1. A preparation method of a catalyst for a water electrolysis hydrogen production system is characterized by comprising the following steps:

s1, preparing a porous carbon material;

s2, carrying out surface modification on the porous carbon material by using a coupling agent;

s3, mixing gamma-manganese dioxide, cobalt nitrate and nickel nitrate, adding absolute ethyl alcohol to form a mixed solution, adding the modified porous carbon material, dispersing uniformly, carrying out hydrothermal reaction at 100-200 ℃, adding a sulfur-containing compound solution with the concentration of 10-30%, mixing uniformly, filtering, adding the mixture into N, N-dimethylformamide, refluxing for 1-3h at 180-200 ℃, centrifuging, washing and drying to obtain an intermediate, wherein the mass ratio of the porous carbon material, the mixed solution and the sulfur-containing compound is 1-1.5:2-3:3-5, and the mass ratio of the nickel nitrate, the cobalt nitrate, the gamma-manganese dioxide and the absolute ethyl alcohol is 0.1-0.3:0.1-0.3:0.06-0.1: 1;

s4, placing the intermediate into a mixed solution prepared from graphene oxide, a carbon nano tube and a DMF solution, uniformly mixing, adding chloroplatinic acid, performing ultrasonic treatment for 20-30min, adding a reducing agent, performing water bath at 40-60 ℃ for 20-24h, and annealing to prepare the catalyst for the water electrolysis hydrogen production system, wherein the mass ratio of the graphene oxide, the carbon nano tube and the DMF solution is 1:1-2:10-20, the mass ratio of the intermediate to the mixed solution is 1:1-2, and the mass ratio of the chloroplatinic acid, the reducing agent and the graphene oxide is 0.02-0.05:0.4-0.8: 1.

2. The method for preparing the catalyst for the water electrolysis hydrogen production system according to claim 1, characterized in that: in step S1, the porous carbon material is prepared as follows:

placing 0.2-0.25 weight part of carbon nano tube in ethanol, carrying out ultrasonic dispersion for 25-30min to obtain a suspension, adding 3-4 weight parts of PMMA and 0.9-1 weight part of a dimethyl amide solution with the mass fraction of polyacrylonitrile being 1%, carrying out ultrasonic dispersion for 10-20min, heating to 80-90 ℃, calcining for 2-2.5h at the temperature of 350-400 ℃ in a nitrogen atmosphere, then calcining for 2-2.5h at the temperature of 750-800 ℃, and cooling to room temperature to obtain the porous carbon material.

3. The method for preparing the catalyst for the hydrogen production system by electrolyzing water according to claim 1, wherein the step S2 is specifically performed by: placing the porous carbon material in toluene, carrying out ultrasonic dispersion for 30-40min, adding a coupling agent, refluxing for 20-22h at the temperature of 130-150 ℃, centrifuging, and carrying out vacuum drying, wherein the mass ratio of the porous carbon material to the toluene to the coupling agent is 1-2:5-6: 0.4-0.5.

4. The method for preparing the catalyst for the system for producing hydrogen by electrolyzing water as claimed in claim 3, wherein the coupling agent is one or a combination of KH-570 silane coupling agent, KH-550 silane coupling agent and KH-560 silane coupling agent.

5. The method for preparing the catalyst for the hydrogen production system by electrolyzing water according to claim 1, wherein the graphene oxide is prepared by the following steps: putting graphene into a DMF solution, carrying out ultrasonic oscillation for 1-1.5h, adding ethylenediamine, carrying out water bath reflux for 10-12h at the temperature of 80-90 ℃, cooling to room temperature, washing with the DMF solution, and carrying out vacuum drying to obtain graphene oxide, wherein the mass ratio of the graphene to the DMF solution to the ethylenediamine is 2-3:1-2: 3-4.

6. The method for preparing the catalyst for the water electrolysis hydrogen production system according to claim 1, wherein in the step S4, after annealing, the catalyst is put into a mixed solution, uniformly stirred, separated, dried, roasted for 2-3 hours in an inert atmosphere, and then etched in an HF solution, the mixed solution is prepared by mixing ethyl orthosilicate, resorcinol, sodium carbonate and formaldehyde aqueous solution according to a mass ratio of 2-4:2.5-3:3-4:3-5, and the mass ratio of the catalyst to the mixed solution is 2-5: 5-7.

7. The method for preparing the catalyst for the hydrogen production system by electrolyzing water as claimed in claim 6, wherein the inert gas is argon, the temperature-raising speed during the calcination is 2-10 ℃/min, and the calcination temperature is 650-850 ℃.

8. The method for preparing the catalyst for the hydrogen production system by electrolyzing water as in claim 6, wherein the HF solution has a mass solubility of 5-10% and an etching time of 1-6 h.

9. A catalyst for a water electrolysis hydrogen production system, which is characterized by being prepared by the preparation method of the catalyst for the water electrolysis hydrogen production system according to any one of claims 1 to 8.

Background

Hydrogen energy has received much attention as a clean and renewable energy source with high energy, and among the numerous methods for producing hydrogen, electrochemical hydrolysis hydrogen production is a well-known, relatively simple and practical way. The electrocatalytic decomposition of water consists of two half reactions of hydrogen evolution reaction and oxygen evolution reaction, theoretically, only 1.23V of voltage can be generated, but actually, the applied voltage is 1.8-2.0V and is far higher than the theoretical voltage due to the generation of overpotential.

In industry, noble metals such as platinum, ruthenium, palladium, iridium and oxides thereof, such as ruthenium oxide or iridium oxide, are commonly used as catalysts to reduce the overpotential of oxygen evolution reaction, wherein the hydrogen production effect of platinum is optimal, and the content of noble metals such as platinum in earth crust is only 3.7 × 10^-6The noble metal catalyst is extremely rare and high in cost, and after the noble metal catalyst reacts for a period of time, the noble metal catalyst is easy to agglomerate and poor in dispersity, so that the structure of the catalyst is changed, and the catalytic performance of the catalyst is influenced.

