阅读说明：本技术 高效电催化材料及其制备方法 (High-efficiency electrocatalytic material and preparation method thereof ) 是由 邹继兆 张盛礁 曾燮榕 刘鹏 于 2019-09-19 设计创作，主要内容包括：本发明涉及电催化材料技术领域,具体提供一种高效电催化材料及其制备方法。所述制备方法包括以下步骤：提供沸石咪唑-四唑型骨架材料；在保护气氛下对沸石咪唑-四唑型骨架材料进行碳化处理,得到氮掺杂的多孔碳材料；在保护气氛下将活化剂与所述氮掺杂的多孔碳材料进行混料并活化处理,得到高效电催化材料。本发明的制备方法获得的高效电催化材料具有介孔结构和多级孔结构,且比表面积达到2800m<Sup>2</Sup>/g～3350m<Sup>2</Sup>/g,有良好的电催化性能。(The invention relates to the technical field of electrocatalytic materials, and particularly provides a high-efficiency electrocatalytic material and a preparation method thereof. The preparation method comprises the following steps: providing a zeolitic imidazole-tetrazole type framework material; carbonizing the zeolite imidazole-tetrazole type framework material under a protective atmosphere to obtain a nitrogen-doped porous carbon material; and mixing an activating agent and the nitrogen-doped porous carbon material in a protective atmosphere, and activating to obtain the high-efficiency electro-catalytic material. The high-efficiency electro-catalytic material prepared by the preparation method has a mesoporous structure and a hierarchical pore structure, and the specific surface area reaches 2800m 2 /g～3350m 2 Has good electrocatalytic performance per gram.)

1. the preparation method of the high-efficiency electrocatalytic material is characterized by comprising the following steps of:

providing a zeolitic imidazole-tetrazole type framework material;

Carbonizing the zeolite imidazole-tetrazole type framework material under a protective atmosphere to obtain a nitrogen-doped porous carbon material;

and mixing and activating an activating agent and the nitrogen-doped porous carbon material under a protective atmosphere to obtain the high-efficiency electro-catalytic material.

2. The method for preparing a high efficiency electrocatalytic material as set forth in claim 1, wherein said nitrogen-doped porous carbon material: the activating agent is 1: 1-5.

3. the method for preparing a high efficiency electrocatalytic material as set forth in any one of claims 1 to 2, wherein said activating agent is any one of potassium hydroxide, sodium hydroxide, phosphoric acid, and zinc chloride.

4. The method for preparing the high-efficiency electrocatalytic material as set forth in claim 1, wherein the temperature rise rate of the activation treatment is (5-10) ° c/min, the reaction temperature is (650-800) ° c, and the reaction time is (1-2) hours.

5. The method for preparing the high-efficiency electrocatalytic material as set forth in claim 1, wherein the temperature rise rate of the carbonization treatment is (5-10) ° c/min, and the temperature is maintained for (1-3) hours after the temperature is raised to (800-1000) ° c.

6. The method of preparing a high efficiency electrocatalytic material as set forth in claim 1, wherein said zeolitic imidazole-tetrazole-type framework material is prepared by the following method:

dissolving 2-ethylimidazole, 5-methyltetrazole and anhydrous zinc acetate in a mixed solvent of dimethylformamide and ethanol, and placing the mixture in a reaction kettle (110-125 ℃) for heat preservation treatment to obtain the zeolite imidazole-tetrazole type framework material.

7. the method for preparing the high efficiency electrocatalytic material as set forth in claim 6, wherein the molar ratio of 2-ethylimidazole: 5-methyltetrazole: anhydrous zinc acetate: 0.9-1.1;

And/or the heat preservation time is (70-74) h.

8. The method for preparing a high efficiency electrocatalytic material as set forth in claim 1, wherein said atmosphere is any one of nitrogen, argon, and helium.

9. The method for preparing a high efficiency electrocatalytic material as set forth in claim 1, further comprising the step of washing the obtained high efficiency electrocatalytic material with a hydrochloric acid solution and deionized water.

10. a high efficiency electrocatalytic material, wherein said high efficiency electrocatalytic material has a specific surface area of 2800m²/g～3350m²Between/g, has a mesoporous structure and a hierarchical pore structure; the high-efficiency electrocatalytic material is prepared by the preparation method of any one of claims 1-9.

