CN110116025A - Covalent triazine class framework compound and MoS2The preparation method of compound liberation of hydrogen catalyst and the application of liberation of hydrogen catalyst - Google Patents

Abstract

The invention discloses a preparation method of a covalent triazine skeleton compound and MoS2 composite _hydrogen evolution catalyst and the application of the hydrogen evolution catalyst, wherein the covalent triazine skeleton compound and MoS2 composite _hydrogen evolution catalyst is anhydrous zinc chloride and Terephthalonitrile is used as a raw material to obtain a covalent triazine skeleton compound, and then the powder of the covalent triazine skeleton compound is reacted with ammonium acid and thiourea to finally obtain a covalent triazine skeleton compound and auxiliary MoS ₂ for hydrogen evolution catalyst. The above preparation method is simple and convenient to operate, low in cost, easy to prepare in large quantities, and can be widely used in industrial electrocatalytic hydrogen evolution reactions.

Description

Preparation method of covalent triazine skeleton compound and MoS composite hydrogen evolution catalyst and Application of hydrogen evolution catalyst

technical field

The invention belongs to the field of catalyst preparation, and relates to a preparation method of a hydrogen evolution catalyst, specifically, a preparation method of a covalent triazine skeleton compound and MoS2 composite _hydrogen evolution catalyst and an application of the hydrogen evolution catalyst.

Background technique

In response to the global energy and environmental crisis, the development of renewable energy and technology has become a trend. As a clean energy with no pollution, abundant reserves and high utilization rate, hydrogen energy is considered to be an ideal substitute for fossil energy in the future.

In the current industrial production, electrolysis of water technology is an important way to produce hydrogen on a large scale, but commercial hydrogen production by electrolysis of water requires efficient catalysts to reduce energy consumption, so as to ensure a large cathodic current density at a low overpotential. Among them, platinum as a catalyst is the catalyst with the best catalytic effect in the hydrogen production process, which is due to the metal Pt has the best H ⁺ adsorption and desorption ability, but because platinum is scarce and expensive in nature, platinum as a catalyst and Not well developed in industrial production. Therefore, it is urgent to develop low-cost, high-activity electrocatalytic hydrogen evolution catalysts to replace noble metal platinum for industrial hydrogen production.

Contents of the invention

The technical problem to be solved in the present invention is to provide a preparation method of a covalent triazine skeleton compound and MoS2 composite hydrogen evolution catalyst, aiming to provide a kind of electrocatalytic hydrogen evolution reaction that can replace metal Pt and be applied to industrial production Electrocatalysts for the preparation of hydrogen to reduce the cost of electrocatalytic hydrogen evolution reactions.

In order to solve the problems of the technologies described above, the technical solution adopted in the present invention is:

A kind of preparation method of covalent triazine skeleton compound and MoS Composite _hydrogen evolution catalyst, this synthesis method is carried out according to the following steps sequence:

(1) The preparation of the covalent triazine skeleton compound comprises the following steps carried out in sequence:

A1) Use a vacuum pump to degas and keep it at 5-10mim, then seal the container in a degassed state;

A2) Heat the sealed container at room temperature to 300-500°C at a constant speed, keep it for 30-40 hours, then cool to room temperature, open the container, and obtain mixture A;

A3) After mixture A is ground into powder, zinc chloride is removed to obtain black powder B;

A4) After rinsing the black powder B, dry it at 100-150° C. for 20-30 hours to obtain substance C, which is a covalent triazine skeleton compound;

(2) Preparation of MoS ₂ composites

Dissolve substance C, ammonium molybdate, and thiourea powder in water, stir for 2-5 hours to form a uniform solution, then transfer the uniform solution to a 25ml polytetrafluoroethylene-lined stainless steel autoclave, and keep it at 180-250°C for 16 After ~24h, the solution D was obtained, and then the solution D was washed at least 5 times with ultrapure water and alcohol to remove useless ions, and dried in vacuum at 30-80°C for 24h, and finally the covalent triazine skeleton compound and MoS ₂ composite materials.

As a limitation to step A1) in the present invention: the formation process of the vacuum environment in the step A1) is: anhydrous zinc chloride and terephthalonitrile are added in a heat-resistant glass tube, and then degassed and removed with a vacuum pump Oxygen, after keeping for 5-10 minutes, use a vacuum pump to degas and seal the glass tube with an alcohol blowtorch.

