CN112609199A - Electrocatalysis H2O2Solution preparation method and device - Google Patents

Abstract

Translated fromChinese

本发明公开了一种电催化H₂O₂溶液制备方法及装置，该制备方法包括以下步骤：(1)将水在阳极进行电解，产生H⁺和O₂，将氧气在阴极电解，得到HO^2–；(2)H⁺和HO^2–分别通过阳离子交换膜和阴离子交换膜进入固体电解质层中直接合成H₂O₂；(3)在固体电解质层中通入水，利用水将H₂O₂带出；该装置包括阳极、阴极和储存罐，阳极与阴极之间设置有固体电解质层，储存罐接在固体电解质层上，阳极内部依次为阳极流道、阳极集流板、气体扩散层、阳极催化层、阳离子交换膜，IrO₂/GCN阳离子交换膜紧贴固体电解质层表面紧密贴合。该制备方法原料为水和氧气，不添加有机溶剂，制备过程绿色环保，能够直接生成高浓度的过氧化氢，不进行提纯，降低制备过程的危险性。

The invention discloses a method and device for preparing an electrocatalytic H₂ O₂ solution. The preparation method includes the following steps: (1) electrolyzing water at an anode to generate H⁺ and O₂ , and electrolyzing oxygen at a cathode to obtain HO^2– ; (2) H⁺ and HO^2– enter the solid electrolyte layer through the cation exchange membrane and anion exchange membrane respectively to directly synthesize H₂ O₂ ; (3) Pour water into the solid electrolyte layer, and use water to convert H₂ O_2. Take out; the device includes an anode, a cathode and a storage tank, a solid electrolyte layer is arranged between the anode and the cathode, the storage tank is connected to the solid electrolyte layer, and the inside of the anode is followed by an anode flow channel, an anode current collector, and a gas diffusion layer. , anode catalytic layer, cation exchange membrane, IrO₂ /GCN cation exchange membrane closely adhered to the surface of the solid electrolyte layer. The raw materials of the preparation method are water and oxygen, no organic solvent is added, the preparation process is green and environmentally friendly, high-concentration hydrogen peroxide can be directly generated without purification, and the risk of the preparation process is reduced.

Description

ElectrocatalysisH2O2Solution preparation method and device

Technical Field

The invention relates to a method for producing H₂O₂Solution preparation method and device, more specifically relates to electrocatalytic H₂O₂A method and apparatus for preparing a solution.

Background

Hydrogen peroxide H₂O₂Hydrogen peroxide, also known as hydrogen peroxide, is a raw material or product suitable for various industrial applications, and the aqueous solution of the hydrogen peroxide has strong oxidizing property and is suitable for medical use, food and environmental disinfection. Furthermore, hydrogen peroxide plays a key role in the semiconductor industry as a wafer cleaner and is used as an epoxidation reagent for the production of propylene oxide by the hydrogen peroxide to propylene oxide HPPO process. The traditional preparation method of hydrogen peroxide is anthraquinone method for producing hydrogen peroxide H₂O₂This process typically produces a hydrogen peroxide mixture at a concentration of 1 wt% to 2 wt%. The method comprises the following steps of reacting 2-ethyl anthraquinone EAQ with hydrogen at a certain temperature and under a certain pressure under the action of a catalyst to generate 2-ethyl hydrogen anthraquinone, carrying out oxidation reduction reaction on the 2-ethyl hydrogen anthraquinone and oxygen at a certain temperature and under a certain pressure, reducing the 2-ethyl hydrogen anthraquinone to generate 2-ethyl anthraquinone and simultaneously generate hydrogen peroxide, extracting to obtain a hydrogen peroxide aqueous solution, and purifying by heavy aromatics to obtain the qualified hydrogen peroxide aqueous solution. This process is not only relatively complex and has low yield, but also requires further expensive purification and distillation to achieve concentrations suitable for commercial use. The whole process requires a centralized infrastructure, and therefore, transportation and storage of the hydrogen peroxide solution present safety hazards.

Disclosure of Invention

The purpose of the invention is as follows: the invention aims to provide the electrocatalytic H with safe preparation process and high concentration of prepared products₂O₂The invention also provides a device used in the preparation method.

