Electrochemical reaction system for simultaneous progress of active hydrogen peroxide production and biomass upgrading

Abstract

The present invention provides an electrochemical reaction system for the simultaneous production of active hydrogen peroxide and the high-value processing of biomass, more specifically comprising: a first electrode comprising a layer of a bismuth-platinum mixed catalyst; a second electrode comprising a layer of an oxidized carbon nanotube catalyst; and an ion exchange membrane between the first electrode and the second electrode. Furthermore, an integrated system for the production of electrochemical compounds utilizing the electrochemical reaction system of the present invention may be further provided.

Description

Technology Field

[0001] The present disclosure relates to an electrochemical reaction system for the simultaneous production of active hydrogen peroxide and the high value-added processing of biomass, according to embodiments of the present disclosure. Background Technology

[0002] Recently, attempts have been made to develop electrochemical catalytic processes for the efficient production of high-value chemical products using biomass-extracted raw materials; in particular, glycerol is produced as an important byproduct in the biodiesel production process. Generally, the oxidation reaction of glycerol is studied primarily in heterogeneous catalysis using pressurized oxygen as the oxidant. Compounds such as glyceraldehyde (GAD), glyceric acid (GLA), and hydroxypyruvic acid (HPA) are known as selective oxidation products of glycerol. For example, these compounds have high industrial value as they can be converted into various products, such as cosmetic ingredients and polymer synthesis. However, there is a disadvantage in that product yield is poor due to a problem where selectivity decreases as the conversion rate increases. In addition, when operating a system for the glycerol oxidation reaction using external electrical or light energy generally produced from fossil fuels, environmentally unfriendly or large-scale issues arise. Therefore, there is an urgent need to develop methods to produce compounds such as the aforementioned oxidation reaction products efficiently, environmentally friendly, and at low cost through the selective oxidation of glycerol. The problem to be solved

[0003] According to one embodiment, the present invention aims to solve the aforementioned problems by providing an eco-friendly electrochemical reaction system capable of simultaneously producing sustainable active hydrogen peroxide and increasing the value of biomass using chemical energy without the aid of light energy or external electrical energy.

[0004] The present invention provides a method for producing a compound by electrochemical reaction, which involves the production of hydrogen peroxide and the addition of biomass using an electrochemical reaction system according to embodiments of the present invention.

[0005] The present invention provides an integrated system for producing a compound through hydrogen peroxide production and glycerol selective oxidative decomposition using an electrode system according to embodiments of the present invention.

[0006] However, the problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned problems will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0007] According to one embodiment, the electrochemical reaction system may comprise: a first electrode comprising a layer of a bismuth-platinum mixed catalyst; a second electrode comprising a layer of an oxidized carbon nanotube catalyst; and an ion exchange membrane between the first electrode and the second electrode.

[0008] According to one embodiment, the first electrode may be an oxidative active electrode for biomass-derived organic compounds, and the second electrode may be an oxygen reduction active electrode for hydrogen peroxide production.

[0009] According to one embodiment, the electrochemical reaction system may be bias-free and the electrochemical reaction system may be light energy irradiator-free.

[0010] According to one embodiment, the electrochemical reaction system may carry out an active electrocatalytic reaction in an environment where light energy is not irradiated and external electrical energy is not applied.

[0011] According to one embodiment, the first electrode may oxidize and decompose a biomass-derived organic compound through an electrocatalytic reaction and supply the generated electrons to the second electrode.

[0012] According to one embodiment, the biomass-derived organic compound is glycerol, and the first electrode may produce at least one or all of glyceraldehyde (GAD), glyceric acid (GLA), and hydroxypyruvic acid (HPA) as decomposition products through oxidative decomposition of glycerol.

[0013] According to one embodiment, the bismuth-platinum mixed catalyst is a Pt / C catalyst particle coated with bismuth, wherein the bismuth may be coated in an amount of 10% to 40% by weight relative to the total weight of Pt in the Pt / C catalyst.

[0014] According to one embodiment, the second electrode generates hydrogen peroxide, and the hydrogen peroxide may pass through the ion exchange membrane and be further used as an oxidizing agent for biomass-derived organic compounds in the first electrode region.

[0015] According to one embodiment, the oxidation-treated carbon nanotube may be oxidized by immersing the carbon nanotube in an acid solution at 70°C to 90°C for 20 to 50 hours.

[0016] According to one embodiment, the acid solution may be a nitric acid solution with a concentration of 50% to 70%.

