CN111905739B

Movatterモバイル変換

Info

Publication number: CN111905739B
Application number: CN202010907721.6A
Authority: CN
Inventors: 吴宇恩; 赵长明
Original assignee: Anhui Entropy Card Technology Co ltd
Current assignee: Anhui Entropy Card Technology Co ltd
Priority date: 2020-08-31
Filing date: 2020-08-31
Publication date: 2023-02-10
Anticipated expiration: 2040-08-31
Also published as: CN111905739A

Abstract

The invention discloses a preparation method of a catalyst applied to an oxygen generator, which comprises the following steps: the catalyst applied to the oxygen generator is prepared by taking carbon carrier vulcan BP-2000 carbon black as a raw material and hydroxyl free radicals with strong oxidizing property as an oxidizing source and carrying out hydroxyl free radical oxidation treatment on the carbon black. The carbon carrier vulcan BP-2000 carbon black is used as a raw material, hydroxyl radicals with strong oxidizing property are used as an oxidation source, and the carbon black is subjected to hydroxyl radical oxidation treatment to obtain the catalyst.

Description

Preparation method of catalyst applied to oxygen generator

Technical Field

The invention relates to the technical field of catalysts, in particular to a preparation method of a catalyst applied to an oxygen generator.

Background

Oxygen is one of essential elements for maintaining human life, has irreplaceable effect in the metabolic activity of organisms, and has very wide application scenes. The existing oxygen production technology can be divided into two main categories of physical method oxygen production and chemical method oxygen production. The physical method mainly comprises a low-temperature rectification method, a pressure swing adsorption method and a membrane separation method, and the chemical method mainly comprises a chemical agent oxygen generation method and an electrolysis method. The low-temperature distillation method is only suitable for the field of large-scale oxygen production due to large investment, high energy consumption and complex operation. The pressure swing adsorption method is the method which is used most frequently in household oxygenerators on the market at present, and realizes oxygen-nitrogen separation by a method of adsorbing nitrogen at high pressure and desorbing nitrogen at low pressure based on the selective adsorption of oxygen and nitrogen in air by a molecular sieve. The membrane separation method has the advantages of compact equipment, low cost, simple and convenient operation and the like, but the concentration of enriched oxygen is generally lower and depends on the performance of the membrane. Although the chemical oxygen production method has the advantages of convenience, rapidness, high purity of the prepared oxygen and the like, the production process consumes more energy, and the whole process is accompanied with the generation of byproduct hydrogen, so that great potential safety hazards exist.

The electrochemical oxygen generator is an electrolytic cell for electrolyzing air, and its structure is similar to that of fuel cell, and is mainly formed from anode, cathode and electrolyte. Under the action of potential difference, oxygen in air is consumed by an Oxygen Reduction Reaction (ORR) at the cathode, and Oxygen precipitation reaction (OER) at the anode generates high-purity Oxygen; the conductive ions in the electrolyte migrate under the action of the potential difference and the concentration gradient. The whole process is a process for realizing oxygen enrichment by taking air as a raw material through an electrochemical method, and pure oxygen with the purity of 99.9 percent can be obtained at the anode. In order for the catalyst to possess as high a catalytic activity as possible, it should have a moderate oxygen binding energy. The ability of oxygen electrocatalytic reduction is limited due to the adsorption of oxygen on the surface of the electrode, the activation of O-O bonds, the diffusion of oxides and the like, and the finding of a suitable catalyst is particularly critical.

Disclosure of Invention

The invention mainly aims to provide a preparation method of a catalyst applied to an oxygen generator, and aims to provide a high-efficiency electrocatalyst applied to the oxygen generator.

In order to achieve the aim, the invention provides a preparation method of a catalyst applied to an oxygen generator, which comprises the following steps:

the catalyst applied to the oxygen generator is prepared by taking carbon carrier vulcan BP-2000 carbon black as a raw material and hydroxyl free radicals with strong oxidizing property as an oxidizing source and carrying out hydroxyl free radical oxidation treatment on the carbon black.

