KR20190057245A - Methods for manufacturing catalysts for producing hydrogen peroxide, and catalysts for producing hydrogen peroxide manufactured by thereof - Google Patents

Abstract

Provided is a method for manufacturing a catalyst for producing hydrogen peroxide, which comprises following steps of: adding silica particles to a polymerization precursor of a polymer precursor and conducting a reaction thereof to manufacture a silica-polymer composite material; removing silica particles from a carbonized silica-polymer composite material to form a porous carbon support; and adding a manganese precursor to the porous carbon support and conducting a reaction thereof to manufacture the catalyst for producing hydrogen peroxide comprising a composite of a manganese oxide and the porous carbon support.

Description

TECHNICAL FIELD [0001] The present invention relates to a catalyst for the production of hydrogen peroxide, and a catalyst for producing hydrogen peroxide produced therefrom. BACKGROUND ART < RTI ID = 0.0 >

The present invention relates to a process for producing a novel catalyst for hydrogen peroxide generation and a catalyst for producing hydrogen peroxide.

Hydrogen peroxide is a powerful oxidizer, a chemical used in various fields such as chemical synthesis, wastewater treatment chemicals, bleaching of paper pulp and fiber dyeing. In particular, since hydrogen peroxide decomposes only water molecules, it is environmentally friendly compared to chlorine based oxidizing agents, and such hydrogen peroxide is evaluated as a substitute for chlorine based materials. In the bleaching of paper pulp, due to the strong bleaching power of hydrogen peroxide, it can be widely used for deinking of high paper and bleaching of various kinds of pulp. In the case of fiber bleaching, it is possible to maintain the strength of fiber without damaging the fiber with abundant bleaching power, .

In addition, hydrogen peroxide reduces BOD (Biochemical Oxygen Demand), COD (chemical oxygen demand), etc., and can be used for hydrogen sulfide-based desulfurization, decolorization, and phenol treatment.

Hydrogen peroxide is mainly synthesized by a chemical synthesis method using anthranuinone in a large capacity. This process recovers hydrogen peroxide which is generated additionally by liquid-liquid extraction when alkyl and tracquinone dissolved in an organic solvent are sequentially reacted in the presence of a catalyst in a reduction and oxidation process Method. However, this process requires a large amount of energy accompanied by continuous hydrogenation and oxidation, and there is a problem that environmental pollutants are generated in each step reaction.

Also, as one of the methods for synthesizing hydrogen peroxide, an electrochemical method through an oxygen reduction reaction, which is one reaction of a fuel cell, has been proposed. The method of electrochemically synthesizing hydrogen peroxide has the advantage of producing hydrogen peroxide directly in the field. It does not produce by-products of environmental pollutants in addition to water, and it is stable compared to the method of making hydrogen peroxide directly using hydrogen and oxygen Synthesis method. A method of generating hydrogen peroxide electrochemically utilizes an oxygen reduction reaction occurring at the anode of a fuel cell. In a fuel cell, hydrogen is separated into hydrogen ions and electrons at the cathode, and oxygen reduction reaction occurs at the anode, and hydrogen and oxygen meet, and water is generated to generate energy. At this time, the oxygen reduction reaction is catalyzed by two reaction mechanisms in an acidic electrolyte. 2 O ₂ + 2H ⁺ + 2e ^- → H ₂ O ₂ ), and 4 electrons react to produce water (O ₂ + 4H ⁺ + 4e ^- → H ₂ O).

Accordingly, in order to generate hydrogen peroxide electrochemically, it is important to develop a catalyst that causes two-electron reactions to occur well.

On the other hand, it is known that the catalyst used in the two-electron reaction is a platinum-based catalyst, a noble metal catalyst, etc. Cobalt / carbon materials and nitrogen-doped carbon materials are used as non-precious metal catalysts. There is a problem that it is not widely used. There is a problem that the electrochemical activity for the formation of hydrogen peroxide is inferior in the case of the noble metal catalyst.

Journal of Physical Chemistry C, 118, 30063 (2014), Nature Materials, 12, 1137 (2013), Nano Letters, 14, 1603 (2014), Nature Communications, 7, 10922 (2016). Fellinger, Tim-Patrick, et al. &Quot; Mesoporous nitrogen-doped carbon for the electrocatalytic synthesis of hydrogen peroxide. &Quot; Journal of the American Chemical Society 134.9 (2012): 4072-4075. Electrochmica Acta, 56, 9074 (2011), Journal of Applied Electrochemistry, 36, 863 (2006), Reaction Chemical Engineering,

In an embodiment of the present invention, a method for preparing a catalyst for producing hydrogen peroxide using a manganese precursor and a catalyst for producing hydrogen peroxide are provided.