In view of the above-mentioned related technologies, the inventors consider that the development of a catalyst having good stability and capable of reducing the amount of noble metal used as much as possible is an urgent problem to be solved.

Disclosure of Invention

In order to reduce the use amount of noble metals and improve the stability of the catalyst, the application provides the catalyst for the water electrolysis hydrogen production system and the preparation method thereof.

In a first aspect, the application provides a preparation method of a catalyst for a hydrogen production system by water electrolysis, which adopts the following technical scheme:

a preparation method of a catalyst for a water electrolysis hydrogen production system comprises the following steps:

s1, preparing a porous carbon material;

the interconnected pore structure of the porous carbon is favorable for the diffusion of related molecules of oxygen reduction reaction, and the carbon skeleton plays the role of electron conduction in the oxygen reduction process and is favorable for improving the electrocatalytic activity

S2, carrying out surface modification on the porous carbon material by using a coupling agent;

s3, mixing gamma-manganese dioxide, cobalt nitrate and nickel nitrate, adding absolute ethyl alcohol to form a mixed solution, adding the modified porous carbon material, dispersing uniformly, carrying out hydrothermal reaction at 100-200 ℃, adding a sulfur-containing compound solution with the concentration of 10-30%, mixing uniformly, filtering, adding the mixture into N, N-dimethylformamide, refluxing for 1-3h at 180-200 ℃, centrifuging, washing and drying to obtain an intermediate, wherein the mass ratio of the porous carbon material, the mixed solution and the sulfur-containing compound is 1-1.5:2-3:3-5, and the mass ratio of the nickel nitrate, the cobalt nitrate, the gamma-manganese dioxide and the absolute ethyl alcohol is 0.1-0.3:0.1-0.3:0.06-0.1: 1;

s4, placing the intermediate into a mixed solution prepared from graphene oxide, a carbon nano tube and a DMF solution, uniformly mixing, adding chloroplatinic acid, performing ultrasonic treatment for 20-30min, adding a reducing agent, performing water bath at 40-60 ℃ for 20-24h, and annealing to prepare the catalyst for the water electrolysis hydrogen production system, wherein the mass ratio of the graphene oxide, the carbon nano tube and the DMF solution is 1:1-2:10-20, the mass ratio of the intermediate to the mixed solution is 1:1-2, and the mass ratio of the chloroplatinic acid, the reducing agent and the graphene oxide is 0.02-0.05:0.4-0.8: 1.

By adopting the technical scheme, because the output of the transition metals of nickel, cobalt and manganese is high, the sale price of nickel is about 133000 yuan/ton, the sale price of cobalt is about 131800 yuan/ton, the sale price of manganese is about 6800 yuan/ton, the price of platinum is about $ 2000/ounce, the transition metal which is rich in content and more expensive is used to replace the more expensive platinum metal, so that the usage amount of the platinum metal is reduced, thereby saving the cost, adopting the porous carbon material as the framework, increasing the affinity of the porous carbon material and the transition metal oxide after the treatment of the coupling agent, preparing nickel sulfide and cobalt sulfide by using the nickel nitrate, the cobalt nitrate and the sulfur-containing compound to react, filling and loading the nickel sulfide and the cobalt sulfide in the pores of the porous carbon material, enhancing the hydrogen production effect, and gamma-manganese dioxide is used as a manganese source, and after the gamma-manganese dioxide is added, Ni-MnCo with smaller size can be generated.₂O4_.5Burs enable the surface of the porous carbon material to be fully loaded, so that excellent catalytic performance is shown; then, platinum is loaded by graphene oxide, oxygen-containing functional groups in the graphene oxide can be removed by annealing, the graphene oxide is converted into graphene, the graphene film is of a laminated structure, carbon nanotubes are positioned between graphene layers, due to pi-pi stacking effect and van der Waals force effect in the graphene, the graphene is endowed with good film-forming property, and porous carbon is used as a porous carbonThe graphene/carbon nanotube composite film is formed on the surface of the material, so that nickel sulfide, cobalt sulfide and Ni-MnCo are added₂O_4.5The stability between the burs and the porous carbon material and the carbon nano tube count can reduce the accumulation effect between graphene carbon atoms, increase the mechanical strength of the graphene film, increase the specific surface area of the graphene film and the interlayer spacing of the graphene carbon atoms, and the compactness of the carbon nano tube can be increased by the graphene, so that the catalytic activity of the catalyst is improved.

In addition, in the water electrolysis reaction, an acid solution is often adopted as an electrolyte, but nickel sulfide, cobalt sulfide and the like are easily dissolved in the acid solution, so that the catalytic activity and the stability are reduced, the transition metal oxide is wrapped in the graphene/carbon nanotube composite membrane to form a composite structure of the transition metal oxide and a carbon material, the problem of a solvent of the transition metal oxide in the acid solution can be effectively solved, the adjacent metal nanoparticles can be prevented from being polymerized, and the hydrogen production activity and the stability of the catalyst are improved.

Preferably, in step S1, the porous carbon material is prepared by the following steps:

placing 0.2-0.25 weight part of carbon nano tube in ethanol, carrying out ultrasonic dispersion for 25-30min to obtain a suspension, adding 3-4 weight parts of PMMA and 0.9-1 weight part of a dimethyl amide solution with the mass fraction of polyacrylonitrile being 1%, carrying out ultrasonic dispersion for 10-20min, heating to 80-90 ℃, calcining for 2-2.5h at the temperature of 350-400 ℃ in a nitrogen atmosphere, then calcining for 2-2.5h at the temperature of 750-800 ℃, and cooling to room temperature to obtain the porous carbon material.