Technical Field

The invention belongs to the technical field of electrocatalytic materials, and particularly relates to a high-efficiency electrocatalytic material and a preparation method thereof.

background

Zeolite imidazole-tetrazole type frameworks (ZTIFs) are Metal Organic Frameworks (MOFs) of fixed crystal form.

In 2018, the Zhongzhao and the like adopt a zeolite imidazole-tetrazole type framework (ZTIF-1 for short) material with an SOD type topological structure as a precursor, and a nitrogen-doped porous carbon material (NNPC for short) is obtained through one-step carbonization, and the material obtained after carbonization has a high specific surface area and a rich pore channel structure, so that the absorption and desorption of electrons and the transmission of charges are facilitated, and in addition, the material has high nitrogen content (about 15 percent), and the nitrogen atom doping mode is in-situ nitrogen doping, so that the nitrogen-doped porous carbon material with good supercapacitor performance is obtained.

However, although NNPC has a good application prospect in the field of supercapacitors, its electrocatalytic performance is low, mainly because the channel structure of NNPC is not abundant and there are few defects in the material, it is not possible to provide sufficient active sites for catalytic reactions.

Disclosure of Invention

Aiming at the problems of poor electrocatalysis performance and the like caused by the insufficient pore structure, few internal defects of the material, few electrocatalysis active sites of the prior NNPC material, the invention provides a high-efficiency electrocatalysis material and a preparation method thereof.

In order to achieve the purpose, the technical scheme of the invention is as follows:

A preparation method of a high-efficiency electrocatalytic material comprises the following steps:

providing a zeolitic imidazole-tetrazole type framework material;

carbonizing the zeolite imidazole-tetrazole type framework material under a protective atmosphere to obtain a nitrogen-doped porous carbon material;

And mixing an activating agent and the nitrogen-doped porous carbon material in a protective atmosphere, and performing activation treatment to obtain the high-efficiency electro-catalytic material.

Accordingly, a high efficiency electrocatalytic material having a specific surface area of 2800m²/g～3350m²Between/g, has a mesoporous structure and a hierarchical pore structure; the high-efficiency electrocatalytic material is prepared by the preparation method.

The invention has the technical effects that:

Compared with the prior art, the preparation method of the high-efficiency electrocatalytic material provided by the invention has the advantages that the zeolite imidazole-tetrazole type framework material with a stable three-dimensional structure is activated by adopting the activating agent, so that a large number of mesoporous structures are generated on the basis of the original microporous structure of the zeolite imidazole-tetrazole type framework material to form a hierarchical pore structure, and the specific surface area reaches 2800m²/g～3350m²The preparation method has the characteristics of simple process, controllable material structure and the like.

The high-efficiency electrocatalytic material of the invention has the specific surface area as high as 2800m²/g～3350m²The catalyst has a micropore structure, a mesopore structure and a hierarchical pore structure, so that the catalyst has a good catalytic reaction substance transmission channel and good electrocatalysis performance.

drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is an XRD pattern of intermediate ZTIF-1 prepared in example 1;

FIG. 2 is an XRD pattern of the high efficiency electrocatalytic material NHPC3-700 prepared in example 1;

FIG. 3 is an SEM picture of a high-efficiency electrocatalytic material NHPC3-700 prepared in example 1;

FIG. 4 is an SEM image of a high-efficiency electro-catalytic material NHPC2-700 prepared in example 2;

FIG. 5 is an SEM photograph of the high-efficiency electro-catalytic material NHPC3-800 prepared in example 3;

FIG. 6 is an SEM image of the NNPC material obtained in the comparative example;

FIG. 7 is an adsorption equilibrium isotherm of NHPC3-700 prepared in example 1 and NNPC prepared in a comparative example;

FIG. 8 is a plot of the pore size distribution of NHPC3-700 prepared in example 1 and NNPC prepared in a comparative example;

FIG. 9 shows N of the high efficiency electrocatalytic materials prepared in examples 1-3₂Adsorption isotherms;

FIG. 10 is a graph showing pore size distribution curves of the high efficiency electrocatalytic materials prepared in examples 1 to 3;