In one embodiment of the present invention, there is provided a method for producing a catalyst for hydrogen peroxide, comprising the steps of: adding silica particles to a polymerization precursor of a polymer precursor and reacting them to prepare a silica-polymer composite; Carbonizing the silica-polymer composite material; Removing the silica particles from the carbonized silica-polymer composite to form a porous carbon support; And reacting the porous carbon support with a manganese precursor, thereby preparing a catalyst for producing hydrogen peroxide including a composite of manganese oxide and porous carbon support; A method for producing a catalyst for hydrogen peroxide generation is provided.

In an exemplary embodiment, the silica particles may be added in an amount of 700 to 900 parts by weight based on 100 parts by weight of the polymer precursor.

In an exemplary embodiment, the silica particles may have a size of 3 to 30 nm.

In an exemplary embodiment, the step of removing the silica particles may be carried out using a basic solution.

In an exemplary embodiment, the polymer precursor comprises at least one member selected from the group consisting of aniline, acetylene, pyrrole, thiophene and sulfanitride, and the manganese precursor comprises manganese acetate, manganese nitrate, and manganese sulfate One or more selected from the group.

In an exemplary embodiment, the manganese precursor may be added in an amount of 500 to 7,000 parts by weight based on 100 parts by weight of the porous carbon support.

In an exemplary embodiment, the step of reacting the porous carbon support and the manganese precursor may be performed at 250 to 500 < 0 > C.

In an exemplary embodiment, when the silica particles are added to the polymerization process of the polymer precursor, an initiator is further added and the initiator is selected from the group consisting of ammonium persulfate ((NH ₄ ) ₂ S ₂ O ₈ ), ammonium persulfate ((NH ₄ ) ₂ S ₂ O ₈ ), hydrogen peroxide, manganese oxide, potassium bichromate, potassium iodate, ferric chloride, potassium permanganate, potassium bromate, and potassium chlorate.

In another embodiment of the present invention, there is provided a catalyst for hydrogen peroxide generation, wherein the catalyst for hydrogen peroxide generation comprises a complex of manganese oxide and a porous carbon support, wherein the porous carbon support is nitrogen-doped .

In an exemplary embodiment, the manganese oxide comprises at least one selected from the group consisting of manganese dioxide (MnO ₂ ), manganese trioxide (Mn ₂ O ₃ ), manganese oxide (Mn ₃ O ₄ ), and manganese oxide (MnO) The porous carbon support may include a plurality of pores, and the pores may have a size of 3 to 30 nm.

In an exemplary embodiment, the catalyst for hydrogen peroxide generation may comprise 60 to 7,000 parts by weight of manganese oxide, based on 100 parts by weight of the porous carbon support.

According to embodiments of the present invention, as a catalyst for generating hydrogen peroxide, a catalyst for producing hydrogen peroxide which produces hydrogen peroxide through a two-electron reaction can be produced.

Further, according to embodiments of the present invention, a catalyst for producing hydrogen peroxide can be produced at a relatively low cost. In addition, the catalyst exhibits stable hydrogen peroxide selectivity even under low voltage and high voltage conditions, and thus can be widely used in the technical field requiring the production of hydrogen peroxide.

In addition, when the catalyst for hydrogen peroxide generation is used, a two-electron reaction can occur well, and the efficiency of hydrogen peroxide generation can be significantly increased as compared with the case of using a conventional catalyst.

FIG. 1 is a schematic view showing a method for producing a catalyst for hydrogen peroxide generation according to an embodiment of the present invention.
FIGS. 2A and 2B are TEM photographs of the catalysts for generating hydrogen peroxide produced according to Example 1, and FIGS. 2C and 2D are TEM photographs of the catalysts for generating hydrogen peroxide produced according to Example 5. FIG.
FIGS. 3A and 3B are graphs showing values measured under an oxygen atmosphere using an RRDE (Rotating Ring Disk Electrode) electrode for the hydrogen peroxide generating catalyst produced according to Example 5. FIG.
4A and 4B are graphs showing the results of measurement of carbon material containing nitrogen produced according to Comparative Example 1 under an oxygen atmosphere using an RRDE electrode.
FIGS. 5A and 5B are graphs showing the results of measurement under oxygen using an RRDE electrode for a carbon material containing nitrogen and manganese prepared according to Example 1. FIG.
6 is a graph showing XRD results of the catalysts for hydrogen peroxide according to Examples 1 to 2 and Example 5 (Example 1: MnNC_5g, Example 2: MnNC_10g, Example 5: Mn Post treatment).
FIGS. 7A and 7B are graphs showing XPS results of the carbon material containing nitrogen and manganese produced according to Example 1. FIG.
FIGS. 8A to 8D show the structures of the materials produced according to Example 5, FIGS. 8A to 8C are diagrams showing XPS results, and FIG. 8D is a table summarizing the results.
9 is a graph showing changes in the amount of hydrogen peroxide produced according to changes in the amount of manganese precursor added in Examples 5 to 7;

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Although the embodiments of the present invention have been described with reference to the accompanying drawings, it is to be understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the present invention.

