CN114335574A

CN114335574A - Non-noble metal catalyst for fuel cell and preparation method thereof

Info

Publication number: CN114335574A
Application number: CN202111504090.4A
Authority: CN
Inventors: 陈忠伟; 马歌; 王新; 韦小玲
Original assignee: Advanced Energy Industry Research Institute Guangzhou Co ltd
Current assignee: Advanced Energy Industry Research Institute Guangzhou Co ltd
Priority date: 2021-12-10
Filing date: 2021-12-10
Publication date: 2022-04-12

Abstract

The invention belongs to the technical field of fuel cells, and particularly relates to a non-noble metal catalyst for a fuel cell and a preparation method thereof. The preparation method of the non-noble metal catalyst for the fuel cell comprises the following steps: (1) preparing a hydrogel; (2) preparing the graphene oxide loaded cobaltosic oxide nanosheet composite material. The preparation method has simple synthesis steps, can obtain the catalyst by only one-step reduction, has strong controllability of reaction parameters, and is easy to realize industrial production and popularization.

Description

Non-noble metal catalyst for fuel cell and preparation method thereof

Technical Field

The invention belongs to the technical field of fuel cells, and particularly relates to a non-noble metal catalyst for a fuel cell and a preparation method thereof.

Background

The vigorous popularization and use of hydrogen energy provide an excellent approach with wide prospect for reducing environmental pollution and solving energy crisis at present. The application technology of hydrogen energy is developed and matured gradually, the industrial chain of hydrogen energy is improved day by day, and the development prospect of hydrogen energy is also concerned by the whole world. The fuel cell does not need to pass through Carnot cycle, has small energy loss and high energy utilization efficiency, and has the advantages of environmental friendliness, such as green and clean performance and the like, so the fuel cell becomes an ideal mode for reasonably utilizing hydrogen energy. The hydrogen energy and the fuel cell can promote the economic society to develop low carbon, so that the hydrogen energy and the fuel cell are continuously and stably attached and supported by the world multi-national government.

Fuel cells use electrochemical reactions to convert chemical energy of matter directly into electrical energy. It has higher energy conversion efficiency relative to the heat engine. In addition, when hydrogen is used as fuel, the generated product is mainly water in the process of energy conversion, and nitrogen and sulfur oxides and the like are not generated to cause environmental pollution, so the hydrogen is regarded as a clean power generation system. Fuel cells are considered to exhibit a wide range of prospects in the fields of military, civilian use, and the like because of their many excellent characteristics.

The non-platinum catalyst selected by the current fuel cell comprises carbon-based transition metal sulfide, carbide, nitride, carbon nitride compound, oxide, oxynitride and the like, but the ORR activity and the catalytic stability of the catalyst are still different from those of the traditional Pt-based catalyst. And the existing non-noble metal catalyst preparation process has complicated steps, too many dependent variable factors and difficult control of reaction conditions, thereby influencing the catalytic activity and stability of the prepared non-noble metal catalyst.

Disclosure of Invention

The present invention aims to provide a non-noble metal catalyst for fuel cells and a preparation method thereof, aiming at the defects. The preparation method has simple synthesis steps, can obtain the catalyst by only one-step reduction, has strong controllability of reaction parameters, and is easy to realize industrial production and popularization.

The technical scheme of the invention is as follows: a preparation method of a non-noble metal catalyst for a fuel cell comprises the following steps:

(1) preparing a hydrogel: firstly, dissolving graphene oxide, cobalt chloride and potassium cobalt cyanide in deionized water, and uniformly mixing to obtain a mixed solution; then standing the obtained mixed solution at 50 ℃ to obtain black hydrogel;

(2) preparation of graphene oxide negativeCobaltosic oxide supported nanosheet composite material: firstly preparing NaBH₄Aqueous solution, then NaBH₄And (3) adding the aqueous solution into the hydrogel obtained in the step (1) for constant-temperature reaction to obtain the graphene oxide loaded cobaltosic oxide nanosheet composite material.

The molar ratio of cobalt chloride to potassium cobalt cyanide in the step (1) is 2: 1.

The amount of the graphene oxide in the step (1) is 0.1 g-10 g; the deionized water is 3-10 mL.

And (2) standing for 6-24 hours in the step (1).

NaBH in the step (2)₄The concentration of the aqueous solution is 0.1-10 g/mL; the dosage is 80-100 mL.

The temperature of the constant-temperature reaction in the step (2) is 60-80 ℃, and the time of the constant-temperature reaction is 3-12 hours.

The non-noble metal catalyst for the fuel cell prepared by the preparation method.

The fuel cell adopts the non-noble metal catalyst prepared by the preparation method. And dispersing the obtained graphene oxide-loaded cobaltosic oxide nanosheet in ethanol and water to obtain an electrocatalyst dispersion liquid which is used as a fuel cell catalyst.

The invention has the beneficial effects that: the preparation method adopts a chemical reduction method to obtain a mixture of cobaltosic oxide nanosheets loaded on graphene oxide sheets, and the mixture is used as a fuel cell catalyst. The synthesis steps are simple, the catalyst can be obtained by only one-step reduction, the sol-gel is combined with the one-step reduction, the controllability of reaction parameters is strong, and the industrial production and popularization are easy to realize.