[0017] According to one embodiment, the carbon nanotube has a diameter of 5 nm to 150 nm and a length of 0.5 μm to 150 μm, and the ratio of the length to the diameter of the carbon nanotube may be 10 to 60,000.

[0018] According to one embodiment, the ion exchange membrane may comprise a cation exchange membrane, an anion exchange membrane, or both.

[0019] According to one embodiment, the layer of the bismuth-platinum mixed catalyst and the layer of the oxidized carbon nanotube catalyst each further comprise a polymer electrolyte, wherein the polymer electrolyte is a perfluorinated sulfonic acid electrolyte, and the polymer electrolyte may be included in an amount of 0.01 to 10 parts by weight per 100 parts by weight of each catalyst.

[0020] According to one embodiment, the platinum content in the bismuth-platinum mixed catalyst may be 15 to 20 weight percent.

[0021] An integrated apparatus for producing an electrochemical compound according to one embodiment may include: a reaction unit comprising an electrochemical reaction system according to embodiments of the present invention; an oxygen gas supply unit; and a collection unit for individually separating and collecting the oxidative decomposition product of a biomass-derived organic compound produced at a first electrode of the electrochemical reaction system and hydrogen peroxide produced at a second electrode.

[0022] A method for producing an electrochemical compound according to one embodiment utilizes an electrochemical reaction system according to embodiments of the present invention and comprises: a step of oxidizing and decomposing a bios-derived organic compound by an electrocatalytic reaction at a first electrode; and a step of generating hydrogen peroxide by supplying oxygen gas at a second electrode; wherein the hydrogen peroxide passes through an ion exchange membrane to further oxidize and decompose the bios-derived organic compound in the electrolyte of the first electrode, and the oxidative decomposition of the bios-derived organic compound may proceed in an environment in which light energy and external electrical energy are not introduced.

[0023] According to one embodiment, the step of oxidatively decomposing the bios-derived organic compound may be carried out at a temperature of 40°C or lower. Effects of the invention

[0024] The present invention can provide an electrochemical reaction system capable of producing continuous, eco-friendly hydrogen peroxide through the enhanced oxidation performance of biomass-derived organic compounds (e.g., glycerol) by a bismuth-platinum mixed catalyst and the oxygen reduction reaction of an oxidized carbon nanotube (O-CNT) catalyst placed on a gas diffusion electrode. The electrochemical reaction system of the present invention can enable not only the oxidation of derived organic compounds (e.g., glycerol) but also the selective high-value addition of various organic materials that can be easily oxidized with the help of an oxidizing agent such as hydrogen peroxide. Brief explanation of the drawing

[0025] FIG. 1 is a schematic diagram of the simultaneous active hydrogen peroxide production and glycerol oxidation using an oxidized carbon nanotube and a bismuth-platinum mixed catalyst in an electrochemical reaction system of the present invention according to one embodiment. FIG. 2a is the ratio of bismuth (Bi) to Pt / C measured by XPS (X-ray photoelectron spectroscopy) of the catalyst synthesized in the example according to one embodiment. FIG. 2b compares the characteristic analysis and performance of a glycerol oxidation active electrocatalyst in an electrochemical reaction system of the present invention according to one embodiment. Figure 3 shows a comparison of the characteristics and performance of an oxygen reduction active electrocatalyst in an electrochemical reaction system of the present invention according to one embodiment. FIG. 4 shows experimental results illustrating the realization of an active high-value compound system and improved glycerol oxidation performance in the electrochemical reaction system of the present invention according to one embodiment. Figure 5 shows experimental results determining the glycerol oxidation efficiency according to the real-time use of hydrogen peroxide in the electrochemical reaction system of the present invention, according to one embodiment. Specific details for implementing the invention

[0026] Embodiments of the present invention will be described in detail below with reference to the attached drawings. In describing the present invention, specific descriptions of related known functions or configurations will be omitted if it is determined that such detailed descriptions may unnecessarily obscure the essence of the present invention. Furthermore, the terms used in this specification are used to appropriately express preferred embodiments of the present invention, and these may vary depending on the intentions of the user or operator, or the conventions of the field to which the present invention belongs. Accordingly, the definitions of these terms should be based on the content throughout this specification. Identical reference numerals in each drawing indicate identical components.

[0027] Throughout the specification, when it is stated that a component is located "on" another component, this includes not only cases where a component is in contact with another component, but also cases where another component exists between the two components.

[0028] Throughout the specification, when a part is described as "including" a certain component, this means that it does not exclude other components but may include additional components.