In this specification, the fact that a material is doped with nitrogen means that the material contains a plurality of nitrogen atoms.

Catalyst for hydrogen peroxide generation

In one embodiment of the present invention, there is provided a catalyst for the production of hydrogen peroxide, comprising a composite of a manganese oxide and a porous carbon support, wherein the porous carbon support is provided with a catalyst for producing nitrogen-doped hydrogen peroxide. The catalyst for hydrogen peroxide generation may have a more economical advantage than conventional catalysts because it contains manganese (Mn) instead of conventional platinum-based catalysts and non-noble metal-based catalysts.

Exemplary Embodiments The manganese oxide may be bonded onto the porous carbon support and may be selected from the group consisting of manganese dioxide (MnO ₂ ), manganese trioxide (Mn ₂ O ₃ ), manganese oxide (Mn ₃ O ₄ ), and manganese oxide (MnO) ≪ RTI ID = 0.0 > and / or < / RTI >

In addition, the porous carbon support may be a nitrogen-doped porous polymer material, for example, the porous carbon support may be a mesoporous polyaniline. Thus, when the porous carbon support is mesoporous polyaniline, the hydrogen peroxide generation efficiency can be further improved.

In an exemplary embodiment, the porous carbon support comprises a plurality of pores, and the pores may have a size of 3 to 30 nm. If the porous carbon support comprises pores having a size within the above range, the activity of the catalyst can be further increased.

Meanwhile, the catalyst for hydrogen peroxide generation may include 60 to 7,000 parts by weight of manganese oxide with respect to 100 parts by weight of the porous carbon support. If the range of the manganese oxide in the catalyst for hydrogen peroxide generation is out of the above range, the hydrogen peroxide generation efficiency may be insufficient.

In one embodiment, the catalyst for hydrogen peroxide generation may comprise 100 to 5,000 parts by weight of manganese oxide, more specifically 500 to 3,000 parts by weight of manganese oxide, based on 100 parts by weight of the porous carbon support. have.

In an exemplary embodiment, the hydrogen peroxide selectivity of the catalyst for hydrogen peroxide generation may be greater than 60% at 0.6V.

Process for producing hydrogen peroxide generation catalyst

In one embodiment of the present invention, there is provided a process for producing a catalyst for hydrogen peroxide generation, comprising the steps of: adding silica particles to a polymerization precursor of a polymer precursor and reacting them to prepare a silica-polymer composite material; Carbonizing the silica-polymer composite material; Removing the silica particles from the carbonized silica-polymer composite to form a porous carbon support; And reacting the porous carbon support with a manganese precursor, thereby preparing a catalyst for producing hydrogen peroxide including a composite of manganese oxide and porous carbon support; A method for producing a catalyst for hydrogen peroxide generation is provided.

Fig. 1 schematically shows each step of the production method of the catalyst for hydrogen peroxide generation. Hereinafter, a detailed description will be given with reference to this.

First, the silica particles are added to the polymerization process of the polymer precursor and reacted to prepare a silica-polymer composite material. That is, silica particles may be added to the polymerization precursor of the polymer precursor and reacted together to form a polymer material carrying silica particles. Hereinafter, this is referred to as a silica-polymer composite material.

In an exemplary embodiment, the polymeric precursor may comprise at least one member selected from the group consisting of aniline, acetylene, pyrrole, thiophene, and sulfanitride, and the polymeric material bearing the silica particles may comprise polyaniline .

On the other hand, the silica particles may be supported in a plurality of polymeric materials, and may be added in an amount of 700 to 900 parts by weight based on 100 parts by weight of the polymer precursor. When the silica particles are added in an amount of less than 700 parts by weight, the specific surface area of the finally produced hydrogen peroxide generating catalyst may be small and the efficiency of the catalyst may be lowered. When the amount of the silica particles is more than 900 parts by weight, Rather, the catalyst efficiency may be lowered.