The technical scheme is as follows: electrocatalytic process according to the invention₂O₂The solution preparation method comprises the following steps:

(1) electrolyzing water at the anode to produceH⁺And O₂Oxygen is cathodically electrolyzed to give HO^2–；

(2)H⁺And HO^2–Directly synthesizing H in the solid electrolyte layer through the cation exchange membrane and the anion exchange membrane respectively₂O₂；

(3) Introducing water into the solid electrolyte layer, and introducing H into the solid electrolyte layer by using the water₂O₂And (6) taking out.

Wherein water is electrolyzed under acidic conditions of pH 2-4, and O is generated after water electrolysis₂Introducing cathode for electrolysis, wherein the catalytic layers used by the anode and the cathode are respectively IrO₂a/GCN heterogeneous layer and a cationic surfactant treated oxidized carbon black OCB catalyst layer; in thestep 2, the cation exchange membrane and the anion exchange membrane are respectively a Nafion 177 membrane and a Nafion 177 membrane

X37-50Grade 60 film.

Electrocatalytic process according to the invention₂O₂The device used in the solution preparation method comprises an anode, a cathode and a storage tank, wherein a solid electrolyte layer is arranged between the anode and the cathode, and the storage tank is connected on the solid electrolyte layer.

The anode comprises an anode collector plate, a gas diffusion layer, an anode catalyst layer and a cation exchange membrane, wherein the inside of the anode is sequentially provided with the anode collector plate, the gas diffusion layer, the anode catalyst layer and the cation exchange membrane, the cation exchange membrane is tightly attached to the surface of the solid electrolyte layer, the anode catalyst layer and the solid electrolyte layer are kept airtight, an anode flow channel is arranged on the anode collector plate and comprises a water inlet flow channel, a water outlet flow channel and an oxygen outlet, acid water is introduced into the water inlet flow channel₂the/GCN heterogeneous layer is a graphitized carbon nitride GCN nanosheet and IrO₂The cathode of the synthesized heterostructure layer is sequentially provided with a cathode collector plate, a gas diffusion layer, a cathode catalyst layer and an anion exchange membrane, the cathode catalyst layer is an oxidized carbon black cathode catalyst layer, a gas flow channel is arranged on the cathode collector plate and comprises a gas inlet flow channel and a gas outlet flow channel, the anion exchange membrane is tightly attached to the solid electrolyte layer, the cathode catalyst layer and the solid electrolyte layer are kept sealed, and the solid electrolyte layer is arranged between the cathode catalyst layer and the solid electrolyte layerThe bottom of the electrolyte layer is provided with a water inlet, the upper end of the electrolyte layer is connected with a storage tank through a water outlet, the solid electrolyte layer is a porous styrene-divinylbenzene sulfonated copolymer with the aperture of 50-300 mu m, the anode and the cathode are powered through a solar power supply system, the solar power supply system comprises a solar panel, a rectifier connected with the solar panel and a storage battery connected with the rectifier, and the storage battery is respectively connected with the anode and the cathode.

The working principle is as follows: the gas diffusion layer provides a gas channel for electrode reaction, plays the roles of supporting a catalyst layer and stabilizing an electrode structure, establishes a bridge from the millimeter scale of a gas flow channel to the nanometer scale of a catalyst, and respectively leads a reactant H to be generated when hydrogen peroxide is prepared₂O and O₂Respectively introducing into gas diffusion layer, introducing into functionalized electrode layer containing oxygen evolution reaction and oxygen reduction catalyst, while maintaining sulfuric acid water solution circulation at anode side, and introducing into gas diffusion layer₂O is electrolyzed under acidic condition to generate H⁺And O₂Humidification oxygen O is injected into the cathode side₂Is reduced to HO^2–Generation of H⁺And HO^2-Then respectively enters the porous solid electrolyte of the central part through the cation exchange membrane and the anion exchange membrane to react to generate H₂O₂Then the water is taken out by the deionized water flow of the middle layer; the oxidation reaction at the anode side is more easily catalyzed by the electrocatalysis and reacted with the cathode 2e^–ORR coupling, the all-solid-state electrolyte can prevent the interference of foreign ions in the electrolyte, eliminate the influence of pH change and other side reactions on the purity of the hydrogen peroxide solution, meanwhile, the porous structure of the solid electrolyte is favorable for ion transmission, and after the porous structure is subjected to sulfonation hydrophilic modification, H can be further improved⁺And OOH^-The ion transmission speed shows the obvious advantages of small internal ohmic loss and high yield after the fast combination of the anions and the cations, and simultaneously, the solar energy is coupled with the hydrogen peroxide production device, and the hydrogen peroxide production device can obtain the hydrogen peroxide with the lower voltage of only 2.5V₂Easier and safer H⁺Therefore, the prepared hydrogen peroxide has higher purity and higher speed, and the preparation process and the storage process are safer; the graphitized carbon nitride has a unique C site, and particularly, the graphitized carbon nitride is induced by a coordination environment rich in NIrO₂And GCN, the electron structure of the Ir active site with low coordination number is finally adjusted, the excellent OER performance is shown under the acidic condition, the chemical stability is extremely high to prevent corrosion and oxidation, and the IrO is selected as the anode catalyst layer₂the/GCN heterogeneous layer can ensure the production of H + at the anode.

