阅读说明：本技术 铁单原子掺杂碳材料负载金属纳米簇复合催化剂及其制备方法与应用 (Iron single atom doped carbon material loaded metal nano-cluster composite catalyst and preparation method and application thereof ) 是由 孙源卿 刘坚 罗佳庆 马靖文 徐春明 于 2021-09-29 设计创作，主要内容包括：本发明提供一种铁单原子掺杂碳材料负载金属纳米簇复合催化剂及其制备方法与应用。该制备方法包括：获取多孔导电载体上负载有铁掺杂碳前驱体的基底材料；将金属纳米簇负载到基底材料上,然后进行高温热解到所述铁单原子掺杂碳材料负载金属纳米簇复合催化剂。所述催化剂为包括多孔导电载体、铁单原子掺杂碳材料和金属纳米簇的复合材料。铁单原子掺杂碳材料负载金属纳米簇复合催化剂用于催化电解水阴极析氢反应和阳极析氧反应中的至少一者。本发明提供的铁单原子掺杂碳材料负载金属纳米簇复合催化剂催化活性高、稳定性好、合成方法简单。(The invention provides an iron single atom doped carbon material loaded metal nano-cluster composite catalyst, and a preparation method and application thereof. The preparation method comprises the following steps: obtaining a substrate material loaded with an iron-doped carbon precursor on a porous conductive carrier; and loading the metal nanoclusters on a substrate material, and then carrying out high-temperature pyrolysis to obtain the iron monoatomic doped carbon material loaded metal nanocluster composite catalyst. The catalyst is a composite material comprising a porous conductive carrier, an iron single atom doped carbon material and a metal nanocluster. The iron single atom doped carbon material loaded metal nano-cluster composite catalyst is used for catalyzing at least one of cathode hydrogen evolution reaction and anode oxygen evolution reaction of electrolyzed water. The iron monoatomic doped carbon material loaded metal nano-cluster composite catalyst provided by the invention has the advantages of high catalytic activity, good stability and simple synthesis method.)

1. A preparation method of an iron monatomic doped carbon material loaded metal nanocluster composite catalyst comprises the following steps:

obtaining a substrate material loaded with an iron-doped carbon precursor on a porous conductive carrier;

and loading the metal nanoclusters on a substrate material, and then carrying out high-temperature pyrolysis to obtain the iron monoatomic doped carbon material loaded metal nanocluster composite catalyst.

2. The production method according to claim 1, wherein the metal nanoclusters include one or a combination of two or more of Au nanoclusters, Pt nanoclusters, Pd nanoclusters, Ag nanoclusters, and Cu nanoclusters.

3. The production method according to claim 1 or 2, wherein the metal nanoclusters are produced by:

mixing a first solvent, a metal salt, a stabilizer and a reducing agent, adjusting the pH value to be alkalescent, and carrying out reduction reaction to obtain a mixed solution; adding a precipitator into the mixed solution to obtain a precipitate, namely the metal nanocluster;

preferably, the stabilizer comprises one or more of glutathione, bovine serum albumin, polymethyl acrylate and polyacrylic acid;

preferably, the reducing agent comprises one or a combination of more than two of hydrazine hydrate, sodium borohydride and citric acid;

preferably, the metal salt comprises Au³⁺Salt, Pt⁴⁺Salt, Pd²⁺Salt, Ag⁺Salt and Cu²⁺One or a combination of two or more of the salts; more preferably, the metal salt comprises HAuCl₄、H₂PtCl₆、Na₂PdCl₄、PdCl₂、AgNO₃、CH₃COOAg、AgF、Ag₂SO₄、AgClO₄、CuCl₂、CuNO₃、CuSO₄And CH₃One or a combination of two or more of COOCu;

more preferably, the molar ratio of the stabilizer, the reducing agent and the metal ions in the metal salt is 5-30:1-20: 1;

preferably, the reduction reaction is carried out at 60-90 ℃;

preferably, isopropanol is selected as the precipitating agent.

4. The production method according to claim 1, wherein the porous conductive support has a three-dimensional network structure; preferably, the porous conductive carrier is one or a combination of more than two of foamed nickel, foamed copper and graphene foam materials.

5. The production method according to claim 1 or 4, wherein the iron monoatomic doped carbon material is further doped with a nitrogen element;

preferably, the iron-doped carbon precursor is iron-doped polypyrrole;

more preferably, the base material having the iron-doped carbon precursor supported on the porous conductive support comprises:

mixing a second solvent, a pyrrole monomer and a ferric ion salt, and polymerizing on a porous conductive carrier by taking the ferric ion salt as an initiator to obtain the substrate material through reaction;

preferably, the ferric ion salt is FeCl₃；

Preferably, the molar ratio of the pyrrole monomer to the ferric ion is 5:1-20: 1;

preferably, the pyrrole monomer and the porous conductive carrier are used in a ratio of 0.01g to 1cm²-0.5g:1cm²；

Preferably, the porous conductive carrier is pretreated before use to remove a surface oxide layer and hetero ions;

preferably, the reaction temperature of the polymerization is 10 to 60 ℃.