In one embodiment, the silica particles may have a particle size of from 3 to 30 nm, and if they have a size of less than 3 nm, the final surface area of the catalyst for hydrogen peroxide generation may be too small to reduce the efficiency of the catalyst, The manganese oxide may be doped in a small area, which may lead to a reduction in catalyst efficiency.

On the other hand, when the silica particles are added to the polymerization process of the polymer precursor, an initiator for polymerization may be further added to improve the reactivity, wherein the initiator is added in an amount of 100 to 400 parts by weight based on 100 parts by weight of the polymer precursor . When the initiator is added in an amount of less than 100 parts by weight, the effect of improving the reactivity may be insufficient. When the amount of the initiator is more than 400 parts by weight, an excessive amount of initiator may be added to the polymer precursor, which may adversely affect the reactivity.

In an exemplary embodiment, the initiator is ammonium persulfate _{((NH 4) 2 S 2} O 8), ammonium persulfate _{((NH 4) 2 S 2} O 8), hydrogen peroxide, manganese dioxide, potassium dichromate, potassium iodate , Ferric chloride, potassium permanganate, potassium bromate, and potassium chlorate.

Although not shown, after the polymerization step, the silica-polymer composite material may be washed with distilled water to a pH of 5 to 6 and then dried at a temperature of 60 to 70 ° C.

Thereafter, the silica-polymer composite material is carbonized. Specifically, the graphite structure of the silica-polymer composite material can be developed by carrying out a carbonization process at a high temperature by thermal energy.

In the exemplary embodiment, the carbonization process may cause a large defect in the carbonization process due to an unnecessary chemical reaction when another reactive gas is introduced during the carbonization process. Therefore, the carbonization process can be performed in an inert atmosphere using a high temperature carbonization furnace have. For example, the inert atmosphere may be argon, nitrogen atmosphere.

In an exemplary embodiment, the carbonization process may be conducted under an inert atmosphere such as a nitrogen atmosphere.

In an exemplary embodiment, the carbonization process may be performed at a temperature in the range of about 600-1,800 < 0 > C. If the carbonization process is carried out at a temperature lower than 600 ° C., the carbon content may be lowered due to a low hydrocarbon yield, and when the temperature exceeds 1,800 ° C., decomposition of the silica-polymer composite material may occur.

In an exemplary embodiment, the carbonization process may be performed for about 1 to 4 hours. If the carbonization process is performed for less than one hour, the carbonization yield may be low and the carbon content may decrease. If the carbonization process exceeds 4 hours, the decomposition of the silica-polymer composite material may occur.

In one embodiment, the carbonization process may be performed by heat treating the silica-polymer composite material for 1 to 3 hours at a temperature of 700 to 900 ° C.

Thereafter, the silica particles may be removed from the carbonized silica-polymer composite material to form a porous carbon support.

Specifically, the silica particles are removed from the silica-polymer composite material subjected to the carbonization process through an etching process.

In one embodiment, the etching process may be conducted using a basic solution, and may be performed by hydrothermal reaction for 12 to 36 hours. The silica particles can be easily removed without deteriorating the physical properties of the polymer material. Through this process, the silica particles are removed from the silica-polymer composite material, and thus, a plurality of pores can be formed in the polymer material (for example, polyaniline when produced using aniline).

In an exemplary embodiment, the pores may have a size of 3 to 30 nm.

After the polymerization step, although not shown, the silica-polymer composite material may be washed with distilled water to a pH of 5 to 6, and then dried at a temperature of 60 to 70 ° C.

Thereafter, a manganese precursor is added to the porous carbon support and then reacted to prepare a catalyst for producing hydrogen peroxide including a composite of manganese oxide and porous carbon support.

Specifically, after the porous carbon support is impregnated with a solvent such as ethanol, methanol, etc., a manganese precursor is added and stirred, and then they are reacted.

In an exemplary embodiment, the manganese precursor may comprise at least one selected from the group consisting of manganese acetate, manganese nitrate, and manganese sulphate.

Meanwhile, the step of adding the manganese precursor to the porous carbon support is carried out at a temperature of 80 to 90 ° C. In this case, a solvent such as ethanol, methanol or the like may be volatilized.

At this time, the manganese precursor may be added in an amount of 500 to 7,000 parts by weight based on 100 parts by weight of the porous carbon support. The more the manganese oxide is contained in the catalyst for generating hydrogen peroxide to which the manganese precursor is added to the final stage, the catalyst efficiency is favorable, but if the catalyst is excessively contained, the inherent physical properties of the catalyst may be lowered.

In an exemplary embodiment, the reaction process may be conducted under an inert atmosphere, since other reaction gases may enter into a large defect due to an unnecessary chemical reaction.

