KR20210119756A - Catalysts containing sulfate-functionalized metal oxide for electro-fenton reaction system, electrode comprising the same and electro-fenton reaction system using the same - Google Patents

Abstract

The present invention relates to a catalyst for an electro-Fenton reaction system, an electrode comprising the same, and an electro-Fenton reaction system using the same. More specifically, the present invention provides a catalyst for an electro-Fenton reaction system comprising at least one type of (M_A)_Z(M_B)_3_-ZO_4 catalyst crystal particle whose surface is functionalized with a sulfate ion (SO_4^2-), an electrode comprising the same, and an electro-Fenton reaction system using the same. The purpose of the present invention is to decompose hardly decomposable organic matter based on a heterogeneous catalytic reaction by dispersing a sulfate anion (SO_4^ˑ-) functional group, which has a longer lifespan, a wider pH range, and similar oxidizing power compared to a hydroxyl functional group (-OH), on the surface of (M_A)_Z(M_B)_3_-ZO_4 catalyst.

Description

Catalyst for an electric Fenton reaction system containing a metal oxide functionalized with sulfate ions, an electrode including the same, and an electric Fenton reaction system using the same FENTON REACTION SYSTEM USING THE SAME}

The present invention provides a catalyst for an electrical Fenton reaction system comprising at least one kind of catalyst crystal particles represented by [Formula 1] functionalized with _{sulfate ions (SO 4} ^2- ) on the surface for efficient decomposition of difficult-to-decompose organic matter, such An electrode comprising a catalyst and an electrical Fenton reaction system using such an electrode.

One of the waste water treatment technology that is spotlighted in recent years is a radical (radical, for example, ^· OH or SO ₄ ^{· -)} having a high activity to produce / thriving an oxidizing agent in the waste water contained in the water I homogeneous organic material having a degradable or toxic It is an advanced oxidation process (AOP) that oxidatively decomposes based on a catalytic reaction. One of the representative AOPs is a single catalyst process that is miniaturized and commercialized in sewage/wastewater treatment plants. It applies a voltage between an anode that is not coated with a catalyst and a cathode that is coated with a catalyst to remove difficult-to-decompose organic materials. It is an electro-Fenton reaction process that oxidatively decomposes based on a homogeneous catalytic reaction. This provides three major advantages. For example, 1) an infinite amount of hydrogen peroxide (H ₂ O ₂ ) can be supplied (2H ⁺ + O ₂ + 2e ^- → H ₂ O ₂ ) by oxygen reduction occurring at the cathode, 2) H ₂ O oxidation occurring at the anode ^{_{(H 2 O → · OH +}} H + + e -) , or the oxidation of the surface of the catalyst coated on the cathode metal species of not more than 2 species ^(δ M ^+, M: metal; δ≤2) of hydrogen peroxide by heterogeneous catalyst ( heterogeneous catalysis) the decomposition or homogeneous catalysts (homogeneous catalysis) peroxide catalyst decomposition reaction by the decomposition ^{_{(H 2 O 2 → · OH}} + OH -) capable of a significant amount of ^· OH supplied by the points, and 3) the above-described hydrogen peroxide catalytic Cracking The resulting M ^(δ+1)+ is reduced to M ^δ+ by abundant electrons (e ^{- ) inside the reaction solution (M (δ+1)+} + e ^- → M ^δ+ ) for hydrogen peroxide-catalyzed decomposition reaction. It boils down to recyclability.

In spite of the above advantages, the disadvantages presented below limit the large-scale commercialization of the electrical Fenton reaction process for wastewater treatment. ^{First, a limited amount of M δ+} species present on the catalyst surface coated on the cathode continuously ^{converts M (δ+1)+} species formed as a result of hydrogen peroxide catalytic decomposition into M δ+ species by electrons (e ⁻ ). Despite recovery, it ultimately produces a limited amount of ^· OH, which slows the rate of decomposition of recalcitrant organics by ^{· OH.} Second, the electric Fenton reaction process carried out under relatively harsh conditions ^{causes continuous and severe leaching of M δ+} species present on the catalyst surface coated on the cathode, which limits the number of uses of the coated catalyst and organic matter. It causes a decrease in the decomposition performance. ^{Third, in the case of ·} OH applied to the electric Fenton reaction process, since the lifespan is relatively short, the decomposition efficiency of organic substances is lowered, and ^{· ·} OH has a problem that requires a pH in a limited range for the efficient production of OH.

(Prior Document 1) Laid-Open Patent Publication No. 10-1990-12674

The present invention to solve various problems, including the problems as described above, ^- with a long life, 2) the oxidizing power similar to a wide pH range, and 3) more than OH Contrast 1) SO ₄ ^{· -} functional group (M _{A) Z} (M _{B) 3-Z} O ₄ were dispersed in the catalyst surface and an object thereof is to decompose the decomposable organic material I on the basis of heterogeneous catalytic reactions.

In addition, the present invention, but leads to continuous ^· OH produced, the existing electrical Fenton presented with disadvantages of the processes 1) slow I serious reaction active points peeling decomposable organic matter decomposition reaction rate, 2) (M ^{δ +} leaching), 3), limited catalyst An object of the present invention is to provide a catalyst for an electric Fenton reaction system capable of solving problems such as lifespan, an electrode including the same, and an electric Fenton reaction system using the same.

However, these problems are exemplary, and the scope of the present invention is not limited thereto.

According to one aspect of the present invention for solving the above problems, a catalyst for an electric Fenton reaction system is provided, comprising at least one kind of catalyst crystal particles represented by [Formula 1] whose _{surface is functionalized with SO 4} ^2- .

[Formula 1]

_{(M A) Z (M B} ) 3-Z O 4

(where M _A and M _B are metals, and Z is a real number having a value between 0 and 3)

According to an embodiment of the present invention, the catalyst crystal particles may have a porous structure.

According to an embodiment of the present invention, the catalyst crystal particles may have a diameter of 0.1 nm to 500 μm.

According to one embodiment of the present invention, the SO ₄ ^2- The (M _A) functionalized with _{Z (M B) 3-Z} O 4 crystals of the metal particles (M _A or M _B) are lithium (Li), magnesium ( Mg), calcium (Ca), barium (Ba), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), cadmium (Cd), titanium ( Ti), germanium (Ge), tin (Sn), aluminum (Al), chromium (Cr), gallium (Ga), and may be at least one selected from the group consisting of indium (In) or a combination thereof.

According to one aspect of the present invention for solving the above problems, the catalyst for the electric Fenton reaction system; a support on which the catalyst is supported; a substrate on which the carrier is coated; and a binder interposed between the carrier and the substrate to increase coating adhesion.

According to an embodiment of the present invention, the carrier, carbon (C), Al ₂ O ₃ , MgO, ZrO ₂ , CeO ₂ , TiO ₂ and SiO _{2 It} may be any one.

According to an embodiment of the present invention, 0.01 to 50 parts by weight of the catalyst may be included with respect to 100 parts by weight of the support.

According to an embodiment of the present invention, the binder may be an insoluble polymer.

According to one aspect of the present invention for solving the above problems, there is provided an electrical Fenton reaction system comprising the electrode and an aqueous electrolyte solution.