6. The production method according to claim 1 or 3, wherein the supporting of the metal nanoclusters to the base material is achieved by means of impregnation; preferably, the loading of the metal nanoclusters onto the base material includes:

dipping the substrate material into the dispersion liquid of the metal nanoclusters for a period of time to realize loading of the metal nanoclusters to the substrate material; wherein, in the dispersion liquid of the metal nanocluster, the volume of the dispersion liquid of the metal nanocluster is taken as a reference, and the concentration of the metal nanocluster is 0.75mmol/L-15 mmol/L.

7. The production method according to claim 1 or 3,

the high-temperature pyrolysis is carried out under a protective atmosphere;

the temperature of the high-temperature pyrolysis is 300-600 ℃.

8. An iron single atom doped carbon material loaded metal nano-cluster composite catalyst is a composite material comprising a porous conductive carrier, an iron single atom doped carbon material and a metal nano-cluster;

preferably, the metal nanoclusters comprise one or a combination of more than two of Au nanoclusters, Pt nanoclusters, Pd nanoclusters, Ag nanoclusters and Cu nanoclusters;

preferably, the porous conductive support has a three-dimensional network structure; more preferably, the porous conductive carrier is foamed nickel;

preferably, the iron monatomic doped carbon material is further doped with a nitrogen element;

preferably, the average particle size of the metal nanoclusters is 3 to 6 nm.

9. The catalyst according to claim 8, wherein the iron monatomic doped carbon material-supported metal nanocluster composite catalyst is prepared by the method for preparing an iron monatomic doped carbon material-supported metal nanocluster composite catalyst according to any one of claims 1 to 7.

10. The use of the iron monatomic doped carbon material-supported metal nanocluster composite catalyst according to claim 8 or 9 in an electrolyzed water reaction, wherein the iron monatomic doped carbon material-supported metal nanocluster composite catalyst is used for catalyzing at least one of a cathodic hydrogen evolution reaction and an anodic oxygen evolution reaction of the electrolyzed water.

Technical Field

The invention belongs to the technical field of catalyst preparation, and particularly relates to an iron single atom doped carbon material loaded metal nanocluster composite catalyst, and a preparation method and application thereof.

Background

Hydrogen energy is used as an efficient and clean renewable energy source, and a hydrogen production technology gradually becomes a hot spot of worldwide research. The hydrogen production by water electrolysis is a clean, efficient, sufficient-raw-material and sustainable new energy technology, and is an effective way for solving the current energy problems and environmental problems. However, the two half reactions involved in the water splitting reaction make the water splitting reaction difficult to proceed due to the slow reaction kinetics, and the industrialization of the water electrolysis hydrogen production technology is greatly limited. The overpotential of Hydrogen Evolution Reaction (HER) and Oxygen Evolution Reaction (OER) can be reduced by coating the catalyst on the cathode and the anode of the electrolytic cell, the voltage required by water electrolysis is reduced, the water electrolysis efficiency is effectively improved, and the water electrolysis reaction is promoted to be carried out. Therefore, it has become one of the focuses of current scientific research to design and develop an efficient, stable, and low-cost catalyst for electrolyzing water.

The research reports that the full-hydrolysis water catalyst can be divided into a noble metal catalyst and a non-noble metal catalyst. At present, the best performance of the noble metal catalyst is mainly Pt catalyst, such as Pt/NiO @ Ni/NF and Pt @ DNA-GC; the non-noble metal catalyst is mainly a catalyst composed of transition metal and phosphorus, sulfur, boron, carbon, nitrogen, etc., such as Fe-N-C, NiFe₂O₄@ MOF-74, and the like. TheseThe catalyst can effectively reduce the overpotential of the electrolytic water reaction, but the preparation process of the catalytic material is more complicated and harsh, and the self reaction stability of the catalyst still needs to be further improved.

Therefore, the development of an electrolytic water catalyst with simple and convenient preparation process, excellent catalytic performance and stable reaction process is still a problem to be solved in the field.

Disclosure of Invention

The invention aims to provide an electrocatalytic full-hydrolysis catalyst with high catalytic activity, good stability and simple synthesis method and a preparation method thereof.

In order to achieve the above object, the present invention provides a method for preparing a metal nanocluster composite catalyst supported by an iron monatomic doped carbon material, comprising:

obtaining a substrate material loaded with an iron-doped carbon precursor on a porous conductive carrier;

and loading the metal nanoclusters on a substrate material, and then carrying out high-temperature pyrolysis to obtain the iron monoatomic doped carbon material loaded metal nanocluster composite catalyst.

According to the preparation method, the metal nanoclusters are loaded on a special substrate material (the substrate material of the porous conductive carrier loaded with the iron-doped carbon precursor is a self-supporting catalyst substrate simultaneously containing iron and carbon elements), and the special catalyst material taking the porous conductive carrier as the substrate and the iron single-atom-doped carbon material loaded metal nanoclusters as the loading component is obtained through high-temperature pyrolysis. The catalyst material can be effectively used as an electrocatalytic full-hydrolysis catalyst.