Alternatively, the step of subjecting carbon black to hydroxyl radical oxidation treatment using carbon carrier vulcan BP-2000 carbon black as a raw material and a hydroxyl radical having a strong oxidizing property as an oxidation source to prepare a catalyst for use in an oxygen generator, comprises:

dispersing carbon carrier vulcan BP-2000 carbon black in deionized water to form a precursor solution;

adding a hydrogen peroxide solution and ferrous sulfate powder into the precursor solution, and carrying out oxidation treatment by utilizing a Fenton reaction to obtain a semi-finished product solution;

and washing the semi-finished product solution to remove redundant iron ions in the semi-finished product solution, then extracting solid matters in the semi-finished product solution and drying to obtain the powdery catalyst.

Alternatively, in the step of dispersing the carbon support vulcan BP-2000 carbon black in deionized water to form a precursor solution:

the concentration of the carbon black in the precursor solution is 5-10 mg/mL; and/or the presence of a gas in the atmosphere,

the particle size of the carbon black is 25-50 mu m.

Optionally, in the step of adding a hydrogen peroxide solution and ferrous sulfate powder to the precursor solution, and performing oxidation treatment by fenton reaction to obtain a semi-finished solution:

the mass fraction of the hydrogen peroxide solution is 10-30%, and in every 100mL of the precursor solution, the volume of the hydrogen peroxide solution is 5-20 mL, and the mass of the ferrous sulfate powder is 8-10 g; and/or the presence of a gas in the atmosphere,

the reaction temperature of the Fenton reaction is 40-60 ℃, and the reaction time is 1-5 h; and/or the presence of a gas in the gas,

the pH value of the Fenton reaction is 2.0-4.0.

Optionally, the step of washing the semi-finished solution to remove excess iron ions in the semi-finished solution, then extracting solid substances in the semi-finished solution and drying to obtain the powdered catalyst comprises:

firstly, washing the semi-finished product solution by using a sulfuric acid solution, washing off redundant iron ions in the semi-finished product solution, then washing by using deionized water until filtrate is neutral, then separating solid matters in the semi-finished product solution, and carrying out vacuum drying at normal temperature to prepare the powdery catalyst.

adding a hydrogen peroxide solution into the precursor solution, and then irradiating by using a UV lamp to enable photochemical oxidation reaction to occur in the solution to prepare the catalyst in the form of solution.

the concentration of the carbon black in the precursor solution is 5-10 mg/mL; and/or the presence of a gas in the gas,

the particle size of the carbon black is 25-50 mu m.

Alternatively, in the step of adding a hydrogen peroxide solution to the precursor solution and then irradiating the solution with a UV lamp to cause a photochemical oxidation reaction in the solution, the catalyst in the form of a solution is prepared:

the mass fraction of the hydrogen peroxide solution is 10-30%, and the volume of the hydrogen peroxide solution added in each 100mL of the precursor solution is 5-20 mL.

the wavelength range of the UV lamp is 200-450 nm, and the irradiation time of the UV lamp for irradiation is 1-3 h; and/or the presence of a gas in the atmosphere,

the pH value of the solution is 5.5-6.7 when the UV lamp is used for irradiation.

Furthermore, the invention also provides an electrochemical oxygen generator, wherein a catalyst is placed in the electrochemical oxygen generator, and the catalyst is prepared by the preparation method of the catalyst applied to the oxygen generator.

According to the technical scheme provided by the invention, carbon carrier vulcan BP-2000 carbon black is used as a raw material, hydroxyl free radicals with strong oxidizing property are used as an oxidation source, and the carbon black is subjected to hydroxyl free radical oxidation treatment to obtain the catalyst.

Drawings

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, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other related drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic flow chart of an embodiment of the method for preparing a catalyst for use in an oxygen plant according to the present invention;

FIG. 2 is a schematic flow chart of another embodiment of the method for preparing a catalyst used in an oxygen generator according to the present invention;

FIG. 3 is a TEM image of the microstructure of the raw material BP-2000 carbon black;

FIG. 4 is a TEM image of the microstructure of BP-2000 carbon black after oxidation treatment by Fenton reaction;

FIG. 5 is a TEM image of the microstructure of BP-2000 carbon black after oxidation treatment by UV lamp irradiation;

FIG. 6 is an FI-IR chart of BP-2000 carbon black after Fenton reaction oxidation treatment and UV lamp irradiation oxidation treatment, respectively;

FIG. 7 shows N of a catalyst obtained by subjecting BP-2000 carbon black to Fenton's reaction oxidation treatment and UV lamp irradiation oxidation treatment, respectively₂ Adsorption-desorption curves;

FIG. 8 is a graph showing the comparison of the performance of a catalyst obtained by subjecting BP-2000 carbon black to Fenton reaction oxidation treatment and UV lamp irradiation oxidation treatment, respectively, to prepare an electrode.

