Membrane electrode for preparation of hydrogen peroxide by means of oxygen reduction, preparation method therefor, and membrane electrode reactor

Abstract

A membrane electrode for the preparation of hydrogen peroxide by means of oxygen reduction, a preparation method therefor, and a membrane electrode reactor. The membrane electrode comprises a cathode oxygen reduction electrode, a cation exchange membrane and an anode oxygen evolution electrode, which are stacked, wherein the cation exchange membrane is located between the cathode oxygen reduction electrode and the anode oxygen evolution electrode, and every two of the cathode oxygen reduction electrode, the cation exchange membrane and the anode oxygen evolution electrode are physically connected; the cathode oxygen reduction electrode comprises a cathode porous substrate layer and a cathode active layer, the cathode active layer comprising a cathode catalyst and a cation regulating and controlling material; and the anode oxygen evolution electrode comprises an anode porous substrate layer and an anode active layer, the anode active layer comprising an anode catalyst. The membrane electrode is suitable for the preparation of hydrogen peroxide by means of oxygen reduction, and has good hydrogen peroxide selectivity and high Faraday efficiency.

Description

Membrane electrode for preparing hydrogen peroxide by oxygen reduction, preparation method thereof, and membrane electrode reactor

[0001] Related applications

[0002] This application claims priority to Chinese patent application No. 2024100104057, filed on January 4, 2024, entitled “Membrane electrode for preparing hydrogen peroxide by oxygen reduction, its preparation method and membrane electrode reactor”, the entire text of which is hereby incorporated by reference. Technical Field

[0003] The present application relates to the technical field of electrocatalysis and electrochemical reactors, and in particular to a membrane electrode for preparing hydrogen peroxide by oxygen reduction, a preparation method thereof, and a membrane electrode reactor. Background Art

[0004] As a clean oxidant, hydrogen peroxide can be used in a variety of applications, including disinfection, water treatment, chemical synthesis, and paper bleaching. The electrochemical oxygen reduction method for synthesizing hydrogen peroxide is environmentally friendly and can leverage the development advantages of green power technology. The raw materials are water, oxygen, or air. Driven by electrical energy, a two-electron electrocatalytic oxygen reduction reaction occurs, producing a hydrogen peroxide aqueous solution. This green, clean, and efficient method meets the needs of miniaturization and discrete manufacturing.

[0005] Currently, most electrosynthesis processes of hydrogen peroxide are carried out in electrolyte solutions. The resulting aqueous hydrogen peroxide solution contains a large amount of electrolytes such as acids, bases or salts, requiring high-cost separation and purification to obtain pure aqueous hydrogen peroxide solution.

[0006] Summary of the Invention

[0007] Based on this, it is necessary to provide a membrane electrode for preparing hydrogen peroxide by oxygen reduction, a preparation method thereof, and a membrane electrode reactor.

[0008] In one aspect of the present application, a membrane electrode for preparing hydrogen peroxide by oxygen reduction is provided, comprising a cathode oxygen reduction electrode, a cation exchange membrane, and an anode oxygen evolution electrode arranged in a stacked manner, wherein the cation exchange membrane is located between the cathode oxygen reduction electrode and the anode oxygen evolution electrode, and the cathode oxygen reduction electrode, the cation exchange membrane, and the anode oxygen evolution electrode are interconnected in a physical manner;

[0009] The cathode oxygen reduction electrode includes a cathode porous substrate layer, and further includes a cathode active layer disposed on the cathode porous substrate layer or a cathode active material supported in the cathode porous substrate layer, wherein the cathode active layer or the cathode active material respectively includes a cathode catalyst and a cation regulating substance;

[0010] The anode oxygen evolution electrode includes an anode porous substrate layer, and further includes an anode active layer arranged on the anode porous substrate layer or an anode active material supported in the anode porous substrate layer, and the anode active layer or the anode active material respectively contain an anode catalyst.

[0011] In some embodiments, the cathode active layer is disposed between the cathode porous base layer and the cation exchange membrane.

[0012] In some embodiments, the anode active layer is disposed between the anode porous base layer and the cation exchange membrane.