In the preparation method, after the metal nanoclusters are loaded on a special substrate material (the substrate material is a self-supporting catalyst substrate which contains iron and carbon elements and is a substrate with an iron-doped carbon precursor loaded on a porous conductive carrier) and subjected to high-temperature pyrolysis, the iron-doped carbon precursor which plays a role in stabilizing the surface of the metal nanoclusters is carbonized, the metal nanoclusters can be highly dispersed in a carbon material, the average particle size is about 3-6nm in a better embodiment, and the high utilization efficiency of the metal elements is realized.

In the above preparation method, preferably, the metal nanoclusters include one or a combination of two or more of Au nanoclusters, Pt nanoclusters, Pd nanoclusters, Ag nanoclusters, Cu nanoclusters, and the like.

In the above preparation method, preferably, the metal nanoclusters are prepared by:

mixing a first solvent, a metal salt, a stabilizer and a reducing agent, adjusting the pH value to be alkalescent, and carrying out reduction reaction to obtain a mixed solution; adding a precipitator into the mixed solution to obtain a precipitate, namely the metal nanocluster;

more preferably, the stabilizer comprises one or more of glutathione, bovine serum albumin, polymethyl acrylate, polyacrylic acid and the like; further preferably, the stabilizing agent is glutathione;

more preferably, the reducing agent comprises one or a combination of two or more of hydrazine hydrate, sodium borohydride, citric acid and the like; further preferably, the reducing agent is hydrazine hydrate;

more preferably, the metal salt comprises Au³⁺Salt, Pt⁴⁺Salt, Pd²⁺Salt, Ag⁺Salt and Cu²⁺One or a combination of two or more of salts and the like; more preferably, the metal salt comprises HAuCl₄、H₂PtCl₆、Na₂PdCl₄、PdCl₂、AgNO₃、CH₃COOAg、AgF、Ag₂SO₄、AgClO₄、CuCl₂、CuNO₃、CuSO₄And CH₃COOCu and the like;

more preferably, the molar ratio of the stabilizer, the reducing agent and the metal ions in the metal salt is 5-30:1-20: 1;

more preferably, the reduction reaction is carried out at 60-90 ℃ (e.g., at 80 ℃);

more preferably, the first solvent is water;

more preferably, the precipitating agent is isopropanol;

more preferably, the addition volume of the precipitant is 3 times or more the volume of the mixed solution;

in a specific embodiment, a proper amount of metal ion solution is dispersed in 5-10mL of water, stabilizer glutathione and reducing agent hydrazine hydrate are added, the mixture is fully and uniformly mixed, the pH value is adjusted to be slightly alkaline, and the mixture reacts for 4 hours at 80 ℃ to obtain a reduced mixed solution; adding a precipitator into the mixed solution, and centrifuging for 15min at 6500r/min after precipitation to obtain precipitate, namely the metal nanocluster;

wherein the concentration of the metal ions in the metal ion solution is preferably 1mmol/L-50mmol/L, and more preferably 10mmol/L-30 mmol/L;

wherein the metal ion solution preferably comprises HAuCl₄、H₂PtCl₆、Na₂PdCl₄、PdCl₂、AgNO₃、CH₃COOAg、AgF、Ag₂SO₄、AgClO₄、CuCl₂、CuNO₃、CuSO₄And/or CH₃An aqueous solution of COOCu.

In the above production method, preferably, the porous conductive support has a three-dimensional network structure; more preferably, the porous conductive carrier is selected from one or a combination of more than two of foamed nickel, foamed copper and graphene foam materials.

In the above production method, preferably, the iron monoatomic doped carbon material is further doped with a nitrogen element; more preferably, the substrate material loaded with the iron-doped carbon precursor on the porous conductive carrier is a self-supporting catalyst substrate simultaneously containing iron, nitrogen and carbon elements; further preferably, the iron-doped carbon precursor is iron-doped polypyrrole.

In the above production method, preferably, obtaining a base material having an iron-doped carbon precursor supported on a porous conductive support includes:

mixing a second solvent, a pyrrole monomer and a ferric ion salt, and polymerizing in a porous conductive carrier by taking the ferric ion salt as an initiator to obtain the substrate material through reaction;

more preferably, the ferric ion salt is FeCl₃；

More preferably, the molar ratio of the pyrrole monomer to the ferric ion is 5:1-20: 1;

more preferably, the pyrrole monomer and the porous conductive carrier are used in a ratio of 0.01g to 1cm²-0.5g:1cm²；