The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are conventional products which are not indicated by manufacturers and are commercially available.

The electrochemical oxygen generator is an electrolytic cell for electrolyzing air, and its structure is similar to that of fuel cell, and is mainly formed from anode, cathode and electrolyte. Under the action of potential difference, oxygen in air is consumed by an Oxygen Reduction Reaction (ORR) at the cathode, and Oxygen precipitation reaction (OER) at the anode generates high-purity Oxygen; the conductive ions in the electrolyte migrate under the action of the potential difference and the concentration gradient. In the whole process, the oxygen enrichment is realized by taking air as a raw material through an electrochemical method, and pure oxygen with the purity as high as 99.9 percent can be obtained at the anode. In order for the catalyst to possess as high a catalytic activity as possible, it should have a moderate oxygen binding energy. The ability of oxygen electrocatalytic reduction is limited due to the adsorption of oxygen on the surface of the electrode, the activation of O-O bonds, the diffusion of oxides and the like, and the finding of a suitable catalyst is particularly critical.

In view of the above, the present invention provides a method for preparing a catalyst for use in an oxygen generator, comprising the steps of: the catalyst applied to the oxygen generator is prepared by taking carbon carrier vulcan BP-2000 carbon black as a raw material and hydroxyl free radicals with strong oxidizing property as an oxidizing source and carrying out hydroxyl free radical oxidation treatment on the carbon black. The commercial BP-2000 is high-conductivity carbon black capable of maintaining physical properties under the condition of low carbon black filling, is widely applied to the fields of semiconductors and chemical industry, is cheap and easy to obtain, and is suitable for being used as a catalyst. When the catalyst is applied to an electrochemical oxygen generator, the catalyst can be prepared by taking air as a raw material and utilizing electric energy to generate pure oxygen under the action of potential difference, has excellent catalytic performance and can effectively reduce energy consumption. In addition, the preparation method of the catalyst provided by the invention can adjust the specific reaction mode and reaction conditions in the preparation process according to different product requirements so as to correspondingly obtain the solid powdery catalyst or the aqueous catalyst solution.

In one embodiment of the preparation method of the catalyst applied to the oxygen generator, the prepared catalyst is solid powder and is prepared by adopting an advanced oxidation technology. The advanced oxidation technology is a technology for oxidizing and decomposing organic matters into small molecules until the small molecules are completely degraded by utilizing a very strong oxidizing group, namely hydroxyl free radical (OH), generated in a chemical reaction and a series of chain reactions. The advanced oxidation technology has the characteristics of strong oxidation capacity, wide adaptability, convenient operation and the like, and is widely applied to the field of water treatment. Common advanced oxidation processes are Fenton, photochemical and the like. The Fenton system has strong oxidizing capability mainly because the system can generate high-activity hydroxyl free radicals (OH), and has the advantages of simple operation, rapid reaction, simple conditions and the like. The reaction process is as follows:

Fe²⁺ +H₂ O₂ →Fe³⁺ +OH^- +·OH

hydroxyl radical (. OH) has extremely high oxidizing property, and this reaction is often used for sewage treatment in industrial production. The principal principle of the Fenton process is Fe²⁺ Catalysis H₂ O₂ OH is produced, these radicals are able to transfer electrons in the system and in this way propagate the radical chain reaction. Part of the propagated hydroxyl radicals attack organic matters to separate hydrogen ions, the organic matters become free radicals R DEG without the hydrogen ions, and the free radicals can be further decomposed into small molecules or inorganic matters by a system; and the other part of hydroxyl free radicals can attack C-C bonds or C-H bonds in the organic matter, and the BP-2000 is subjected to oxidation treatment by utilizing the strong oxidation capacity of the reaction.

