阅读说明：本技术 一种电解产氯的碳基阳极材料的制备方法与应用 (Preparation method and application of carbon-based anode material for producing chlorine through electrolysis ) 是由 尹华杰 舒亚婕 于 2021-07-26 设计创作，主要内容包括：本发明属于电催化技术领域,具体涉及一种电解产氯的碳基阳极材料的制备方法与应用,所述方法包括下列步骤：获取碳基原材料；对所述碳基原材料进行第一处理,以获得掺杂非金属碳基材料、掺杂非贵金属碳基材料和负载非贵金属氧化物碳基材料料中至少一种的碳基阳极材料；所述第一处理包括所热处理、化学处理、电化学处理和水热处理中至少一种；通过掺杂不同元素,引入官能团的种类和数量,达到对催化剂活性中心以及电化学产氯反应中间体对氯离子的吸附能和活化能的精确调控。碳基原材料价格低廉,碳基阳极材料在酸性条件下性能稳定,解决了现有技术中进行电解产氯的电极价格高昂、供求紧缺以及在酸性条件下不稳定,易溶出、钝化等技术问题。(The invention belongs to the technical field of electrocatalysis, and particularly relates to a preparation method and application of a carbon-based anode material for producing chlorine by electrolysis, wherein the method comprises the following steps: obtaining a carbon-based raw material; performing first treatment on the carbon-based raw material to obtain a carbon-based anode material doped with at least one of a non-metal carbon-based material, a non-noble metal carbon-based material and a non-noble metal oxide carbon-based material; the first treatment comprises at least one of the thermal, chemical, electrochemical and hydrothermal treatments; different elements are doped, and the types and the number of functional groups are introduced, so that the adsorption energy and the activation energy of the catalyst active center and an electrochemical chlorine generation reaction intermediate to chloride ions are accurately regulated and controlled. The carbon-based raw material has low price, the carbon-based anode material has stable performance under the acidic condition, and the technical problems of high price, supply and demand shortage, instability, easy dissolution, passivation and the like of an electrode for producing chlorine by electrolysis in the prior art are solved.)

1. A method for preparing a carbon-based anode material for producing chlorine by electrolysis, which is characterized by comprising the following steps:

obtaining a carbon-based raw material;

performing first treatment on the carbon-based raw material to obtain a carbon-based anode material doped with at least one of a non-metal carbon-based material, a non-noble metal carbon-based material and a non-noble metal oxide carbon-based material;

the first treatment comprises at least one of the thermal, chemical, electrochemical and hydrothermal treatments;

doping atoms of the non-metal carbon-based material are non-metal atoms, and the non-metal atoms comprise at least one of oxygen, boron, nitrogen and sulfur atoms; the doping atoms of the non-noble metal-doped carbon-based material are non-noble metal atoms, the non-noble metal comprises at least one of cobalt, iron, copper, nickel and manganese, the dopant loading the non-noble metal oxide is a non-noble metal oxide, and the non-noble metal oxide comprises at least one of cobalt-containing oxide, iron-containing oxide, copper-containing oxide, nickel-containing oxide and manganese-containing oxide.

2. The method of claim 1, wherein the non-metallic carbon-based material is doped such that the molar ratio of non-metallic atoms to carbon atoms is greater than 1: 100.

3. In the non-noble metal-doped carbon-based material and the non-noble metal oxide-loaded carbon-based material, the molar ratio of non-noble metal atoms to carbon atoms is more than 1: 100.

4. The method of claim 1, wherein the heat treating comprises heating the carbon-based raw material at 300 ℃ to 1000 ℃ for 1 to 4 hours in a protective atmosphere.

5. The method of claim 4, wherein the protective atmosphere comprises: any one of oxygen, hydrogen, nitrogen and ammonia.

6. The method of claim 1, wherein the electrochemical processing comprises:

taking a carbon-based raw material as an electrode, and carrying out anodic oxidation or cathodic reduction deposition reaction in an electrolytic cell containing soluble non-noble metal salt solutions of different elements or ammonium-containing precursors to obtain a first carbon-based material containing different functional groups or element doping and oxide deposition;

and washing and drying the first carbon-based material to obtain the carbon-based anode material.

7. The method of claim 6, wherein the soluble non-noble metal salt solution comprises at least one of a non-noble metal-containing sulfate solution, a nitrate solution, and an acetate solution.

8. The method of claim 6, wherein the ammonium precursor comprises at least one of melamine, urea, ammonium chloride, ammonium bromide, ammonium carbonate, and ammonium bicarbonate.

9. A gas diffusion electrode comprising a carbon-based anode material prepared by the method of any one of claims 1 to 8 as a starting material for the electrolytic production of chlorine.

10. An anode electrode comprising a carbon-based anode material prepared by the method of any one of claims 1 to 8 applied to a substrate comprising any one of titanium, lead, conductive glass and stainless steel as an anode.