Has the advantages that: compared with the prior art, the invention has the following remarkable advantages: 1. the raw materials are water and oxygen, the hydrogen peroxide is prepared by electrolysis, no organic solvent is added, and the preparation process is green and environment-friendly; 2. can directly generate high-concentration hydrogen peroxide without purification, thereby reducing the risk.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic view of the structure of an anode current collecting plate;

FIG. 3 is a schematic diagram of a cathode current collector structure;

FIG. 4 is a hydrogen peroxide selectivity test chart;

fig. 5 is a current-voltage graph of the present invention.

Detailed Description

Electrocatalytic H as shown in FIG. 1₂O₂The solution preparation device comprises an anode, a cathode and a storage tank 13, wherein a solid electrolyte layer 14 is arranged between the anode and the cathode, and an anode current collecting plate 16, a gas diffusion layer 3 and IrO are sequentially arranged in the anode₂a/GCN anode catalyst layer 4 and a cation exchange membrane 5, wherein the cation exchange membrane 5 is tightly attached to the surface of the solid electrolyte layer 14, an anode flow channel is arranged on the anode collector plate 16, and the cation exchange membrane 5 is tightly attached to the solid electrolyte layer 14 to keep IrO₂The anode catalyst layer 4 and the solid electrolyte layer 14 of the/GCN are relatively sealed, the cathode is internally provided with a cathode collector plate 17, a gas diffusion layer 3, an OCB cathode catalyst layer 11 and an anion exchange membrane 12 in sequence, the anion exchange membrane 12 is tightly attached to the surface of the solid electrolyte layer 14, a gas flow channel is arranged on the cathode collector plate 17, the anion exchange membrane 12 is tightly attached to the solid electrolyte layer 14, the OCB cathode catalyst layer 11 and the solid electrolyte layer 14 are kept relatively sealed, and the cation exchange membrane 5 and the anion exchange membrane 12 are respectively a Nafion 177 membrane and are respectively arranged on the solid electrolyte layer 14

An X37-50Grade 60 membrane, wherein a solid electrolyte layer 14 is a porous styrene-divinylbenzene sulfonated microsphere copolymer with the aperture of 100 μm, a gas diffusion layer 3 is a commercial Sigracet 36BB GDL electrode, the bottom of the solid electrolyte layer 14 is provided with a water inlet 15, the upper end of the solid electrolyte layer is connected with a storage tank 13 through a water outlet, an anode and a cathode are powered by a solar power supply system, the solar power supply system comprises a solar panel 1, a rectifier 2 connected with the solar panel 1 and a storage battery 18 connected with the rectifier 2, the storage battery 18 is respectively connected with the anode and the cathode, the gas diffusion layer 3 is a commercial Sigracet 35BC GDL electrode, a gas channel is provided for electrode reaction, a catalyst layer and a stable electrode structure are supported, as shown in figure 2, an anode current collecting plate 16 is a titanium alloy plate, and the anode current channel comprises a water inlet flow channel 6; as shown in fig. 3, the cathode collector plate 17 is a titanium alloy plate, the cathode flow channel includes an inlet flow channel 9 and an outlet flow channel 10, and the surface of the OCB cathode catalyst layer 11 is surface-activated by CTAB cations; IrO₂The preparation processes of the/GCN anode catalyst layer 4, the OCB cathode catalyst layer 11 and the solid electrolyte layer 14 are as follows:

(1)IrO₂/GCNanode catalyst layer 4

1.0g of melamine was placed in a muffle furnace at 3 ℃ for min^-1Heating at 550 ℃ for 2h, cooling to room temperature in a furnace to obtain massive Graphitized Carbon Nitride (GCN), immersing the synthesized massive GCN in 6M HCl, performing ultrasonic treatment for 1h, stirring at room temperature for 6h, centrifugally collecting functionalized GCN nanosheets, washing with deionized water, and drying at 60 ℃ to obtain GCN nanosheets; adding 7mg of K to 30ml of deionized water₂IrCl₆And 10mg of GCN nanoplatelets, the mixture was heated to 80 ℃ and continuously stirred for 6 hours, and then transferred to a 50ml stainless steel autoclave and maintained at 180 ℃ for 4 hours. The resulting product was collected by centrifugation and rinsed several times with deionized water. The final sample was dried at 80 ℃ and then annealed in air at 350 ℃ for 2h to obtain IrO₂a/GCN heterogeneous layer.

(2) OCBcathode catalyst layer 11

And dispersing the oxidized carbon black OCB in a 1 wt% PAA solution for 30 minutes for PAA modification to form a cationic surface activity treated oxidized carbon black cathode material.

(3)Solid electrolyte layer 14

Swelling the styrene-divinylbenzene copolymer microspheres by using a swelling agent 1, 2-dichloroethane, adding concentrated sulfuric acid, respectively carrying out sulfonation reaction for 3 hours at 110 ℃, washing with acetone to remove 1, 2-dichloroethane after the reaction is finished, finally washing with deionized water until the filtrate is neutral, and drying to obtain the porous styrene-divinylbenzene sulfonated microsphere copolymer.

When in use, the reactants respectively contain H of sulfuric acid₂O and O₂H containing sulfuric acid is introduced into the anodeinlet flow passage 6 and the cathode inlet flow passage 9₂O enters thegas diffusion layer 3 from the waterinlet flow passage 6, and the wet oxygen enters thegas diffusion layer 3 through the gasinlet flow passage 9 and then respectively enters IrO₂The anode catalytic layer and the OCB cathode catalytic layer of the/GCN anode are kept for 1.5mL min at the anode side in the process^-1Circulation of the aqueous sulfuric acid solution at 0.5M, H₂O is electrolyzed under acidic condition to generate H⁺And O₂The following reaction takes place:

H₂o electrolysis reaction OER: 2H₂O–4e^-→4H⁺+O₂

H⁺Through the cation exchange membrane into thesolid electrolyte layer 14, O₂The oxygen flows out through anoxygen outlet 8, the oxygen can also be introduced into the cathode for utilization, and the water flows out through a wateroutlet flow passage 7.

The cathode side was injected with humidified oxygen of 50sccm, O₂Is reduced to HO^2–The following reaction takes place:

2e^–O₂reduction reaction 2e^–-ORR：O₂+H₂O+2e^–→HO^2–+OH^–

The residual oxygen flows out through the airoutlet flow passage 10, and the generated HO^2-Thesolid electrolyte 14 is introduced into the central portion through the anion exchange membrane, and thesolid electrolyte 14 reacts to produce H₂O₂，

H₂O₂The synthesis reaction of (1): HO^2–+H⁺→H₂O₂

Last H₂O₂Taken off by the flow of deionized water of the intermediate layer H₂O₂The solution flows to thestorage tank 13 for storage.

As shown in FIG. 4, under a potential window of 0.3-0.5V, the activated carbon black OCB catalyst layer has greatly improved hydrogen peroxide selectivity and H is greatly improved relative to carbon black CB and unactivated carbon black OCB₂0₂The percent is more than 90 percent, which is caused by that the surface-activated oxidized carbon black OCB catalyst layer has increased-C ═ O and C-OO-functional groups and surface-C ═ O and-COO^-The radicals are the drivers of peroxide generation, leading to H₂O₂The selectivity of (A) is greatly improved. As shown in FIG. 5, raw CB showed a typical two-step ORR in alkaline medium, the first step (0.4-0.8V)_RHE) On the ring plate there is mainly an oxygen peroxide reduction followed by a ring hydrogen peroxide to hydroxide re-reduction step (<0.35V_RHE). These distinguishing features can be obtained by the ring current density j of the hydrogen peroxide generation step on the ring disk_RIncrease of (d) and disc current density j in the hydrogen peroxide decomposition step_DIs observed. When the surfactants are oppositely charged after the addition of the ionic surfactant, the profile changes significantly while the initial potential remains unchanged, i.e., reaction activation is not affected.