Referring to fig. 1, in this embodiment, the preparation method of the catalyst for use in an oxygen generator includes the following steps:

s10a, dispersing carbon carrier vulcan BP-2000 carbon black in deionized water to form a precursor solution;

in this example, the concentration of carbon black in the precursor solution was 5 to 10mg/mL. The specific implementation manner of step S10a is: adding a commercial carbon carrier vulcan BP-2000 carbon black into deionized water, and mechanically stirring for 20-25 h to uniformly disperse the carbon black to obtain the precursor solution. In other embodiments of the present invention, carbon black may also be dispersed using, for example, magnetic stirring. In addition, the particle size of the carbon black is preferably 25 to 50 μm, and in this example, the carbon black may be subjected to a pretreatment such as grinding before the carbon black is added to deionized water, and for example, the carbon black may be ground with a mortar or a commercial ball mill for 15 to 30min so that the particle size of the carbon black becomes 25 to 50 μm. In other embodiments of the present invention, commercial carbon support vulcan BP-2000 carbon black having a particle size in the range of 25 to 50 μm may also be purchased directly.

Step S20a, adding a hydrogen peroxide solution and ferrous sulfate powder into the precursor solution, and carrying out oxidation treatment by utilizing Fenton reaction to obtain a semi-finished product solution;

in this embodiment, the mass fraction of the hydrogen peroxide solution is 10 to 30%, and the volume of the hydrogen peroxide solution added to each 100mL of the precursor solution is 5 to 20mL, and the mass of the ferrous sulfate powder added to the precursor solution is 8 to 10g. Adding hydrogen peroxide solution and ferrous sulfate powder into the precursor solution according to the proportion, and then carrying out Fenton reaction in the system, namely realizing the hydroxyl radical oxidation treatment of the carbon black to obtain a semi-finished product solution. Wherein, the conditions of the fenton reaction are preferably set as follows: the reaction temperature is 40-60 ℃, and the reaction time is 1-5 h. More preferably, the optimum pH of the fenton reaction is maintained between 2.0 and 4.0, and can be specifically achieved by adding a certain amount of acid to the reaction system, and the reaction efficiency of the fenton reaction is higher in this pH range.

And S30a, washing the semi-finished product solution to remove redundant iron ions in the semi-finished product solution, then extracting solid matters in the semi-finished product solution and drying to obtain the powdery catalyst.

In a specific operation, the washing of the semi-finished product solution in step S30 may specifically include steps of acid washing and water washing, and it is proposed that a conventional solid-liquid separation method such as filtration and suction filtration may be used as a method for washing solid matters in the semi-finished product solution. Preferably, in this embodiment, the step S30 specifically includes the following steps: firstly, washing the semi-finished product solution by using a sulfuric acid solution with the pH value of 2.0, washing off redundant iron ions in the semi-finished product solution, then washing by using deionized water until filtrate is neutral, then carrying out suction filtration on the washed semi-finished product solution, collecting obtained solid matters, and carrying out vacuum drying at normal temperature until the solid matters are powdery to prepare the powdery catalyst.

In another embodiment of the method for preparing the catalyst applied to the oxygen generator, the prepared catalyst is a liquid-phase catalyst and adopts UV (Ultraviolet)/H₂ O₂ And (3) preparing by an advanced oxidation process. UV/H₂ O₂ The advanced oxidation process belongs to one photochemical oxidation method, and has the advantages of strong oxidation capacity, high treatment efficiency, no selectivity, no secondary pollution, green and environment-friendly products and the like. UV/H₂ O₂ The main process dependence is on H₂ O₂ OH generated under the excitation of ultraviolet light has an oxidation-reduction potential E as high as 2.80V, is second to fluorine in oxidizability, and the rest OH is decomposed into H₂ O and O₂ . The BP-2000 is treated by the photochemical oxidation method, has the advantages of no residual medicament, clean product and the like, and is suitable for large-scale production of the catalyst solution which can be directly used for the gas diffusion electrode.