Technical Field

The invention belongs to the technical field of electrocatalysis, and particularly relates to a preparation method and application of a carbon-based anode material for producing chlorine by electrolysis.

Background

The electrochemical catalysis for generating chlorine is one of the most valuable and widely applied electrochemical reactions at present, and the application fields of the electrochemical catalysis for generating chlorine comprise the chlor-alkali industry, seawater electrolysis, seawater antifouling electrolysis, sewage treatment, chemical synthesis and the like. One of the keys to electrochemical chlorine generation is the anode for electrolysis. Graphite is selected as a chlorine evolution anode in the chlor-alkali industry in the early days, but the required working voltage is large, the corrosion resistance is poor, and the service life is short, so titanium-based metal oxide with high stability is developed, and in the development and application of the past decades, a series of multi-element composite coating electrodes, namely Dimension Stable Anodes (DSA), which are formed by loading noble metal oxides such as ruthenium, iridium and the like as active components on a metal titanium plate and mixing titanium dioxide are gradually formed.

Although the DSA electrode as a chlorine evolution anode shows excellent catalytic activity and stability in the chlor-alkali industry, the needed precious metal is high in price, the supply and demand are in short supply, and under an acidic condition, the solid solution structure of the metal oxide is unstable and easy to dissolve out, so that potential environmental risks are caused. Aiming at the seawater or sewage with low chloride ion concentration, the side reaction oxygen evolution activity of the DSA electrode is high, the metal oxide solid solution structure is easy to damage, and meanwhile, various anions and cations exist in the seawater, so that the active components are easy to lose, the titanium matrix is passivated, and the DSA electrode fails. The above disadvantages severely restrict the mass production of the noble metal-based DSA electrode and the expanded application of the technology in various fields.

In recent years, a great deal of research finds that the nonmetallic carbon-based material shows excellent performance comparable to that of a noble metal catalyst in electrochemical oxygen reduction reaction and fuel cells. However, the research on the carbon-based material in the field of chlorine generation by electrolysis is still insufficient. In view of the low cost and high designability of carbon-based materials, the practical development of high-performance carbon-based electrolysis chlorine production catalysts and electrode materials undoubtedly has important application value and scientific significance.

Disclosure of Invention

The application provides a carbon-based anode material for producing chlorine by electrolysis and application thereof, which are used for solving the technical problems that an electrode for producing chlorine by electrolysis in the prior art is high in price, short in supply and demand, unstable and easy to dissolve out under an acidic condition and the like.

A method of preparing a carbon-based anode material, the method comprising the steps of:

obtaining a carbon-based raw material;

performing first treatment on the carbon-based raw material to obtain a carbon-based anode material doped with at least one of a non-metal carbon-based material, a non-noble metal carbon-based material and a non-noble metal oxide carbon-based material;

the first treatment comprises at least one of the thermal, chemical, electrochemical and hydrothermal treatments;

doping atoms of the non-metal carbon-based material are non-metal atoms, and the non-metal atoms comprise at least one of oxygen, boron, nitrogen and sulfur atoms; the doping atoms of the non-noble metal-doped carbon-based material are non-noble metal atoms, the non-noble metal comprises at least one of cobalt, iron, copper, nickel and manganese, the dopant loading the non-noble metal oxide is a non-noble metal oxide, and the non-noble metal oxide comprises at least one of cobalt-containing oxide, iron-containing oxide, copper-containing oxide, nickel-containing oxide and manganese-containing oxide.

Optionally, in the doped non-metal carbon-based material, the molar ratio of the non-metal atoms to the carbon atoms is greater than 1: 100.

Optionally, in the non-noble metal-doped carbon-based material and the non-noble metal oxide-supported carbon-based material, the molar ratio of the non-noble metal atoms to the carbon atoms is greater than 1: 100.

Optionally, the heat treatment includes heating the carbon-based raw material at 300-1000 ℃ for 1-4 hours in a protective atmosphere.

Optionally, the protective atmosphere comprises: any one of oxygen, hydrogen, nitrogen and ammonia.

Optionally, taking a carbon-based raw material as an electrode, and performing anodic oxidation or cathodic reduction deposition reaction in an electrolytic cell containing soluble non-noble metal salt solutions of different elements or ammonium-containing precursors to obtain a first carbon-based material containing different functional groups or element doping and oxide deposition;

and washing and drying the first carbon-based material to obtain the carbon-based anode material.

Optionally, the soluble non-noble metal salt solution comprises at least one of a non-noble metal-containing sulfate solution, a nitrate solution, and an acetate solution.

Optionally, the ammonium precursor comprises at least one of melamine, urea, ammonium chloride, ammonium bromide, ammonium carbonate and ammonium bicarbonate.