[0013] In some embodiments, the cationic regulating substance includes a cationic polymer and / or a crown ether complexed with a metal ion; and / or the cathode catalyst is one or more of an oxidized carbon material, a metal single atom doped carbon material, and a metal nanocluster doped carbon material.

[0014] In some embodiments, the cationic polymer comprises one or more of Fumasep anion exchange resin, Alykmer anion exchange resin, Piperion anion exchange resin, Sustainion anion exchange resin, quaternized polyethyleneimine, cross-linked polydiallyldimethylammonium chloride, quaternary ammonium poly(n-methyl-piperidine-co-p-terphenyl), quaternary amino poly(arylperfluoroalkylene), poly(terphenylpiperidinium-trifluoroacetophenone), poly(diphenyl-co-terphenylpiperidinium) (PDTP), branched poly(terphenylpiperidinium), and poly(fluorenyl-co-terphenylpiperidinium) (PFAP).

[0015] In some embodiments, the metal ion-complexed crown ether includes one or more of 18-crown-6 complexed with sodium ions, 15-crown-5 complexed with potassium ions, and 12-crown-4 complexed with sodium ions.

[0016] In some embodiments, the oxidized carbon material comprises one or more of graphene oxide, oxidized carbon nanotubes, and oxidized carbon black; and / or,

[0017] The metal single atom doped carbon material includes one or more of Co and Fe single atom doped carbon materials; and / or,

[0018] The metal nanocluster-doped carbon material includes one or more of a Ni nanocluster-doped carbon material, a Cu nanocluster-doped carbon material, and a Fe nanocluster-doped carbon material.

[0019] In some embodiments, the loading amount of the cathode catalyst in the cathode oxygen reduction electrode is 0.05 to 5 mg / cm 2The cathode oxygen reduction electrode has a cation regulating substance loading of 1 to 500 μg / cm 2 electrode.

[0020] In some embodiments, the mass ratio of the cathode catalyst to the cation regulating substance in the cathode oxygen reduction electrode is 1:(0.0016-0.06), and can be optionally 1:(0.0032-0.06).

[0021] In some embodiments, the anode catalyst includes one or more of iridium oxide, ruthenium oxide, rhodium oxide, iron oxide, cobalt oxide, nickel oxide, perovskite oxide, NiFe oxide, NiFe hydroxide, iron sulfide, cobalt sulfide, nickel sulfide, copper sulfide, manganese sulfide, Ni phosphide, and Fe phosphide.

[0022] In some embodiments, the loading amount of the anode catalyst in the anode oxygen evolution electrode is 0.05 to 20 mg / cm 2 electrode.

[0023] In some embodiments, the cathode active layer includes a cathode catalyst layer and a cation regulating material layer.

[0024] In some embodiments, the porosity of the cathode porous substrate layer is 20% to 80%. Optionally, the cathode porous substrate layer is carbon paper or carbon cloth.

[0025] In some embodiments, the porosity of the anode porous substrate layer is 20% to 80%. Optionally, the anode porous substrate layer is carbon paper, carbon cloth, metal mesh or foam metal.

[0026] In some embodiments, the cation exchange membrane has a thickness of 10 μm to 300 μm. Optionally, the cation exchange membrane is a Nafion membrane.

[0027] In some embodiments, the physical connection is a non-embedded physical contact.

[0028] Another aspect of the present application provides a membrane electrode comprising the following steps:

[0029] Step S10, loading the cathode catalyst and the cation regulating substance on the cathode porous substrate layer to obtain the cathode oxygen reduction electrode;

[0030] Step S20, loading the anode catalyst on the anode porous base layer to obtain the anode oxygen evolution electrode; and

[0031] Step S30 , stacking the cathode oxygen reduction electrode, the cation exchange membrane, and the anode oxygen evolution electrode in sequence.

[0032] In some embodiments, step S10 includes:

[0033] Step S11, placing the cathode catalyst and the cation regulating substance in a solvent and mixing them to obtain a mixed coating;

[0034] Step S13: coating the mixed coating on the cathode porous base layer.