·OH+H₂ O₂ →H₂ O+HO₂ ·

2·OH→H₂ O₂

2HO₂ ·→H₂ O₂ +O₂

Referring to fig. 2, in the embodiment, the preparation method of the catalyst applied to the oxygen generator includes the following steps:

s10b, dispersing carbon carrier vulcan BP-2000 carbon black in deionized water to form a precursor solution;

likewise, the concentration of carbon black in the precursor solution is 5 to 10mg/mL. The specific implementation manner of step S10b is: adding a commercial carbon carrier vulcan BP-2000 carbon black into deionized water, and mechanically stirring for 20-25 h to uniformly disperse the carbon black to obtain the precursor solution. In other embodiments of the present invention, carbon black may be dispersed by, for example, magnetic stirring. In addition, the particle size of the carbon black is preferably 25 to 50 μm, and in this example, the carbon black may be subjected to a pretreatment such as grinding before the carbon black is added to deionized water, and for example, the carbon black may be ground with a mortar or a commercial ball mill for 15 to 30min so that the particle size of the carbon black becomes 25 to 50 μm. In other embodiments of the present invention, commercial carbon support vulcan BP-2000 carbon black having a particle size in the range of 25 to 50 μm may also be purchased directly.

And S20b, adding a hydrogen peroxide solution into the precursor solution, and then irradiating by using a UV lamp to enable photochemical oxidation reaction to occur in the solution, so as to prepare the catalyst in the form of solution.

Similarly, the mass fraction of the hydrogen peroxide solution is 10-30%, and the volume of the hydrogen peroxide solution added is 5-20 mL per 100mL of the precursor solution. And adding a hydrogen peroxide solution into the precursor solution according to the proportion, and irradiating by using a UV lamp to enable the system to generate photochemical oxidation reaction, namely realizing the hydroxyl radical oxidation treatment of the carbon black, wherein the obtained product solution is the catalyst in the form of solution. Wherein, in the process of irradiation by using the UV lamp, the wavelength range of the UV lamp is 200-450 nm, and the irradiation time is 1-3 h. Further, the optimum pH of the solution is maintained at 5.5 to 6.7 by irradiation with a UV lamp, and the reaction efficiency of the photochemical oxidation reaction is higher in this pH range.

The catalyst solution prepared by the photochemical oxidation method is cleaner, no post-treatment such as cleaning is needed, the same volume of absolute ethyl alcohol and a proper amount of nafion solution with 5 percent can be directly added into the prepared catalyst in the solution form, and the catalyst can be filled into a spraying machine for manufacturing an electrode after being uniformly dispersed, for example, the uniformly dispersed mixed slurry is filled into an ultrasonic precise spraying machine and sprayed on carbon paper to manufacture a gas diffusion electrode. The catalyst provided by the present invention can be prepared in a laboratory or by a pilot scale, wherein in the pilot scale preparation step, the photochemical oxidation reaction of the reaction system by irradiation of a UV lamp can be performed by using an ultraviolet advanced oxidation reactor.

The preparation method of the catalyst applied to the oxygen generator provided by the invention takes the carbon carrier vulcan BP-2000 carbon black as a raw material, takes the hydroxyl radical with strong oxidizing property as an oxidation source, and leads the carbon black to be subjected to hydroxyl radical oxidation treatment to obtain the catalyst; in addition, the preparation method of the catalyst provided by the invention can adjust the specific reaction mode and reaction conditions in the preparation process according to different product requirements so as to correspondingly obtain the solid powdery catalyst or the aqueous catalyst dispersion liquid. In addition, the preparation method of the catalyst provided by the invention has the advantages of simple process and low cost, and is easy to realize macro preparation, and 25kg of the catalyst can be produced in a single time by using a 5000L reactor.

In addition, the invention also provides an electrochemical oxygen generator, wherein a catalyst is placed in the electrochemical oxygen generator, and the catalyst is prepared by the preparation method of the catalyst applied to the oxygen generator. Therefore, the electrochemical oxygen generator has higher oxygen generation efficiency and lower energy consumption, and is beneficial to improving the performance and the user experience of the electrochemical oxygen generator.

The technical solutions of the present invention are further described in detail below with reference to specific examples and drawings, it should be understood that the following examples are merely illustrative of the present invention and are not intended to limit the present invention.