By adopting the technical scheme, after roasting, the carbon nano tubes are wound and crosslinked into a macroporous structure with relatively uniform size, the aperture is about 20 mu m, the macropores on the surface of the porous carbon material are beneficial to uniformly attaching metal oxides in the pores, and cobalt sulfide, nickel sulfide and Ni-MnCo₂O_4.5The catalyst is loaded on the pore wall of the porous carbon material, so that the excellent conductivity of the carbon material is combined with the catalytic performance of the catalyst, the oxygen reduction performance of the catalyst is enhanced, and in the oxygen reduction process, macropores in the porous carbon material are beneficial to diffusion of reaction substances such as oxygen, hydroxyl, hydrogen ions and waterThe carbon skeleton can improve the conduction effect of electrons, the microporous structure can effectively accelerate electron transmission and ion diffusion, the super-capacitance performance of the material is effectively improved, and the high specific surface area can enable more electrocatalytic active sites to be exposed on the surface of the catalyst, so that the catalytic effect of the catalyst is improved.

Preferably, the specific method of step S2 is: placing the porous carbon material in toluene, carrying out ultrasonic dispersion for 30-40min, adding a coupling agent, refluxing for 20-22h at the temperature of 130-150 ℃, centrifuging, and carrying out vacuum drying, wherein the mass ratio of the porous carbon material to the toluene to the coupling agent is 1-2:5-6: 0.4-0.5.

By adopting the technical scheme, one end of the coupling agent molecular structure is inorganic and the other end is organic, so that hydroxyl in the coupling agent structure can generate firm bonding effect with hydroxyl on the surface of a porous carbon material, and double bonds contained at the other end of the coupling agent can be combined with nickel sulfide, cobalt sulfide and the like, so that the coupling agent can be used for erecting a molecular bridge between interfaces of metal oxides of the porous carbon material, connecting two materials with different properties together, and playing a role in improving the bonding strength of the porous carbon material and the nickel sulfide and cobalt sulfide, thereby improving the stability of the catalyst.

Preferably, the coupling agent is one or a combination of more of a KH-570 silane coupling agent, a KH-550 silane coupling agent and a KH-560 silane coupling agent.

Preferably, the preparation method of the graphene oxide is as follows: putting graphene into a DMF solution, carrying out ultrasonic oscillation for 1-1.5h, adding ethylenediamine, carrying out water bath reflux for 10-12h at the temperature of 80-90 ℃, cooling to room temperature, washing with the DMF solution, and carrying out vacuum drying to obtain graphene oxide, wherein the mass ratio of the graphene to the DMF solution to the ethylenediamine is 2-3:1-2: 3-4.

By adopting the technical scheme, when the metal platinum is loaded on the graphene oxide, the agglomeration phenomenon is very easy to occur, so that the activity of the catalyst is reduced, the hydrogen production efficiency by water electrolysis is reduced, in order to exert the excellent characteristics of the graphene and improve the dispersibility of the platinum, the ethylenediamine is used for carrying out amino functionalization on the graphene, the amino functionalized graphene not only keeps the excellent characteristics of the graphene crude oil, but also has a large number of polar groups on the surface, so that the platinum is more easily loaded on the surface, the binding force between the metal platinum and the graphene oxide can be increased, the metal platinum is uniformly dispersed on the surface, and the electrochemical characteristics of the catalyst are improved.

Preferably, in the step S4, after annealing, the catalyst is put into the mixed solution, stirred uniformly, separated, dried, calcined for 2 to 3 hours in an inert atmosphere, and then etched in an HF solution, wherein the mixed solution is prepared by mixing tetraethoxysilane, resorcinol, sodium carbonate and formaldehyde aqueous solution according to a mass ratio of 2-4:2.5-3:3-4:3-5, and the mass ratio of the catalyst to the mixed solution is 2-5: 5-7.

By adopting the technical scheme, the graphene oxide and platinum, the porous carbon material and nickel sulfide, cobalt sulfide and Ni-MnCo₂O_4.5The loaded catalyst particles are easy to migrate, agglomerate and grow so as to reduce or even lose catalytic activity, resorcinol and formaldehyde aqueous solution are used as catalysts to prepare high-temperature-resistant phenolic resin, tetraethoxysilane is added to increase the viscosity of the phenolic resin, the catalysts are wrapped in the phenolic resin, and then hydrofluoric acid is used for etching to generate micropores on the surface of the phenolic resin for diffusion of reaction related substances, so that the stability of the catalysts is further improved.

Preferably, the inert gas is argon, the temperature rise speed is 2-10 ℃/min during roasting, and the roasting temperature is 650-850 ℃.

By adopting the technical scheme, after roasting in the argon atmosphere, the solvent in the phenolic resin volatilizes, and the phenolic resin generates high carbon residue, which is beneficial to maintaining the structural stability of the phenolic resin.

Preferably, the mass solubility of the HF solution is 5-10%, and the etching time is 1-6 h.

By adopting the technical scheme, the hydrofluoric acid with the concentration is used for etching the phenolic resin, so that micropores can be generated on the surface of the phenolic resin, and the diffusion of related substances is facilitated.

In a second aspect, the application provides a catalyst for a hydrogen production system by water electrolysis, which adopts the following technical scheme:

a catalyst for a water electrolysis hydrogen production system is prepared by a preparation method of the catalyst for the water electrolysis hydrogen production system.

By adopting the technical scheme, the dosage of the noble metal platinum in the prepared catalyst is low, but the catalyst has good catalytic effect and high stability.

In summary, the present application has the following beneficial effects:

1. because the porous carbon material is adopted to load the transition metal oxides of nickel sulfide, cobalt sulfide and Ni-MnCo₂O_4.5Then, a graphene/carbon nanotube composite membrane loaded with platinum is formed on the surface of the porous carbon material, so that the activity of the catalyst is improved while the use amount of noble metal platinum is reduced, the binding force between the transition metal oxide and the porous carbon material is increased, and the stability of the catalyst is improved; in addition, the coated graphene/carbon nanotube composite membrane can prevent transition metal from being dissolved by acid electrolyte, can also avoid polymerization between adjacent metal nanoparticles, and improves the stability and hydrogen production activity of the catalyst.