[0029] In this document, each of the phrases such as “A or B,” “at least one of A and B,” “at least one of A or B,” “A, B or C,” “at least one of A, B and C,” and “at least one of A, B, or C” may include any one of the items listed together in the corresponding phrase, or all possible combinations thereof. Terms such as “first,” “second,” or “first” or “second” may be used simply to distinguish a component from another component and do not limit the components in any other aspect (e.g., importance or order).

[0030] Hereinafter, the electrochemical reaction system of the present invention and its applications will be described in detail with reference to the embodiments and drawings. However, the present invention is not limited to these embodiments and drawings.

[0031] According to one embodiment, the electrochemical reaction system of the present invention may include a first electrode comprising a layer of a bismuth-platinum mixed catalyst; a second electrode comprising a layer of an oxidized carbon nanotube catalyst; and an ion exchange membrane between the first electrode and the second electrode.

[0032] According to one embodiment, the electrochemical reaction system of the present invention may enable the effective and continuous production of eco-friendly hydrogen peroxide and the high-value processing of biomass-derived organic compounds (e.g., glycerol) by utilizing chemical energy. Referring to FIG. 1, FIG. 1 is a schematic diagram of a process in which active hydrogen peroxide production and glycerol oxidation proceed simultaneously using an oxidized carbon nanotube and a bismuth-platinum mixed catalyst in the electrochemical reaction system of the present invention. The electrochemical reaction system may enable active hydrogen peroxide production and the oxidation activity of biomass-derived organic compounds (e.g., glycerol) by utilizing chemical energy without the addition of external electrical energy or / and light energy.

[0033] According to one embodiment, the first electrode is an oxidative active electrode for biomass-derived organic compounds and is a bismuth-platinum mixed catalyst (e.g., Bi) capable of efficiently oxidizing biomass-derived organic compounds. 1 / 3 Can include @Pt).

[0034] According to one embodiment, the bismuth-platinum mixed catalyst at the first electrode is a bismuth coated on Pt / C catalyst particles, wherein the bismuth may be included in an amount of 10% to 40% by weight; 10% to 30% by weight; 20% to 40% by weight; or 20% to 30% by weight relative to the total weight of Pt in the Pt / C catalyst. By applying the mentioned bismuth loading amount, the glycerol oxidation ability and stability can be improved. The bismuth-platinum mixed catalyst can be obtained by a chemical reduction method after mixing Pt / C catalyst particles and a bismuth precursor. This allows bismuth to be attached very uniformly to the surface of a commercial Pt / C catalyst and can induce effective glycerol oxidation. The bismuth-platinum mixed catalyst has a particle size of 50 nm to 300 nm, and the Pt loading amount may be 15% to 25% by weight. The above-described bismuth-platinum mixed catalyst can induce the oxidation of biomass-derived organic compounds (e.g., glycerol) and enable active hydrogen peroxide production by efficiently utilizing chemical energy. In the above-described bismuth-platinum mixed catalyst, the particle size of platinum (Pt) may be 1 nm to 5 nm; 1.5 nm to 5 nm; or 1.5 nm to 3 nm (this may be an average value).

[0035] According to one embodiment, the bismuth-platinum mixed catalyst at the first electrode can form a layer of catalyst with a thickness of 50 nm or more; 100 nm or more; 200 nm or more; 500 nm or more; or 1000 nm or more.

[0036] According to one embodiment, the first electrode may be an organic compound derived from biomass that comprises at least one, two or more, or all of a carbonyl group (-C=O), a carboxyl group (-COOH), and a hydroxyl group (-OH) within the molecule. For example, it may be at least one of formaldehyde, glycerol, and ethanol, and preferably glycerol. For example, the first electrode may produce at least one of lactic acid (LA), formic acid (FA), tartaric acid (TA), glyceraldehyde (GAD), glyceric acid (GLA), and hydroxypyruvic acid (HPA), or a combination thereof, as a degradation product through the oxidative decomposition of glycerol.

[0037] According to one embodiment, the first electrode can selectively control the oxidation site of a biomass-derived compound (e.g., glycerol) by utilizing hydrogen peroxide generated at the second electrode as an oxidizing agent. That is, this can increase the selectivity and conversion rate of high-value-addable decomposition products from the decomposition oxide of a biomass-derived compound (e.g., glycerol). Preferably, the selectivity of glyceraldehyde (GAD) and glyceric acid in the oxidative decomposition of glycerol can be increased.