Example 1

(1) Grinding 10g of commercial carbon carrier vulcan BP-2000 carbon black for 15min by using a mortar to ensure that the particle size is distributed within the range of 25-50 mu m, then dispersing the carbon black in 2000mL of deionized water, and mechanically stirring for 24h until the carbon black is uniformly dispersed to prepare a precursor solution with the carbon black concentration of 5 mg/mL;

(2) Adding 100mL of hydrogen peroxide solution (with the mass fraction of 20%) and 160g of ferrous sulfate powder into the prepared precursor solution, adjusting the pH value of the solution to be 2.0-4.0, and then treating the solution for 5 hours at 40 ℃ by Fenton reaction to obtain a semi-finished product solution;

(3) Firstly, washing the semi-finished product solution by using a sulfuric acid solution with the pH value of 2.0 to remove iron ions in the semi-finished product solution, then washing the semi-finished product solution by using deionized water until the filtrate is neutral, carrying out suction filtration to separate solid substances in the filtrate, and carrying out vacuum drying at normal temperature to prepare the powdery catalyst.

Example 2

(1) Grinding 16g of commercial carbon carrier vulcan BP-2000 carbon black by using a mortar for 20min to ensure that the particle size is distributed within the range of 25-50 mu m, then dispersing the carbon black in 2000mL of deionized water, and mechanically stirring for 24h until the carbon black is uniformly dispersed to prepare a precursor solution with the carbon black concentration of 8 mg/mL;

(2) Adding 200mL of hydrogen peroxide solution (with the mass fraction of 10%) and 180g of ferrous sulfate powder into the prepared precursor solution, adjusting the pH value of the solution to be 2.0-4.0, and then treating the solution for 3 hours at 50 ℃ by using Fenton reaction to obtain a semi-finished product solution;

Example 3

(1) Grinding 20g of commercial carbon carrier vulcan BP-2000 carbon black for 15min by using a mortar to ensure that the particle size distribution is in the range of 25-50 mu m, then dispersing the carbon black in 2000mL of deionized water, and mechanically stirring for 24h until the carbon black is uniformly dispersed to prepare a precursor solution with the carbon black concentration of 10mg/mL;

(2) Adding 400mL of hydrogen peroxide solution (with the mass fraction of 30%) and 200g of ferrous sulfate powder into the prepared precursor solution, adjusting the pH value of the solution to be 2.0-4.0, and then treating the solution for 1h at 60 ℃ by using Fenton reaction to obtain a semi-finished product solution;

Example 4

(2) Adding 100mL of hydrogen peroxide solution (with the mass fraction of 20%) into the prepared precursor solution, adjusting the pH value of the solution to be between 5.5 and 6.7, and then irradiating by using a low-pressure UV lamp, wherein the wavelength of the UV lamp is 200nm, and the irradiation time of the UV lamp is 3 hours, so as to prepare the catalyst in the form of solution.

Example 5

(2) 200mL of a hydrogen peroxide solution (10% by mass) was added to the prepared precursor solution, the solution was adjusted to a pH value of 5.5 to 6.7, and then irradiation was performed using a low-pressure UV lamp having a wavelength of 254nm and an irradiation time of 2 hours, to prepare a catalyst in the form of a solution.

Example 6

(1) Grinding 20g of commercial carbon carrier vulcan BP-2000 carbon black for 15min by using a mortar to ensure that the particle size is distributed within the range of 25-50 mu m, then dispersing the carbon black in 2000mL of deionized water, and mechanically stirring for 24h until the carbon black is uniformly dispersed to prepare a precursor solution with the carbon black concentration of 10mg/mL;

(2) 400mL of a hydrogen peroxide solution (30 mass percent) was added to the obtained precursor solution, the solution was adjusted to a pH of 5.5 to 6.7, and then irradiated with a low-pressure UV lamp having a wavelength of 450nm for 1 hour to obtain a catalyst in the form of a solution.

Example 7

(1) Grinding 25kg of commercial carbon carrier vulcan BP-2000 carbon black for 30min by using a commercial ball mill to ensure that the particle size distribution is within the range of 25-50 mu m, then adding the carbon black into deionized water to prepare 5000L of 5mg/mL solution, and mechanically stirring for 24h until the solution is uniformly dispersed to obtain a precursor solution;

(2) Diluting a hydrogen peroxide solution with the mass fraction of 30% to 2000mg/L, placing the hydrogen peroxide solution in a dosing barrel, and injecting the hydrogen peroxide solution into a reaction tank through a dosing pump;

(3) Using a UV advanced oxidation reactor, the treatment scale is 5m³ H, containing eight ultraviolet lamps (low-pressure mercury lamp) arranged spirally with wavelength of 254nm, total power of 2000W, and ultraviolet dose of 250-450 mJ/cm² Starting the ultraviolet advanced oxidation reactor for preheating for 30min, injecting a precursor solution and a hydrogen peroxide solution into the reaction tank (the addition amount of the hydrogen peroxide solution is 10mL in every 100mL of the precursor solution), and stably running for 2h to prepare the catalyst in a solution state.