Drawings

Fig. 1 is a SEM comparison of the electrocatalysts prepared in example 1 and comparative example 1.

Figure 2 is a LSV scanning contrast plot of the electrocatalysts prepared in example 1 and comparative example 1.

Detailed Description

The present invention will be further described with reference to the following specific examples and drawings, which are not intended to limit the invention in any manner. Reagents, methods and apparatus used in the present invention are conventional in the art unless otherwise indicated.

Unless otherwise indicated, reagents and materials used in the present invention are commercially available.

Example 1

Weighing 5mmol of cobalt chloride, 2.5mmol of potassium cobalt cyanide and 3g of graphene oxide, dissolving in 5mL of deionized water, and standing in an oven at 50 ℃ for 10h to obtain black hydrogel; preparation of 1g/mL NaBH₄Pouring 100mL of solution into the hydrogel, and stirring at the constant temperature of 80 ℃ for 6 hours to obtain a cobaltosic oxide nanosheet loaded with graphene oxide; and dispersing the obtained graphene oxide-loaded cobaltosic oxide nanosheet in ethanol and water to obtain an electrocatalyst dispersion liquid which is used as a fuel cell catalyst.

Example 2

Weighing 10mmol of cobalt chloride, 5mmol of potassium cobalt cyanide and 4g of graphene oxide, dissolving in 10mL of deionized water, and standing in a 50 ℃ oven for 8 hours to obtain black hydrogel; preparation of 2g/mL NaBH₄Pouring 100mL of solution into the hydrogel, and stirring at the constant temperature of 80 ℃ for 10 hours to obtain a cobaltosic oxide nanosheet loaded with graphene oxide; and dispersing the obtained graphene oxide-loaded cobaltosic oxide nanosheet in ethanol and water to obtain an electrocatalyst dispersion liquid which is used as a fuel cell catalyst.

Example 3

Weighing 3mmol of cobalt chloride, 1.5mmol of potassium cobalt cyanide and 2g of graphene oxide, dissolving in 3mL of deionized water, and standing in an oven at 50 ℃ for 12h to obtain black hydrogel; preparation of 1g/mL NaBH₄Pouring 80mL of solution into the hydrogel, and stirring at the constant temperature of 80 ℃ for 8 hours to obtain a cobaltosic oxide nanosheet loaded with graphene oxide; and dispersing the obtained graphene oxide-loaded cobaltosic oxide nanosheet in ethanol and water to obtain an electrocatalyst dispersion liquid which is used as a fuel cell catalyst.

Comparative example 1

Weighing 5mmol of cobalt chloride and 3g of graphene oxide, and dissolving in 5mL of deionized water; preparation of 1g/mL NaBH₄Pouring 100mL of solution into the mixed solution, and stirring at the constant temperature of 80 ℃ for 6 hours to obtain a composite material of graphene oxide and cobaltosic oxide; will getThe obtained composite material of graphene oxide and cobaltosic oxide is dispersed in ethanol and water to obtain an electro-catalyst dispersion liquid which is used as a fuel cell catalyst.

As can be seen from fig. 1, the graphene oxide supported cobaltosic oxide nanosheet composite electrocatalyst prepared by the preparation method of the invention in fig. 1a has an ultrathin lamellar morphology. This ultra-thin lamellar structure provides a large specific surface area and a rich surface active site. Whereas comparative example 1 in fig. 1b did not undergo the hydrogel-forming step, but only mechanically mixed graphene oxide and cobaltosic oxide particles were obtained.

As can be seen from fig. 2, the half-wave potential of the material prepared in example 1 is larger, the limiting current is also larger, and richer surface active sites and more excellent catalytic activity are represented.

Claims

1. A preparation method of a non-noble metal catalyst for a fuel cell is characterized by comprising the following steps:

(2) preparing a graphene oxide supported cobaltosic oxide nanosheet composite material: firstly preparing NaBH₄Aqueous solution, then NaBH₄And (3) adding the aqueous solution into the hydrogel obtained in the step (1) for constant-temperature reaction to obtain the graphene oxide loaded cobaltosic oxide nanosheet composite material.

2. The method for preparing a non-noble metal catalyst for a fuel cell according to claim 1, wherein the molar ratio of cobalt chloride to potassium cobalt cyanide in the step (1) is 1: 2.

3. The method for preparing a non-noble metal catalyst for a fuel cell according to claim 1, wherein the graphene oxide in the step (1) is 0.1g to 10 g; the deionized water is 3-10 mL.

4. The method for preparing a non-noble metal catalyst for a fuel cell according to claim 1, wherein the step (1) is performed for 6-24 hours.

5. The method of claim 1, wherein the NaBH in step (2) is performed by a method of preparing a non-noble metal catalyst for a fuel cell₄The concentration of the aqueous solution is 0.1-10 g/mL; the dosage is 80-100 mL.

6. The preparation method of the non-noble metal catalyst for the fuel cell according to claim 1, wherein the temperature of the isothermal reaction in the step (2) is 60-80 ℃, and the time of the isothermal reaction is 3-12 h.

7. A non-noble metal catalyst for fuel cells, obtained by the preparation method according to any one of claims 1 to 6.

8. A fuel cell using the non-noble metal catalyst produced by the production method according to claim 1.