More preferably, the second solvent is water;

more preferably, the porous conductive carrier is pretreated before use to remove a surface oxide layer and hetero-ions; further preferably, the porous conductive carrier is pretreated with hydrochloric acid and acetone before use to remove a surface oxide layer and hetero ions;

more preferably, the reaction temperature of the polymerization is from 10 to 60 ℃ (e.g., 30 ℃);

in the above preferred embodiment, the base material obtained by mixing the second solvent, the porous conductive carrier, the pyrrole monomer and the ferric ion salt and performing a polymerization reaction with the ferric ion salt as an initiator is coated with an iron-nitrogen double-doped carbon precursor (iron-doped polypyrrole) on the surface of the porous conductive carrier, that is, the surface of the porous conductive carrier is coated with a material containing iron, nitrogen and carbon elements at the same time. In the preparation method of the substrate material with the iron-doped carbon precursor loaded on the porous conductive carrier, ferric ions are used as an initiator to initiate pyrrole polymerization, iron atoms are introduced into the carbon precursor, and finally the doping of the iron atoms in the carbon layer is completed through the subsequent steps. In the subsequent pyrolysis process, polypyrrole on the surface of the foamed nickel forms a composite carrier, and nitrogen elements in the pyrrole are doped into the carbon layer in the reaction process; fe in polypyrrole carbon layer³⁺The carbon material can form a coordination structure with nitrogen and exists in the carbon layer in a monoatomic form to obtain a monoatomic Fe-doped carbon material; the polypyrrole and the organic ligand on the nano-cluster are carbonized at high temperature, so that the nano-cluster and the carrier form a whole to obtain the active component iron single atom doped carbon material loaded metal nano-cluster composite material. The polymer iron-doped polypyrrole with the surface of the metal nanocluster playing a stabilizing role in the subsequent pyrolysis process is carbonized, the metal nanoclusters can be highly dispersed in a carbon material, the average particle size is about 3-6nm, and the metal element is higherThe utilization efficiency of (2).

In a specific embodiment, 1-20 pieces of foam nickel pretreated by hydrochloric acid and acetone and a certain amount of pyrrole monomer are put into 50mL of deionized water, and a small amount of FeCl is added under the constant temperature condition of 30 DEG C₃The solution is used as an initiator and reacts for 6-12h to prepare iron-doped polypyrrole-coated foamed nickel, and a layer of material containing iron, nitrogen and carbon elements simultaneously is formed; wherein the area of each piece of foam nickel is 2cm²The addition amount of pyrrole monomer is 0.5-10mL, and the concentration is FeCl of 0.045g/mL-0.2g/mL₃The amount of solution added is 1-10 mL.

In the above preparation method, the loading of the metal nanoclusters to the base material may be achieved by means of impregnation; preferably, the loading of the metal nanoclusters onto the base material includes:

dipping the substrate material into the dispersion liquid of the metal nanoclusters for a period of time to realize loading of the metal nanoclusters to the substrate material; wherein, in the dispersion liquid of the metal nanoclusters, the concentration of the metal nanoclusters (based on the volume of the dispersion liquid of the metal nanoclusters) is 0.75mmol/L-15 mmol/L;

more preferably, the time of the impregnation is not less than 4 h;

more preferably, after the base material is immersed in the dispersion liquid of the metal nanoclusters for a period of time, drying is carried out for 3 hours at 60 ℃, so as to realize loading of the metal nanoclusters to the base material;

in the above preferred embodiment, the content of the supported metal nanoclusters may be adjusted by changing the concentration of the metal nanocluster dispersion liquid.

In the above production method, preferably, the high-temperature pyrolysis is carried out under a protective atmosphere; for example in an inert gas atmosphere.

In the preparation method, the temperature of the high-temperature pyrolysis is preferably 300-600 ℃;

in the preferred technical scheme, the number of defect sites and the resistance of the carbon material can be adjusted by changing the pyrolysis temperature (300-600 ℃).

The invention also provides an iron monatomic doped carbon material-loaded metal nanocluster composite catalyst, which is a composite material comprising a porous conductive carrier, an iron monatomic doped carbon material and a metal nanocluster.

The obtained iron monatomic doped carbon material loaded metal nanocluster composite catalyst provided by the invention is a self-supporting multifunctional composite electrocatalytic full-hydrolysis catalyst.

In the above composite catalyst, preferably, the metal nanoclusters include one or a combination of two or more of Au nanoclusters, Pt nanoclusters, Pd nanoclusters, Ag nanoclusters, Cu nanoclusters, and the like.

In the above composite catalyst, preferably, the porous conductive support has a three-dimensional network structure; more preferably, the porous conductive carrier is foamed nickel.

In the above composite catalyst, preferably, the iron monoatomic doped carbon material is further doped with a nitrogen element. Nitrogen atoms in the carbon material can modulate the electronic structure of metal elements, the hydrogen adsorption energy of the metal material is optimized, and meanwhile, hetero atoms in the carbon material are good water adsorption sites; the carbon material wrapping the metal nanoclusters can also effectively prevent the metal nanoclusters from being agglomerated and poisoned, and effectively improve the electrocatalytic activity and stability of the material.

In the above composite catalyst, preferably, the average particle diameter of the metal nanoclusters is 3 to 6 nm.

In the composite catalyst, preferably, the single-atom doped carbon material-supported metal nanocluster composite catalyst is prepared by the preparation method of the single-atom doped carbon material-supported metal nanocluster composite catalyst.