2. In the application, the carbon nano tube is preferably adopted to prepare the porous carbon material, PMMA is taken as a pore-foaming agent, and after sintering, the carbon nano tube is wound and crosslinked to form a macroporous structure with relatively uniform size, so that nickel sulfide, cobalt sulfide and Ni-MnCo are facilitated₂O_4.5The porous carbon material is loaded in pores of the porous carbon material, so that the porous carbon material has excellent conductivity and catalytic activity.

3. According to the preparation method, the porous carbon material is treated by the coupling agent and then mixed with the nickel sulfate and other components for loading, the coupling agent can increase the binding force between the porous carbon material and the transition metal oxide, and the agglomeration between the transition metal oxides is prevented, so that the stability of the catalyst is improved.

4. According to the method, the catalyst is placed in ethyl orthosilicate, resorcinol, formalin and other components to be mixed, then roasting is carried out, phenolic resin is coated on the surface of the catalyst, the load acting force between platinum and graphene oxide or between a porous carbon material and a transition metal oxide can be prevented from weakening, so that the load particles are migrated and agglomerated, and the stability of the catalyst can be improved by coating the phenolic resin on the surface of the catalyst.

Detailed Description

Preparation examples 1 to 3 of porous carbon Material

Preparation examples 1-3 the carbon nanotubes were selected from Hebei ink Yu chemical Co., Ltd, model No. CN 2020; PMMA is selected from China Xin foaming plastic material Co., Ltd, Dongguan city, the model is CLEAR011, polyacrylonitrile is selected from Boyang thermal insulation material sales department, great city, the product number is 9000-1, and the length is 6 mm.

Preparation example 1: putting 0.2kg of carbon nano tube into 5kg of ethanol, carrying out ultrasonic dispersion for 25min at 200w power to obtain a suspension, adding 3kg of a dimethyl amide solution with 1% of PMMA and 0.9kg of polyacrylonitrile by mass fraction, carrying out ultrasonic dispersion for 10min at 200w power, heating to 80 ℃, heating to 350 ℃ at the speed of 5 ℃/min under the nitrogen atmosphere, calcining for 2.5h at 350 ℃, then heating for 30min, calcining for 2.5h at 750 ℃, and cooling to room temperature to obtain the porous carbon material.

Preparation example 2: putting 0.25kg of carbon nano tube into 6kg of ethanol, carrying out ultrasonic dispersion for 30min at the power of 250w to obtain a suspension, adding 3.5kg of a dimethyl amide solution with the mass fraction of PMMA and 1kg of polyacrylonitrile being 1%, carrying out ultrasonic dispersion for 20min at the power of 250w, heating to 90 ℃, heating to 380 ℃ at the speed of 5 ℃/min under the nitrogen atmosphere, calcining for 2h at 380 ℃, heating for 30min, calcining for 2h at 800 ℃, and cooling to room temperature to obtain the porous carbon material.

Preparation example 3: putting 0.25kg of carbon nano tube into 7kg of ethanol, carrying out ultrasonic dispersion for 30min at 200w to obtain a suspension, adding 4kg of a dimethyl amide solution with 1% of PMMA and 1kg of polyacrylonitrile by mass fraction, carrying out ultrasonic dispersion for 20min at 200w, heating to 90 ℃, heating to 400 ℃ at the speed of 5 ℃/min under the atmosphere of nitrogen, calcining for 2.5h at 400 ℃, heating for 30min, calcining for 2.5h at 800 ℃, and cooling to room temperature to obtain the porous carbon material.

Preparation examples 1 to 3 of graphene oxide

Preparation example 1: putting 2kg of graphene into 1kg of DMF solution, carrying out ultrasonic oscillation for 1.5h with the power of 320W, adding 3kg of ethylenediamine, carrying out water bath reflux for 12h at the temperature of 80 ℃, cooling to the room temperature, washing with the DMF solution, and carrying out vacuum drying for 4h at the temperature of 80 ℃ to obtain the graphene oxide, wherein the mass ratio of the graphene to the DMF solution to the ethylenediamine is 2-3:1-2: 3-4.

Preparation example 2: putting 2.5kg of graphene into 1.5kg of DMF solution, carrying out ultrasonic oscillation for 1.3h at the power of 360W, adding 3.5kg of ethylenediamine, refluxing in water bath at 85 ℃ for 11h, cooling to room temperature, washing with the DMF solution, and carrying out vacuum drying at 70 ℃ for 5h to obtain the graphene oxide.

Preparation example 3: putting 3kg of graphene into 2kg of DMF solution, carrying out ultrasonic oscillation for 1h at the power of 400W, adding 4kg of ethylenediamine, refluxing in a water bath for 10h at the temperature of 90 ℃, cooling to the room temperature, washing with the DMF solution, and carrying out vacuum drying for 6h at the temperature of 60 ℃ to obtain the graphene oxide.

Preparation example 1 of gamma-manganese dioxide

Preparation example 1: mixing and stirring 0.06moL/L potassium permanganate solution and 0.08moL/L manganese sulfate solution according to the volume ratio of 5:6 for 30min, standing for 30min until brown black is completely precipitated, performing suction filtration, washing with water until sulfate ions do not exist in the filtrate, drying the filter cake at 80 ℃, and crushing to obtain the gamma-manganese dioxide.