As a limitation to step A3) in the present invention: the method for removing zinc chloride in the step A3) is: first wash the powdered mixture A with deionized water at least three times, and then use dilute acid to stir at room temperature for 10 ~20h is enough.

As a further limitation to step A3) in the present invention: the dilute acid is 0.1 mol/L dilute hydrochloric acid or dilute sulfuric acid.

As a limitation to step A4) in the present invention: the method of rinsing in step A4) is: rinsing with deionized water and organic solvent at least three times respectively.

As a further limitation to step A4) in the present invention: the organic solvent is any one or two of acetone, tetrahydrofuran, and dichloromethane.

As a limitation to step (2) in the present invention: the mass ratio of ammonium molybdate: thiourea: substance C powder added in step (2) is 1:3:1.

As another limitation to the step (2) in the present invention: the alcohol used in the step (2) is one of methanol, ethanol or isopropanol.

The present invention also provides an application of the covalent triazine skeleton compound and MoS2 composite hydrogen evolution catalyst prepared by the above preparation method, and the covalent triazine skeleton compound and MoS2 composite hydrogen evolution catalyst is used in industrial electrocatalytic hydrogen evolution reaction Produce hydrogen.

The present invention has adopted above-mentioned technical scheme, and it compares with prior art, and the technological progress that obtains is:

Covalent triazine framework compound (CTFs) of the present invention and MoS ₂ The preparation method of covalent triazine framework compound (CTFs) in the composite hydrogen evolution catalyst is simple, the cost is low, and the covalent triazine framework compound (CTFs) specific surface area It is large and rich in pores, which is conducive to accelerating mass transfer and charge transfer, and can effectively improve the shortcomings of MoS _{2's poor electrical conductivity and slow electron migration, so that MoS 2 has} better catalytic performance when it is used in electrocatalytic hydrogen evolution reactions. This is because the nitrogen atom in the triazine ring in the covalent triazine framework compound (CTFs) has a heteroatom effect, which improves the electrocatalytic activity of the composite material. Compared with pure molybdenum sulfide, the catalytic performance is greatly improved, and then has It is conducive to the large-scale industrial production of hydrogen energy.

In summary, the present invention is simple and convenient to operate, low in cost, easy to prepare in large quantities, and can be widely used in industrial electrocatalytic hydrogen evolution reactions.

The present invention will be further described in detail in conjunction with specific embodiments below.

Description of drawings

Fig. 1 is respectively pure covalent triazine framework compound, molybdenum sulfide prepared in embodiment 1, and covalent triazine framework compound and MoS _The nitrogen adsorption-desorption curve of composite catalyst;

Fig. 2 is the pore size distribution figure of the covalent triazine skeleton compound prepared in embodiment 1;

Figure 3 shows the covalent triazine skeleton compound and MoS ₂ composite catalyst when the mass ratio of covalent triazine skeleton compound: MoS ₂ is 1:2, 1:1, 2:1 respectively, and pure MoS ₂ , covalent Linear scan curves of electrochemical hydrogen evolution performance of triazine framework compounds and Pt.

Detailed ways

The reagents used in the following examples are all existing commercially available reagents unless otherwise specified, and the test methods are all existing test methods unless otherwise specified.

Example 1 The preparation method of covalent triazine skeleton compound and MoS composite _hydrogen evolution catalyst

In this implementation, proceed in the following order of steps:

(1) The preparation of the covalent triazine skeleton compound comprises the following steps carried out in sequence:

A1) Add anhydrous zinc chloride and terephthalonitrile into the container and mix them into a heat-resistant glass tube, then use a vacuum pump to remove oxygen, keep it for 8 minutes, use a vacuum pump to remove air, and use an alcohol blowtorch to remove the oxygen. Sealed heat-resistant glass tube.

A2) Put the sealed heat-resistant glass tube into a tube furnace, heat it at room temperature to 400° C. at a constant speed, keep it for 40 hours, then cool to room temperature, open the container, and obtain mixture A.

A3) Mixture A was ground into powder, washed 5 times with deionized water, then added with 0.1 mol/L dilute hydrochloric acid, stirred at room temperature for 15 hours, and finally the zinc chloride in mixture A was removed to obtain black powder B.