According to an embodiment of the present invention, the pH of the aqueous electrolyte solution is 5 to 10, and electric power of 2W or less is input to cause an electrical Fenton reaction.

According to an embodiment of the present invention, the electrical Fenton reaction, (1) H ₂ O _{2 by} the heterogeneous decomposition reaction of ^· OH species is formed; (2) SO ₄ ^· by the ^· OH species the functionalized SO ₄ ^{2- paper-step} to be converted into a species; and (3) the SO ₄ ^·- decomposing the difficult-to-decompose organic material by the species.

In accordance with one embodiment of the present invention made as described above, the catalyst SO ₄ ^2- functional groups on the surface by reacting with the OH ^· 1) ^· has a long life and oxidative more than OH, to drive over a wide pH conditions than 2) It is converted to the functional group (surface species) I it is possible to improve the reaction rate of the decomposable organic material decomposition ^- can SO ₄ ^· in.

In addition, according to an embodiment of the present invention, it is possible to reduce the peeling phenomenon of crystal grains occurring during the decomposition of the hardly decomposable organic material, and the performance is maintained even when the catalyst is used several times during the decomposition of the hardly decomposable organic material, and the effect of improving the catalyst life is achieved. have.

Of course, the scope of the present invention is not limited by these effects.

1 is a scanning electron microscopy (SEM) photograph of a catalyst crystal particle according to an embodiment of the present invention.
2 is a schematic diagram illustrating an electro-Fenton reaction system including a catalyst according to an embodiment of the present invention.
3 is a graph showing an X-ray diffraction pattern (XRD pattern) of catalysts according to an embodiment of the present invention.
4 is a graph showing in situ diffuse reflectance infrared fourier transform (DRIFT) spectroscopy results of catalyst surfaces according to an embodiment of the present invention.
5 is a graph showing XPS results in the O 1s region of catalysts according to an embodiment of the present invention.
6 is a graph showing XPS results in the S 2p region of catalysts according to an embodiment of the present invention.
7 is a graph showing the results of a _{hydrogen peroxide (H 2} O ₂ ) decomposition reaction experiment using catalysts according to an embodiment of the present invention.
8 is a graph showing the results of an electrical Fenton phenol decomposition reaction experiment using catalysts according to an embodiment of the present invention.
9 is a graph showing the results of an electrical Fenton phenol decomposition reaction experiment using catalysts according to an embodiment of the present invention.
10 is a graph showing the conversion rate of phenol decomposed over time when the catalyst according to an embodiment of the present invention is used.
11 is a graph showing the results of an electrical Fenton phenol decomposition cycle (recycle) reaction experiment using a catalyst according to an embodiment of the present invention.
12 is a graph showing the results of an electric Fenton aniline decomposition reaction experiment using catalysts according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0023] Reference is made to the accompanying drawings, which show by way of illustration specific embodiments in which the present invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the present invention. It should be understood that the various embodiments of the present invention are different but need not be mutually exclusive. For example, certain shapes, structures, and characteristics described herein with respect to one embodiment may be embodied in other embodiments without departing from the spirit and scope of the invention. In addition, it should be understood that the location or arrangement of individual components within each disclosed embodiment may be changed without departing from the spirit and scope of the present invention. Accordingly, the detailed description set forth below is not intended to be taken in a limiting sense, and the scope of the invention, if properly described, is limited only by the appended claims, along with all scope equivalents to those claimed. In the drawings, like reference numerals refer to the same or similar functions in various aspects, and the length, area, thickness, and the like may be exaggerated for convenience.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings in order to enable those of ordinary skill in the art to easily practice the present invention.

Catalysts for Electrical Fenton Reaction Systems

The present invention relates to a catalyst for an electric Fenton reaction system comprising at least one kind of catalyst crystal grains represented by [Formula 1] functionalized with _{SO 4} ^{2-, an electrode comprising the same, and an electric Fenton reaction system using the same} will be.

[Formula 1]

_{(M A) Z (M B} ) 3-Z O 4

(where M _A and M _B are metals, and Z is a real number having a value between 0 and 3)

The SO ₄ ^2- The (M _A) functionalized with _{Z (M B) 3-Z} O 4 crystals for the particles, the oxidation of metal species (M _A or M _B) is one of 4 can be changed between in have. More particularly, the metal species (M _A or M _B) included in the _{(M A) Z (M B} ) 3-Z O 4 crystal grains functionalized to SO ₄ ^2- is Li (lithium), Mg (magnesium), Ca (calcium), Ba (barium), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), cadmium (Cd), titanium (Ti), It may be at least one selected from the group consisting of germanium (Ge), tin (Sn), aluminum (Al), chromium (Cr), gallium (Ga), and indium (In), or a combination thereof.

Electrical Fenton reaction system catalyst may be prepared in a certain _{(M A) Z (M B} ) 3-Z O 4 crystal way typically be applied to form the particles. For example, the transition metal oxide crystal grains included in the catalyst are hydrothermal synthesis, solvothermal synthesis, mechano-chemical method (ball-milling), non-template or template synthesis method. (non-templated or templated method), impregnation method, dip coating method, calcination pyrolysis method (calcination or thermal decomposition method using M-including complex) can be prepared by one or more methods.

Electrical Fenton reaction system at the anode H ₂ O oxidation (H ₂ O → ^· OH + H ⁺ + e ^-) A (M _A) coated on the ^· OH species formed at the cathode by _Z (M _{B) 3-Z} O ₄ crystal SO ₄ and used as the activator of the SO ₄ ^2- functional groups present on the ^{particle, -} it is possible to form the surface thereof. In order to promote the H ₂ O oxidation reaction, various types of conductive materials may be applied as an anode, for example, graphite may be applied as an anode.

In addition, the catalyst for the electric Fenton reaction system is applied to decompose hydrogen peroxide formed by the ^{oxygen reduction reaction (2H +} + O ₂ + 2e ^- → H ₂ O _{2 ) at the cathode M A} ^δ+ or M _B ^δ+ (δ ≤2) active species may be included on the catalyst surface. Specifically, a _{hydrogen peroxide catalytic decomposition reaction (H 2} O) based on homogeneous catalysis or heterogeneous catalysis using _{M A} ^δ+ or M _B ^δ+ ( ^{named M δ+) active sites} ₂ → ^· OH + OH ^-) and the activation, the reaction results formed ^· SO ₄ ^2- function for using the OH species, the coating on the cathode (M _a) present in the _{Z (M B) 3-Z} O 4 crystal grains It can be converted into the surface species ^- the group SO ₄ ^·. Thus, the hydrogen peroxide M ^{δ +} but contains a lot of active points, single / two kinds of metal oxide catalysts is the synthesis of low-cost easy (reverse) spinel, to facilitate the catalytic decomposition reaction ((M _{A) Z} (M _{B) 3 -Z} O ₄ ) is preferably used as a catalyst to be coated on the cathode.