The invention also provides an application of the iron monatomic doped carbon material loaded metal nanocluster composite catalyst in water electrolysis reaction, and the iron monatomic doped carbon material loaded metal nanocluster composite catalyst is used for catalyzing at least one of cathode hydrogen evolution reaction and anode oxygen evolution reaction of water electrolysis.

Compared with the prior art, the invention has the following advantages:

(1) according to the technical scheme provided by the invention, the metal nanoclusters are loaded on a special substrate material (a substrate material with an iron-doped carbon precursor loaded on a porous conductive carrier), and after high-temperature treatment, the iron-doped carbon precursor with the surface of the metal nanoclusters playing a role in stabilization is carbonized, so that the metal nanoclusters can be highly dispersed in a carbon material, and the higher utilization efficiency of metal elements is improved. The carbon material can also effectively prevent the metal nano-cluster from agglomerating and poisoning, and effectively improve the electrocatalytic activity and stability of the material. In a preferred embodiment, a simple initiator is used for initiating monomer polymerization, so that Fe single atoms are introduced into the carbon material to form a composite catalyst with the metal nanoclusters, and the catalyst remarkably improves the catalytic activity of the material through the synergistic effect generated between the Fe single atoms and the metal nanoclusters.

(2) The technical scheme provided by the invention has the advantages of small environmental pollution, high metal utilization rate, excellent catalytic activity, good catalyst stability, simple method, low cost, easy operation and good repeatability, and is suitable for mass production.

(3) The catalyst material provided by the technical scheme of the invention has excellent electrocatalytic hydrogen evolution reaction activity and oxygen evolution reaction activity, has excellent stability, and is an electrocatalytic full-hydrolysis catalyst with excellent performance.

Drawings

Fig. 1 is a scanning electron microscope image of the composite catalyst supporting copper nanoclusters of example 1.

FIG. 2 is a transmission electron microscope image and a high resolution transmission electron microscope image of copper nanoclusters of example 1.

FIG. 3 is a transmission electron microscopy dark field image corrected for spherical aberration of iron monoatomic and gold nanoclusters in example 2.

FIG. 4 is a plot of the electrocatalytic hydrogen evolution linear sweep voltammetry of the catalyst provided in example 2.

FIG. 5 is a linear sweep voltammetry curve for electrocatalytic oxygen evolution of the catalyst provided in example 2.

Fig. 6 is a graph of the results of the electrocatalytic hydrogen evolution stability tests of the catalysts provided in example 3.

Fig. 7 is a graph of the results of the electrocatalytic oxygen evolution stability tests of the catalysts provided in example 2.

Detailed Description

The technical solutions of the present invention will be described in detail below in order to clearly understand the technical features, objects, and advantages of the present invention, but the present invention is not limited to the practical scope of the present invention.

Example 1

The embodiment provides an iron monatomic doped carbon material-supported metal nanocluster composite catalyst, wherein the catalyst is prepared by the following method:

0.0328g of reduced glutathione as a stabilizer was weighed out and dissolved in 5mL of water, and then 250. mu.L of CuNO with a concentration of 50mmol/L was added₃Stirring the solution and 35 mu L of hydrazine hydrate for 10min, and heating at 80 ℃ for 4h to obtain a reacted mixed solution; washing the reacted mixed solution by taking isopropanol as a precipitator, centrifuging for 15min at 6500r/min, collecting the precipitate, wherein the collected precipitate is the copper nanocluster; dispersing the collected precipitate in 5mL of water to obtain a solution, namely a copper nanocluster dispersion liquid;

ultrasonically treating a cut foam nickel sheet with the shape of 1cm multiplied by 2cm in 0.5mol/L hydrochloric acid solution under the condition of 100Hz for 10min, washing the foam nickel sheet clean by deionized water, ultrasonically treating the foam nickel sheet in acetone solution for 5min at 100Hz, and washing the foam nickel sheet clean by deionized water to obtain pretreated foam nickel with a surface oxide layer and foreign ions removed;

adding 35mL of deionized water into a 250mL three-neck flask, and then adding pretreated foamed nickel and 2.7mL of 99% pure pyrrole monomer to obtain a mixed solution; stirring the mixed solution at the rotating speed of 10r/s under the condition of 30 ℃ constant-temperature water bath, and adding FeCl when the temperature of the mixed solution reaches 30 DEG C₃Solution (0.135g FeCl)₃·6H₂Dissolving O in 5mL of deionized water) as a polymerization initiator, and adding the polymerization initiator into the mixed solution to initiate the pyrrole monomer to perform polymerization reaction on the surface of the foamed nickel to prepare a substrate material;

soaking the substrate material in the copper nano-cluster dispersion liquid for more than 4h to load the metal nano-cluster on the substrate material, and then taking out the loaded substrate material to dry; and roasting the dried product at 600 ℃ in an argon atmosphere to obtain the iron single atom doped carbon material loaded metal nano-cluster composite catalyst (expressed by Cu-ppyFC/NF).