FIG. 11 is a Linear Sweep Voltammogram (LSV) for redox reactions of the high efficiency electrocatalytic materials prepared in examples 1-3 and the materials of the comparative example;

fig. 12 is a Linear Sweep Voltammogram (LSV) for the redox reaction of the high efficiency electrocatalytic material obtained in example 1 and a commercial platinum-carbon material.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

the invention provides a preparation method of a high-efficiency electrocatalytic material, which comprises the following steps:

providing a zeolitic imidazole-tetrazole type framework material;

Carbonizing the zeolite imidazole-tetrazole type framework material under a protective atmosphere to obtain a nitrogen-doped porous carbon material;

and mixing and activating an activating agent and the nitrogen-doped porous carbon material under a protective atmosphere to obtain the high-efficiency electro-catalytic material.

The above-mentioned preparation method is explained in detail below.

The related zeolite imidazole-tetrazole type framework material (ZTIF-1) can be prepared by the following method:

Dissolving 2-ethylimidazole, 5-methyltetrazole and anhydrous zinc acetate in a mixed solvent of Dimethylformamide (DMF) and ethanol, and placing the mixture in a reaction kettle (110-125 ℃) for heat preservation treatment to obtain the zeolite imidazole-tetrazole type framework material.

In the preparation process of the zeolite imidazole-tetrazole type framework material, the raw materials comprise 2-ethylimidazole, 5-methyltetrazole and anhydrous zinc acetate in a molar ratio of (0.9-1.1) to (0.9-1.1); more preferably 2-ethylimidazole, 5-methyltetrazole and anhydrous zinc acetate (0.95 to 1.05): (0.95-1.05): (0.95-1.05).

Preferably, the heat preservation time in the preparation process of the zeolite imidazole-tetrazole type framework material is (70-74) h.

the protective atmosphere involved in the preparation steps can be any one of nitrogen, argon and helium, and side reactions in the carbonization process or the activation process can be avoided through the protection of the protective atmosphere.

Preferably, the carbonization treatment is carried out by heating to 800-1000 ℃ at a heating rate of 5-10 ℃/min and keeping the temperature for 1-3 h. The specific heating rate can be 5 deg.C/min, 6 deg.C/min, 7 deg.C/min, 8 deg.C/min, 9 deg.C/min, 10 deg.C/min, etc. The constant temperature can be 800 ℃, 850 ℃, 900 ℃, 950 ℃, 1000 ℃ and the like, and under the conditions of the heating rate and the heat preservation temperature, the carbonization effect of the zeolite imidazole-tetrazole type framework material has no obvious difference, and the nitrogen-doped porous carbon material can be obtained.

Materials capable of being used as an activator include potassium hydroxide, sodium hydroxide, zinc chloride, phosphoric acid, carbon dioxide and the like, and all the materials have certain activation effect on the nitrogen-doped porous carbon material.

Preferably, the activating agent used in the activating treatment is potassium hydroxide, and among the activating agents, potassium hydroxide can be used for activating to obtain a desired hierarchical pore structure.

Further preferably, the nitrogen-doped porous carbon material has a mass ratio of: the activating agent is 1: 1-5. Such as nitrogen-doped porous carbon materials: the activator can be 1:1, 1:2, 1:3, 1:4 and the like, and within the mass ratio range, the high-efficiency electrocatalytic material is obtained, and the performance difference is not large.

Preferably, the activation siteThe temperature is raised to 650-800 ℃ according to the temperature rise rate of 5-10 ℃/min, and the reaction is carried out for 1-2 h at the constant temperature of 650-800 ℃. Within the temperature rising rate range of the activation reaction temperature, the material performance is not greatly different, and the specific surface area can be changed by adjusting the reaction temperature, so that the total specific surface area of the obtained material is 2800m²/g～3350m²Between/g.

After the activation reaction, the obtained electrocatalytic material is further cleaned by adopting a hydrochloric acid solution and deionized water.

Finally obtaining the mesoporous structure and the hierarchical pore structure with the specific surface area of 2800m²/g～3350m²a high efficiency electrocatalytic material between/g.

The preparation method has the characteristics of cheap and easily obtained raw materials, simple preparation process, controllable material structure and the like.

in order to more effectively explain the technical solution of the present invention, a plurality of specific examples are described below.