[0038] According to one embodiment, the second electrode may be a gas diffusion electrode (GDE) comprising a layer of an oxidized carbon nanotube catalyst, which is an oxygen reduction active electrode for generating hydrogen peroxide. The second electrode can generate hydrogen peroxide by reducing dissolved oxygen gas (O2) using electrons supplied from the first electrode. This allows for the efficient generation of hydrogen peroxide through oxygen reduction by applying an oxidized carbon nanotube (O-CNT) which is an oxygen reduction active electrocatalyst.

[0039] According to one embodiment, the oxidized carbon nanotube (O-CNT) may be surface-oxidized by immersing the carbon nanotube in an acidic solution at 70°C to 90°C for 20 to 50 hours. The acidic solution may be a nitric acid solution with a concentration of 50% or more; 60% or more; or 50% to 70%. The carbon nanotube may have a diameter of 5 nm to 50 nm; 5 nm to 30 nm; or 5 nm to 15 nm and a length of 0.5 µm to 150 µm; 1 µm to 120 µm; or 10 µm to 100 µm. Additionally, the ratio of the carbon nanotube length to the diameter may be 10 to 60,000; 1,000 to 60,000; or 10,000 to 60,000. Alternatively, it may be 55,000 to 60,000. The carbon nanotubes may be multi-walled carbon nanotubes, such as single-walled or double-walled carbon nanotubes. Through this oxidation treatment, surface oxidation of the carbon nanotubes can be induced and interaction with oxygen can be enhanced. In addition, by introducing it into a gas diffusion electrode, the number of effective collisions with oxygen can be maximized.

[0040] According to one embodiment, the layer of the bismuth-platinum mixed catalyst and the layer of the oxidized carbon nanotube catalyst may each further comprise a polymer electrolyte. The polymer electrolyte may include a polymer electrolyte used in an ion exchange membrane, for example, Nafion, which is a perfluorinated sulfonic acid electrolyte. The polymer electrolyte may be included in an amount of 0.01 to 10 parts by weight; 0.05 to 5 parts by weight; or 0.05 to 2 parts by weight, per 100 parts by weight of each of the bismuth-platinum mixed catalyst and the oxidized carbon nanotube catalyst. By applying the polymer electrolyte, the stability and performance of each catalyst can be improved, and the performance of the electrochemical reaction system can be improved.

[0041] According to one embodiment, the electrochemical reaction system may be bias-free and / or light energy irradiator-free (e.g., solar lamp). This allows for the simultaneous oxidative decomposition of biomass-derived compounds at the first electrode and the production of hydrogen peroxide at the second electrode by utilizing chemical energy without the application of external electrical energy and / or light energy (solar energy) in the operation of the first electrode and the second electrode. That is, the electrochemical reaction system can continuously carry out an active electrocatalytic reaction in an environment without the introduction of external electrical energy and light energy.

[0042] According to one embodiment, the first electrode oxidatively decomposes a biomass-derived organic compound through an electrocatalytic reaction and supplies the generated electricity to the second electrode, and the second electrode can generate hydrogen peroxide through oxygen reduction. The hydrogen peroxide can pass through the ion exchange membrane and be further utilized as an oxidizing agent to further carry out the selective oxidative decomposition of the biomass-derived organic compound. This allows for the oxidative decomposition of the biomass-derived organic compound (e.g., glycerol) remaining at the first electrode and increases the selectivity of the oxidation reaction to obtain a decomposition product of high economic value.

[0043] According to one embodiment, the ion exchange membrane allows hydrogen peroxide generated at the second electrode to pass through and be supplied to the first electrode, and the ion exchange membrane may include a cation exchange membrane, an anion exchange membrane, or both. Preferably, it may include an anion exchange membrane. The permeability of hydrogen peroxide (e.g., permeability or permeation rate) can be controlled by applying a ratio of the cation exchange membrane and the anion exchange membrane. This utilizes the fact that hydrogen peroxide exists as an anion in a basic environment, and appropriate permeation can aid in glycerol oxidation, enabling high selectivity and high addition.

[0044] According to one embodiment, the ion exchange membrane may be applied without limitation as long as it is applicable to the electrochemical reaction system of the present invention, for example, the anion exchange membrane may comprise at least one of Selemion and Piperion, and the cation exchange membrane may comprise a sulfonated hydrocarbon polymer such as Nafion.