Constant voltage 2.13V was applied by solar cell, by potassium permanganate titration and H₂O₂The invention provides a standard test paper colorimetric method, and the standard test paper colorimetric method is used for preparing 3.3mmol cm^-2h^-1(0.4488g h^-1) H of (A) to (B)₂O₂The preparation efficiency of the high purity solution is shown in table 1:

TABLE 1 preparation of invention H₂O₂Efficiency of high purity solution

Time

10h

30h

50h

70h

90h

120h

Faraday efficiency

95.6％

94.8％

95.1％

95.4％

95.3％

94.2％

Intensity of current

60mA

60mA

60mA

60mA

60mA

60mA

Claims (10)

1. Electrocatalysis H₂O₂The solution preparation method is characterized by comprising the following steps:

(1) mixing waterElectrolysis at the anode to produce H⁺And O₂Oxygen is cathodically electrolyzed to give HO^2–；

(2)H⁺And HO^2–Directly synthesizing H in the solid electrolyte layer through the cation exchange membrane and the anion exchange membrane respectively₂O₂；

(3) Introducing water into the solid electrolyte layer, and introducing H into the solid electrolyte layer by using the water₂O₂And (6) taking out.

2. Electrocatalytic H according to claim 1₂O₂The solution preparation method is characterized in that in the step 1, water is electrolyzed under an acidic condition with pH 2-4, and O generated after water electrolysis₂Introducing cathode for electrolysis, wherein the catalytic layers used by the anode and the cathode are respectively IrO₂a/GCN heterogeneous layer and a cationic surfactant treated oxidized carbon black catalyst layer.

3. Electrocatalytic H according to claim 1₂O₂The solution preparation method is characterized in that the cation exchange membrane and the anion exchange membrane in the step 2 are respectively a Nafion 177 membrane and a Nafion 177 membrane

X37-50Grade 60 film.

4. An electrocatalytic H according to claim 1₂O₂The device used in the solution preparation method is characterized by comprising an anode, a cathode and a storage tank (13), wherein a solid electrolyte layer (14) is arranged between the anode and the cathode, and the storage tank (13) is connected to the solid electrolyte layer (14).

5. The device according to claim 4, wherein an anode current collecting plate (16), a gas diffusion layer (3), an anode catalyst layer (4) and a cation exchange membrane (5) are arranged inside the anode in sequence, the cation exchange membrane (5) is tightly attached to the surface of the solid electrolyte layer (14), and an anode flow channel is arranged on the anode current collecting plate (16).

6. The device according to claim 5, wherein the anode flow channel comprises a water inlet flow channel (6), a water outlet flow channel (7) and an oxygen outlet (8), and the anode catalytic layer (4) is IrO₂a/GCN heterogeneous layer.

7. The device according to claim 4, characterized in that the cathode comprises a cathode collector plate (17), a gas diffusion layer (3), a cathode catalyst layer (11) and an anion exchange membrane (12) inside the cathode in sequence, the cathode catalyst layer (11) is an oxidized carbon black cathode catalyst layer, and a gas flow channel is arranged on the cathode collector plate (17) and comprises a gas inlet flow channel (9) and a gas outlet flow channel (10).

8. The device according to claim 7, wherein the anion exchange membrane (12) is tightly affixed to the solid electrolyte layer (14).

9. The device according to claim 4, wherein the solid electrolyte layer (14) is provided with a water inlet (15) at the bottom and a storage tank (13) at the upper end through a water outlet, and the solid electrolyte layer (14) is porous styrene-divinylbenzene sulfonated copolymer with a pore diameter of 50-300 μm.

10. The device according to claim 4, characterized in that the anode and the cathode are powered by a solar power supply system comprising a solar panel (1), a rectifier (2) connected to the solar panel (1) and a battery (18) connected to the rectifier (2), the battery (18) being connected to the anode and the cathode, respectively.

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