Examples

In the embodiment, the carbon nano tube is selected from Hebei ink Yu chemical Co., Ltd, and the model is CN 2020; the graphene oxide is selected from Shanghai Wanzhan Fine chemical Co., Ltd, and the model is WSG-M; the KH570 silane coupling agent is selected from Guangzhou Baozcheng New Material science and technology Limited; the KH550 silane coupling agent is selected from Fuquyi chemical engineering Co., Ltd; KH560 silane coupling agent is selected from Nanjing Xuan Hao New Material science and technology Limited

Example 1: the preparation method of the catalyst for the water electrolysis hydrogen production system comprises the following steps:

s1, preparing a porous carbon material, wherein the porous carbon material is selected from preparation example 1 of the porous carbon material;

s2, carrying out surface modification on the porous carbon material by using a coupling agent, wherein the specific operation method comprises the following steps: placing 1kg of porous carbon material in 5kg of toluene, ultrasonically dispersing for 30min at the power of 400W, adding 0.4kg of coupling agent, refluxing for 20h at 130 ℃, centrifuging for 5min at the rotating speed of 8000rpm, and vacuum drying for 6h at 60 ℃, wherein the silane coupling agent is KH570 silane coupling agent;

s3, mixing 0.06kg of gamma-manganese dioxide, 0.1kg of cobalt nitrate and 0.1kg of nickel nitrate, adding 1kg of absolute ethyl alcohol to form a mixed solution, adding 1kg of modified porous carbon material into 2kg of the mixed solution, dispersing uniformly, performing hydrothermal reaction at 100 ℃ for 3 hours, adding 3kg of sulfur-containing compound solution with the concentration of 10%, mixing uniformly, filtering, adding into 10kg of N, N-dimethylformamide, refluxing at 180 ℃ for 3 hours, centrifuging, washing and drying to obtain an intermediate, wherein the gamma-manganese dioxide is prepared from preparation example 1 of gamma-manganese dioxide;

s4, putting 1kg of intermediate into 1kg of mixed solution, mixing the mixed solution with 1kg of graphene oxide, 1kg of carbon nano tube and 10kg of DMF solution, uniformly mixing the intermediate and the mixed solution, adding 0.02kg of chloroplatinic acid, performing ultrasonic treatment at 250W for 30min, adding 0.4kg of reducing agent, performing water bath at 40 ℃ for 24h, and annealing at 200 ℃ for 1h to obtain the catalyst for the hydrogen production system by electrolyzing water.

Example 2: a catalyst for hydrogen production from electrolyzed water, which is different from example 1 in that, in step S1, a porous carbon material was produced from preparation example 2 of a porous carbon material.

Example 3: a catalyst for hydrogen production from electrolyzed water, which is different from example 1 in that, in step S1, a porous carbon material was produced from preparation example 3 of a porous carbon material.

Example 4: a catalyst for hydrogen production from electrolyzed water, which is different from that of example 1 in that in step S1, the porous carbon material is selected from commercially available products, selected from Shanghai Wan Fine chemical Co., Ltd., model number WSG-C81.

Example 5: a catalyst for an electrolytic water hydrogen production system is different from that of the embodiment 1 in that in step S1, a porous carbon material is prepared by carbonizing molasses with the concentration of 52.5% at 180 ℃ for 4 hours, then carrying out suction filtration, washing and drying, then mixing the carbonized molasses with potassium hydroxide according to the mass ratio of 1:3, activating at 800 ℃ for 2 hours, washing and drying.

Example 6: the preparation method of the catalyst for the water electrolysis hydrogen production system comprises the following steps:

s1, preparing a porous carbon material, wherein the porous carbon material is selected from preparation example 1;

s2, carrying out surface modification on the porous carbon material by using a coupling agent, wherein the specific operation method comprises the following steps: placing 1.5kg of porous carbon material in 5.5kg of toluene, ultrasonically dispersing for 30min at the power of 400W, adding 0.5kg of coupling agent, refluxing for 20h at 130 ℃, centrifuging for 5min at the rotating speed of 8000rpm, and vacuum drying for 6h at 60 ℃, wherein the silane coupling agent is KH550 silane coupling agent;

s3, mixing 0.08kg of gamma-manganese dioxide, 0.2kg of cobalt nitrate and 0.2kg of nickel nitrate, adding 1kg of absolute ethyl alcohol to form a mixed solution, adding 1.3kg of modified porous carbon material into 2.5kg of the mixed solution, dispersing uniformly, carrying out hydrothermal reaction at 100 ℃ for 3h, adding 4kg of sulfur-containing compound solution with the concentration of 10%, mixing uniformly, filtering, adding into 10kg of N, N-dimethylformamide, refluxing at 180 ℃ for 3h, centrifuging, washing and drying to obtain an intermediate, wherein the gamma-manganese dioxide is prepared by preparation example 1 of gamma-manganese dioxide;

s4, putting 1kg of intermediate into 1.5kg of mixed solution, mixing the mixed solution with 1kg of graphene oxide, 1.5kg of carbon nano tube and 15kg of DMF solution, uniformly mixing the intermediate and the mixed solution, adding 0.04kg of chloroplatinic acid, performing ultrasonic treatment for 30min under 250W, adding 0.6kg of reducing agent, performing water bath for 24h at 40 ℃, and annealing for 1h at 200 ℃ to obtain the catalyst for the hydrogen production system by electrolyzing water.

Example 7: the preparation method of the catalyst for the water electrolysis hydrogen production system comprises the following steps:

s1, preparing a porous carbon material, wherein the porous carbon material is selected from preparation example 1;

s2, carrying out surface modification on the porous carbon material by using a coupling agent, wherein the specific operation method comprises the following steps: placing 2kg of porous carbon material in 6kg of toluene, carrying out ultrasonic dispersion for 30min at the power of 400W, adding 0.5kg of coupling agent, refluxing for 20h at 130 ℃, centrifuging for 5min at the rotating speed of 8000rpm, and carrying out vacuum drying for 6h at 60 ℃, wherein the silane coupling agent is KH560 silane coupling agent;