[0035] In some embodiments, step S10 includes:

[0036] Step S12, placing the cathode catalyst in a solvent to obtain a cathode catalyst coating;

[0037] Step S14, coating the cathode catalyst coating on the cathode porous base layer to form a cathode catalyst layer;

[0038] Step S16, placing the cationic regulating substance in a solvent to obtain a cationic regulating substance coating;

[0039] Step S18: coating the cation regulating substance coating on the cathode catalyst layer to form a cation regulating substance layer.

[0040] Another aspect of the present application provides a membrane electrode reactor comprising the membrane electrode.

[0041] Compared with the traditional membrane electrode, the membrane electrode provided by the present application adds a cationic regulating substance at the cathode, changes the cathode interface state, blocks a large number of protons migrating from the anode, and reduces the proton concentration on the cathode catalyst surface, thereby accelerating the electrochemical reaction of OOH in pure water. - Ion migration inhibits the 4-electron reduction reaction of oxygen to produce water, thereby improving the selectivity of hydrogen peroxide (Faraday efficiency).

[0042] The membrane electrode used in this application has the characteristics of simple structure and good stability. The cationic control substance used can form a three-dimensional ion conduction network structure with the catalyst layer. The electrolytic cell has low ion conduction resistance, low cell voltage and low energy consumption.

[0043] The membrane electrode reactor provided in this application uses pure water, oxygen or air as raw materials, does not use electrolyte solution, the process is green and clean, and the hydrogen peroxide produced can meet the needs of disinfection, drifting and other processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the conventional technology, the following briefly introduces the drawings required for use in the embodiments or the conventional technology descriptions. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the disclosed drawings without any creative work.

[0045] FIG1 is a schematic structural diagram of a membrane electrode according to one embodiment.

[0046] FIG2 is a schematic structural diagram of a cathode oxygen reduction electrode according to one embodiment.

[0047] FIG3 is a schematic structural diagram of an anode oxygen evolution electrode according to one embodiment.

[0048] FIG4 is a schematic structural diagram of a cathode active layer according to one embodiment.

[0049] FIG5 is a schematic structural diagram of a membrane electrode according to an embodiment.

[0050] FIG6 is a schematic structural diagram of a membrane electrode according to an embodiment.

[0051] FIG7 is a schematic structural diagram of a reaction system for preparing hydrogen peroxide by oxygen reduction according to one embodiment.

[0052] Among them, the figure numbers are:

[0053] 10-cathode oxygen reduction electrode, 20-cation exchange membrane, 30-anode oxygen evolution electrode, 12-cathode porous substrate layer, 14-cathode active layer, 16-integrated cathode oxygen reduction electrode, 32-anode porous substrate layer, 34-anode active layer, 36-integrated anode oxygen evolution electrode, 141-cathode catalyst layer, 142-cation regulation material layer, 1-oxygen or air feed line, 2-cathode pure water feed line, 3-gas-liquid mixer, 4-back pressure valve, 5-cathode outlet line, 6-membrane electrode, 7-cathode flow channel chamber, 8-anode flow channel chamber, 9-electrochemical workstation (power supply), 10-anode pure water inlet line, 11-anode outlet line. DETAILED DESCRIPTION

[0054] To facilitate understanding of the present application, a more comprehensive description of the present application will be provided below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present application. However, the present application may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure of the present application.

[0055] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0056] In this application, "first aspect", "second aspect", "third aspect", etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or quantity, nor can they be understood as implicitly indicating the importance or quantity of the indicated technical features.

[0057] In this application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0058] In this application, "one or more" refers to any one, any two, or any two or more of the listed items.

[0059] In this application, when referring to numerical ranges, unless otherwise specified, the numerical ranges are considered continuous and include the minimum and maximum values ​​of the range, as well as every value between such minimum and maximum values. Further, when a range refers to an integer, every integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe a feature or characteristic, the ranges can be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges subsumed therein.

[0060] Unless otherwise specified, the percentage contents mentioned in this application refer to mass percentage for solid-liquid mixture and solid-solid mixture, and refer to volume percentage for liquid-liquid mixture.

[0061] The percentage concentrations mentioned in this application, unless otherwise specified, refer to the final concentration, which refers to the percentage of the added component in the system after the addition of the component.