In addition, the electrical system Fenton reaction catalysts are SO ₄ ^· on the basis of radical movement (transfer radical) to SO ₄ ^2- functional groups of the surface of the catalyst in the above-mentioned species, ^· OH ^- it is possible to form the surface species, by using them, It can promote the decomposition of difficult-to-decompose organic substances. Therefore, in the transition metal oxide catalyst surface SO ₄ ^2- in the functional group can contain a lot of (inverse) spinel single / dissimilar metal oxide catalyst to the ((M _{A) Z} (M _{B) 3-Z} O _4), the cathode It is preferable to use it as a catalyst to be coated.

The transition metal catalyst surfaces ^δ M ⁺ and SO ₄ ^2- are functional groups (reverse) spinel single / different metal oxides ((M _A, which may be maximized as described above), _Z (M _{B) 3-Z} O ₄ ), but the implementation of the catalyst surface, by controlling the (M _{a) Z} (M _{B) 3-Z} O ₄ type of M _a / M _B of the surface, a stoichiometric (Z), or SO ₄ ^2- functionalized (sulfated) conditions The catalyst performance can be improved.

According to an embodiment of the present invention, the sulfation treatment may be performed by a reactive gas including _{SO 2} and O _{2 .} The concentration of SO ₂ and O ₂ is in the range of 10 ppm to 10 ⁵ ppm, the flow rate is 10 ^-5 mL min ^-1 to 10 ⁵ mL min ^-1 , and the pressure is 10 ^-5 bar to 10 ⁵ bar. can have a range. In addition, the sulfuration treatment may be performed at a temperature range of 200° C. to 800° C. for 0.1 hours to 24 hours.

If the conditions for processing the sulfated catalyst less than the foregoing range, (M _{A) Z} may be out of SO ₄ ^2- functionalized effect of _{(M B) 3-Z O} 4 catalyst. In addition, it can be not less than the foregoing range, (M _{A) Z} (M _{B) 3-Z} O ₄ ^{+ δ} M species that promote hydrogen peroxide decomposition reaction activity of the catalyst by the excess of functionalized surfaces are destroyed. Therefore, the sulfation treatment of the catalyst can be performed within the range of the above-mentioned conditions.

Embodiment for electrically Fenton reaction system, the catalyst according to the embodiment of the present invention, a surface area of more wide ^δ M ^{+ OH,} in the form of the speed and by the species of the catalyst ^surface, SO SO ₄ ^2- of the functional group of the OH ^{species, _4-surface} The rate of conversion to species can be accelerated (Schemes 1 and 2). The faster that the above-mentioned speed, SO ₄ ^{· -} so to surface species are abundant in the reaction system may eventually promote decomposition of harmful substances.

Scheme (1): SO ₄ ^2- + ^· OH + H ⁺ →SO ₄ ^·- + H ₂ O

Scheme (2): SO ₄ ^2- + ^· OH → SO ₄ ^·- + OH ^-

According to one embodiment of the invention, the _{(M A) Z (M B} ) 3-Z O 4 crystal grains functionalized with SO ₄ ^2- may be a porous structure, the number of days that 0.1 nm to 500㎛ diameter.

1 shows the morphology of Mn _Z Fe _3-Z O ₄ (Z = 3, 2, 1.5, 1, 0; _{named Mn Z ) catalysts functionalized with SO 4} ^2- according to an embodiment of the present invention.

As shown in Figure _{1, (M A) Z (} M B) 3-Z O 4 crystal grains are 1) size is less than or, 2) a porous or case have a rough surface projections are formed, the surface area is increased hydrogen peroxide because the catalytic cracking reaction is faster ^· SO ₄ catalyst of SO ₄ ^2- surface functional groups by the formation rate and species of the ^· OH ^· OH ^- can accelerate the rate of conversion to the surfaces thereof.

Further, (M _A) when _Z has the _{(M B) 3-Z O} 4 determine two features of the particle is described above, it may be coated with a stronger intensity to a cathode. This means that the eddy current of the aqueous electrolyte solution in which the electric Fenton reaction is performed and the leaching phenomenon of the catalyst due to external power are reduced, so that the life of the electrode is increased. When the catalyst is peeled off from the electrode, ^· OH generation reaction or SO ₄ ^{· ·} decomposition of difficult-to-decompose organics can be carried out by the exfoliated catalyst species based on homogeneous catalysis. In this case, there is a problem in that the efficiency of decomposing difficult-to-decompose organic substances is reduced and the number of times of use of the electric Fenton catalyst is limited.

That is, the more reduced the peeling phenomenon, ^· OH generated reaction or SO ₄ ^{· -} a i by the decomposition reaction of the decomposable organic material coated on the cathode _{(M A) Z (M B} ) 3-Z O 4 crystal heterogeneous catalyst according to the particle Because it occurs by heterogeneous catalysis, the performance of the electric Fenton reaction catalyst can be maintained even after several uses. _{Therefore, (M A) Z (M} B) 3-Z O 4 crystal grains in accordance with an embodiment of the present invention may have a rough surface characteristic of the porous in order to suppress the release from the electrodes.

Electrodes for Electrical Fenton Reaction Systems

Hereinafter, an electrode including a catalyst for an electric Fenton reaction system will be described.

According to an embodiment of the present invention, an electrode for an electric Fenton reaction system is an electrode for an electric Fenton reaction system including a catalyst for an electric Fenton reaction system, a carrier on which the catalyst for the electric Fenton reaction system is supported, the catalyst is supported It may include a substrate on which a support is formed and a binder interposed between the support and the substrate to increase coating adhesion.

For the electrical system, the Fenton reaction catalyst, comprising a _{(M A) Z (M B} ) 3-Z O 4 -functionalized with SO ₄ ^2- as described above. The catalyst may be directly coated on the substrate, but may be supported on a support for more stable and efficient electrode construction. In this case, the carrier may be formed on at least one surface of the substrate, and preferably, it may be coated on both surfaces of the substrate. The substrate may be a type of conductive material commonly used in electrochemical reactions. For example, graphite or a metal such as copper, aluminum or the like may be used.

In addition, according to an embodiment of the present invention, the support _{is any one of carbon (C), Al 2} O ₃ , MgO, ZrO ₂ , CeO ₂ , TiO ₂ and SiO ₂ , and 100 parts by weight of the support. The catalyst for the electric Fenton reaction system may contain 0.01 to 50 parts by weight.

The catalyst-supported carrier may be coated on the substrate using an impregnation method. At this time, the content of the coated catalyst can be adjusted to ^{improve the efficiency of ·} OH generation reaction or the decomposition reaction of difficult-to-decompose organics by _{SO 4} ^{·- and ·} OH to smoothly move to the surface SO ₄ ^{2-functional group of the catalyst.}

When the catalyst and the substrate are coated, the adhesion between the catalyst and the substrate may be improved by using a binder. In this case, the binder may be an insoluble polymer, preferably, polyvinylidene fluoride (PVDF). The binder can improve the coating adhesion between the catalyst-supported carrier and the substrate, and if it has insoluble properties, the binder does not dissolve in the aqueous solution even if the electric Fenton reaction is repeatedly performed, so that the peeling of the catalyst can be prevented. . That is, it is possible to improve the lifetime characteristics of the electrode for the electric Fenton reaction system by suppressing the peeling of the catalyst.

Electrical Fenton Reaction System

2 is a schematic diagram illustrating an electro-Fenton reaction system 100 including a catalyst 160 according to an embodiment of the present invention.

