Method for rapidly preparing monatomic catalyst and application of monatomic catalyst

Abstract

The invention discloses a method for rapidly preparing a monatomic catalyst and application of the monatomic catalyst in hydrogen production through water electrolysis. The method comprises the following steps that S1, metal inorganic salt, a foaming agent and a carbon-based organic matter are weighed according to a certain proportion and poured into an agate mortar to be ground so that the metal inorganic salt, the foaming agent and the carbon-based organic matter can be evenly mixed; s2, the mixture is poured into a ceramic crucible, a combustion improver is added and ignited, and the mixture rapidly burns and expands to generate a bundle of porous black foamed materials; and S3, taking out the cooled black foamed material, and grinding to obtain the target carbon-based metal monatomic catalyst material. Metal atoms in the prepared monatomic catalyst are well dispersed, and meanwhile the monatomic catalyst has the advantages of being simple, rapid, low in manufacturing cost, fluffy in structure, high in conductivity, good in electrocatalytic activity and easy to prepare on a large scale.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon-based metal single-atom catalysts, and in particular to a method for rapidly preparing a single-atom catalyst and application thereof. Background Art

[0002] Carbon-based metal single-atom catalysts are a new type of catalyst material proposed in recent years. They have many characteristics such as maximizing atomic utilization, isolated active sites, and catalytic activity different from conventional catalysts, and therefore have attracted the attention of academia and industry. Carbon-based metal single-atom catalysts achieve atomic-level catalytic site dispersion by dispersing single metal atoms on carbon carriers, thereby maximizing atomic utilization. This structure not only provides highly isolated active centers, avoiding the interaction between atoms in traditional nanoparticles, but also combines the advantages of high activity of homogeneous catalysts and stability and easy separation of heterogeneous catalysts. Since there is no interaction between each individual metal atom, the catalytic performance of the active site can be very unique, depending on the interaction between the metal atom and other adjacent atoms. At present, through the joint efforts of researchers at home and abroad, various types of metal single-atom catalysts have been developed, which are mainly used in many fields such as electrocatalysis, photocatalysis, environmental monitoring and energy conversion. Among them, carbon-based metal single-atom catalysts play a vital role in hydrogen production by water electrolysis. This process requires highly active, low-cost and stable electrocatalysts, and carbon-based metal single-atom catalysts just meet these requirements. Carbon-based metal single-atom catalysts are usually used in electrocatalytic hydrogen evolution reactions, which can provide maximum atomic utilization efficiency and minimize catalyst dosage, thus showing great application potential. For example, single-atom iron catalysts prepared on porous carbon supports show excellent electrolytic water splitting activity and stability. The high performance of this catalyst is due to its good conductivity, high specific surface area and controllability. The synthesized hollow carbon sphere-supported single-atom metal cobalt catalyst has a specific electronic structure, which gives it a weak Cl - adsorption capacity, thus showing excellent catalytic activity, selectivity and Cl resistance - Corrosive, high efficiency and long-term stability are achieved in the application of electrolysis of seawater to produce hydrogen. Platinum is one of the traditional water electrolysis catalysts, but it is costly and has limited stability. By dispersing platinum on a carrier in the form of single atoms, the catalyst cost can be reduced and the stability can be improved, showing excellent performance in the electrolysis of water to produce hydrogen. In addition, the design and synthesis strategies of carbon-based metal single-atom catalysts are crucial to their application in hydrogen electrochemical cycles. Researchers have developed a variety of methods to prepare and characterize such materials to optimize their performance in the process of electrolysis of water to produce hydrogen, providing new possibilities for the development of green energy.

[0003] At present, researchers have developed a variety of methods for preparing single-atom catalysts, including coprecipitation, atomic layer deposition, hydrothermal synthesis, electrostatic adsorption, step-by-step reduction, impregnation, vapor deposition, sol-gel, carbon material-assisted, etc. However, most of the methods are still in the laboratory stage, and the preparation methods have certain limitations in controlling synthesis conditions, equipment requirements, and raw material acquisition, resulting in the existence of uneven bonding between metal ions and carriers, agglomeration and abnormal growth of catalysts, destruction of the structure of the carrier or sintering of the catalyst, inability to accurately control the dispersion of metal ions and the bonding mode of the carrier, high preparation cost, long preparation cycle, and unstable structure in the prepared single-atom catalysts. These problems have severely limited their practical applications. Therefore, it is imperative to develop a fast, efficient, and universal method for preparing carbon-based metal single-atom catalysts. Summary of the invention

[0004] In order to overcome the shortcomings of existing preparation technology, one of the purposes of the present invention is to provide a method for rapidly preparing single-atom catalysts to solve the above-mentioned traditional technical problems. The method has the advantages of rapid preparation, low price and excellent electrocatalytic performance.

[0005] The second purpose of the present invention is to provide a single-atom catalyst prepared by the above-mentioned method for rapidly preparing a single-atom catalyst and to apply it to hydrogen evolution catalytic reactions in new energy fields such as water electrolysis to produce hydrogen.