A gas diffusion electrode comprising said carbon-based anode material for the electrolytic production of chlorine.

An anode electrode comprises a carbon-based anode material coated on a substrate as an anode, wherein the substrate comprises any one of titanium, lead, conductive glass and stainless steel.

Compared with the prior art, the technical scheme provided by the embodiment of the application has the following advantages:

according to the embodiment of the application, the large specific surface area and the electrical conductivity of the carbon-based raw material are fully utilized, different elements are doped and the type and the number of functional groups are introduced through treatment, the coordination number and the local atomic structure of an active site in the monatomic catalyst are accurately designed and finely regulated, the central structure and the electronic characteristic of the active site are explored, the characteristics such as the adsorption performance and the activation energy of chlorine ions are explored, and the accurate regulation and control of the adsorption energy of the electrochemical chlorine-producing reaction intermediate is achieved. The carbon-based raw material is low in price, the developed carbon-based anode material is stable under an acidic condition, and the technical problems that a precious metal-based DSA electrode for producing chlorine through electrolysis in the prior art is high in price, short in supply and demand, unstable under an acidic condition and easy to dissolve out are solved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without inventive exercise.

FIG. 1 is a scanning electron micrograph of O-BP synthesized according to an embodiment of the present invention;

FIG. 2 is a transmission electron micrograph of O-BP synthesized according to an embodiment of the present invention;

FIG. 3 is a graph showing polarization curves of O-BP and other carbon-based materials synthesized by examples of the present invention;

FIG. 4 is a polarization curve diagram of the O-BP catalyst prepared by the present invention in a low concentration NaCl solution under a neutral condition;

FIG. 5 is a graph of O-BP polarization curves at different pH conditions;

FIG. 6 is a graph of the stability and Faraday efficiency of O-BP and graphite in 4M NaCl, pH 1 electrolyte;

FIG. 7 is a polarization curve of O-BP under conditions of 4M NaCl, pH 1 and normal temperature;

FIG. 8 is a graph showing the polarization of O-BP in 4M NaCl at pH 1 at 70 ℃;

FIG. 9 is a graph showing polarization curves of the carbon cloth after the oxidation treatment (O-CC) and the untreated Carbon Cloth (CC);

FIG. 10 is an appearance view of a modified carbon cloth O-CC;

FIG. 11 is a flow chart of a method for preparing a carbon-based anode material for the electrolytic production of chlorine.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In a first aspect, the present application provides a method for preparing a carbon-based anode material for the electrolytic production of chlorine, as shown in fig. 11, the method comprising the steps of:

s1, obtaining a carbon-based raw material;

s2, carrying out first treatment on the carbon-based raw material to obtain a carbon-based anode material doped with at least one of a non-metal carbon-based material, a non-noble metal carbon-based material and a non-noble metal oxide carbon-based material;

the first treatment comprises at least one of the thermal, chemical, electrochemical and hydrothermal treatments;

in the embodiment of the present application, the first processing includes the following steps:

acid treatment

The method can be used for treating carbon cloth, carbon velvet, carbon fiber, carbon felt and the like. Cutting carbon cloth into desired size, soaking in a certain amount of 98% H₂SO₄And 70% HNO₃In the aqueous solution of (3), preferably, the volume ratio may be: v (H)₂SO₄):V(HNO₃):V(H₂O) ═ 1:1:1-1:1: 5. The mixed solution is heated to 50-90 ℃ to react for 12-24 hours. After the reaction, the mixture is cooled to room temperature, washed by deionized water and dried in a vacuum drying oven at 60 ℃ for 12-24 hours, and named as A-CC.

Thermal treatment

The method realizes doping treatment: a carbon material doped with non-metal atoms, said non-metal atoms comprising at least one of boron atoms, nitrogen atoms, and sulfur atoms. Co-roasting the carbon-based material and the precursor (such as ammonium salt) in different atmospheres, and treating for 1-4 hours at the temperature of 300-1000 ℃. The different atmospheres include oxygen, hydrogen, nitrogen, ammonia, and the like.

The method can be used for treating carbon cloth, carbon velvet, carbon fiber and the like. And (3) placing the cut carbon cloth in a muffle furnace or a tubular furnace, and heating for 1-4 hours at 300-1000 ℃ in the atmosphere of air, nitrogen, ammonia and carbon dioxide. In this experiment, the acid-treated A-CC was calcined in air at 500 ℃ for 2 hours, designated O-CC, and the appearance is shown in FIG. 10, and the polarization curve is shown in FIG. 9.