s3, mixing 0.1kg of gamma-manganese dioxide, 0.3kg of cobalt nitrate and 0.3kg of nickel nitrate, adding 1kg of absolute ethyl alcohol to form a mixed solution, adding 1.5kg of modified porous carbon material into 3kg of the mixed solution, dispersing uniformly, performing hydrothermal reaction at 100 ℃ for 3 hours, adding 5kg of sulfur-containing compound solution with the concentration of 10%, mixing uniformly, filtering, adding into 10kg of N, N-dimethylformamide, refluxing at 180 ℃ for 3 hours, centrifuging, washing and drying to obtain an intermediate, wherein the gamma-manganese dioxide is prepared by the preparation example 1 of gamma-manganese dioxide;

s4, putting 1kg of intermediate into 2kg of mixed solution, mixing the mixed solution with 1kg of graphene oxide, 2kg of carbon nano tube and 20kg of DMF solution, uniformly mixing the intermediate and the mixed solution, adding 0.05kg of chloroplatinic acid, performing ultrasonic treatment at 250W for 30min, adding 0.8kg of reducing agent, performing water bath at 40 ℃ for 24h, and annealing at 200 ℃ for 1h to obtain the catalyst for the hydrogen production system by electrolyzing water.

Example 8: the preparation method of the catalyst for the water electrolysis hydrogen production system comprises the following steps:

s1, preparing a porous carbon material, wherein the porous carbon material is selected from preparation example 1;

s2, carrying out surface modification on the porous carbon material by using a coupling agent, wherein the specific operation method comprises the following steps: placing 1kg of porous carbon material in 5kg of toluene, carrying out ultrasonic dispersion for 40min at 200W, adding 0.4kg of coupling agent, refluxing for 22h at 150 ℃, centrifuging for 5min at 8000rpm, and carrying out vacuum drying for 5h at 80 ℃, wherein the silane coupling agent is KH570 silane coupling agent and KH550 silane coupling agent with the mass ratio of 1: 1;

s3, mixing 0.06kg of gamma-manganese dioxide, 0.1kg of cobalt nitrate and 0.1kg of nickel nitrate, adding 1kg of absolute ethyl alcohol to form a mixed solution, adding 1kg of modified porous carbon material into 2kg of the mixed solution, performing hydrothermal reaction at 150 ℃ for 2 hours after uniform dispersion, adding 3kg of a sulfur-containing compound solution with the concentration of 30%, uniformly mixing, filtering, adding into 10kg of N, N-dimethylformamide, refluxing at 200 ℃ for 1 hour, centrifuging, washing and drying to obtain an intermediate, wherein the gamma-manganese dioxide is prepared from preparation example 1 of gamma-manganese dioxide;

s4, putting 1kg of intermediate into 1kg of mixed solution, mixing the mixed solution with 1kg of graphene oxide, 1kg of carbon nano tube and 10kg of DMF solution, uniformly mixing the intermediate and the mixed solution, adding 0.2kg of chloroplatinic acid, performing ultrasonic treatment at 300W for 20min, adding 0.4kg of reducing agent, performing water bath at 60 ℃ for 20h, and annealing at 200 ℃ for 1h to obtain the catalyst for the hydrogen production system by electrolyzing water.

Example 9: the preparation method of the catalyst for the water electrolysis hydrogen production system comprises the following steps:

s1, preparing a porous carbon material, wherein the porous carbon material is selected from preparation example 1;

s2, carrying out surface modification on the porous carbon material by using a coupling agent, wherein the specific operation method comprises the following steps: placing 1kg of porous carbon material in 5kg of toluene, carrying out ultrasonic dispersion for 35min at the power of 300W, adding 0.4kg of coupling agent, refluxing for 21h at 140 ℃, centrifuging for 5min at the rotating speed of 8000rpm, and carrying out vacuum drying for 5.5h at 70 ℃, wherein the silane coupling agent is KH570 silane coupling agent and KH550 silane coupling agent with the mass ratio of 1: 1;

s3, mixing 0.06kg of gamma-manganese dioxide, 0.1kg of cobalt nitrate and 0.1kg of nickel nitrate, adding 1kg of absolute ethyl alcohol to form a mixed solution, adding 1kg of modified porous carbon material into 2kg of the mixed solution, dispersing uniformly, performing hydrothermal reaction at 200 ℃ for 2 hours, adding 3kg of a sulfur-containing compound solution with the concentration of 30%, mixing uniformly, filtering, adding into 10kg of N, N-dimethylformamide, refluxing at 190 ℃ for 2 hours, centrifuging, washing and drying to obtain an intermediate, wherein the gamma-manganese dioxide is prepared from preparation example 1 of gamma-manganese dioxide;

s4, putting 1kg of intermediate into 1kg of mixed solution, mixing the mixed solution with 1kg of graphene oxide, 1kg of carbon nano tube and 10kg of DMF solution, uniformly mixing the intermediate and the mixed solution, adding 0.2kg of chloroplatinic acid, carrying out ultrasonic treatment at 280W for 25min, adding 0.4kg of reducing agent, carrying out water bath at 50 ℃ for 22h, and annealing at 200 ℃ for 1h to obtain the catalyst for the hydrogen production system by electrolyzing water.

Example 10: a catalyst for hydrogen production by electrolysis of water, which is different from example 1 in that graphene oxide is prepared from preparation example 1 of graphene oxide in step S4.

Example 11: a catalyst for hydrogen production by electrolysis of water, which is different from example 1 in that graphene oxide is prepared from preparation example 2 of graphene oxide in step S4.

Example 12: a catalyst for hydrogen production by electrolysis of water, which is different from example 1 in that graphene oxide is produced from preparation example 3 of graphene oxide in step S4.

Example 13: a catalyst for a water electrolysis hydrogen production system is different from that in the embodiment 10, in the step S4, after annealing, 2kg of the catalyst is put into a mixed solution of 3kg of absolute ethyl alcohol and 0.2kg of strong ammonia water with the mass concentration of 28%, after ultrasonic homogenization, 5kg of a mixed solution consisting of 2kg of ethyl orthosilicate, 2.5kg of resorcinol, 3kg of sodium carbonate and 3kg of formaldehyde water with the mass concentration of 40% is added, after stirring homogenization, separation and drying are carried out, under the argon atmosphere, the temperature is raised to 650 ℃ at the temperature raising rate of 2 ℃/min, roasting is carried out for 3h, and then etching is carried out for 6h in an HF solution with the mass concentration of 5%.