Thereafter, the porous carbon support and the manganese precursor are reacted in a temperature range of 250 to 500 ° C to bind the manganese oxide and the porous carbon support. The manganese precursor is oxidized at a temperature within the above range to form a manganese oxide, and the manganese oxide thus formed may be combined with the porous carbon support to form a composite of the manganese oxide and the porous carbon support. If the reaction proceeds below the above-mentioned temperature range, manganese oxide may not be formed, and if the reaction proceeds in excess of 500 ° C, physical properties of the porous carbon support and / or manganese oxide may be impaired.

Meanwhile, in the method for producing a hydrogen peroxide generating catalyst, a catalyst for producing hydrogen peroxide can be prepared by varying the time of introduction of the manganese precursor. Specifically, when the silica particles are added to the polymerization process of the polymer precursor, the manganese precursor is added together It is possible.

However, when the manganese oxide, which is an oxide of the manganese precursor, is bonded to the porous carbon support after the silica particles are removed, the manganese oxide and the porous carbon support are more easily bonded and the specific surface area of the porous carbon support is high, It is considered that the content of manganese oxide in the catalyst for hydrogen peroxide generation is higher. Accordingly, when the manganese precursor is added to the porous carbon support after the removal of the silica particles, the catalytic efficiency of the catalyst for generating hydrogen peroxide is considered to be better.

In an exemplary embodiment, the hydrogen peroxide selectivity of the catalyst for hydrogen peroxide generation may be greater than 60% at 0.6V.

Thus, the catalyst for hydrogen peroxide can be produced through the above-described process. The catalyst for hydrogen peroxide generation may have a more economical advantage than conventional catalysts because it contains manganese (Mn) instead of conventional platinum-based catalysts and non-noble metal-based catalysts. In addition, the catalyst exhibits stable hydrogen peroxide selectivity even under low voltage and high voltage conditions, and thus it is considered that the catalyst can be widely used in a technical field requiring generation of hydrogen peroxide.

Hereinafter, the present invention will be described in more detail with reference to Examples. It is to be understood by those skilled in the art that these embodiments are only for illustrating the present invention and that the scope of the present invention is not construed as being limited by these embodiments.

Example

Comparative Example  1 (nitrogen Doped  Preparation of carbon catalyst)

Polymerization was carried out at 5 ° C with 2 ml of aniline, 16 g of silica particles (particle size: 5 nm) and 3.14 g of ammonium persulfate ((NH ₄ ) ₂ S ₂ O ₈ ) as an oxidizing agent in a formic acid solution. Then, the resultant material was washed with distilled water to a pH value of about 5-6. The washed material was then dried in an oven at 60-70 ° C for a day and then the resulting material was heat treated at 800 ° C for 2 hours under an argon atmosphere. Subsequently, hydrothermal reaction was carried out for 24 hours at 100 ° C in a solution of 1 M NaOH to remove the silica particles. Then, the resultant material was washed with distilled water to a pH value of about 5-6 and then dried in an oven at 60-70 ° C for about one day. Then, the produced material was heat-treated at 800 ° C for 2 hours under an argon atmosphere to prepare a catalyst for producing hydrogen peroxide.

Comparative Example  2 and 3

The catalyst for the production of hydrogen peroxide was prepared by carrying out the same process except that the size of the silica particles in Comparative Example 1 was changed to 12 nm (Comparative Example 1) and 20 nm (Comparative Example 2).

Example  1 (nitrogen and manganese Doped  Preparation of carbon catalyst)

Aniline 2 ml, 16 g of silica particles (particle size: 12 nm), and ammonium sulfate _{(NH 4) 2 S 2 O} 8 3.14 g and 5 g of manganese acetate were stirred at 5 DEG C while stirring in a formic acid solution. Thereafter, the resulting material was washed with distilled water to a pH value of about 5-6, and then dried in an oven at 60-70 ° C. for one day. Then, the resultant material was heat-treated at a temperature of 800 ° C for 2 hours under an argon atmosphere, and then silica particles were removed by hydrothermal reaction at a temperature of 100 ° C in a 1 M NaOH solution for 24 hours. Thereafter, the catalyst was washed with distilled water to a pH value of about 5-6, dried in an oven at 60-70 ° C for a day, and then heat-treated at 800 ° C for 2 hours under an argon atmosphere to obtain a catalyst for producing hydrogen peroxide .

Example  2

Except that the amount of manganese acetate added in Example 1 was changed to 10 g instead of 5 g, a catalyst for producing hydrogen peroxide was prepared.

