-2 And 3.98A cm ^-2 When the two are combined, the current density value can be as high as 6.95 cm compared with 300 sieve ^-2 82.41% and 74.62% as compared to 60 screening. This may be explained by the active sites, the more nickel the better the performance. However, once the results of comparing the membrane|300|60 and the membrane|60|300, the only difference is the 13.38% improvement in membrane|300|60 performance given that both catalysts have the same active sites, demonstrating the great impact of the application on mass transfer limitations.

Referring to FIG. 7, in the three electrode system, the single 60 mesh nickel mesh bubble formation and removal time was 169 seconds, the 300 mesh time from generation to bubble one was 194 seconds, the 300|60 mesh combined test of the present application was 42 seconds. As mentioned above, the 300|60 design of the present application has an optimal water splitting facilitation function.

The comparison of the pure nickel fabrication of the present application with complex composite catalysts is illustrated in fig. 8, where the combination process and materials of the present application are capable of achieving and outperforming the more complex prepared catalysts reported in the literature. FIG. 9 is a graph illustrating the performance of the nickel screen 300|60 under various pressures provided by the present application; FIG. 10 is a 300|60 SEM image of the nickel screen provided by the present application at various pressures, and it is apparent from FIG. 9 that the nickel screen laminate prepared at 10MPa pressure has the best effect.

The above description is only of the preferred embodiments of the present application and it is not intended to limit the scope of the present application, but various modifications and variations can be made by those skilled in the art. Variations, modifications, substitutions, integration and parameter changes may be made to these embodiments by conventional means or may be made to achieve the same functionality within the spirit and principles of the present application without departing from such principles and spirit of the application.

Claims

1. An MEA water splitting device for water splitting catalysis, comprising a nickel screen stack and an MEA device, wherein the nickel screen stack is placed in the MEA device;

2. An MEA water splitting device for use in water splitting catalysis according to claim 1 wherein the nickel mesh stack comprises a 60 mesh nickel mesh and a 300 mesh nickel mesh.

3. The MEA water splitting device for water splitting catalysis according to claim 1, wherein the two nickel screens are 0.5-2 cm long and 0.5-2 cm wide.

4. An MEA water splitting device for water splitting catalysis according to claim 1, wherein the area of the nickel screen stack is 1 cm ² 。

5. The method for preparing the MEA water splitting device for water splitting catalysis according to any one of claims 1 to 4, comprising the following steps:

s5, completely aligning the two processed nickel screens, and then placing the nickel screens into a tablet press to make nickel screen lamination;

step S6, placing the nickel screen lamination into an MEA device.

6. The method for preparing an MEA water splitting device for water splitting catalysis according to claim 5, wherein the pure HCl solution in step S2 is 3 mol HCl solution.

7. The method for preparing the MEA water splitting device for water splitting catalysis according to claim 5, wherein in the step S3, the cleaning time is 1-3 hours.

8. The method for preparing an MEA water splitting device for water splitting catalysis according to claim 5, wherein in step S5, the pressure applied by the tablet press is 10 MPa.

9. The method according to claim 5, wherein in the step S5, the two nickel meshes are 1 cm in length and 1 cm in width.

10. The method for preparing an MEA water splitting device for water splitting catalysis according to claim 5, wherein a thin film is further arranged on the outer side of the 300 mesh nickel screen.