A4) Use deionized water to rinse the black powder B 5 times, then use dichloromethane to rinse the black powder B 4 times again, transfer the rinsed black powder B to a vacuum oven, and dry at 100°C 24h, to obtain substance C, which is a covalent triazine skeleton compound;

(2) Preparation of MoS ₂ composites

Dissolve the covalent triazine skeleton compound, ammonium molybdate, and thiourea powder in water (the mass ratio of ammonium molybdate: thiourea powder: covalent triazine skeleton compound is 1:3:1), and stir for 2 hours to form homogeneous solution, and then transfer the homogeneous solution to a 25ml polytetrafluoroethylene-lined stainless steel autoclave, and keep it at 180 ° C for 20 hours to obtain solution D, then wash solution D with ultrapure water for 5 times, and then use methanol to dissolve Solution D was washed 6 times to remove useless ions in solution D; then vacuum-dried at 80°C for 24 hours to finally obtain a composite material of covalent triazine framework compound and MoS ₂ .

And described covalent triazine framework compound and MoS _The nitrogen adsorption-desorption curve of the composite material is as shown in Figure 1, as can be seen from Figure 1, the specific surface area of the covalent triazine framework prepared by Example 1 is large, when After compounding with molybdenum disulfide, due to the restricted growth of molybdenum disulfide in the pores of the covalent triazine framework, the channels are blocked, which directly proves the successful preparation of the composite material. The pore size distribution of the covalent triazine framework compound and MoS2 composite hydrogen evolution catalyst prepared in this example is shown in Figure ₂ , and it can be seen from Figure ₂ that the covalent triazine framework compound and MoS2 composite hydrogen evolution catalyst has multiple Hierarchical pore structure, which is conducive to charge transfer and mass transfer, which in turn is beneficial to improve the electrocatalytic performance.

Example 2-8 Preparation method of covalent triazine skeleton compound and MoS composite _hydrogen evolution catalyst

Examples 2-8 are respectively a preparation method of a covalent triazine skeleton compound and MoS composite _hydrogen evolution catalyst, the preparation method is the same as the preparation method of Example 1, the difference lies in the steps involved in each step The reaction conditions, the substances used and the dosage are different, see Table 1 for details

Table 1

Example ₉ Application of Covalent Triazine Skeleton Compound and MoS Hydrogen Evolution Catalyst

This example provides a covalent triazine skeleton compound and MoS2 composite hydrogen evolution catalyst prepared by using any one of the covalent triazine skeleton compound and MoS2 composite _hydrogen evolution catalyst preparation method in Examples ₁ to 8 The application of it is used as a catalyst in the industrial electrocatalytic hydrogen evolution reaction to prepare hydrogen.

The mass ratio of MoS ₂ : covalent triazine skeleton compound A in the covalent triazine skeleton compound and MoS ₂ composite hydrogen evolution catalyst obtained in Examples 1 to 8 is 1:1, which is applied to the electrocatalytic hydrogen evolution reaction , the linear scanning curve of performance is shown in the a curve of Fig. 2, and this embodiment is also according to the preparation method of embodiment 1～8 simultaneously, by changing the amount of ammonium molybdate, thiourea and substance C in step (2), respectively The MoS ₂ : covalent triazine framework compound mass ratio of 1:2, 2:1 covalent triazine framework compound and MoS ₂ composite hydrogen evolution catalyst was obtained. When the above two substances are applied to the electrocatalytic hydrogen evolution reaction, the linear scanning curves of their performance are shown in the b curve and c curve of Fig. 2 respectively. For comparison, this example also tested the performance linear scan curves of unadded pure MoS ₂ , metal Pt, and pure covalent triazine skeleton compounds when they were applied to the electrocatalytic hydrogen evolution reaction, specifically as follows As shown in the d curve, e curve, and f curve in Fig. 2, it can be known from Fig. 2 that pure MoS ₂ and the covalent triazine skeleton compound prepared by the preparation method of Examples 1 to 8 are more pure than MoS ₂ composite catalyst. _The potentials of MoS2 are all small, that is, they can be used as catalysts in electrocatalytic hydrogen evolution reactions, and compared with other ratios of covalent triazine skeleton compounds and MoS2 composite _hydrogen evolution catalysts, the preparation methods of Examples 1 to 8 prepared The obtained covalent triazine framework compound and MoS ₂ composite catalyst have the best minimum overpotential performance, much better hydrogen evolution performance than pure MoS ₂ and pure covalent triazine framework compound, and are closest to the performance of metal Pt, so MoS ₂ : When the mass ratio of covalent triazine skeleton compound is 1:1, it is most suitable for industrial electrocatalytic hydrogen evolution production.