2, the electric Fenton reaction system 100 is a second electrode (cathode) on which the electrolyzer 110, the aqueous electrolyte solution 120, the first electrode 130 and the catalyst 160 are coated ( 140) may be included. The first electrode 130 and the second electrode 140 may be connected by a power source. A (M _A) proposed by the embodiment of the invention _{Z (M B) 3-Z} O 4 crystal catalyst (160) comprising particles is by using the non-coated anode (130) rich by H ₂ O oxidation ^Produces OH species. Further, by using the (M _{A) Z} (M _{B) 3-Z} O ₄ crystals coated with the cathode 140, the catalyst 160 containing particles proposed by the present invention, H ₂ O ₂ generated from the cathode surface The instantaneous hydrogen peroxide catalytic decomposition reaction is realized by ^{M δ+} species contained on the surface of the transition metal oxide catalyst. ^{Due to this, the rate of production of ·} OH species by the hydrogen peroxide catalytic decomposition reaction based on heterogeneous catalysis under specific reaction conditions is further increased.

Importantly, the above-described H ₂ O oxidation and hydrogen peroxide catalyst the greater the production rate of the formed ^· OH species by decomposition, 1) ^· SO ₄ present in the catalyst 160, the surface coating to the cathode 140 of the OH species ^2- The movement speed to the functional group increases, 2) ^· OH And SO ₄ SO ₄ ^· by radical movement (transfer radical) reaction between ^2-growing species to form on the surface of the catalyst addition rate, and, 3) SO ₄ ^· based on the ultimate heterogeneous catalytic reactions to (heterogeneous catalysis) ^- species High-efficiency decomposition of organic materials is possible by

The first electrode 130 and the second electrode 140 may be made of a conductive material. For example, it may be graphite. At least one surface of the second electrode 140 may be coated with the catalyst 160, the catalyst 160 is _{Mn Z} Fe _3-Z O ₄ functionalized with _{SO 4} ^{2- according to the embodiment of the present invention described above.} (Z = 3, 2, 1.5, 1, 0; _{named as Mn Z} ) It may be a catalyst including crystal grains.

The aqueous electrolyte solution 120 is an aqueous solution used for the electrical Fenton reaction, and has ^{a concentration of 10 -4} to 10 mol/L Na ₂ SO ₄ , NaNO ₃ , NH ₄ F, KF, KCl, KBr, KI, NaF, NaCl , NaBr, NaI, any one or a combination thereof may be optionally used.

Hereinafter, a process in which an organic material is decomposed through a catalytic reaction occurring in the electric Fenton reaction system 100 will be described. The reactions occurring in the electric Fenton reaction system 100 are summarized in the following reaction formulas (3) to (10).

Scheme (3): 2H ₂ O → O ₂ + 4H ⁺ + 4e ^-

Scheme (4): O ₂ + 2H ⁺ + 2e ^- → H ₂ O ₂

Scheme (5): M ^(δ+1)+ + e ^- → M ^δ+

Scheme (6): M ^δ+ + H ₂ O ₂ → M ^(δ+1)+ + OH ^- + ^· OH

Reaction Scheme _{(7): H 2 O →} · OH + H + + e -

Scheme (8): SO ₄ ^2- + ^· OH + H ⁺ → SO ₄ ^·- + H ₂ O

Scheme (9): SO ₄ ^2- + ^· OH → SO ₄ ^·- + OH ^-

Scheme (10): SO ₄ ^·- + e ^- → SO ₄ ^2-

First, water is decomposed into _{oxygen (O 2} ) and hydrogen ions (H ⁺ ) by an oxidation reaction by an external power source in the first electrode 130 . In addition, oxygen (O ₂ ) and hydrogen ions (H ⁺ ) formed at this time undergo a reduction reaction at the second electrode 140 to form _{hydrogen peroxide (H 2} O _{2 ).} The number of generated hydrogen peroxide, a transition metal oxide crystals the oxidation divalent metal species or less contained in the particles (M ^{δ +)} and the metal species react with the oxidation number ^{(δ + 1) (M (} δ + 1) +) and ^· OH The metal species having an oxidation number (δ+1) (M ^(δ+1)+ ) is reduced by electrons (e ⁻ ) to recover a metal species having an oxidation number of 2 or less (M ^{δ+ ).} This means that the oxidation number (δ+1) formed during the reaction of a metal species having an oxidation number of 2 or less (M ^δ+ ) and hydrogen peroxide (H ₂ O ₂ ) is the oxidation number of a metal species (M ^(δ+1)+ ) It is possible to solve the problem of recovery to the following metal species (M ^δ+ ), and to continuously supply hydrogen peroxide (H ₂ O ₂ ) by supplying _{oxygen (O 2 ) due to electrolysis of water.} ^{In addition, continuous supply of ·} OH by oxidation of _{H 2} O in the first electrode 130 is also possible.

In other words, the sikidoe peroxide catalyst degradation reactions that occur in the first electrode (130) H ₂ O oxidation, and a second electrode 140 takes place ^in, increasing the production rate of OH, generated ^· OH is coated on the second electrode surface of the catalyst (160) The surface of SO ₄ interacts with ^2- _{functional groups to form SO 4} ^·- surface species. The more abundant of the surface functional groups are SO ₄ ^2- coated catalyst (160) SO ₄ ^{· -} it is possible to improve the performance of the decomposition reaction of the organic material by ^- increasing the production rate of the surface species and, therefore, SO ₄ ^·. In the case of _{SO 4} ^·- , which is not used for decomposition of organic matter, it is reduced by ^{electrons (e -} _{) to recover the SO 4} ^2- functional group, and can be continuously used for the formation of _{SO 4} ^{·- surface species in the future.}

_{SO 4} ^·- generated through the above reaction can decompose difficult-to-decompose or toxic organic substances. Organic substances can be phenol-based toxic substances, carcinogens and mutagenic substances. Specifically, a structure in which at least one of carbons of a monocyclic or polycyclic aromatic material is substituted with oxygen (O), nitrogen (N) or sulfur (S) is a main chain Branched as a backbone, alkane, alkene, alkyne, amine, amide, nitro, alcohol, ether, halide (halide), thiol (thiol), aldehyde (aldehyde), ketone (ketone), ester (ester), may be a material containing various functional groups such as carboxylic acid (carboxylic acid) or derivatives thereof.

Meanwhile, according to an embodiment of the present invention, the pH of the aqueous electrolyte solution in which the reaction of the catalyst occurs is 5 to 10, and the electric Fenton reaction may be performed at a power of 2W or less.

_{SO 4} ^{·- is} generated on the surface of the catalyst coated on the second electrode 140 inside the aqueous electrolyte solution 120 of the electric Fenton reaction, and the decomposition reaction of the organic material by _{SO 4} ^{·- proceeds.} At this time, when the pH of the aqueous electrolyte solution 120 is acidic (pH < 5) or basic (pH > 10) or the external power is more than 2W, the transition metal oxide in the catalyst 160 coated on the second electrode 140 Separation of crystal grains or SO ₄ ^2- functional groups may occur. Oxidation of homogeneous by exfoliation changes the pH of the aqueous electrolyte solution with a ^{metal ion (M δ+} ) and SO ₄ ^{2- functional group with a divalence or less, and is} a major active factor in OH and SO ₄ ^{− production reactions.} can be The peeling phenomenon lowers the organic material decomposition efficiency and durability of the electric Fenton reaction system when the Fenton reaction proceeds for a long period of time. Therefore, in the electric Fenton reaction system for high-efficiency and continuous decomposition of organic materials, power of 2 W or less can be input when the pH of the aqueous electrolyte solution 120 is 5 to 10, and more preferably, the pH of the aqueous electrolyte solution 120 is 7 to 0.04W or less of power may be input.