[0045] According to one embodiment, the present invention may provide a method for producing an electrochemical compound using an electrochemical reaction system according to embodiments of the present invention. The method may include the step of oxidatively decomposing a bios-derived organic compound by an electrocatalytic reaction at a first electrode; and the step of generating hydrogen peroxide by an electrocatalytic reaction by supplying oxygen gas at a second electrode. For example, referring to FIG. 1, FIG. 1 is a schematic diagram of a process in which active hydrogen peroxide production and glycerol oxidation proceed simultaneously using an oxidized carbon nanotube and a bismuth-platinum mixed catalyst in an electrochemical reaction system of the present invention. By utilizing high-efficiency, high-stability catalysts for each reaction, the oxidative decomposition of glycerol and active hydrogen peroxide are generated, and high-selectivity high-addition of glycerol can be achieved by utilizing the oxidation ability of hydrogen peroxide. The above method for producing the electrochemical compound may further utilize the generated hydrogen peroxide as an oxidizing agent, which allows the hydrogen peroxide to pass through an ion exchange membrane and oxidatively decompose biomass-derived organic compounds (e.g., glycerol) within the electrolyte of the first electrode. Through this process, sustainable active hydrogen peroxide production and highly selective high-value-added production through the oxidative decomposition of biomass organic compounds can be carried out simultaneously. Furthermore, the oxidative decomposition of the biomass-derived organic compounds and the generation of hydrogen peroxide may proceed in an environment without the introduction of external electrical energy and / or light energy.

[0046] According to one embodiment, the step of oxidatively decomposing the bios-derived organic compound may be carried out at a temperature of 40°C or lower; 30°C or lower; or room temperature (rt).

[0047] According to one embodiment, the present invention may provide an integrated device utilizing an electrochemical reaction system according to embodiments of the present invention. The integrated device collects and processes products from the oxidative decomposition of biomass-derived organic compounds and hydrogen peroxide. The integrated device may include a reaction unit comprising an electrochemical reaction system according to embodiments of the present invention; an oxygen gas supply unit; and a collection unit for individually separating and collecting the oxidative decomposition product of biomass-derived organic compounds produced at a first electrode of the electrochemical reaction system and the hydrogen peroxide produced at a second electrode.

[0048] According to one embodiment, the electrochemical reaction system in the integrated apparatus comprises a first electrode comprising a layer of the aforementioned bismuth-platinum mixed catalyst; a second electrode comprising a layer of an oxidized carbon nanotube catalyst; and an ion exchange membrane between the first electrode and the second electrode, and can provide a highly selective oxidative decomposition process by obtaining a high-value product through the oxidative decomposition of a biomass-derived organic compound (e.g., glycerol), generating hydrogen peroxide, and further utilizing the hydrogen peroxide as an oxidizing agent for the oxidative decomposition of the biomass-derived organic compound.

[0049] According to one embodiment, the collection unit separates and collects compounds generated in the first electrode region and the second electrode region, respectively, and various oxidative decomposition products of the first electrode region can be obtained by each substance using generally known purification or separation techniques for organic compounds.

[0050] The present invention will be explained in more detail below through examples and comparative examples. However, the following examples are merely illustrative of the present invention, and the scope of the present invention is not limited to the following examples.

[0051] Examples

[0052] Synthesis of glycerol oxidation active electrocatalyst

[0053] Bi (1 / x) @Pt's composite

[0054] A chemical reduction method was used for the synthesis of Bi(1 / x)@Pt. First, predetermined amounts of Pt / C (20 wt%, 500 mg), deionized water (250 mL), and nitric acid (10 M, 0.15 mL) were added to a 600 mL beaker. Next, the mixed solution was vigorously stirred for 12 hours. Subsequently, Bi in Bi(NO3)3·5H2O 3+( 100 mg) and nitric acid (5 M, 50 mL) were added, and then stirred for an additional 30 minutes in a 600 mL beaker. Here, 100 mg, 33.3 mg, and 8.33 mg of Bi 3+ Bi(1 / 1)@Pt, Bi(1 / 3)@Pt, and Bi(1 / 18)@Pt were obtained, respectively, by adding them to the mixed solution. Next, potassium hydroxide (8 M, approx. 30 mL) was added to neutralize the mixed solution (pH range = approx. 7-10), and NaBH4 (0.05 M, 50 mL) was slowly added dropwise to uniformly reduce the bismuth species on the Pt / C phase. Finally, the product was filtered, washed several times with water, and vacuum dried at 25 °C.