Claims (9)

1. a kind of covalent triazine class framework compound and MoS₂The preparation method of compound liberation of hydrogen catalyst, it is characterised in that: the synthesis Method sequentially carries out according to the following steps:

(1) preparation of covalent triazine class framework compound, including the following steps successively carried out:

A1) anhydrous zinc chloride and terephthalonitrile are added in container after mixing, are deaerated using vacuum pump and keep 5~10mim, so Container is sealed under degassing phase afterwards；

A2) container after sealing is cooled to room temperature in room temperature constant-speed heating to 300~500 DEG C, and after keeping 30~40h, is beaten Container is opened, mixture A is obtained；

A3) mixture A is pulverized last, removes zinc chloride, obtains black powder B；

A4) by after black powder B elution, dry 20~30h, obtains substance C, as covalent triazine class skeleton at 100~150 DEG C Compound；

(2) MoS₂The preparation of composite material

Substance C, ammonium molybdate, thiocarbamide powder is soluble in water, and 2~5h of stirring forms homogeneous solution, is then transferred to homogeneous solution In 25ml polytetrafluoroethyllining lining stainless steel autoclave, and be maintained at 180~250 C react 16~24 h after, obtain solution D, Then solution D is washed till respectively to ultrapure water and alcohol 5 times few, removal unwanted ion, and be dried in vacuo for 24 hours at 30~80 DEG C, Finally obtain covalent triazine class framework compound and MoS₂Composite material.

2. covalent triazine class framework compound according to claim 1 and MoS₂The preparation method of compound liberation of hydrogen catalyst, Be characterized in that: the step A1) in vacuum environment forming process are as follows: anhydrous zinc chloride and terephthalonitrile are added to heat-resisting Glass tube in, then with vacuum pump deaerate removal oxygen, keep 5~10min after, on one side utilize vacuum pump degassing while utilize Alcohol blast burner sealed glass tube.

3. covalent triazine class framework compound according to claim 1 or 2 and MoS₂The preparation side of compound liberation of hydrogen catalyst Method, it is characterised in that: the step A3) in removal zinc chloride method are as follows: grind into powder is mixed with deionized water first It closes object A at least to wash three times, then stirs 10~20h at room temperature using diluted acid.

4. covalent triazine class framework compound according to claim 3 and MoS₂The preparation method of compound liberation of hydrogen catalyst, Be characterized in that: the diluted acid is the dilute hydrochloric acid or dilute sulfuric acid of 0.1mol/L.

5. covalent triazine class framework compound according to claim 1 or 2 and MoS₂The preparation side of compound liberation of hydrogen catalyst Method, it is characterised in that: the step A4) in the method that elutes are as follows: at least elution three respectively of deionized water and organic solvent It is secondary.

6. covalent triazine class framework compound according to claim 5 and MoS₂The preparation method of compound liberation of hydrogen catalyst, Be characterized in that: the organic solvent is acetone, tetrahydrofuran, any one or two kinds in methylene chloride.

7. covalent triazine class framework compound according to claim 1 and MoS₂The preparation method of compound liberation of hydrogen catalyst, Be characterized in that: the ammonium molybdate being added in the step (2): thiocarbamide: the powder quality ratio of substance C is 1:3:1.

8. according to claim 1, covalent triazine class framework compound and MoS described in any one of 2,4,6,7₂Compound liberation of hydrogen The preparation method of catalyst, it is characterised in that: alcohol used in the step (2) is methanol, one in ethyl alcohol or isopropanol Kind.

9. covalent triazine class framework compound as claimed in any of claims 1 to 8 and MoS₂Compound liberation of hydrogen catalyst Preparation method preparation covalent triazine class framework compound and MoS₂A kind of application of compound liberation of hydrogen catalyst, feature exist In: the covalent triazine class framework compound and MoS₂Compound liberation of hydrogen catalyst is used in industrial electrocatalytic hydrogen evolution reaction prepare Hydrogen.