[0006] One of the purposes of the present invention is achieved by the following technical solution: A method for rapidly preparing a single-atom catalyst comprises the following steps: S1: weigh the metal inorganic salt, foaming agent and carbon-based organic matter in a certain proportion and pour them into an agate mortar to grind them to make them evenly mixed; S2: Pour the above mixture into a ceramic crucible, add a combustion aid and ignite it, the mixture burns and expands rapidly and produces a beam of porous black foam-like material; S3: Take out the cooled black foam material and grind it to obtain the target carbon-based metal single atom catalyst material.

[0007] Furthermore, the mass ratio of the foaming agent to the carbon-based organic matter is 1:2-1:6, such as 1:2, 1:3, 1:4, 1:5, 1:6.

[0008] Furthermore, the molar ratio of the metal inorganic salt to the carbon-based organic matter is 1:5-1:15, such as 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15.

[0009] Furthermore, the metal in the metal inorganic salt is, but not limited to, one of iron, cobalt, nickel, ruthenium, iridium and platinum.

[0010] Furthermore, the carbon-based organic matter is one or more of, but not limited to, sucrose, glucose, fructose, maltose and lactose.

[0011] Furthermore, the foaming agent is but not limited to sodium bicarbonate or potassium bicarbonate.

[0012] Furthermore, in step S2, the combustion aid is alcohol, and the alcohol is ignited, and the high temperature is used to promote the rapid decomposition of the foaming agent, carbon-based organic matter and metal inorganic salts, and the carbon skeleton produced by the reaction of the carbon-based organic matter is used to anchor the metal single atoms in situ, and at the same time, the large amount of gas produced by the foaming agent is used to make the product loose, porous and evenly dispersed.

[0013] The second object of the present invention is achieved by adopting the following technical solution: A single-atom catalyst prepared by any of the above methods for rapidly preparing a single-atom catalyst is used in hydrogen production by water electrolysis.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The single-atom catalyst prepared by the method for rapidly preparing a single-atom catalyst of the present invention has good dispersion of metal atoms, and has the advantages of being simple and rapid, low in raw material and manufacturing costs, fluffy structure, high in electrical conductivity, good in electrocatalytic activity and easy in large-scale preparation. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 HRTEM photos of single-atom catalyst materials prepared in Examples 1-6: a. iron; b. cobalt; c. nickel; d. ruthenium; e. iridium; f. platinum.

[0016] Figure 2 The electrocatalytic hydrogen evolution performance of the single atom catalyst materials prepared in Examples 1-6. DETAILED DESCRIPTION

[0017] Below, in conjunction with specific embodiments, the present invention is further described. It should be noted that, under the premise of not conflicting, the embodiments described below or the technical features can be arbitrarily combined to form new embodiments. If specific conditions are not specified in the embodiments, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0018] Unless otherwise specified, the reagents used in the examples can be purchased from the market.

[0019] Example 1 Weigh ferric nitrate, sodium bicarbonate and sucrose into an agate mortar, where the mass ratio of sodium bicarbonate to sucrose is 1:2, and the molar ratio of ferric nitrate to sucrose is 1:15. Grind vigorously to mix them evenly. Pour the above mixture into a ceramic crucible, then add alcohol and ignite it. The mixture quickly burns and expands to produce a porous black foam material. Finally, the cooled black foam material is taken out and ground to obtain a carbon-based metal iron single atom catalyst material. The microscopic morphology is as follows Figure 1 As shown in a. As can be seen from the figure, the iron atoms in the catalyst material are anchored in the carbon matrix in the form of independent individuals, are well dispersed, have no aggregation, and have the characteristics of structural stability.

[0020] Example 2 Weigh cobalt nitrate, potassium bicarbonate and glucose into an agate mortar, where the mass ratio of potassium bicarbonate to glucose is 1:3, and the molar ratio of cobalt nitrate to glucose is 1:13. Grind vigorously to mix them evenly. Pour the above mixture into a ceramic crucible, then add alcohol and ignite it. The mixture quickly burns and expands to produce a porous black foam material. Finally, the cooled black foam material is taken out and ground to obtain a carbon-based metal cobalt single atom catalyst material. The microscopic morphology is as follows Figure 1 As shown in b. As can be seen from the figure, the cobalt atoms in the catalyst material are anchored in the carbon matrix in the form of independent individuals, are well dispersed, do not aggregate, and have the characteristics of structural stability.

[0021] Example 3 Weigh nickel nitrate, sodium bicarbonate and fructose into an agate mortar, where the mass ratio of sodium bicarbonate to fructose is 1:4, and the molar ratio of nickel nitrate to fructose is 1:11. Grind vigorously to mix them evenly. Pour the above mixture into a ceramic crucible, then add alcohol and ignite it. The mixture quickly burns and expands to produce a porous black foam material. Finally, the cooled black foam material is taken out and ground to obtain a carbon-based metal nickel single atom catalyst material. The microscopic morphology is as follows Figure 1 As shown in c. As can be seen from the figure, the nickel atoms in the catalyst material are anchored in the carbon matrix in the form of independent individuals, are well dispersed, do not aggregate, and have the characteristics of structural stability.