Example  3 to 4

The same process was carried out except that the size of the silica particles in Example 1 was changed to 12 nm (Example 3) and 20 nm (Example 4) to prepare a catalyst for hydrogen peroxide generation.

Example  5 (Nitrogen Doped  Manganese in the carbon material Post-processed  Preparation of catalyst <

Aniline 2 ml, 16 g of silica particles (particle size: 12 nm), and ammonium sulfate _{(NH 4) 2 S 2 O} 8 3.14 g of the polymer was reacted in a formic acid solution and the polymerization was carried out at 5 ° C. The resulting material was washed with distilled water to a pH value of about 5-6, and then dried in an oven at 60-70 ° C. for one day. The resulting material was heat-treated at 800 ° C. for 2 hours under an argon atmosphere, and silica particles were removed by hydrothermal reaction at a temperature of 100 ° C. in a 1 M NaOH solution for 24 hours. Thereafter, the resultant material was washed with distilled water to a pH value of about 5-6, and then dried in an oven at 60-70 ° C for a day. Then, 5 g of manganese acetate in a mass ratio of 0.1 g of the carbon material was impregnated with a solvent such as ethanol or methanol, and the mixture was stirred at a temperature of 80 to 90 ° C. Then, the produced material was heat-treated at 800 ° C for 2 hours under an argon atmosphere to prepare a catalyst for producing hydrogen peroxide.

Example  6 to 8

The same procedure was followed except that the mass ratio of manganese acetate to 0.1 g of the carbon material in Example 5 was changed to 0.5 g (Example 6), 2 g (Example 7) and 7 g (Example 8) to produce hydrogen peroxide Lt; / RTI >

Example  9 and 10

The catalyst for the production of hydrogen peroxide was prepared by carrying out the same process except that the size of the silica particles was changed to 5 nm and 20 nm in Example 5.

[Experimental Example]

Experimental Example  1. Evaluation of reactivity to oxygen reduction reaction of synthesized nitrogen and nitrogen and manganese-containing carbon materials

First, the oxygen reduction reactivity is measured by using a counter electrode using a Pt wire, a reference electrode using a saturated calomel electrode (SCE), and a working electrode composed of a catalyst Electrode system (three electrode system).

At this time, 5 mg of the working electrode was mixed with 50 μl of Nafion solution and 500 μl of isopropyl alcohol solution of the catalyst according to Examples and Comparative Examples, And 15 μl of the solution was put on the disk electrode portion of the rotating ring disk electrode.

The oxygen reduction experiments were carried out in an oxygen saturated 1M HClO ₄ electrolyte and the amount of hydrogen peroxide produced during the oxygen reaction was obtained through a rotating ring disc electrode with a voltage of 1.0 V vs RHE.

FIGS. 3A and 3B show the oxygen reduction reactivity results of the carbon catalyst produced according to Example 5 of the present invention. FIG. Specifically, in FIGS. 3A and 3B, 5 g of manganese acetate was impregnated with 0.1 g of the nitrogen-doped carbon material produced in Example 5, followed by heat treatment at 800 ° C. in argon, The electrochemical results are shown. At this time, the upper graph of FIG. 3A shows the value of the ring disk electrode and the lower graph shows the current value of the disk electrode. The graph of FIG. 3B shows the relationship between the disc current value and the ring disc current value obtained in accordance with FIG. 3A using n = 4 * I _d / (I _d + (I _r / N)) and H ₂ O ₂ (% ) = 200 * (I _r / N) / (I _d + (I _r / N)) and the selectivity of hydrogen peroxide. Where I _d and I _r are the values of the disc current and ring disk current, respectively, corrected for values on argon, which is an inert gas, and the N value is 0.37 as the value of the collection efficiency.

3A and 3B, it was confirmed that the catalyst prepared according to Example 5 exhibited a very high production rate with a yield of 57% and 62% hydrogen peroxide at 0.2 V and 0.7 V (vs RHE), respectively I could.

4A and 4B show RRDE results of the catalyst prepared using the porous carbon material containing only nitrogen without the precursor of manganese produced by Comparative Example 1. FIG. In the case of the catalyst according to Comparative Example 1, 4 electrons were observed in almost all the voltage regions (FIG. 4b), and the hydrogen peroxide was not more than 15% %, Respectively.

Therefore, when a catalyst is prepared using a carbon material containing nitrogen and manganese rather than a catalyst prepared using a carbon material containing only nitrogen, the reaction proceeds by a two-electron reaction in the progress of the oxygen reduction reaction. The selectivity to hydrogen peroxide was also increased.