Fig. 1 is a scanning electron microscope image of the composite catalyst loaded with copper nanoclusters. The scanning electron microscope photo shows that the carrier foam nickel of the catalyst presents a three-dimensional net structure. Polypyrrole growing on the surface of the foamed nickel is uniformly coated on the surface of the foamed nickel after carbonization to form a continuous carbon layer, and the microstructure of the continuous carbon layer is shown in fig. 1. FIG. 2 is a transmission electron micrograph of the copper nanocluster-supported composite catalyst, from which it can be seen that the supported copper nanoclusters are uniformly dispersed in the carbon layer, the size of the Cu nanoclusters is about 5nm and the particle size is uniform, and the inset in FIG. 2 is a high-resolution transmission electron micrograph of the Cu nanoclusters showing that the size of the Cu nanoclusters is about 5.2nm and the lattice spacing of the nanoclusters isAs can be seen from fig. 1 and 2, the copper nanoclusters are supported on an iron-nitrogen co-doped carbon material generated by carbonizing polypyrrole, and are fixed on the surface of the foamed nickel by the iron-nitrogen co-doped carbon material.

Comparative example 1

The present comparative example provides a composite catalyst, wherein the catalyst was prepared by the following method:

0.0153g of reduced glutathione as a stabilizer was weighed out and dissolved in 5mL of water, followed by sequentially adding 80. mu.L of HAuCl at a concentration of 50mmol/L₄Stirring the solution and 20 mu L of hydrazine hydrate for 10min, and heating at 80 ℃ for 4h to obtain a reacted mixed solution; washing the reacted mixed solution by taking isopropanol as a precipitator, centrifuging for 15min at 6500r/min, collecting the precipitate, wherein the collected precipitate is the gold nanocluster; dispersing the collected precipitate in 5mL of water to obtain a solution, namely a gold nanocluster dispersion liquid (yellow solution);

ultrasonically treating a cut foam nickel sheet with the shape of 1cm multiplied by 2cm in 0.5mol/L hydrochloric acid solution under the condition of 100Hz for 10min, washing the foam nickel sheet clean by deionized water, ultrasonically treating the foam nickel sheet in acetone solution for 5min at 100Hz, and washing the foam nickel sheet clean by deionized water to obtain pretreated foam nickel with a surface oxide layer and foreign ions removed;

adding 35mL of deionized water into a 250mL three-neck flask, and then adding pretreated foamed nickel and 2.7mL of 99% pure pyrrole monomer to obtain a mixed solution; stirring the mixed solution at the rotating speed of 10r/s under the condition of 30 ℃ constant-temperature water bath, adding ammonium persulfate serving as a polymerization initiator into the mixed solution when the temperature of the mixed solution reaches 30 ℃, initiating a pyrrole monomer to generate a polymerization reaction on the surface of the foamed nickel, and preparing to obtain a substrate material;

soaking the substrate material in the gold nano-cluster dispersion liquid for more than 4h to load the metal nano-clusters on the substrate material, and then taking out the loaded substrate material to dry; and roasting the dried product at 600 ℃ in an argon atmosphere to obtain the composite catalyst (represented by a non-iron initiating catalyst).

Comparative example 2

The present comparative example provides a composite catalyst, wherein the catalyst was prepared by the following method:

0.0153g of reduced glutathione as a stabilizer was weighed out and dissolved in 5mL of water, followed by sequentially adding 80. mu.L of HAuCl at a concentration of 50mmol/L₄Stirring the solution and 20 mu L of hydrazine hydrate for 10min, and heating at 80 ℃ for 4h to obtain a reacted mixed solution; washing the reacted mixed solution by taking isopropanol as a precipitator, centrifuging for 15min at 6500r/min, collecting the precipitate, wherein the collected precipitate is the gold nanocluster; dispersing the collected precipitate in 5mL of water to obtain a solution, namely a gold nanocluster dispersion liquid (yellow solution);

adding 35mL of deionized water into a 250mL three-neck flask, and then adding 2.7mL of 99% pure pyrrole monomer to obtain a mixed solution; stirring the mixed solution at the rotating speed of 10r/s under the condition of 30 ℃ constant-temperature water bath, and adding FeCl when the temperature of the mixed solution reaches 30 DEG C₃Solution (0.425g FeCl₃·6H₂Dissolving O in 5mL of deionized water) as a polymerization initiator, and adding the polymerization initiator into the mixed solution to initiate the pyrrole monomer to perform polymerization reaction to prepare a carbon precursor material;

dipping the carbon precursor material in the gold nanocluster dispersion liquid for more than 4 hours to load the metal nanoclusters on the carbon precursor material, and then taking out the loaded carbon precursor material to dry; and roasting the dried product at 600 ℃ in an argon atmosphere to obtain the composite catalyst (expressed by a non-foam nickel catalyst).