[0055] The chemical reduction method was used for the synthesis of Bi(1 / x)@Pt. First, a predetermined amount of carbon (Vulcan XC-72R, 400 mg), 100 mg of platinum (as H2PtCl6), deionized water (250 mL), and nitric acid (10 M, 0.15 mL) were added to a 600 mL beaker. Then, the mixed solution was vigorously stirred for 12 hours. Next, Bi3+ 33.3 mg (of Bi(NO3)3) was added and stirred for an additional 30 minutes. Next, potassium hydroxide (8 M, approx. 30 mL) was added to neutralize the mixed solution (pH range = approx. 7-10), and NaBH4 (0.05 M, 50 mL) was slowly added dropwise to homogeneously reduce the bismuth species in Pt / C. Finally, the product was filtered, washed several times with water, and vacuum dried at 25 °C.

[0056] Figure 2a shows the ratio of bismuth (Bi) to Pt / C measured by XPS (X-ray photoelectron spectroscopy). Bi (1 / x) @Pt (x = 1, 3, 18) is the Bi cluster loaded into Pt / C, and x is the ratio of Bi to Pt (w / w). Also, Pt / C, Bi (1 / 18) @Pt, Bi (1 / 3) @Pt and Bi (1 / 1) In @Pt, Pt is 20 wt%, 19.7 wt%, 18.4 wt%, and 16.3 wt%, respectively. The particle size of the Pt nanoparticles is 2.5 nm to 3.0 nm.

[0057] Anode preparation

[0058] 5 mg of Bi(1 / x)@Pt catalyst and 10 μl of Nafion solution were dispersed in 1 mL of ethanol by sonication for at least 30 minutes to form a uniform ink. Then, the catalyst ink was prepared with a cross-sectional area of ​​1 x 1 cm 2 It was loaded onto phosphorus hydrophilic carbon paper and dried in the ambient atmosphere. The obtained mass loading was 0.5 mg cm⁻³ geo -2 am.

[0059] Preparation of oxidized CNTs (O-CNTs)

[0060] Multiwalled CNTs (MWCNTs) were oxidized by a commonly known acid treatment. First, 400 mg of MWCNTs and 400 mL of nitric acid (60 wt%) were added to a 500 mL three-necked round-bottom glass flask. Next, the flask was fitted with a magnetic stirrer and a thermometer and placed in a temperature control unit within a reflux system. The temperature was maintained at 80 °C for 48 hours, after which the slurry was cooled to room temperature (approx. 25 °C), poured, filtered, and washed several times with distilled water until a neutral pH was reached. Finally, the sample was dried overnight in a vacuum oven at 60 °C.

[0061] Cathode manufacturing

[0062] A uniform ink was formed by dispersing 1 mg of O-CNT catalyst and 10 μl of Nafion solution in 1 mL of ethanol by sonication for at least 30 minutes. Next, the catalyst ink was loaded onto hydrophobic carbon paper (Sigracet 39BB) with an area of ​​1 x 1 cm 2 It was used as a phosphorus gas diffusion layer and dried in the ambient atmosphere. The obtained mass loading was 0.1 mg cm⁻³. -2 am.

[0063] Electrochemistry experiment

[0064] Electrochemical measurements of the half-cell were performed in a standard three-electrode system with an anode and a cathode separated by a Nafion 117 membrane (DuPont). Pt mesh (1 x 1 cm) 2Hg / HgO and V(V) were used as counter and reference electrodes. All potentials for the Hg / HgO electrode were measured and converted to the RHE reference scale by the equation E(V vs. RHE) = E(V vs. Hg / HgO) + 0.0592 × pH + 0.118. The Nafion 117 membrane was pretreated with distilled water for approximately 2 hours to allow for sufficient expansion. For the glycerol oxidation half-cell, Pt-based materials (Pt / C, Bi(1 / 18)@Pt, Bi(1 / 3)@Pt, and Bi(1 / 1)@Pt) were used. During glycerol oxidation, the anode solution was stirred using a magnetic rod. For the oxygen reduction half-cell, O-CNT was used, and high-purity O2 (99.995%) was continuously supplied to the cathode compartment during oxygen reduction. Electrochemical measurements of the entire cell were performed in a standard two-electrode system with a cathode and anode separated by Nafion and Selemion, and no membrane was used. All potentials in this study were measured relative to the counter electrode.