FIG. 3 is a TEM image showing the micro-morphology of BP-2000 carbon black used as a raw material in an example of the present invention, and FIGS. 4 and 5 are TEM images showing the micro-morphology of BP-2000 carbon black after Fenton oxidation treatment and photochemical oxidation treatment, respectively. As can be seen from FIGS. 2 to 5, BP-2000 carbon black was in the form of powder having a uniform particle size distribution before and after oxidation treatment, and had a large specific surface area.

FIG. 6 shows FI-IR diagrams of BP-2000 carbon black after Fenton's reaction oxidation treatment and photochemical oxidation treatment, and it can be seen from FIG. 6 that Fenton's reaction oxidation treatment and photochemical oxidation treatment by UV lamp irradiation can induce the generation of a large amount of active oxygen-containing groups on the surface of BP-2000 carbon black.

FIG. 7 shows N of a catalyst obtained by subjecting BP-2000 carbon black to Fenton's reaction oxidation treatment and UV lamp irradiation oxidation treatment, respectively₂ As can be seen from FIG. 7, the catalyst prepared by the present invention has a large number of pores inside, a large specific surface area, and is favorable for the generation of oxygen in the reaction.

FIG. 8 shows a comparison of the oxygen generation rate test of the MEA electrode system after the BP-2000 carbon black is treated with Fenton reaction oxidation treatment and UV lamp irradiation oxidation treatment to prepare the catalyst. As can be seen from FIG. 8, the catalysts prepared by the two oxidation treatment methods have little difference in performance, and the concentration of the generated oxygen is above 95%. The catalyst solution prepared by the photochemical oxidation method is cleaner, does not need post-treatment such as cleaning and the like, and can be directly used for manufacturing electrodes.

The above is only a preferred embodiment of the present invention, and it is not intended to limit the scope of the invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention shall be included in the scope of the present invention.

Claims

1. An electrochemical oxygen generator is characterized in that a catalyst is placed in the electrochemical oxygen generator, and the catalyst is prepared by the following preparation method: dispersing carbon carrier vulcan BP-2000 carbon black in deionized water to form a precursor solution; adding a hydrogen peroxide solution into the precursor solution, and then irradiating by using a UV lamp to enable the solution to generate photochemical oxidation reaction so as to prepare a catalyst in a solution form;

adding the same volume of absolute ethyl alcohol and a proper amount of 5% nafion solution into the prepared catalyst in the solution form, uniformly dispersing, filling into an ultrasonic precision spraying machine, and spraying on carbon paper to prepare a gas diffusion electrode;

wherein, the step of adding hydrogen peroxide solution into the precursor solution, and then irradiating by using a UV lamp to cause photochemical oxidation reaction in the solution to prepare the catalyst in the form of solution comprises the following steps:

the wavelength range of the UV lamp is 200 to 450nm, and the irradiation time of the UV lamp for irradiation is 1 to 3h; the pH of the solution was 5.5 to 6.7 when irradiated with a UV lamp.

2. The electrochemical oxygen generator of claim 1, wherein in the step of dispersing the carbon support vulcan BP-2000 carbon black in deionized water to form a precursor solution:

the concentration of carbon black in the precursor solution is 5 to 10mg/mL.

3. The electrochemical oxygen generator of claim 1, wherein in the step of dispersing the carbon support vulcan BP-2000 carbon black in deionized water to form a precursor solution:

the particle size of the carbon black is 25 to 50 mu m.

4. The electrochemical oxygen generator of claim 1, wherein the step of adding a hydrogen peroxide solution to said precursor solution and irradiating the solution with a UV lamp to cause photochemical oxidation reaction to produce the catalyst in solution form comprises:

the mass fraction of the hydrogen peroxide solution is 10-30%, and the volume of the hydrogen peroxide solution added into each 100mL of the precursor solution is 5-20mL.