Example 14: a catalyst for a water electrolysis hydrogen production system is different from that in the embodiment 10, in the step S4, after annealing, 4kg of the catalyst is put into a mixed solution of 3kg of absolute ethyl alcohol and 0.2kg of strong ammonia water with the mass concentration of 28%, after ultrasonic homogenization, 6kg of a mixed solution consisting of 3kg of ethyl orthosilicate, 2.8kg of resorcinol, 3.5kg of sodium carbonate and 4kg of formaldehyde water with the mass concentration of 40% is added, after stirring homogenization, separation and drying are carried out, under the atmosphere of argon, the temperature is raised to 750 ℃ at the temperature raising rate of 6 ℃/min, roasting is carried out for 2h, and then etching is carried out for 4h in an HF solution with the mass concentration of 8%.

Example 15: a catalyst for a hydrogen production system by water electrolysis is different from that of embodiment 10 in that, in step S4, after annealing, 5kg of the catalyst is put into a mixed solution of 3kg of absolute ethyl alcohol and 0.2kg of strong ammonia water with the mass concentration of 28%, after ultrasonic homogenization, 7kg of a mixed solution consisting of 4kg of ethyl orthosilicate, 3kg of resorcinol, 4kg of sodium carbonate and 5kg of formaldehyde water with the mass concentration of 40% is added, after stirring homogenization, separation and drying are carried out, the temperature is raised to 850 ℃ at the temperature raising rate of 10 ℃/min under the argon atmosphere, roasting is carried out for 1h, and then etching is carried out for 1h in an HF solution with the mass concentration of 10%.

Comparative example

Comparative example 1: a catalyst for hydrogen production by electrolysis of water, which is different from example 1 in that carbon fibers of equal mass are substituted for a porous carbon material in step S2.

Comparative example 2: a catalyst for an electrolytic water hydrogen production system, which is different from example 1 in that step S2 is not included.

Comparative example 3: a catalyst for hydrogen production by electrolysis of water, which is different from example 1 in that γ -manganese dioxide is not added in step S3.

Comparative example 4: a catalyst for a hydrogen production system by electrolyzing water, which is different from example 1 in that nickel nitrate is not added in step S3.

Comparative example 5: a catalyst for a hydrogen production system by electrolyzing water, which is different from example 1 in that cobalt nitrate is not added in step S3.

Comparative example 6: a catalyst for a hydrogen production system by electrolyzing water, which is different from example 1 in that step S4 is not performed.

Comparative example 7: a catalyst for a hydrogen production system by electrolyzing water, which is different from example 1 in that graphene oxide is not added in step S4.

Comparative example 8: a catalyst for hydrogen production by electrolysis of water, which is different from example 1 in that carbon nanotubes are not added in step S4.

Comparative example 9: a catalyst for hydrogen production by water electrolysis is prepared by weighing 1g of chloroplatinic acid hexahydrate and dissolving in 250mL of deionized water to prepare a chloroplatinic acid solution; weighing 3g of copper nitrate trihydrate and dissolving the copper nitrate trihydrate in 250mL of deionized water to prepare a copper nitrate solution; weighing 18.75g of trisodium citrate dihydrate, and dissolving in 250mL of deionized water to prepare a sodium citrate solution; and preparing a sodium borohydride aqueous solution with the concentration of 0.15mol/L in an ice bath environment.

30mg of VXC-72 carbon black was weighed and dispersed in 500mL of deionized water by ultrasonic dispersion. 4.05mL of the above-prepared chloroplatinic acid solution, 28.36mL of the copper nitrate solution and 40mL of the trisodium citrate dihydrate solution were measured, added thereto, and stirred for 2 hours. And (3) placing the mixed solution in an ice bath environment, stirring and introducing nitrogen for protection. After stirring for 1 hour, 52mL of the aqueous sodium borohydride solution prepared above was added dropwise. And continuously stirring for 8-10 hours in an ice bath environment and under the nitrogen protection atmosphere, and stopping the reaction. And separating solid particles by a vacuum filtration device. Washing the obtained product with deionized water for 6-8 times, drying, and grinding for later use. Namely a PtCu/C catalyst (Pt0.1Cu0.9/C) with a mass ratio of Pt to Cu of 1: 9.

Comparative example 10: selected from platinum-carbon catalysts sold by Ningbo science, Innovation energy science and technology, Inc., having a product number of HiCaP 10.

Performance test A catalyst was prepared in accordance with each example and each comparative example, and according to the test using the catalyst prepared in each example or comparative example as a working electrode, a carbon rod as a counter electrode, a saturated calomel electrode as a reference electrode, 1mol/l potassium hydroxide as an electrolyte, an electrochemical workstation (CHI760E) as a test instrument, and a current density at different points was measured using cyclic voltammetry at a scanning rate of 5mV/s as shown in Table 1, and the area of the electrode material immersed in the electrolyte was 1cm during the test²(ii) a The preparation method of the working electrode comprises the following steps: the catalyst prepared in each example or comparative example was accurately weighed at 7mg, 2mg of conductive carbon black in a mortar, ground for 20 minutes, added with 50uL of a binder solution (prepared by dissolving 0.2g of PVDF in 10mL of NMP), continuously ground, and then coated on a surface of 1cm²And drying the nickel foam in a vacuum drying oven for 12 hours.

While examining the current density of the catalyst prepared in each example and each comparative example in a KOH electrolyte of 1mol/L at 10mA/cm²Stability tests were performed under the conditions.