5A and 5B show RRDE results of the catalyst prepared using the carbon material pretreated with the manganese precursor according to Example 1. FIG. Although the amount of hydrogen peroxide was slightly increased over the entire period compared with the value of FIG. 4b containing only nitrogen, the manganese precursor shown in FIG. 3b had lower hydrogen peroxide selectivity than the post-treated carbon material Respectively.

3A to 5B, it was confirmed that the selectivity to hydrogen peroxide was significantly increased when manganese was added to the carbon material containing only nitrogen, and in particular, the carbon material after the manganese precursor was subjected to post- It was confirmed that the selectivity to hydrogen peroxide greatly increased when the catalyst was prepared.

Experimental Example  2. Evaluation of reactivity to oxygen reduction reaction according to manganese precursor contents

FIG. 9 is a graph showing changes in the amount of hydrogen peroxide produced when the amount of manganese precursor added when the manganese precursor was post-treated was changed.

 As shown in FIG. 9, the amounts of manganese precursor were increased to 0.5 g, 2 g, and 5 g based on 0.1 g of nitrogen-containing carbon material in the course of producing carbon material according to Examples 5 to 7, And the selectivity to hydrogen peroxide was increased by two electron reactions. In addition, it can be predicted that the selectivity for hydrogen peroxide increases in Example 8 as the two-electron reaction proceeds more.

Experimental Example  3. Assessment of Physical Properties of Synthesized Nitrogen and Carbon Substances Containing Nitrogen and Manganese

The carbon catalysts prepared in Examples 1, 2 and 5 were subjected to TEM analysis, XRD analysis and XPS analysis, respectively, and the results are shown in FIGS. 2, 6, 7 and 8.

First, FIGS. 2A and 2B show that a porous carbon material is formed through the TEM result of the material produced according to the first embodiment. Referring to FIGS. 2c and 2d, it can be seen that manganese oxide is deposited on the porous carbon material through the TEM results of the material produced according to Example 5. FIG.

On the other hand, in the XRD results of FIG. 6, it can be seen that MnNC_5g and MnNC_10g prepared according to Examples 1 and 2 do not have thin peaks and only wide peaks are present. This shows that amorphous carbon material exists In the case of manganese oxide, the amount of manganese oxide is too small and no peak is observed. In contrast, in Example 5 (Mn post treatment) in which the precursor of manganese was post-treated, peaks corresponding to MnO were observed, indicating that when the manganese precursor was post-treated, a larger amount of manganese oxide was produced .

7A and 7B show XPS results of the manganese and nitrogen-containing carbon materials produced by Example 1. FIG. Here, as in the case of XRD results, the amount of manganese oxide produced is very small, so that manganese is not observed even in the result of XPS, a surface analysis technique. At this time, the elements of the produced material were nitrogen, oxygen, and carbon, respectively, and the amounts were 4.55 at.%, 4.77 at.%, And 90.68 at.%. As a result of analyzing the nitrogen peak, the amount of pyridic N, pyrrolic N, quaternary N, and oxidized N, as shown in FIG. 7B, , Respectively, were found to be 19.8 at.%, 9.8 at.%, 48.9 at.% And 21.3 at%, respectively.

Figures 8a to 8d show the XPS results of the manganese-post-treated material of the carbon containing nitrogen produced by Example 5. As can be seen from the Survey analysis, the elements present on the surface of the produced material are carbon, manganese, oxygen and nitrogen, and the amounts thereof are 76.76 at.%, 4.72 at.%, 12.67 at.% And 5.85 at. . The composition of the nitrogen present on the surface of the material is pyridine N, pyrrolic N, quaternary N, oxidized N 14.5, Quaternary nitrogen (N) occupied the largest portion at 11.7, 45.1 and 14.5 at.%. It was confirmed that the oxidized form of manganese occupies the most part, which is the value of Mn ^{2 +} , which corresponds to the oxidation number of manganese of MnO shown in XRD.

As described above, the catalyst for producing hydrogen peroxide produced according to the embodiment of the present invention may include a porous carbon support and manganese oxide formed thereon, and may have the following differentiation from the known catalyst for hydrogen peroxide generation .

1) As a catalyst for generating hydrogen peroxide, platinum-based catalysts (Non-Patent Document 1) and the like are used as a catalyst for oxygen reduction reaction. Even if the selectivity for two-electron reaction or hydrogen peroxide generation is high, The practical applicability of the catalyst is low. In contrast, the catalyst prepared according to the embodiment of the present invention differs in that the selectivity to hydrogen peroxide is increased by utilizing a manganese-based catalyst which is very economical in terms of cost.