Electrochemical treatment

The method can be used for treating carbon cloth, carbon velvet, carbon fiber and the like. Using the cut carbon cloth as an electrolytic cell anode, using 1% -10% sulfuric acid/sodium sulfate/sodium bisulfate/sodium bicarbonate as electrolyte (ammonium sulfate/ammonium bisulfate/ammonium bicarbonate and the like if doped with nitrogen), and carrying out anodic oxidation treatment at the temperature of 30-50 ℃. Taking a carbon rod as a counter electrode and a saturated calomel electrode as a reference electrode, and carrying out 5-15 times of cyclic voltammetry scanning on carbon cloth at a potential of 0.0-2.0V at a scanning speed of 10-100 mV/s. Then fixing the voltage to 1.5-2.5V, and carrying out deep anodic oxidation on the carbon cloth by adopting a chronopotentiometry analysis method, wherein the reaction time is 5-30 minutes. The reacted electrode was washed several times with deionized water and dried in a vacuum oven at 60 ℃ for 12-24 hours.

The method can realize doping treatment: a carbon material doped with non-metal atoms, said non-metal atoms comprising at least one of boron atoms, nitrogen atoms, and sulfur atoms.

The cut carbon cloth is used as an anode of an electrolytic cell, a carbon rod is used as a counter electrode, a saturated calomel electrode is used as a reference electrode, the reaction temperature is 30-50 ℃, and 5-15 times of cyclic voltammetry scanning is carried out on the carbon cloth at the scanning rate of 10-100mV/s and in the mixed solution containing soluble non-noble metal salt solution, at least one of sulfate, nitrate and acetate and sodium nitrate, and the potential is in the range of 0-1.5V. And washing the electrode subjected to electrochemical deposition with deionized water for several times, and drying in a vacuum drying oven at 60 ℃ for 12-24 hours.

Hydrothermal reaction

The method can realize doping treatment: a carbon material doped with non-metal atoms, said non-metal atoms comprising at least one of boron atoms, nitrogen atoms, and sulfur atoms.

The impregnation of the carbon-based material in the ammonium precursor includes at least one of melamine, urea, ammonium chloride, ammonium bromide, ammonium carbonate, ammonium bicarbonate, and the like. The solution is put into a hydrothermal kettle and heated to 50-180 ℃ for reaction for 12-24 hours. After the reaction is finished, cooling to room temperature, washing with deionized water, and drying in a vacuum drying oven at 60 ℃ for 12-24 hours. Obtaining a carbon-based material doped with nitrogen atoms

The method can realize the carbon-based material doped or loaded with non-noble metal atoms or oxides, wherein the non-noble metal atoms comprise at least one of cobalt, iron, copper, nickel and manganese.

The carbon-based material is immersed in a soluble non-noble metal salt solution, and the carbon-based material is respectively and independently selected from at least one of sulfate, nitrate and acetate. The solution is put into a hydrothermal kettle and heated to 50-180 ℃ for reaction for 12-24 hours. After the reaction is finished, cooling to room temperature, washing with deionized water, and drying in a vacuum drying oven at 60 ℃ for 12-24 hours.

The carbon-based anode material is coated on a titanium sheet, a titanium net, foamed titanium, a stainless steel sheet, a stainless steel net, foamed stainless steel, a lead sheet, a lead net, ITO, carbon cloth, carbon paper, a carbon felt and other conductive matrixes to serve as an anode.

Graphite, high-conductivity carbon black powder (acetylene black, vulcan xc-72R, BP2000, Ketjen black), carbon nano tubes, activated carbon, carbon gel, carbonized biomass (chitosan, cellulose, lignin), carbon nano molecular sieve, carbon material doped with at least one non-metal atom of oxygen atom, oxygen functional group, boron atom, nitrogen atom and sulfur atom and carbon-based anode material doped or loaded with at least one non-noble metal atom or oxide of cobalt, iron, copper, nickel and manganese element are coated on a titanium sheet, a titanium mesh, titanium foam, a stainless steel sheet, a stainless steel mesh, stainless steel foam, a lead sheet, a lead mesh, ITO, carbon cloth, carbon paper, carbon felt and other conductive substrates as anodes.

(1) Firstly, the titanium material is pretreated. The titanium plate, titanium mesh, titanium tube or grid casting material of ASTM grade 1 or 2 is used, and is subjected to sand blasting, degreasing, acid treatment (oxalic acid and the like), water washing and drying treatment.

Carrying out sand blasting treatment on the titanium matrix to increase the roughness of the matrix;

degreasing to remove oil stains on the surface of the titanium substrate: putting the titanium matrix after sand blasting into 80 ℃ alkali liquor (NaHCO)₃NaOH or Na3PO 4);

etching the substrate by means of an acid (oxalic acid, hydrochloric acid): soaking and etching the substrate for 1 to 5 hours in 5 to 30 percent oxalic acid at the temperature of between 60 and 100 ℃.

Washing with deionized water, and drying.