Hereinafter, embodiments for helping understanding of the present invention will be described. However, the following examples are provided only to help the understanding of the present invention, and the embodiments of the present invention are not limited to only the following examples.

Example

Examples 1 to 5: Mn _Z (Z = 3, 2, 1.5, 1, 0) Preparation of catalyst

As shown in Table 1, porous crystalline Mn _Z catalysts were prepared by solvothermal synthesis. Specifically, 177.6 g of (Z×10) mmol of MnCl ₂ .4H ₂ O, ((3-Z)×10) mmol of FeCl ₃ .6H ₂ O, 3.6 g of NaNO ₃ and 1 g of polyethylene glycol of ethylene glycol solution was stirred at 25 °C for 30 minutes, and then exposed to solvothermal reaction conditions at 200 °C for 12 hours in an autoclave reactor to obtain a solid. The obtained solid was filtered/washed using distilled water and ethanol, dried at 70° C., and dried at 100° C. for 1 hour _{to prepare Mn Z} catalysts, which are referred to as Examples 1 to 5. _{Hereinafter, the Mn 3} O _4, Mn ₂ Fe ₁ O _4, Mn _1.5 Fe _1.5 O _4, Mn ₁ Fe ₂ O _4, Fe ₃ O ₄ catalysts according to Examples 1 to 5 are respectively prepared according to the molar ratio of manganese. Mn _3, Mn _2, Mn _1.5, Mn _1, Mn ₀ will be named.

Example 1 Example 2 Example 3 Example 4 Example 5 precursor MnCl ₂ 4H ₂ O (mmol) 30 20 15 10 0 FeCl ₃ 6H ₂ O (mmol) 0 10 15 20 30 product Mn ₃ (Mn ₃ O ₄ ) Mn ₂
(Mn ₂ Fe ₁ O ₄ ) Mn _1.5
(Mn _1.5 Fe _1.5 O ₄ ) Mn ₁ (Mn ₁ Fe ₂ O ₄ ) Mn ₀ (Fe ₃ O ₄ )

Examples 6 to 10: Mn _Z (S) (Z = 3, 2, 1.5, 1, 0) Preparation of catalyst

_{The Mn z} catalysts prepared in Examples 1 to 5 were exposed at 500° C. for 1 hour under an atmosphere of 500 ppm SO _{2 /3} vol.% O ₂ and a flow rate of 500 mL min ^-1 diluted with N _{2 and then} Cool to room temperature under N _{2 atmosphere. The Mn Z} (S) catalysts prepared according to the above conditions are referred to as Examples 6 to 10. Hereinafter, the catalysts according to Examples 6 to 10 were prepared according to the molar ratio of manganese, respectively. Mn ₃ (S) _, Mn ₂ (S) _, Mn _1.5 (S) _, Mn ₁ (S) _, Mn ₀ (S) will be named.

The catalysts prepared in Examples 1 to 10 were analyzed using an X-ray diffractometer (XRD), and the resultant X-ray diffraction pattern (XRD pattern) is shown in FIG. 3 shown in Referring to FIG. 3 , the catalyst of Example 1 has a normal spinel type tetragonal Mn ₃ O ₄ phase, and the catalyst of Example 2 has a partially normal spinel type cubic phase. Has a normal (cubic Mn ₂ Fe ₁ O ₄ phase), the catalyst of Example 4 has a partial inverse spinel type cubic _{phase (cubic Mn 1} Fe ₂ O ₄ phase), the catalyst of Example 5 It can be seen that has an inverse spinel type cubic _{phase (cubic Fe 3} O _{4 phase).} On the other hand, the catalyst of Example 3 has a previously unreported random spinel type cubic phase (indicated by *). However, the catalyst of Example 3 has a crystalline phase similar to that of Examples 2 and 4 described above, except that the diffraction positions (2 theta) exist between the positions of the diffractions of Examples 2 and 4 (2 theta). Therefore, it can be seen that it was synthesized to have a desirable crystalline phase.

It can be seen that the crystalline phases of the catalysts of Examples 7 to 9 functionalized with SO ₄ ^{2- are the same as the crystalline phases of Examples 2 to 4 above.} This is because the functionalization of the surface by _{SO 4} ^2- of the catalysts of Examples 6 to 8 does not suggest a new bulk phase such as _{MnSO 4} and Fe ₂ (SO _{4 ), so the bulk phase of the catalyst} phase) is not affected. On the other hand, in the case of Example 6, it can be seen that it also has an _{orthorhombic MnSO 4} phase, which is not observed in Example 1, which means that the functionalization of the catalyst surface by _{SO 4} ^2- _{causes some of the Mn 3} O ₄ crystal phases. It means transformation into MnSO _{4 .} In addition, in the case of Example 10, since the temperature (500° C.) used for functionalization of the catalyst surface by _{SO 4} ^2- _{of Example 6 is high, the metastable cubic Fe 3} O ₄ crystal phase is stable rhombohedral (rhombohedral) ) It can be seen that the _{Fe 2} O _{3 crystal phase changes.} However, in the case of Example 10, since a new bulk phase such as _{Fe 2} (SO _{4 ) is not presented, the functionalization of the catalyst surface by SO 4} ^2- affects the bulk phase of the catalyst. It can be seen that they do not give

In order to observe the physical properties of the catalysts of Examples 6 to 10 (Mn _{z (S)) functionalized with SO 4} ^{2-, various techniques were analyzed.} Mn _z (S) catalysts show a porous morphology, as evidenced by the BET surface area values of the catalysts (5-25 m ² g _CAT ^{−1 ).} In addition, _{quantitative analysis using X-ray fluorescence spectroscopy (XRF) shown in Table 2 that Mn z} (S) catalysts have a metal (Mn+Fe)/oxygen (O) (molar basis) defined in stoichiometry. It can be seen from the results. In the case of Mn ₃ (S) of Example 6, it can be seen that the value of sulfur (S)/metal (Mn+Fe) (molar basis) is very large compared to the catalysts of Examples 7 to 10 (Table 2) ). This is consistent with the result of generating an additional bulk phase, MnSO ₄ , by the SO ₄ ^2- _{functionalization of Mn 3 as} the catalyst of Example 1 described above.