[0062] The temperature parameters in this application, unless otherwise specified, allow for both constant temperature treatment and treatment within a certain temperature range. The constant temperature treatment allows for temperature fluctuations within the precision range of instrument control.

[0063] In this application, method steps that do not emphasize temperature generally refer to method steps performed at normal temperature or room temperature. In this article, normal temperature and room temperature are equivalent and interchangeable, and the specific temperature refers to 22°C to 25°C.

[0064] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0065] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0066] Unless otherwise specified, all steps of the present application may be performed sequentially or randomly. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order, for example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0067] Unless otherwise specified, the terms "include" and "comprising" used in this application may be open-ended or closed-ended. For example, "include" and "comprising" may mean that other components not listed may also be included or that only the listed components are included.

[0068] Unless otherwise specified, the term "or" is used in this application to be inclusive. For example, the phrase "A or B" means "A, B, or both A and B." More specifically, the condition "A or B" is satisfied if any of the following conditions are met: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0069] Membrane electrode reactors (MEA) are important devices for producing hydrogen peroxide in pure water. The electrolyte in these reactors is replaced with a cationic modulator, resulting in purer hydrogen peroxide. Advanced MEA is crucial for producing hydrogen peroxide, especially for its efficient synthesis.

[0070] Due to the destructive effect of rapid electrowetting on the reactive three-phase interface of air diffusion electrodes under high current density operating conditions, the industrial conversion of this electrochemical two-electron oxygen reduction to hydrogen peroxide is challenged by poor selectivity and durability. In particular, the Faradaic efficiency of existing membrane electrodes for oxygen reduction to hydrogen peroxide still needs to be improved.

[0071] Therefore, in the first aspect of the present application, a membrane electrode for preparing hydrogen peroxide by oxygen reduction is provided, referring to Figure 1, which includes a cathode oxygen reduction electrode 10, a cation exchange membrane 20 and an anode oxygen evolution electrode 30 arranged in a stacked manner, wherein the cation exchange membrane 20 is located between the cathode oxygen reduction electrode 10 and the anode oxygen evolution electrode 30, and the cathode oxygen reduction electrode 10, the cation exchange membrane 20 and the anode oxygen evolution electrode 30 are interconnected in a physical manner.

[0072] Referring to Figures 2 and 5 , in some embodiments, cathode oxygen reduction electrode 10 includes a cathode porous substrate layer 12 and a cathode active layer 14. Cathode active layer 14 contains a cathode catalyst and a cation-regulating substance. In some embodiments, cathode active layer 14 is disposed adjacent to cation exchange membrane 20, that is, between cathode porous substrate layer 12 and cation exchange membrane 20.

[0073] Referring to FIG. 6 , in other embodiments, the cathode oxygen reduction electrode 10 includes a cathode porous substrate layer 12 and a cathode active material. The cathode active material includes a cathode catalyst and a cation regulating material. The cathode active material is distributed in the cathode porous substrate layer 12 to form an integrated cathode oxygen reduction electrode 16. That is, the cathode oxygen reduction electrode 10 is not layered at this time.

[0074] Referring to FIG3 , in some embodiments, the anode oxygen evolution electrode 30 includes an anode porous substrate layer 32 and an anode active layer 34. The anode active layer 34 includes an anode catalyst. In some embodiments, the anode active layer 34 is disposed adjacent to the cation exchange membrane 20, that is, between the anode porous substrate layer 32 and the cation exchange membrane 20.

[0075] Please refer to Figure 6. In other embodiments, the anode oxygen evolution electrode 30 includes an anode porous base layer 32 and an anode active material. The anode active material includes an anode catalyst. The anode active material is distributed in the anode porous base layer 32 to form an integrated anode oxygen reduction electrode 36. That is, the anode oxygen evolution electrode 30 is not layered at this time.

[0076] It can be understood that the above-mentioned embodiments of the cathode oxygen reduction electrode 10 and the anode oxygen evolution electrode 30 can be arbitrarily combined, for example, only the cathode oxygen reduction electrode 10 has a multi-layer structure, and the anode oxygen evolution electrode 30 has a single-layer structure, or only the anode oxygen evolution electrode 30 has a multi-layer structure, and the cathode oxygen reduction electrode 10 has a single-layer structure, or both have single-layer structures, or both have multi-layer structures.