[0065] Figure 2b shows the characterization and performance of the glycerol oxidation electrocatalyst. In Figure 2b (a), the active site can be maximized by uniformly depositing bismuth on top of Pt / C. In Figure 2b (b), it can be observed that the oxidation number of Pt changes as the amount of bismuth increases. In Figure 2b (c), if the amount of bismuth is excessive, O L It can be observed that the proportion increases. In other words, it can be confirmed that there is bismuth that aggregates with a lattice structure. In Fig. 2b (d), it can be seen that glycerol oxidation ability and stability are improved when an appropriate amount of bismuth is added. In Figs. 2b (f), (g), and (h), Bi (1 / 3)The cause of the performance and stability differences between @Pt and Pt / C was identified, and it was found that carbon monoxide is generated during glycerol oxidation in Pt / C, which can cause catalyst poisoning. Additionally, the COO- functional groups generated during glycerol oxidation in (g) and (h) of Fig. 2b are Bi (1 / 3) It can be confirmed that a faster onset voltage is observed at @Pt.

[0066] Figure 3 shows the analysis and performance of the oxygen reduction electrocatalyst. In Figures 3 (a) and (b), it can be confirmed that the bulk tube shape does not change before and after oxidation treatment. Additionally, in Figure 3 (c), it can be confirmed that their crystallinity does not change. However, a clear difference in the presence or absence of oxygen elements on their surface is observed (Figure 3 (d)). Furthermore, in Figure 3 (e), the I of the O-CNT D / I G The increase in the ratio indicates that surface defects can be identified. This confirms the presence of oxygen-containing functional groups (Fig. 3(f)). In other words, since functional group-carbon bonds are weaker than carbon-carbon bonds in carbon nanotubes, they decompose at low temperatures. As shown in Figs. 3(g) and (h), when a gas diffusion electrode (GDE) is applied, it can be observed that performance is significantly improved compared to the oxygen reduction reaction using dissolved oxygen. In addition, stability in a basic environment was confirmed (Fig. 3(i)).

[0067] Figure 4 shows measurement results to identify the causes of the realization of an active high-value compound system and enhanced glycerol oxidation performance in the electrochemical reaction system of the present invention. In Figures 4 (a), (b), and (c), it was experimentally demonstrated that continuous active production of high-value compounds is possible by connecting the glycerol oxidation electrocatalyst and the oxygen reduction catalyst. In Figure 4 (d), the electrochemical reaction system of the present invention realizes an active hydrogen peroxide production system, which demonstrates the highest fuel production rate among systems developed to date. Furthermore, through Density Functional Theory (DFT), Bi (1 / 3) It was confirmed whether the glycerol oxidation performance of @Pt is superior to that of Pt / C.

[0068] Figure 5 evaluates the efficiency of glycerol oxidation according to the real-time utilization of hydrogen peroxide in the electrochemical reaction system of the present invention. In Figure 5(a), hydrogen peroxide is an anion (HO2) in a basic environment. -Since it exists as ), the membrane can be moved using charge characteristics. The membranes used in this embodiment are a cation exchange membrane (CEM) and an anion exchange membrane (AEM), and an environment without an exchange membrane (NoM) was also fabricated and evaluated. In Fig. 5(b), it can be seen that there is no significant change in system stability regardless of which exchange membrane is used in the electrochemical reaction system of the present invention. However, in Fig. 5(c), it can be seen that the amount of hydrogen peroxide remaining at the end differs depending on the experimental environment related to the exchange membrane. This suggests that the hydrogen peroxide was consumed or decomposed in some way depending on the experimental environment. In Fig. 5(d), it can be seen that the selectivity of glycerol oxide in the residual solution after the experiment differs significantly depending on the experimental environment related to the presence or absence of the exchange membrane and the type of exchange membrane in each electrochemical reaction system. Consequently, if AEM is used to enable it to function as a suitable oxidizing agent, a highly selective glycerol oxidation reaction occurs at the oxidation electrode, and significant economic profit can be obtained (Fig. 5 (e)).

[0069] The present invention relates to Bi with excellent glycerol oxidation performance. (1 / 3) By introducing a Pt catalyst and an oxidation-treated carbon nanotube catalyst into a gas diffusion electrode, an electrochemical reaction system capable of simultaneously carrying out active hydrogen peroxide generation and glycerol oxidation can be provided.

[0070] The present invention relates to oxidized carbon nanotubes (O-CNT) capable of efficiently generating hydrogen peroxide through oxygen reduction and a bismuth-platinum mixed catalyst (Bi) capable of efficiently oxidizing glycerol, a representative biomass. 1 / 3By utilizing @Pt), an active high-value compound production system capable of efficiently utilizing chemical energy can be provided. The hydrogen peroxide produced within the system can operate as a real-time eco-friendly oxidizing agent by appropriately exchanging the ion exchange membrane in the center, and can improve the selectivity of high-value compounds for glycerol oxidation.