Example 2

The embodiment provides an iron monatomic doped carbon material-supported metal nanocluster composite catalyst, wherein the catalyst is prepared by the following method:

0.0153g of reduced glutathione as a stabilizer was weighed out and dissolved in 5mL of water, followed by sequentially adding 80. mu.L of HAuCl at a concentration of 50mmol/L₄Stirring the solution and 20 mu L of hydrazine hydrate for 10min, and heating at 80 ℃ for 4h to obtain a reacted mixed solution; washing the reacted mixed solution by taking isopropanol as a precipitator, centrifuging for 15min at 6500r/min, collecting the precipitate, wherein the collected precipitate is the gold nanocluster; dispersing the collected precipitate in 5mL of water to obtain a solution, namely a gold nanocluster dispersion liquid (yellow solution);

ultrasonically treating a cut foam nickel sheet with the shape of 1cm multiplied by 2cm in 0.5mol/L hydrochloric acid solution under the condition of 100Hz for 10min, washing the foam nickel sheet clean by deionized water, ultrasonically treating the foam nickel sheet in acetone solution for 5min at 100Hz, and washing the foam nickel sheet clean by deionized water to obtain pretreated foam nickel with a surface oxide layer and foreign ions removed;

adding 35mL of deionized water into a 250mL three-neck flask, and then adding pretreated foamed nickel and 2.7mL of 99% pure pyrrole monomer to obtain a mixed solution; stirring the mixed solution at the rotating speed of 10r/s under the condition of 30 ℃ constant-temperature water bath, and adding FeCl when the temperature of the mixed solution reaches 30 DEG C₃Solution (0.425g FeCl₃·6H₂Dissolving O in 5mL of deionized water) as a polymerization initiator, and adding the polymerization initiator into the mixed solution to initiate the pyrrole monomer to perform polymerization reaction on the surface of the foamed nickel to prepare a substrate material;

soaking the substrate material in the gold nano-cluster dispersion liquid for more than 4h to load the metal nano-clusters on the substrate material, and then taking out the loaded substrate material to dry; and roasting the dried product at 600 ℃ in an argon atmosphere to obtain the iron monatomic doped carbon material supported metal nanocluster composite catalyst (expressed by Au-ppyFC/NF).

As shown in FIG. 3, under a spherical aberration transmission electron microscope, the Au nanoclusters have a size of 2-4nm, are uniform in particle size, and are uniformly dispersed with a large number of iron monoatomic atoms on the surface of the carbon material.

The iron monatomic doped carbon material-supported metal nanocluster composite catalyst prepared in the embodiment is used as a sample to be tested to perform an electrolytic water hydrogen evolution performance test:

when the electrolytic water hydrogen evolution reaction test is carried out, the model of the used electrochemical workstation is Shanghai Chenghua CHI760e, the electrolyte solution is 1.0mol/L potassium hydroxide solution, the reference electrode is a mercury/mercury oxide electrode, the counter electrode is a graphite electrode, and the working electrode is a sample to be tested (1cm multiplied by 2 cm). And connecting each electrode with an electrochemical workstation and extending into the electrolyte, wherein the depth of the working electrode extending into the liquid level is 0.5 cm. The test is carried out by using a linear sweep voltammetry method, an instrument is adopted to automatically compensate the resistance, the sweep range is-0.9V to-1.5V, and the sweep rate is 5 mV/s.

For comparison, the performance test of hydrogen evolution by electrolyzed water of the catalyst provided in comparative example 1, the catalyst provided in comparative example 2, and a commercial 20% platinum-carbon catalyst (Michelin brand CAS number: 7440-06-4) under the same conditions was performed, and the results are shown in FIG. 4. As can be seen from FIG. 4, the current reached 10mA/cm²The overpotential required for the process is 56.9mV for hydrogen evolution of the iron monatomic doped carbon material-supported metal nanocluster composite catalyst provided by the embodiment; a commercial 20% platinum-carbon catalyst (Michelin brand CAS number 7440-06-4) with a hydrogen evolution overpotential of 36mV under the same conditions; the performance of hydrogen evolution by electrolysis of water of the catalysts provided by the comparative examples 1 and 2 is far lower than that of the catalyst provided by the embodiment under the same condition, which shows that the iron monatomic doped carbon material loaded metal nanocluster composite catalyst provided by the invention has excellent and very excellent hydrogen evolution activity, and meanwhile, the introduction of the carrier and the metal Fe monatomic is proved to be an important factor of the excellent performance of the catalyst, and the defect is not available.

The iron monatomic doped carbon material-supported metal nanocluster composite catalyst provided by the embodiment is used as a sample to be tested to perform an electrolytic water oxygen evolution performance test:

when the electrolytic water oxygen evolution reaction test is carried out, the model of the used electrochemical workstation is Shanghai Chenghua CHI760e, the electrolyte solution is 1.0mol/L potassium hydroxide solution, the reference electrode is a mercury/mercury oxide electrode, the counter electrode is a graphite electrode, and the working electrode is a sample to be tested (1cm multiplied by 2 cm). And connecting each electrode with an electrochemical workstation and extending into the electrolyte, wherein the depth of the working electrode extending into the liquid level is 0.5 cm. The test is carried out by using a linear sweep voltammetry method, an instrument is adopted to automatically compensate the resistance, the sweep range is 1V to 2V, and the sweep rate is 5 mV/s.