(2) Mixing the above materials with alcohol (such as isopropanol and butanol) to obtain coating slurry, and spray-coatingThe titanium substrate is evenly coated on the pretreated titanium substrate by brushing, dipping and the like, the steps are repeated for 1-10 times after the solvent is removed by drying at 60-100 ℃, and finally the titanium substrate is roasted for 1-3 hours at the temperature of 300-1000 ℃. Repeating the above steps until the coating reaches 10-100g/m²。

Coating a carbon material and a carbon-based material doped or loaded with at least one non-noble metal atom or oxide of cobalt, iron, copper, nickel and manganese elements on a titanium sheet, a titanium mesh, titanium foam, a stainless steel sheet, a stainless steel mesh, stainless steel foam, a lead sheet, a lead mesh, ITO, carbon cloth, carbon paper, a carbon felt and other conductive substrates as an anode. The method comprises the following steps: dipping, sol-gel, electrodeposition, and the like.

Doping atoms of the non-metal carbon-based material are non-metal atoms, and the non-metal atoms comprise at least one of oxygen, boron, nitrogen and sulfur atoms; the doping atoms of the non-noble metal-doped carbon-based material are non-noble metal atoms, the non-noble metal comprises at least one of cobalt, iron, copper, nickel and manganese, the dopant doped with the non-noble metal oxide is a non-noble metal oxide, and the non-noble metal oxide comprises at least one of cobalt-containing oxide, iron-containing oxide, copper-containing oxide, nickel-containing oxide and manganese-containing oxide.

In the embodiment of the application, a non-metallic carbon-based material is firstly proposed to be used as a chlorine separation reaction anode to replace the traditional DSA electrode taking ruthenium oxide as an active component. The carbon-based anode material has high-efficiency catalytic activity, selectivity and long-acting stability, and meanwhile, the preparation method is simple, low in cost and simple in process, and can be suitable for large-scale industrial production. The carbon-based anode material has high catalytic activity and selectivity and long-acting stability under strong acid conditions, the preparation method is simple and economic, and is suitable for large-scale industrial production, and the characteristics of the center structure and the electronic characteristic of an active site, the adsorption performance and the activation energy of chloride ions and the like are explored by accurately designing and finely regulating the coordination number and the local atomic structure of the active site in the monatomic catalyst.

In an embodiment of the present application, the carbon-based raw material is a carbon-based material formed by a substrate carbon and doping atoms, and the substrate carbon includes: at least one of graphite, carbon black powder, carbon nanotubes, activated carbon, carbon fibers, and carbonized biomass.

Any one of the substrate carbons in the embodiments of the present application can achieve the purpose of the embodiments of the present invention, and can be used in the fields of chlorine production by electrolysis in a laboratory or chlorine production by electrolysis in an industrial large scale, seawater electrolysis, and the like.

In an embodiment of the present application, the chemical treatment includes an acid treatment.

In the embodiment of the application, the substrate carbon is subjected to non-metal atom doping or non-noble metal oxide loading treatment to obtain a loaded carbon-based material, and then the loaded carbon-based material is treated to obtain a carbon-based anode material.

In an embodiment of the present application, the carbon fiber includes: at least one of carbon paper, carbon velvet, carbon cloth and graphite felt; the carbonized biomass includes: at least one of chitosan, cellulose and lignin.

In the embodiment of the application, the carbon black powder can be acetylene black or a type of carbon black powder which is commercially available and has the model number of VulcanXC-72R, BP2000 and Ketjen carbon black.

In the embodiment of the application, the doping atoms or dopants are non-noble metal oxides, and can participate in the subsequent reaction, so that the carbon-based material obtains oxygen-containing functional groups to generate chlorine through electrolysis.

In the embodiment of the application, the specific surface area of the carbon-based anode material is more than 500m²The higher specific surface area can effectively adsorb chlorine, so that the chlorine can be conveniently reacted.

As an alternative embodiment, in the doped non-metal carbon-based material, the molar ratio of non-metal atoms to carbon atoms is greater than 1: 100; in the non-noble metal-doped carbon-based material and the non-noble metal oxide-loaded carbon-based material, the molar ratio of non-noble metal atoms to carbon atoms is greater than 1: 100.

In an embodiment of the present application, the carbon-based anode material has a carbon-based anode material having an oxygen-containing functional group; the oxygen-containing functional group includes: at least one of a hydroxyl group, a carbonyl group, a carboxyl group, and an ester group.

In the embodiment of the application, hydroxyl, carbonyl, carboxyl and ester groups in the oxygen-containing functional groups can participate in the reaction in the subsequent electrolytic chlorine production process, and the accurate regulation and control of the adsorption energy of the intermediate in the electrolytic chlorine production reaction is achieved by changing the filling degree of the carbon atom p orbit in the carbon-based material near the Fermi level.