Example 6 Example 7 Example 8 Example 9 Example 10 Mn ₃ (S) Mn ₂ (S) Mn _1.5 (S) Mn ₁ (S) Mn ₀ (S) Metal (Mn+Fe)/Oxygen (O) 0.79
(±0.09) 0.77
(±0.05) 0.78
(±0.03) 0.79
(±0.02) 0.78
(±0.02) Sulfur (S)/Metal (Mn+Fe) 0.22
(±0.03) 0.04
(<±0.01) 0.02
(<±0.01) 0.01
(<±0.01) 0.01
(<±0.01)

^{For quantitative analysis of M δ+} surface species (N _CO ) to which carbon monoxide (CO) having Lewis acid properties is accessible, the catalysts of Examples 6 to 10 were analyzed using CO-pulsed chemisorption. In the case of Mn ₃ (S) and Mn ₀ (S) of _{Examples 6 and 10, higher NCO} values were provided compared to other catalysts (≥ 0.27 μmol _CO g _CAT ^-1 for Mn ₃ ( _{S) and Mn 0 (S)} ; ≤ ~ 0.15 μmol CO g CAT -1 for Mn 2 (S), Mn 1.5 (S), and Mn 1 (S)). This may mean that in Example 6 and Example 10, the Mn ₃ (S) and Mn ₀ (S) can improve the efficiency of the hydrogen peroxide decomposition catalyst improves the productivity of the ^· OH other catalyst preparation.

FIG. 4 shows 100° C. to 200° C. of Mn ₃ (S), Mn _1.5 (S) and Mn _{0 (S) catalysts functionalized with SO 4} ^2- according to Examples 6, 8 and 10 of the present invention; A graph showing the results of background-subtracted, in situ diffuse reflectance infrared fourier transform (DRIFT) spectroscopy of NH _{3 saturated catalyst surfaces.} In contrast to the CO-pulsed chemisorption result, the area under the peaks representing M ^δ+ surface species accessible to NH ₃ with Lewis acid properties (L _{) was Mn 3} (S) → Mn at 100° C. to 200° C. ₀ (S) → Mn _1.5 (S) was found to increase in the order. In addition, in _{the case of Mn 1.5} (S) of Example 8, it can be seen that, despite the increase in temperature from 100° C. to 200° C., the area under the L peak is maintained the largest. This is because Mn _1.5 (S) _{of Example 8 has a greater Lewis acid strength compared to Mn 3} (S) and Mn ₀ (S), so it facilitates adsorption between the _{reactants H 2} O ₂ and M ^{δ+ surface species.} It means that the hydrogen peroxide-catalyzed decomposition reaction can be carried out most efficiently, and thus Mn _1.5 (S) can show ^{improved ·} _{OH productivity compared to Mn 3} (S) and Mn ₀ (S).

_{5 shows Mn 3} (S), Mn ₂ (S), Mn _1.5 (S), Mn ₁ (S) and Mn ₀ (S) functionalized with _{SO 4} ^2- according to Examples 6 to 10 of the present invention; ) A graph showing the results of X-ray photoelectron (XP) spectroscopy in the O 1s region of catalysts. All catalysts have O _β (lattice O), O _α (chemically-susceptible O) and O _α ' (O of chemisorbed H ₂ O) surface species. In the case of Mn _1.5 (S) of Example 8, it has the largest amount of O _α surface species, which means that ^{the amount of electrons (e −} ) present on the catalyst surface is the most abundant. This means that the reduction of ^{M (δ+1)+} surface species formed as a result of the hydrogen peroxide catalytic decomposition reaction ^{to M δ+} surface species is most active in _{Mn 1.5} ^{(S) of Example 8, and} OH per unit time This means that the productivity of Example 8 can be maximized in _{Mn 1.5 (S).}

_{6 shows Mn 3} (S), Mn ₂ (S), Mn _1.5 (S), Mn ₁ (S) and Mn ₀ (S) functionalized with _{SO 4} ^2- according to Examples 6 to 10 of the present invention. ) is a graph showing the XPS results in the S 2p region of the catalysts. All catalysts had SO ₃ ^2- and SO ₄ ^2- surface species, and in _{the case of Mn 1.5} (S) of Example 8, it was found that it had the highest amount of SO ₄ ^{2- surface species.} This is the largest amount present in the Mn _1.5 of Example 8 compared to the other catalysts (S) SO ₄ ^2- radical surface moving from the ^rich, OH, near the paper (transfer radical) in the amounts of SO ^_4, by ^- This means that the probability of metastasis to surface species is very high per unit time. Importantly, all the analysis results described above _{mean that Mn 1.5} (S) of Example 8 can show the greatest decomposition efficiency of hardly decomposable organic matter.

Hereinafter, the performance of the electric Fenton system using the catalysts of Examples 3 and 6 to 10 will be described with reference to FIGS. 7 to 12 .

Experimental Example 1: Hydrogen peroxide (H ₂ O ₂ ) decomposition experiment

Examples 6 to 10 as a catalyst, the electrode is a graphite electrode, a hard-to-decompose organic material is hydrogen peroxide (hydrogen peroxide, H ₂ O ₂ ), and Na ₂ SO ₄ Reaction experiment in the absence of electricity using an aqueous electrolyte solution carry out When the catalyst is coated on the electrode, poly(vinylidene fluoride) (PVDF) is used as a binder. 0.2 g of the catalyst, and a 100 mL aqueous solution in which 0.2 mol of _{Na 2} SO _{4 is dissolved is used as a reaction solution.} Reaction experiments are performed at 25° C. and pH 7. _{The amount of H 2} O ₂ used in the reaction is _{the amount of H 2} O ₂ observed after the reaction proceeds for 8 hours in the absence of phenol under the electrical Fenton reaction experimental conditions of Experimental Example 2 below (N _H2O2,0 : 0.13 mmol) _H2O2 for Mn ₃ (S); 0.18 mmol _H2O2 for Mn ₂ (S); 0.26 mmol _H2O2 for Mn _1.5 (S); 0.22 mmol _H2O2 for Mn ₁ (S); 0.23 mmol _H2O2 for Mn ₀ (S)). The experiment-safe obtained through the conversion of a H ₂ O ₂ corrects the measured value obtained by the first reaction fitting graph ^{(pseudo-1 st -order kinetic fitting} , -ln (C H2O2 / C H2O2,0) VS. time) The slope of H ₂ O ₂ is equal to the rate constant of the decomposition reaction ( k _APP , min ^-1 ).

Multiplies the N _H2O2,0 the _APP k of the catalyst, the _CO value N (the above, access to the CO available Lewis acid catalyst number of moles per gram) as an initial H ₂ O included in divided amount of the catalyst (0.2g) used this _{2 The} decomposition reaction rate (-r _H2O2,0 , min ^-1 ) was calculated and is shown in FIG. 7 . As predicted in the analysis of the physical properties of the catalysts of Examples 6 to 10, the catalyst of Mn _1.5 (S) of Example 8 is different from other catalysts (Mn ₃ (S), Mn ₂ (S), Mn ₁ (S) ) and Mn ₀ (S)) compared to -r _{H 2 O 2,0} values were found to be improved. This result means that the Mn _1.5 (S) catalyst can show improved decomposing ability of difficult-to-decompose organic matter compared to other catalysts. In addition, the results of I SO ₄ ^2- functionalized _{(M A) Z (M B} ) 3-Z O 4 with M _A / M type and the stoichiometry of the _B interior to a continuous improvement in resolution decomposable organic matter (Z ) means that the desired choice is important.