TABLE 1 electrolytic data for catalysts

From the porous carbon materials prepared in examples 1 to 3 using the porous carbon materials of the present application in preparation examples 1 to 3, current densities at different potentials in Table 1 were found to be 10mA/cm²In the case of examples 1 to 3, the overpotential was about 1.48V, the case of example 4 was a commercially available porous carbon material, and the case of example 5 was a porous carbon material prepared by using molasses, and the overpotential was about 1.52V, which was larger than that of examples 1 to 3, at 10mA/cm2 in examples 4 and 5, compared to examples 1 to 3, and therefore, the porous carbon materials prepared in examples 1 to 3 had better activity.

Catalysts prepared in examples 6-9Agent when the current density is 10mA/cm²The overpotential was not much different from that of examples 1 to 3, and the catalysts of examples 10 to 12 had a current density of 10mA/cm²When the overvoltage was about 1.45V, the current density of the catalyst in examples 13 to 15 reached 10mA/cm²The overvoltage was about 1.41, and the catalytic activity was superior to that of examples 1 to 12.

In comparative example 1, equal-quality carbon fibers are used to replace the porous carbon material, and the overpotential of the catalyst prepared in comparative example 1 is reduced, so that the catalytic activity is reduced.

In comparative example 2 in which the porous carbon material was not treated with the coupling agent, it was shown from the data in Table 1 that the catalyst in comparative example 2 reached a current density of 10mA/cm²When the overpotential is about 1.49V, the catalytic activity is reduced as compared with example 1.

The catalysts prepared in comparative examples 3 to 5, to which gamma-manganese dioxide, nickel nitrate and cobalt nitrate were not added in comparative example 3, comparative example 4 and comparative example 5, respectively, had current densities of 10mA/cm at a potential of 1.5V²And so its catalytic activity is less than that of example 1.

In comparative example 6, the graphene oxide, the carbon nanotube and the chloroplatinic acid are not used for carrying and coating, and in comparative example 6, the current density of the catalyst is only 8.65mA/cm at the potential of 1.5V²When the current density reaches 10mA/cm²When it is used, its potential value is large, and therefore its catalytic activity is poor.

The data in table 1 show that the catalysts prepared in comparative example 7 and comparative example 8 reach a current density of 10mA/cm without adding graphene oxide and without adding carbon nanotubes in comparative example 7 and comparative example 8²When the potential was about 1.49V, which was larger than that in example 1, the catalytic activity was decreased.

Comparative example 9 is a catalyst prepared by the prior art, comparative example 10 is a commercially available carbon platinum catalyst, and it can be seen from comparative example 1, comparative example 9 and comparative example 10 that the current density reached 10mA/cm²When it is used, its potential is higher than that of example 1, and therefore its catalytic activity is inferior to that of the present application.

TABLE 2 stability testing of catalysts

Examples 1 to 3 Using the porous carbon materials prepared in the present application, respectively, in a KOH solution of 1mol/L at 10mA/cm²Under the current density, the voltage value is 1.48-1.49V in 10 hours, the voltage value is 1.54-1.56 in 30 hours, the growth rate is 3.4-5.4%, the potential value is not changed greatly, and the stability is better.

Example 4 is a commercially available porous carbon material, example 5 is a porous carbon material prepared by using molasses, and the catalyst prepared in examples 4 to 5 was used in a KOH solution of 1mol/L at a concentration of 10mA/cm in comparison with examples 1 to 3²The fluctuation in potential at the current density was large, and after 30 hours of use, the voltages of examples 4 and 5 were 1.68V and 1.69V, and the voltage increase rate of example 4 was 10.52% and the voltage increase rate of example 5 was 10.45% compared to 10 hours, and the stability was inferior to that of example 1.

The catalysts of examples 6-9 had a voltage of 1.54-1.56V after 30 hours of use and a voltage of 1.1.47-1.49 at 10 hours, and the rate of voltage increase was comparable to that of example 1.

In examples 10 to 12, the voltage of the graphene oxide prepared by the present application was 1.45 to 1.46V after 10 hours of use, and after 30 hours of use, the voltage was 1.50 to 1.51V, and the voltage increase rate was 2.74 to 4.13%.

Examples 13 to 15 the stability of the catalysts obtained by post-treating the catalysts with a phenol resin was improved in addition to example 10, and after the test for 30 hours, the constant potential at a constant current density of 10mA/cm2 was 1.42 to 1.43V, and the change value was not large as compared with that in 10 hours, which shows that the stability of examples 13 to 15 was further improved as compared with examples 1 and 10.

In comparative example 1, equal mass of carbon fiber is used to replace the porous carbon material, and comparison shows that the voltage increase rate in comparative example 1 is 9.8%, and the voltage change rate is obviously increased compared with that in example 1, which indicates that the stability of the carbon fiber is inferior to that in example 1 of the present application.

The porous carbon material of comparative example 2, which was treated without using a coupling agent, had a voltage increase rate of 4.7% which was not much different from those of examples 1 to 3.

In comparative example 3, comparative example 4 and comparative example 5, in which gamma-manganese dioxide, nickel nitrate and cobalt nitrate were not added, respectively, the voltage increase rates of the catalysts prepared in comparative examples 3 to 5 were not greatly changed as compared with those of examples 1 to 3.

In comparative example 6, the graphene oxide, the carbon nanotube and the chloroplatinic acid were not used for loading and coating, the voltage was 1.71V after 30 hours of use, and the growth rate was 12%, the change rate was large and the stability was decreased compared with 10 hours of use.

In comparative example 7, no graphene oxide was added, in comparative example 8, no carbon nanotube was added, and in comparative examples 7 to 8, the voltage change was large after 30 hours of use and the stability was decreased, as compared with example 1.

Comparative example 9 is a platinum-carrying catalyst prepared by the prior art, comparative example 10 is a commercially available carbon platinum catalyst, and comparative example 9 and comparative example 10 have a large potential change value and poor stability at 25 hours, compared with example 1.

The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.