In the embodiment of the present application, the carbon-based anode material may have the following chemical formula:

in the examples of the present application, the carbon-based anode material is stable in an environment of pH 1 to 14. Preferably, under acidic conditions (pH)<3) And (4) stabilizing. At 100mA/cm²The voltage change of the O-BP is not more than 0.02V under the constant current density, and the O-BP is relatively stable within 264 hours. At the same time, the current density is 0.5A/cm²And the voltage change is not more than 0.05V within 100 hours.

As an alternative embodiment, the heat treatment comprises heating the carbon-based raw material at 300 ℃ to 1000 ℃ for 1 to 4 hours under a protective atmosphere.

In the embodiment of the application, the heat treatment mode is co-roasting.

As an alternative embodiment, the protective atmosphere comprises: any one of oxygen, hydrogen, nitrogen and ammonia.

As an alternative embodiment, a carbon-based raw material is used as an electrode, and anodic oxidation or reduction deposition reaction is carried out in an electrolytic cell containing soluble non-noble metal salt solution of different elements or ammonium-containing precursors, so as to obtain a first carbon-based material containing different functional groups or element doping and oxide deposition;

and washing and drying the first carbon-based material to obtain the carbon-based anode material.

The reason for the electrochemical treatment is to achieve doping of the non-noble metal or non-metallic or non-noble metal oxide, the non-noble metal atoms can be doped into the carbon substrate by anodic oxidation or cathodic reduction deposition, or the oxide thereof can be electrodeposited on the carbon substrate. Electrochemical treatment is an oxidation or reduction treatment, such as electron oxidation at the anode or reduction of metal cations at the cathode, as well as thermal and hydrothermal treatments.

As an alternative embodiment, the soluble non-noble metal salt solution is selected from non-noble metal-containing sulfate, nitrate and acetate solutions because any solution; the reason why the ammonium precursor includes at least one ammonium precursor of melamine, urea, ammonium chloride, ammonium bromide, ammonium carbonate and ammonium bicarbonate is nitrogen doping; can achieve the purpose of reaction.

A gas diffusion electrode comprising said carbon-based anode material for the electrolytic production of chlorine.

An anode electrode comprises a carbon-based anode material coated on a substrate as an anode, wherein the substrate comprises any one of titanium, lead and conductive glass stainless steel.

The present invention will be described in detail below with reference to examples and experimental data.

Example 1

In the present embodiment, the non-metal atom is an oxygen atom, and the base carbon is highly conductive carbon black powder BP 2000. The carbon-based anode material, namely the carbon-based catalyst, with at least one of oxygen-containing functional groups of hydroxyl, carbonyl, carboxyl and ester is prepared by a high-temperature heat treatment method, and is named as O-BP. The specific preparation steps of the O-BP are as follows: weighing a certain amount of BP2000 in a corundum crucible, placing the corundum crucible in a muffle furnace, raising the temperature from room temperature to 400-600 ℃ at the speed of 5-10 ℃/min, keeping the temperature for 1-5 hours, and then naturally cooling to obtain powder, namely O-BP which can be used as an anode material for electrochemical chlorine generation.

FIGS. 1 and 2 show scanning electron micrographs and transmission electron micrographs of the synthesized O-BP, which is seen to exhibit an irregular "onion carbon" structure with rough surfaces and amorphous edges.

Example 2

In this embodiment, a carbon-based material doped with at least one non-metal atom selected from boron atoms, nitrogen atoms, and sulfur atoms is used as the carbon-based anode material. The non-metal atoms are oxygen atoms, and the substrate carbon is carbon fiber. A carbon-based anode material having at least one of oxygen-containing functional groups of hydroxyl, carbonyl, carboxyl and ester groups, i.e., a carbon-based catalyst, is prepared by a high-temperature heat treatment method, and is named as O-CF.

The preparation method comprises the following specific steps: and (3) carrying out continuous anodic oxidation treatment on the surface of the carbon fiber by taking the carbon fiber as an oxidation anode and a graphite rod as a cathode. 5-10% of ammonium bicarbonate is used as electrolyte, the electrolysis time is 50 seconds to 5 minutes, the electrolysis temperature is 22 to 80 ℃, the control of the oxidation process is realized by adjusting the current intensity to be 50mA to 5A in the anodic oxidation process, in order to obtain the electrolyte solution on the surface of the carbon fiber, the carbon fiber after the anodic oxidation treatment is washed to be neutral by deionized water and is put into an oven at the temperature of 80 to 120 ℃ to be dried for 2 to 8 hours. The O-CF carbon-based material can be used as an anode material for electrochemically generating chlorine.

Example 3

In this embodiment, a carbon-based material doped with at least one non-metal atom selected from boron atoms, nitrogen atoms, and sulfur atoms is used as the carbon-based anode material. In this embodiment, the non-metal atoms are nitrogen atoms and the carbon-based material is selected from carbon nanotubes.