[0022] Example 4 Weigh ruthenium trichloride, potassium bicarbonate and maltose into an agate mortar, where the mass ratio of potassium bicarbonate to maltose is 1:5, and the molar ratio of ruthenium trichloride to maltose is 1:9, and grind vigorously to mix them evenly. Pour the above mixture into a ceramic crucible, then add alcohol and ignite it. The mixture quickly burns and expands to produce a beam of porous black foamy material. Finally, the cooled black foamy material is taken out and ground to obtain a carbon-based metal ruthenium single-atom catalyst material. The microscopic morphology is as follows Figure 1 As shown in d. As can be seen from the figure, the ruthenium atoms in the catalyst material are anchored in the carbon matrix in the form of independent individuals, are well dispersed, have no aggregation, and have the characteristics of structural stability.

[0023] Example 5 Weigh iridium trichloride, sodium bicarbonate and lactose into an agate mortar, where the mass ratio of sodium bicarbonate to lactose is 1:6, and the molar ratio of iridium trichloride to lactose is 1:7. Grind vigorously to mix them evenly. Pour the above mixture into a ceramic crucible, then add alcohol and ignite it. The mixture quickly burns and expands to produce a beam of porous black foamy material. Finally, take out the cooled black foamy material and grind it to obtain a carbon-based metal iridium single atom catalyst material. The microscopic morphology is as follows Figure 1 As shown in e. As can be seen from the figure, the iridium single atoms in the catalyst material are anchored in the carbon matrix in the form of independent individuals, are well dispersed, have no aggregation phenomenon, and have the characteristics of structural stability.

[0024] Example 6 Weigh chloroplatinic acid, potassium bicarbonate and sucrose into an agate mortar, where the mass ratio of potassium bicarbonate to sucrose is 1:4, and the molar ratio of chloroplatinic acid to sucrose is 1:5, and grind vigorously to mix them evenly. Pour the above mixture into a ceramic crucible, then add alcohol and ignite it. The mixture quickly burns and expands to produce a beam of porous black foamy material. Finally, the cooled black foamy material is taken out and ground to obtain a carbon-based metal platinum single atom catalyst material. The microscopic morphology is as follows Figure 1 As shown in Figure f, it can be seen that the platinum atoms in the catalyst material are anchored in the carbon matrix in the form of independent individuals, are well dispersed, have no aggregation, and have the characteristics of structural stability.

[0025] Performance Test: 1. Electrocatalytic hydrogen evolution performance test The electrocatalytic hydrogen evolution performance of the carbon-based metal single atom catalysts of Examples 1-6 in 1 M KOH electrolyte was tested. The test results are as follows: Figure 2 shown.

[0026] Depend on Figure 2 It can be seen that the best performance among the six examples is the noble metal single atom catalyst system represented by platinum, iridium and ruthenium (Examples 4-6), followed by the non-noble metal single atom catalyst system represented by cobalt, nickel and iron (Examples 1-3). In addition, the three noble metal single atom catalysts show excellent electrocatalytic hydrogen evolution activity, which is only slightly different from the commercial noble metal material Pt / C. Considering the cost of use and electrocatalytic performance, the catalysts in Examples 4-6 have certain advantages.

[0027] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A method for rapidly preparing a single-atom catalyst, characterized in that: The following steps are involved: S1: weigh the metal inorganic salt, foaming agent and carbon-based organic matter in a certain proportion and pour them into an agate mortar to grind them to make them evenly mixed; S2: Pour the above mixture into a ceramic crucible, add a combustion aid and ignite it, the mixture burns and expands rapidly and produces a beam of porous black foamy material; S3: Take out the cooled black foam material and grind it to obtain the target carbon-based metal single atom catalyst material.

2. The method for rapidly preparing a single-atom catalyst according to claim 1, characterized in that: The mass ratio of the foaming agent to the carbon-based organic matter is 1:2-1:6, and the molar ratio of the metal inorganic salt to the carbon-based organic matter is 1:5-1:

15.

3. The method for rapidly preparing a single-atom catalyst according to claim 1, characterized in that: The metal in the metal inorganic salt is one of iron, cobalt, nickel, ruthenium, iridium and platinum.

4. The method for rapidly preparing a single-atom catalyst according to claim 1, characterized in that: The carbon-based organic matter is one or more of sucrose, glucose, fructose, maltose or lactose.

5. The method for rapidly preparing a single-atom catalyst according to claim 1, characterized in that: The foaming agent is sodium bicarbonate or potassium bicarbonate.

6. The method for rapidly preparing a single-atom catalyst according to claim 1, characterized in that: The combustion improver is alcohol.

7. A single-atom catalyst prepared by the method for rapidly preparing a single-atom catalyst as described in any one of claims 1 to 6 is used in hydrogen production by electrolysis of water.

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