[0077] In some embodiments, cation exchange membrane 20 comprises a cation exchange resin.

[0078] It should be noted that the cathode oxygen reduction electrode 10, the cation exchange membrane 20 and the anode oxygen evolution electrode 30 are connected to each other in a physical connection, and the physical connection is a non-embedded physical contact, that is, the cathode oxygen reduction electrode 10 and the cation exchange membrane 20 are in physical contact or close physical contact, and the close physical contact is limited to the contact between the two, which means that the contact effect is better, that is, all the contactable surfaces of the two are tightly fitted, and they are all in contact at the macroscopic structure, rather than partial or complete fusion, mutual penetration or mutual embedding of the two in terms of molecular structure.

[0079] For example, when heat treatment is used to combine the cathode oxygen reduction electrode 10 and the cation exchange membrane 20, if this causes at least part of the cation regulating substance and the cation exchange resin in the cation exchange membrane 20 to fuse with each other, penetrate with each other, or embed with each other, this will affect the migration of protons, thereby increasing the proton concentration on the cathode catalyst. In this case, such combination violates the purpose of the present application.

[0080] In some embodiments, the cationic modulating substance is a cationic polymer and / or a metal ion complexed crown ether.

[0081] Optionally, the cationic polymer includes one or more of an ammonium polymer resin, an imidazolium polymer resin, a phosphonium and an organometallic cationic polymer resin. Further optionally, specific examples of the cationic polymer are selected from, but not limited to, Fumasep anion exchange resin, Alykmer anion exchange resin, Piperion anion exchange resin, Sustainion anion exchange resin, quaternized polyethyleneimine, cross-linked polydiallyldimethylammonium chloride, quaternary ammonium poly(n-methyl-piperidine-co-p-terphenyl), quaternary amino poly(aryl perfluoroalkylene), poly(terphenylpiperidinium-trifluoroacetophenone), poly(diphenyl-co-terphenylpiperidinium) (PDTP), branched poly(terphenylpiperidinium) and poly(fluorenyl-co-terphenylpiperidinium) (PFAP) and combinations thereof.

[0082] Fumasep anion exchange resin is primarily composed of a polysulfone-based quaternary ammonium polymer. Alykmer anion exchange resin is primarily composed of a polyarylpiperidine. Piperion anion exchange resin is primarily composed of a polyarylpiperidine. Sustainion anion exchange resin is primarily composed of imidazole-functionalized polystyrene.

[0083] Optionally, the metal ion-complexed crown ether includes one or more of 18-crown-6 complexed with sodium ions, 15-crown-5 complexed with potassium ions, and 12-crown-4 complexed with sodium ions.

[0084] In some embodiments, the cathode catalyst is one or more of an oxidized carbon material, a metal single atom-doped carbon material, or a metal nanocluster-doped carbon material.

[0085] Optionally, the oxidized carbon material includes one or more of graphene oxide, oxidized carbon nanotubes and oxidized carbon black.

[0086] Optionally, the metal single atom-doped carbon material includes one or more of Co and Fe single atom-doped carbon materials.

[0087] Optionally, the metal nanocluster-doped carbon material includes one or more of a Ni nanocluster-doped carbon material, a Cu nanocluster-doped carbon material, and a Fe nanocluster-doped carbon material.

[0088] Further optionally, the carbon material in the metal single atom-doped carbon material and the metal nanocluster-doped carbon material includes one or more of carbon black, graphene, carbon nanotubes, oxidized carbon black, oxidized graphene, and oxidized carbon nanotubes.

[0089] In some embodiments, the cathode catalyst loading in the cathode oxygen reduction electrode 10 is 0.05 to 5 mg / cm 2 Electrode, for example, may be packaged as but not limited to 0.05 mg / cm 2 Electrode, 0.1mg / cm 2 Electrode, 0.5mg / cm 2 Electrode, 1mg / cm 2 Electrode, 1.5mg / cm 2 Electrode, 2mg / cm 2 Electrode, 2.5mg / cm 2 Electrode, 3mg / cm 2 Electrode, 3.5mg / cm 2 Electrode, 4mg / cm 2 Electrode, 4.5mg / cm 2 Electrode, 5mg / cm 2 electrode and the range between any two of the above values.