The preparation method comprises the following specific steps: weighing a certain amount of carbon nano tubes, placing the carbon nano tubes and melamine in an agate mortar, and fully grinding for 20 minutes to uniformly mix the carbon nano tubes and the melamine; transferring the ground sample to a porcelain boat, placing the porcelain boat in a tube furnace, introducing nitrogen into the tube furnace for 30 minutes to ensure that air is exhausted, setting the heating rate to be 5-10 ℃/min, maintaining the temperature at 400-700 ℃ for 2-3 hours, and continuously introducing nitrogen after the reaction is finished until the temperature is reduced to room temperature to obtain a nitrogen-doped carbon nanotube material, wherein the atomic percentage of nitrogen atoms to carbon atoms is more than 1%, and the carbon-based anode material is obtained and used for electrochemically generating chlorine.

Example 4

In this embodiment, a carbon-based material supporting an oxide containing at least one non-noble metal of cobalt, iron, copper, nickel, and manganese is selected as the anode material. In the embodiment, the non-noble metal element is manganese, the carbon-based material is carbon cloth, and the prepared carbon cloth is made.

Tool bodyThe preparation method comprises the following steps: weighing 2mmol of CoSO₄·7H₂Dissolving O in 50mL deionized water, stirring for 30min, adding 0.2g carbon nanotube, stirring, soaking for 10 hr, washing with deionized water for 2-3 times to remove Co adsorbed on surface²⁺And drying for 10-12 hours, placing the dried sample in a tube furnace, introducing argon, heating to 600-900 ℃, and pyrolyzing at constant temperature for 2-3 hours to obtain the cobalt-doped carbon nanotube material which can be used as an anode material for electrochemically generating chlorine.

Example 5

In this embodiment, a carbon-based material doped with at least one non-metal atom selected from boron atoms, nitrogen atoms, and sulfur atoms and supporting an oxide containing at least one non-noble metal selected from cobalt, iron, copper, nickel, and manganese elements is used as the carbon-based anode material. In this embodiment, the non-metal atoms are nitrogen atoms, the non-noble metal element is cobalt, and the carbon-based material is carbon nanotubes. The preparation method comprises the following specific steps: weighing 2mmol of CoSO₄·7H₂O,2mmolNH₄And F and 5mmol of urea are dissolved in 50mL of deionized water, 0.5g of the nitrogen-doped carbon nano tube in the embodiment 3 is added after the mixture is fully stirred for 30 minutes, the mixture is added into a hydrothermal kettle after the mixture is stirred for 10 minutes to carry out hydrothermal reaction, the hydrothermal temperature is 80-180 ℃, and the reaction time is 8-24 hours. After the reaction is finished and the natural cooling is carried out, the obtained sample is washed and dried, and the dried sample is placed in a tube furnace argon atmosphere to be calcined for 3-5 hours at the temperature of 200-800 ℃ to obtain the Co-loaded material₃O₄The nitrogen-doped carbon nanotube material can be used as an anode material for electrochemically generating chlorine.

Example 6

The use of the O-BP catalyst prepared in example 1 in electrochemical chlorine-generating reactions against the background of the chlor-alkali industry:

the electrochemical chlorine generation performance of the O-BP electrocatalyst was tested on an electrochemical workstation model CHI760D (shanghai chenghua) using a three electrode system with an electrolyte solution of 4M nacl, pH 1, silver/silver chloride (Ag/AgCl, 3M) electrode and graphite rods as reference and counter electrodes, respectively. The prepared O-BP catalyst and 5 wt% Nafion solution were dispersed in 1mL of isopropanol and subjected to water bath sonication for 30min to form a uniform suspension. For rotating disc electricityPerforming polar test, namely uniformly dripping 30-50uL of catalyst dispersion liquid on a glassy carbon electrode with the diameter of 5mm, and drying at room temperature; for stability testing, 100-150uL of catalyst dispersion was uniformly dropped on a catalyst with a diameter of 0.5X 0.5cm²Dried at room temperature. The test potentials applied by all working electrodes (vs. ag/AgCl) were converted to the standard hydrogen potential (vs. rhe): e (rhe) ═ E (Ag/AgCl) +0.059 × pH + 0.197.

Linear Sweep Voltammetry (LSV) at a sweep rate of 10.0mV · s^-1The test was performed. The stability test selects an H-type electrolytic cell, wherein a cation exchange membrane N424 is selected to separate two chambers. Stability at current density j of 100mAcm^-2The measurement was carried out for 264 hours. The cation exchange membrane and electrolyte are periodically replaced to maintain the electrolyte concentration and pH in the anode chamber. The Faraday efficiency of the reaction is determined by a DPD color method to determine the concentration of the solution and gas after the reaction, as shown in figure 6, the O-BP has good stability, and the Faraday efficiency is about 100 percent, which indicates that the O-BP has high selectivity for generating chlorine.