2) In addition, in the case of using a conventional noble metal catalyst, in an example in which mesoporous carbon containing nitrogen is used as a catalyst for the formation of hydrogen peroxide (Non-Patent Document 2), a value Expensive ionic liquids, which are also difficult to apply in practice. In contrast, the catalyst prepared according to the embodiment of the present invention differs in that the selectivity to hydrogen peroxide is increased by utilizing a manganese-based catalyst which is very economical in terms of cost.

3) Another example is the application of cobalt as a catalyst for the formation of hydrogen peroxide by heat treatment with carbon black (Vulcan carbon) (Non-Patent Document 3). The selectivity of hydrogen peroxide at a high voltage (55% @ 0.6 V) is significantly reduced at a high voltage (94% @ 0.2 V), but the hydrogen peroxide is generated in a unit cell of an actual unit cell And the results of the half-cell are actually specified in the paper. On the contrary, the catalyst prepared according to the embodiment of the present invention has a relatively constant selectivity of hydrogen peroxide at low voltage and high voltage, 57% @ 0.2 V and 62% @ 0.6 V, .

Thus, according to embodiments of the present invention, a catalyst for hydrogen peroxide generation can be manufactured at a relatively low cost. In addition, the catalyst exhibits stable hydrogen peroxide selectivity even under low voltage and high voltage conditions, and thus can be widely used in the technical field where hydrogen peroxide generation is required.

The embodiments of the present invention described above should not be construed as limiting the technical idea of the present invention. The scope of protection of the present invention is limited only by the matters described in the claims, and those skilled in the art will be able to modify the technical idea of the present invention in various forms. Accordingly, such improvements and modifications will fall within the scope of protection of the present invention as long as it is obvious to those skilled in the art.

Claims (11)

A process for producing a catalyst for hydrogen peroxide generation,
Adding silica particles to a polymerization precursor of a polymer precursor and reacting them to prepare a silica-polymer composite material;
Carbonizing the silica-polymer composite material;
Removing the silica particles from the carbonized silica-polymer composite to form a porous carbon support; And
Adding a manganese precursor to the porous carbon support and then reacting the mixture to prepare a catalyst for generating hydrogen peroxide including a composite of a manganese oxide and a porous carbon support; Lt; / RTI >
Wherein the hydrogen peroxide selectivity of the catalyst for hydrogen peroxide generation is 60% or more at 0.6V. The method according to claim 1,
Wherein the silica particles are added in an amount of 700 to 900 parts by weight based on 100 parts by weight of the polymer precursor. The method according to claim 1,
Wherein the silica particles have a size of 3 to 30 nm. The method according to claim 1,
Wherein the step of removing the silica particles is carried out using a basic solution. The method according to claim 1,
Wherein the polymer precursor comprises at least one member selected from the group consisting of aniline, acetylene, pyrrole, thiophene, and sulfinitride,
Wherein the manganese precursor comprises at least one selected from the group consisting of manganese acetate, manganese nitrate and manganese sulphate. The method according to claim 1,
Wherein the manganese precursor is added in an amount of 500 to 7,000 parts by weight based on 100 parts by weight of the porous carbon support. The method according to claim 1,
Wherein the step of reacting the porous carbon support and the manganese precursor is carried out at 250 to 500 ° C. The method according to claim 1,
When the silica particles are added to the polymerization process of the polymer precursor, an initiator is further added,
(NH ₄ ) ₂ S ₂ O ₈ ), ammonium persulfate ((NH ₄ ) ₂ S ₂ O ₈ ), hydrogen peroxide, manganese oxide, potassium bichromate, potassium iodate, ferric chloride, Wherein the catalyst further comprises at least one selected from the group consisting of potassium permanganate, potassium bromate and potassium chlorate. As a catalyst for producing hydrogen peroxide,
Wherein the catalyst for hydrogen peroxide generation comprises a composite of a manganese oxide and a porous carbon support,
The porous carbon support is nitrogen-doped,
Wherein the hydrogen peroxide selectivity of the catalyst for hydrogen peroxide generation is 60% or more at 0.6 V. 10. The method of claim 9,
Wherein the manganese oxide includes at least one selected from the group consisting of manganese dioxide (MnO ₂ ), manganese trioxide (Mn ₂ O ₃ ), manganese oxide (Mn ₃ O ₄ ), and manganese oxide (MnO)
Wherein the porous carbon support comprises a plurality of pores,
Wherein the pores have a size of 3 to 30 nm. 10. The method of claim 9,
Wherein the catalyst for producing hydrogen peroxide comprises 60 to 7,000 parts by weight of manganese oxide with respect to 100 parts by weight of the porous carbon support.

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