[0090] In some embodiments, the loading amount of the cationic regulating substance in the cathode oxygen reduction electrode 10 is 1 to 500 μg / cm 2 Electrode, for example, but not limited to 1 μg / cm 2 Electrode, 10 μg / cm 2 Electrode, 50 μg / cm 2 Electrode, 100 μg / cm 2 Electrode, 150 μg / cm 2 Electrode, 200 μg / cm 2 Electrode, 250 μg / cm 2 Electrode, 300 μg / cm 2 Electrode, 350 μg / cm 2 Electrode, 400 μg / cm 2 Electrode, 450 μg / cm 2 Electrode, 500 μg / cm 2 electrode and the range between any two of the above values.

[0091] In some embodiments, the mass ratio of the cathode catalyst to the cation regulating substance in the cathode oxygen reduction electrode 10 is 1:(0.0016-0.06), for example, but not limited to, 1:0.0016, 1:0.0018, 1:0.002, 1:0.003, 1:0.0032, 1:0.005, 1:0.01, 1:0.016, 1:0.02, 1:0.03, 1:0.04, 1:0.048, 1:0.05, 1:0.06, and ranges between any two of the above ratios. Alternatively, the mass ratio of the cathode catalyst to the cation regulating substance in the cathode oxygen reduction electrode 10 is 1:(0.0032-0.06), and further optionally 1:(0.01-0.06). Within this optional range, the proton concentration on the cathode catalyst surface is more conducive to the production of hydrogen peroxide, the selectivity of hydrogen peroxide is better, and the farad rate effect of the membrane electrode reactor is higher.

[0092] In some embodiments, the cathode active layer 14 disposed on the cathode porous substrate layer 12 or the anionic active material loaded in the cathode porous substrate layer 12 is formed by drying a mixed coating comprising a cathode catalyst and a cationic regulating material, and the cathode catalyst and the cationic regulating material do not form obvious stratification.

[0093] In other embodiments, referring to FIG4 , the cathode active layer 14 is a composite layer comprising two layers, a cathode catalyst layer 141 and a cation regulating material layer 142. The cathode catalyst layer 141 is disposed adjacent to the cathode porous substrate layer 12, while the cation regulating material layer 142 is disposed away from the cathode porous substrate layer 12. The cathode catalyst layer 141 is formed by drying a coating containing only the cathode catalyst, while the cation regulating material layer 142 is formed by drying a coating containing only the cation regulating material. The membrane electrode cathode catalyst surface of this embodiment has a lower proton concentration, better hydrogen peroxide selectivity, and a higher Faraday efficiency of the membrane electrode reactor.

[0094] In some embodiments, the porosity of the cathode porous substrate layer 12 is 20% to 80%, for example, but not limited to, 20%, 30%, 40%, 50%, 60%, 70%, 80% and ranges between any two of the above values.

[0095] In some embodiments, the cathode porous substrate layer 12 is carbon paper or carbon cloth.

[0096] In some embodiments, the porosity of the anode porous substrate layer 12 is 20% to 80%, for example, but not limited to, 20%, 30%, 40%, 50%, 60%, 70%, 80% and ranges between any two of the above values.

[0097] In some embodiments, the anode porous substrate 32 is carbon paper, carbon cloth, metal mesh, or metal foam. Specific examples of metal mesh or metal foam include titanium mesh, nickel mesh, nickel foam, and stainless steel mesh.

[0098] In some embodiments, the anode catalyst includes one or more of iridium oxide, ruthenium oxide, rhodium oxide, iron oxide, cobalt oxide, nickel oxide, perovskite oxide, NiFe oxide, NiFe hydroxide, iron sulfide, cobalt sulfide, nickel sulfide, copper sulfide, manganese sulfide, Ni phosphide, and Fe phosphide.