As shown in FIG. 5, it is understood from FIG. 5 that the current reached 10mA/cm²The overpotential required in the process is 290mV, which indicates that the iron monatomic doped carbon material loaded metal nanocluster composite catalyst provided by the invention has excellent and very excellent oxygen evolution activity.

Example 3

The embodiment provides an iron monatomic doped carbon material-supported metal nanocluster composite catalyst, wherein the catalyst is prepared by the following method:

0.0164g of reduced glutathione as a stabilizer was weighed out and dissolved in 5mL of water, and then 150. mu.L of PdCl with a concentration of 50mmol/L was sequentially added₂Stirring the solution and 25 mu L of hydrazine hydrate for 10min, and heating at 80 ℃ for 4h to obtain a reacted mixed solution; washing the reacted mixed solution by taking isopropanol as a precipitator, centrifuging for 15min at 6500r/min, collecting the precipitate, wherein the collected precipitate is the palladium nanocluster; dispersing the collected precipitate in 5mL of water to obtain a solution, namely a palladium nano-cluster dispersion solution;

ultrasonically treating a cut foam nickel sheet with the shape of 1cm multiplied by 2cm in 0.5mol/L hydrochloric acid solution under the condition of 100Hz for 10min, washing the foam nickel sheet clean by deionized water, ultrasonically treating the foam nickel sheet in acetone solution for 5min at 100Hz, and washing the foam nickel sheet clean by deionized water to obtain pretreated foam nickel with a surface oxide layer and foreign ions removed;

adding 35mL of deionized water into a 250mL three-neck flask, and then adding pretreated foamed nickel and 2.7mL of 99% pure pyrrole monomer to obtain a mixed solution; mixing the mixed solution at 30 deg.CStirring at 10r/s under warm water bath condition, and adding FeCl when the temperature of the mixture reaches 30 deg.C₃Solution (0.685g of FeCl)₃·6H₂Dissolving O in 5mL of deionized water) as a polymerization initiator, and adding the polymerization initiator into the mixed solution to initiate the pyrrole monomer to perform polymerization reaction on the surface of the foamed nickel to prepare a substrate material;

dipping the substrate material in the palladium nano-cluster dispersion liquid for more than 4h to load the metal nano-cluster on the substrate material, and then taking out the loaded substrate material to dry; and roasting the dried product at 600 ℃ in an argon atmosphere to obtain the iron single atom doped carbon material supported metal nano-cluster composite catalyst (expressed by Pd-ppyFC/NF).

The iron monatomic doped carbon material-supported metal nanocluster composite catalyst prepared in the embodiment is used as a sample to be tested to perform an electrolytic water hydrogen evolution stability test:

when the electrolytic water hydrogen evolution reaction test is carried out, the model of the used electrochemical workstation is Shanghai Chenghua CHI760e, the electrolyte solution is 1.0mol/L potassium hydroxide solution, the reference electrode is a mercury/mercury oxide electrode, the counter electrode is a graphite electrode, and the working electrode is a sample to be tested (1cm multiplied by 2 cm). And connecting each electrode with an electrochemical workstation and extending into the electrolyte, wherein the depth of the working electrode extending into the liquid level is 0.5 cm. The test is carried out by using a linear sweep voltammetry method, an instrument is adopted to automatically compensate the resistance, the sweep range is-0.9V to-1.5V, and the sweep rate is 5 mV/s. The cyclic voltammetry was subjected to a stability cycle with a sweep range of-0.9V to-1.0V and a sweep rate of 50 mV/s.

As shown in fig. 6, it is understood from fig. 6 that the activity of the sample was slightly attenuated after 5000 cycles of CV scan, indicating that the sample had good stability of hydrogen evolution reaction.

The iron monatomic doped carbon material loaded metal nanocluster composite catalyst provided by the embodiment is used as a sample to be tested to perform an electrolytic water oxygen evolution stability test:

when the electrolytic water oxygen evolution reaction test is carried out, the model of the used electrochemical workstation is Shanghai Chenghua CHI760e, the electrolyte solution is 1.0mol/L potassium hydroxide solution, the reference electrode is a mercury/mercury oxide electrode, the counter electrode is a graphite electrode, and the working electrode is a sample to be tested (1cm multiplied by 2 cm). And connecting each electrode with an electrochemical workstation and extending into the electrolyte, wherein the depth of the working electrode extending into the liquid level is 0.5 cm. The test is carried out by using a linear sweep voltammetry method, an instrument is adopted to automatically compensate the resistance, the sweep range is 1V to 2V, and the sweep rate is 5 mV/s. Cyclic voltammetry was performed with a stability cycle, sweep range of 1.45V to 1.55V, and a sweep rate of 50 mV/s.

As shown in fig. 7, it is understood from fig. 7 that the activity of the sample was slightly attenuated after 5000 cycles of CV scan, indicating that the sample had good stability of oxygen evolution reaction.