Experimental Example 2: Phenol decomposition experiment

Examples 6 to 10 as a catalyst, the electrode is a graphite electrode, the organic material is phenol (phenol, C ₆ H ₅ OH), and Na ₂ SO _{4 An} electrical Fenton reaction experiment is performed using an aqueous electrolyte solution. . When the catalyst is coated on the electrode, poly(vinylidene fluoride) (PVDF) is used as a binder. 0.2 g of the catalyst, 0.1 mmol of phenol (N _{PHENOL, 0} ) and a 100 mL aqueous solution in which 0.2 mol of _{Na 2} SO _{4 is dissolved is used as a reaction solution.} Electrical Fenton reaction experiments were performed at 25° C. and pH 7 with 0.04 W power. ^{The slope of the pseudo-first-order reaction fitting graph (pseudo-1 st} -order kinetic fitting, -ln(C _PHENOL /C _PHENOL,0 ) VS. time) obtained through the conversion rate of phenol corrected for the measured value obtained during the above experiment is It is equal to the rate constant of the reaction in which phenol is decomposed ( k _APP , min ^{-1 ).} _PHENOL multiplied by _{N, 0} (0.1mmol) in _APP k of the catalyst, divided by the value of N _CO (number of moles of Lewis acid per above, a possible approach to the CO catalyst gram) containing the amount of catalyst (0.2g) used this The initial phenol decomposition reaction rate (-r _{PHENOL, 0} , min ^-1 ) was calculated and is shown in FIG. 8 . In addition, in the electrical Fenton reaction experiment, the conversion rate of carbon compared to the conversion rate of _phenol was quantified as η PHENOL, which is shown in FIG. 8 . As predicted in the analysis of the physical properties of the catalysts of Examples 6 to 10, the catalyst of Mn _1.5 (S) of Example 8 is different from other catalysts (Mn ₃ (S), Mn ₂ (S), Mn ₁ (S) ) and Mn ₀ (S)) showed improved -r _PHENOL,0 and η _PHENOL values. In addition, the amounts of Mn and Fe stripped from the catalyst during the phenol decomposition reaction were quantified, and are shown in Table 3. As shown in Table 3, _{the catalyst of Example 8 Mn 1.5} (S) was less than the other catalysts (Mn ₃ (S), Mn ₂ (S), Mn ₁ (S) and Mn ₀ (S)) compared to the amount It can be seen that Mn or Fe is exfoliated. Importantly, the results of the I inherent to SO ₄ ^2- The _{(M A) Z (M B} ) 3-Z O 4 as functionalized to the continuous improvement of the decomposable organic resolution M _A / M _B type and stoichiometric ( It means that the preferred choice of Z) is important.

Example 6 Example 7 Example 8 Example 9 Example 10 Mn ₃ (S) Mn ₂ (S) Mn _1.5 (S) Mn ₁ (S) Mn ₀ (S) Mn (mol. %) 0.18
(< ±0.01) 0.60
(±0.01) 0.03
(±0.01) 0.01
(< ±0.01) - Fe (mol. %) -
0.01
(< ±0.01) 0.03
(±0.01) 0.07
(< ±0.01) 0.06
(<±0.01)

Experimental Example 3: Phenol decomposition experiment including scavenging agent

Example 3 (Mn _1.5) and Example 8 (Mn _1.5 (S)) to the catalyst, but performing the reaction under the same conditions as in Experimental Example 2, ^· OH and SO ₄ ^· formed during the reaction ^- removing (quenching) After the addition of tetrahydrofuran or isopropyl alcohol, which is a scavenging agent, the reaction proceeded in excess, and the results are shown in FIG. 9 . The amount of scavenging agent added during each reaction is 1) Example 3 (Mn _1.5 ) and Example 8 (Mn _1.5 (S)) 2 times the amount of _{H 2} O ₂ generated in the presence of power of the catalysts and 2) Example 3 (Mn _1.5 ) and Example 8 (Mn _1.5 (S)) were derived by adding the bulk S content present in the catalysts. Scavenger (scavenging agent) -r _{PHENOL, 0} values of all the catalyst of Example 3 was added to advanced remover (scavenging agent) -r _{PHENOL, 0} values obtained in the absence _{^{(4.1 min -1 for Mn 1.5;}} 9.3 min -1 for Mn _1.5 (S)). This Example 3 (Mn _1.5) or Example 8 (Mn _1.5 (S)) is applied to the decomposition of the phenol catalyst ^· OH or SO ₄ ^· generated during electrical Fenton ^reaction proceeds by means.

Experimental Example 4: Heterogeneous catalysis-based phenol decomposition

Example 8 (Mn _1.5 (S)) decomposition of the phenol proceeds SO ₄ ^· of the catalyst surface in the ^- in the Example 8 In order to verify the progress by the catalyst, for the experiment in the same conditions as in Experimental Example 24 was performed. At this time, after performing the same as in Experimental Example 2 for 1 hour, the cathode of Example 8 is replaced with a catalyst-free cathode, the reaction aqueous solution is filtered, and the experiment is performed again. Importantly, the conversion of phenol is observed after 01 hours in the absence of a catalyst due to oxidation or even takes place at the anode (anodic oxidation) in the separated catalyst SO ₄ ^{· -} is because active species. In this method, the conversion of phenol with time was monitored and shown in FIG. 10 . Referring to FIG. 10 , the conversion rate of phenol (X _PHENOL ) of the cathodes of Example 8 after 1 hour was observed to be 18.4 (±2.5) %. These values are similar to 16.7 (±0.6) %, which is _{the conversion rate of phenol (X PHENOL} ) due to anodization, observed in the reaction performed without coating the catalyst of Example 8 on the cathode. This means that the phenol decomposition reaction occurs based on heterogeneous catalysis by the _{SO 4 .} ^- active species that are not peeled off by coating the electrode.

Experimental Example 5: Catalyst Durability Test

_{In order to verify the durability of the developed catalyst, Mn 1.5} (S) of Example 8 showing the greatest phenol decomposition performance in Experimental Example 2 was used as a catalyst, and Experimental Example 5 was performed under the same conditions as in Experimental Example 2. After each reaction cycle, the catalyst was washed/dried/accumulated and applied to the next reaction cycle. The results of Experimental Example 5 are shown in FIG. 11 . ^{The slope of the pseudo-first-order reaction fitting graph (pseudo-1 st} -order kinetic fitting, -ln(C _PHENOL /C _PHENOL,0 ) VS. time) obtained through the conversion rate of phenol obtained during this experiment is the reaction in which phenol is decomposed. It is equal to the rate constant of ( k _APP , min ^-1 ). _APP to k of the catalyst N _{PHENOL, 0} (0.1mmol) for multiplying, dividing the amount of the catalyst (0.2g) used this initial phenol decomposition reaction rate (-r _{'PHENOL, 0,} μmol min ^-1 _PHENOL g _CAT ^{- 1} ) was calculated, which is shown in FIG. 11 . For Mn _1.5 (S) _{, the values of -r' PHENOL,0} increased as the reaction cycle increased, from ~1.4 μmol _PHENOL g _CAT ^-1 min ^-1 (1st round) to ~0.4 μmol _PHENOL g _CAT ^-1 min ^-1 ( 5) showed a steady decrease. Nevertheless, the values of -r' _{PHENOL,0 of Mn 1.5} (S) observed in the 5th cycle were found in Example 6 (Mn ₃ (S); 0.1 μmol _PHENOL g _CAT ^-1 min ^-1 ) and Example 10 (Mn ₀ (S); 0.8 μmol _PHENOL g _CAT ^-1 min ^-1 _{) It can be seen that the -r' PHENOL,0} values observed in the first cycle are larger or similar to those of PHENOL,0. Importantly, the results are as in the results of Experimental Example 1 and Experimental Example 2, the I (M _A) functionalized with SO ₄ ^2- to the continuous improvement of the decomposable organic resolution _{Z (M B) 3-Z} O 4 inherent in This means that the preferred choice of the type and stoichiometry (Z) of the M _A /MB _{B is important.}