[0099] The loading amount of the anode catalyst in the anode oxygen evolution electrode 30 can be 0.05 to 20 mg / cm 2 Electrode, for example, but not limited to 0.05 mg / cm 2 Electrode, 0.1mg / cm 2 Electrode, 0.5mg / cm 2 Electrode, 1mg / cm 2 Electrode, 5mg / cm 2 Electrode, 10mg / cm 2 Electrode, 15mg / cm 2 Electrode, 20mg / cm 2 electrode and the range between any two of the above values.

[0100] In some embodiments, the anode porous substrate layer 32 is carbon paper or carbon cloth, and the loading amount of the anode catalyst in the anode oxygen evolution electrode 30 is 0.05 to 5 mg / cm 2 Electrode, for example, but not limited to 0.05 mg / cm 2 Electrode, 0.1mg / cm 2 Electrode, 0.5mg / cm 2 Electrode, 1mg / cm 2 Electrode, 2mg / cm 2 Electrode, 3mg / cm 2 Electrode, 4mg / cm 2 Electrode, 5mg / cm 2 electrode and the range between any two of the above values.

[0101] In some embodiments, the anode porous substrate layer 32 is a metal mesh or foam metal, and the loading amount of the anode catalyst in the anode oxygen evolution electrode 30 is 0.05 to 20 mg / cm 2 Electrode, for example, but not limited to 0.05 mg / cm 2 Electrode, 0.1mg / cm 2 Electrode, 0.5mg / cm 2 Electrode, 1mg / cm 2Electrode, 5mg / cm 2 Electrode, 10mg / cm 2 Electrode, 15mg / cm 2 Electrode, 20mg / cm 2 electrode and the range between any two of the above values.

[0102] In some embodiments, the thickness of the cation exchange membrane 20 is 10 μm to 300 μm, including but not limited to 10 μm, 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm and ranges between any two of the above values.

[0103] In some embodiments, the cation exchange membrane 20 is a Nafion membrane, which may include but is not limited to Nafion 117 membrane, Nafion 211 membrane, and Nafion 212 membrane.

[0104] A second aspect of the present application further provides a method for preparing the membrane electrode according to any embodiment of the first aspect, comprising the following steps:

[0105] Step S10, loading the cathode catalyst and the cation regulating substance on the cathode porous substrate layer 12 to obtain the cathode oxygen reduction electrode 10;

[0106] Step S20, loading the anode catalyst on the anode porous substrate layer 32 to obtain the anode oxygen evolution electrode 30; and

[0107] In step S30 , the cathode oxygen reduction electrode 10 , the cation exchange membrane 20 and the anode oxygen evolution electrode 30 are stacked in sequence.

[0108] In some embodiments, step S10 includes:

[0109] Step S11, placing the cathode catalyst and the cation regulating substance in a solvent and mixing them to obtain a mixed coating;

[0110] In step S13 , the mixed coating is coated on the cathode porous base layer 12 to form a cathode active layer 14 .

[0111] As a possible implementation, the solvent in step S11 is a mixed solvent of isopropyl alcohol and water. Optionally, the volume ratio of isopropyl alcohol to water is 4:1 to 1:1.

[0112] As a possible implementation manner, the concentration of the cathode catalyst in the mixed coating is 1 to 100 mg / mL.

[0113] As a possible implementation method, the concentration of the cationic regulating substance in the mixed coating is 1 to 500 μg / mL.

[0114] In some other embodiments, step S10 includes:

[0115] Step S12, placing the cathode catalyst in a solvent to obtain a cathode catalyst coating;

[0116] Step S14, coating the cathode catalyst coating on the cathode porous base layer 12 to form a cathode catalyst layer 141;

[0117] Step S16, placing the cationic regulating substance in a solvent to obtain a cationic regulating substance coating;

[0118] In step S18 , a cation regulating material coating is applied on the cathode catalyst layer 141 to form a cation regulating material layer 142 .

[0119] As a possible implementation, the solvent in step S12 is a mixed solvent of isopropyl alcohol and water. Optionally, the volume ratio of isopropyl alcohol to water is 4:1 to 1:1.

[0120] As a possible implementation manner, the concentration of the cathode catalyst in the cathode catalyst coating is 1 to 10 mg / mL.

[0121] As a possible implementation, the solvent in step S16 is a mixed solvent of isopropyl alcohol and water. Optionally, the volume ratio of isopropyl alcohol to water is 4:1 to 1:1.