FIG. 3 is a graph showing the polarization of O-BP prepared according to the present invention in 4M NaCl; RuO₂Polarization plots in 4m nacl; polarization graph of BP in 4m nacl; graph for polarization of graphite rod in 4m nacl; O-BP (4 MNaClO)₄) At 4M NaClO₄Polarization curve diagram in environment, it can be seen that the catalyst has more excellent electrocatalytic chlorine generating activity and selectivity compared with other materials.

Example 7

The application of the O-BP catalyst prepared in the example 2 in the electrochemical chlorine generating reaction (CER) with the background of water with low concentration salinity, such as seawater, is as follows:

the electrochemical chlorine generation performance of the O-BP electrocatalyst was tested on an electrochemical workstation model CHI760D (shanghai chenhua) using a three electrode system with an electrolyte solution of 0.33M nacl, pH 7-8, silver/silver chloride (Ag/AgCl, 3M) electrode and graphite rods as reference and counter electrodes, respectively. The prepared O-BP catalyst and 5 wt% Nafion solution were dispersed in 1mL of isopropanol and a homogeneous suspension was formed after 30 minutes of water bath sonication. For the rotating disk electrode test, takeUniformly dripping 30-50uL of catalyst dispersion liquid on a glassy carbon electrode with the diameter of 5mm, and drying at room temperature; for stability testing, 100-150uL of catalyst dispersion was uniformly dropped on a catalyst with a diameter of 0.5X 0.5cm²Dried at room temperature. The test potentials applied by all working electrodes (vs. ag/AgCl) were converted to the standard hydrogen potential (vs. rhe): e (rhe) ═ E (Ag/AgCl) +0.059 × pH + 0.197.

FIG. 4 is a graph showing the polarization of O-BP prepared according to the present invention at a low concentration of 0.33M NaCl at pH 7-8; it can be seen from the figure that O-BP still has good chlorine generating performance.

Detailed explanation of the drawings:

as shown in FIG. 4, the O-BP catalyst prepared by the present invention was used in the presence of neutral low concentration NaCl and NaClO₄The polarization curve in the solution shows that the catalyst still has certain electrochemical chlorine generating activity under the condition of low salinity, and can be subsequently applied to the fields of seawater and the like.

FIG. 5 is a polarization curve diagram of O-BP under different pH conditions, showing that O-BP has higher CER activity under different pH conditions, and H⁺The electrochemical chlorine generating performance of O-BP is slightly influenced, and the carbon-based anode material can be stably used under different pH conditions.

FIG. 6 is a plot of O-BP versus chronopotentiometric potential of a conventional graphite rod and measured at 100mAcm^-2The Faraday efficiency of the O-BP electrode is about 100 percent when the experiment is measured under the condition that the pH value is 1 under the strong acid condition, which shows that the material has high selectivity for producing chlorine; at a current density of 100mAcm^-2In the following, it can be seen that O-BP (the line of the lower horizontal line) has a large voltage required by the common graphite electrode, and has poor stability and fast consumption compared with the common graphite rod, while the voltage of the O-BP electrode is stabilized at about 1.5V in a long time (264 hours), which indicates that the O-BP electrode has high stability and high chlorine selectivity.

In FIG. 7, panel A is a polarization curve plot of O-BP under 4M NaCl, pH 1 and normal temperature conditions, one is a 95% iR corrected O-BP curve and the other is a conventional O-BP polarization curve; the graph B shows the potential of O-BP under different current densities, and the graph shows that the O-BP still has low over potential and stable current potential under high current density and can be used as an anode material for electrochemical chlorine generation.

FIG. 8 is a polarization curve of O-BP under the conditions of 4MNacl, pH 1 and 70 ℃, and comparing with FIG. 9, it can be seen that the required overpotential is further reduced with the temperature increase, and when the current density is 1Acm^-2When the electrochemical chlorine generating anode material is used, the overpotential is only 113mV, which shows that the overpotential of O-BP is low under the industrial environment of chlor-alkali (70 ℃), so that the O-BP can be used as the electrochemical chlorine generating anode material, and the current potential is stable.

Fig. 9 is an electrolyte solution at 4m nacl (pH 1) using Linear Sweep Voltammetry (LSV), room temperature, sweep rate: 5mV s^-1Oxidation treated carbon cloth (O-CC) and untreated commercial Carbon Cloth (CC). The comparison shows that the modified O-CC has excellent CER activity and simultaneously has the high current density of 1A/cm²Still has a low overpotential, indicating industrial applicability, while comparing the electrolyte without NaCl (4M NaClO)₄pH 1), it can be seen that the oxygen generating property by the side reaction is low, thereby indicating that it has a high electrochemical chlorine generating selectivity.

It is noted that, in this document, relational terms such as "first" and "second," and the like, may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The foregoing are merely exemplary embodiments of the present invention, which enable those skilled in the art to understand or practice the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.