Experimental Example 6: Aniline Decomposition Experiment

For application of the developed catalyst, Examples 6 to 10 as a catalyst, the electrode is a graphite electrode, the organic material is aniline (aniline, C ₆ H ₅ NH ₂ ), and Na ₂ SO _{4 An} aqueous electrolyte solution An electrical Fenton reaction experiment was performed using When the catalyst was coated on the electrode, poly (vinylidene fluoride) (PVDF) was used as a binder. 0.2 g of the catalyst, 0.1 mmol of aniline (N _{ANILINE, 0} ), and a 100 mL aqueous solution in which 0.2 mol of _{Na 2} SO _{4 is dissolved is used as a reaction solution.} Electrical Fenton reaction experiments were performed at 25° C. and pH 7 with 0.04 W power. ^{The slope of the pseudo-first-order reaction fitting graph (pseudo-1 st} -order kinetic fitting, -ln(C _ANILINE /C _{ANILINE, 0} ) VS. time) obtained through the conversion rate of aniline corrected for the measured value obtained during the above experiment is It is equal to the rate constant of the reaction in which aniline is decomposed ( k _APP , min ^{-1 ).} _ANILINE multiplied by _{N, 0} (0.1mmol) in _APP k of the catalyst, divided by the value of N _CO (number of moles of Lewis acid per above, a possible approach to the CO catalyst gram) containing the amount of catalyst (0.2g) used this The initial aniline degradation reaction rate (-r _{ANILINE, 0} , min ^-1 ) was calculated, and is shown in FIG. 12 . In addition, during the electrical Fenton reaction experiment, the conversion rate of carbon compared to the conversion rate of aniline _{was quantified as η ANILINE} , which is shown in FIG. 12 . As predicted in the analysis of the physical properties of the catalysts of Examples 6 to 10, the catalyst of Mn _1.5 (S) of Example 8 is different from other catalysts (Mn ₃ (S), Mn ₂ (S), Mn ₁ (S)) ) and Mn ₀ (S)) showed improved -r _ANILINE,0 and η _ANILINE values. Importantly, the results of Experimental Example 6 Experimental Example 1, Experimental Example 2, and as in the results of Experimental Example 5, the I _{(M A) Z (M B} ) functionalized with SO ₄ ^2- to the continuous improvement of the decomposable organic material Resolution the preferred choice of _3-Z O ₄ with M types of _a / M _B and stoichiometry (Z) inherent in a means that is important.

Therefore, for electrically Fenton reaction system, the catalyst in accordance with one embodiment of the present invention sikidoe coating the surface of the SO ₄ ^2- species functionalized _{(M A) Z (M B} ) 3-Z O ₄ as the cathode catalyst, ^· OH _{By dispersing the SO 4} ^·- functional group formed as a result of radical transfer from the catalyst surface, it is possible to decompose difficult-to-decompose organic matter based on heterogeneous catalysis. This I the effectiveness of the decomposable organic material decomposition _{(M A) Z (M B} ) 3-Z O sikimyeo ₄ catalyst M _A / M _B control depending on the type and stoichiometric (Z) or an increase in inherent in the decomposition reaction of It is possible to reduce the delamination of the metal species having a lower oxidation value (M ^δ+ ) or the SO ₄ ^2- functional group from the catalyst surface. Accordingly, there is an effect of improving the performance and lifespan of the electric Fenton reaction system for decomposing organic materials using the catalyst.

Although the present invention has been illustrated and described with reference to preferred embodiments as described above, it is not limited to the above embodiments and is not limited to the above-described embodiments, and various methods can be made by those of ordinary skill in the art to which the invention pertains without departing from the spirit of the present invention. Transformation and change are possible. Such modifications and variations are intended to fall within the scope of the present invention and the appended claims.

100: electric Fenton reaction system
110: electrolyzer
120: aqueous electrolyte solution
130: first electrode
140: second electrode
160: catalyst for electric Fenton reaction system

Claims (11)

A catalyst for an electric Fenton reaction system, comprising at least one kind of catalyst crystal particles represented by [Formula 1] whose surface is _{functionalized with SO 4} ^2-.
[Formula 1]
_{(M A) Z (M B} ) 3-Z O 4
(where M _A and M _B are metals, and Z is a real number having a value between 0 and 3) The method of claim 1,
The catalyst crystal grain is a porous structure, the catalyst for the electric Fenton reaction system. The method of claim 1,
The catalyst crystal particles have a diameter of 0.1 nm to 500 μm, an electric Fenton reaction system catalyst. The method of claim 1,
The metal is lithium (Li), magnesium (Mg), calcium (Ca), barium (Ba), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc At least one selected from the group consisting of (Zn), cadmium (Cd), titanium (Ti), germanium (Ge), tin (Sn), aluminum (Al), chromium (Cr), gallium (Ga), and indium (In) One or a combination thereof, a catalyst for an electrical Fenton reaction system. A catalyst for an electric Fenton reaction system according to any one of claims 1 to 4;
a support on which the catalyst is supported;
a substrate on which the carrier is coated; and
A binder interposed between the carrier and the substrate to increase coating adhesion; Containing,
Electrodes for electrical Fenton reaction systems. 6. The method of claim 5,
The carrier is any one of carbon (C), Al ₂ O ₃ , MgO, ZrO ₂ , CeO ₂ , TiO ₂ and SiO ₂
Electrodes for electrical Fenton reaction systems. 6. The method of claim 5,
Comprising 0.01 to 50 parts by weight of the catalyst relative to 100 parts by weight of the support,
Electrodes for electrical Fenton reaction systems. 6. The method of claim 5,
The binder is an insoluble polymer, an electrode for an electrical Fenton reaction system. an electrode according to claim 5; and
Electrolyte aqueous solution; containing,
Electrical Fenton Reaction System. 10. The method of claim 9,
The pH of the aqueous electrolyte solution is 5 to 10,
Electric Fenton reaction occurs when power of 2W or less is input,
Electrical Fenton Reaction System. 10. The method of claim 9,
The electric Fenton reaction is
(1) step by heterogeneous decomposition of H ₂ O ₂ ^· OH paper formation;
(2) SO ₄ ^· by the ^· OH species the functionalized SO ₄ ^{2- paper-step} to be converted into a species; and
(3) the step of decomposing the difficult-to-decompose organic matter by _{the SO 4} ^{·- species; including,}
Electrical Fenton Reaction System.

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