[0071] Although the embodiments have been described above with reference to limited examples and drawings, those skilled in the art can make various modifications and variations from the description above. For example, suitable results may be achieved even if the described techniques are performed in a different order than described, and / or the described components are combined or assembled in a form different from described, or replaced or substituted by other components or equivalents. Therefore, other implementations, other embodiments, and equivalents to the claims below are also within the scope of the claims.

Claims

Claim 1 An electrochemical reaction system comprising: a first electrode comprising a layer of a bismuth-platinum mixed catalyst; a second electrode comprising a layer of an oxidized carbon nanotube catalyst; and an ion exchange membrane between the first electrode and the second electrode; wherein the first electrode is an oxidative active electrode for biomass-derived organic compounds, the second electrode is an oxygen reduction active electrode for hydrogen peroxide generation, and the first electrode oxidatively decomposes biomass-derived organic compounds through an electrocatalytic reaction and supplies the generated electrons to the second electrode. Claim 2 delete Claim 3 An electrochemical reaction system according to claim 1, wherein the electrochemical reaction system is bias-free and the electrochemical reaction system is light energy irradiator-free. Claim 4 An electrochemical reaction system according to claim 1, wherein the electrochemical reaction system conducts an active electrocatalytic reaction in an environment where light energy is not irradiated and external electrical energy is not applied. Claim 5 delete Claim 6 An electrochemical reaction system according to claim 1, wherein the biomass-derived organic compound is glycerol, and the first electrode produces at least one or all of glyceraldehyde (GAD), glyceric acid (GLA), and hydroxypyruvic acid (HPA) as decomposition products through the oxidative decomposition of glycerol. Claim 7 An electrochemical reaction system according to claim 1, wherein the bismuth-platinum mixed catalyst is formed by coating bismuth onto Pt / C catalyst particles, wherein the bismuth is coated in an amount of 10% to 40% by weight relative to the total weight of Pt in the Pt / C catalyst. Claim 8 An electrochemical reaction system according to claim 1, wherein the second electrode generates hydrogen peroxide, and the hydrogen peroxide passes through the ion exchange membrane and is further used as an oxidizing agent for biomass-derived organic compounds in the first electrode region. Claim 9 An electrochemical reaction system according to claim 1, wherein the oxidized carbon nanotube is oxidized by immersing the carbon nanotube in an acidic solution at 70°C to 90°C for 20 to 50 hours. Claim 10 An electrochemical reaction system according to claim 9, wherein the acid solution is a nitric acid solution with a concentration of 50% to 70% (weight%). Claim 11 An electrochemical reaction system according to claim 9, wherein the carbon nanotubes have a diameter of 5 nm to 150 nm and a length of 0.5 μm to 150 μm, and the ratio of the length to the diameter of the carbon nanotubes is 10 to 60,000. Claim 12 An electrochemical reaction system according to claim 1, wherein the ion exchange membrane comprises a cation exchange membrane, an anion exchange membrane, or both. Claim 13 An electrochemical reaction system according to claim 1, wherein the layer of the bismuth-platinum mixed catalyst and the layer of the oxidized carbon nanotube catalyst each further comprise a polymer electrolyte, wherein the polymer electrolyte is a perfluorinated sulfonic acid electrolyte, and the polymer electrolyte is included in an amount of 0.01 to 10 parts by weight per 100 parts by weight of each catalyst. Claim 14 An electrochemical reaction system according to claim 1, wherein the platinum content of the bismuth-platinum mixed catalyst is 15 to 20 weight%. Claim 15 An integrated apparatus for the production of electrochemical compounds, comprising: a reaction unit including an electrochemical reaction system of claim 1; an oxygen gas supply unit; and a collection unit for individually separating and collecting the oxidative decomposition product of a biomass-derived organic compound generated at a first electrode of the electrochemical reaction system and hydrogen peroxide generated at a second electrode. Claim 16 A method for producing an electrochemical compound using the electrochemical reaction system of claim 1, comprising: a step of oxidizing and decomposing a biomass-derived organic compound by an electrocatalytic reaction at a first electrode; and a step of generating hydrogen peroxide by supplying oxygen gas at a second electrode; wherein the hydrogen peroxide passes through an ion exchange membrane to further oxidize and decompose the biomass-derived organic compound in the electrolyte of the first electrode, and the oxidative decomposition of the biomass-derived organic compound proceeds in an environment in which light energy and external electrical energy are not introduced. Claim 17 A method for producing an electrochemical compound according to claim 16, wherein the step of oxidizing and decomposing the biomass-derived organic compound is carried out at a temperature of 40°C or lower.

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