[0122] As a possible implementation, the concentration of the cationic regulating substance in the cationic regulating substance coating is 1 to 500 μg / mL.

[0123] The third aspect of the present application further provides a membrane electrode reactor, comprising the membrane electrode of any embodiment of the first aspect of the present application.

[0124] In some embodiments, the membrane electrode reactor further comprises other components in addition to the membrane electrode, such as a cathode flow chamber and an anode flow chamber. The components are assembled in the order of cathode flow chamber, cathode oxygen reduction electrode, cation exchange membrane, anode oxygen evolution electrode, and anode flow chamber. Good surface contact must be ensured between adjacent components, and the cathode oxygen reduction electrode, cation exchange membrane, and anode oxygen evolution electrode must fit tightly but remain physically connected.

[0125] In some embodiments, the cathode flow channel chamber is made of graphite or corrosion-resistant metal, including but not limited to one or more of titanium, stainless steel, and Hastelloy. The internal channel width of the cathode flow channel chamber can be 1 to 12 mm, and the channel depth can be 0.5 to 5 mm.

[0126] In some embodiments, the anode flow channel chamber is made of graphite or corrosion-resistant metal, including but not limited to one or more of titanium, stainless steel, and Hastelloy. The internal channel width of the anode flow channel chamber can be 1 to 12 mm, and the channel depth can be 0.5 to 5 mm.

[0127] The following are specific examples. They are intended to further explain this application in detail to help those skilled in the art and researchers further understand it. The relevant technical conditions, etc., do not constitute any limitation on this application. Any modifications made within the scope of the claims of this application are within the scope of protection of the claims of this application.

[0128] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods. Experimental methods without specific conditions specified in the examples were carried out according to conventional conditions, such as those described in literature or books or methods recommended by manufacturers.

[0129] Example 1

[0130] 1 mg of Ni nanocluster-loaded oxidized carbon black catalyst was weighed and mixed with 1.6 μg of Fumasep anion exchange resin in a solvent consisting of 0.6 mL of isopropyl alcohol and 0.4 mL of water. The mixture was dispersed in an ultrasonic oscillator to form a uniform coating. The coating was then sprayed onto a 1 cm × 1 cm GDL carbon paper using an airbrush to create a catalyst loading of 0.2 mg / cm. 2 cathode oxygen reduction electrode.

[0131] A 1cm×1cm titanium mesh loaded with IrO2 was used as the anode oxygen evolution electrode. The IrO2 loading was 2mg / cm 2 .

[0132] The cation exchange membrane used was Nafion 117 membrane with an area of ​​1.2 cm × 1.2 cm.

[0133] The membrane electrode reactor is assembled in the order of cathode flow channel chamber, cathode oxygen reduction electrode, cation exchange membrane, anode oxygen evolution electrode and anode flow channel chamber.

[0134] Example 2

[0135] 2 mg of oxidized carbon black catalyst was weighed and mixed with 100 μg of Piperion anion exchange resin in a solvent consisting of 0.7 mL of isopropyl alcohol and 0.3 mL of water. The mixture was dispersed in an ultrasonic oscillator to form a uniform coating. The coating was then sprayed evenly onto a 2 cm × 2 cm GDL carbon paper using an airbrush to achieve a catalyst loading of 0.4 mg / cm. 2 cathode oxygen reduction electrode.

[0136] RuO2 loaded on 2cm×2cm nickel foam was used as the anode oxygen evolution electrode, and the RuO2 loading amount was 1mg / cm 2 .

[0137] The cation exchange membrane used was Nafion 211 membrane with an area of ​​2.5 cm × 2.5 cm.

[0138] It is assembled in the order of cathode flow channel chamber, cathode oxygen reduction electrode, cation exchange membrane, anode oxygen evolution electrode and anode flow channel chamber.

[0139] Example 3

[0140] 1 mg of Co single-atom catalyst was weighed and mixed with 50 μg of quaternary ammonium poly(n-methyl-piperidinyl-co-p-terphenyl) in a solvent consisting of 0.7 mL of isopropanol and 0.3 mL of water. The mixture was dispersed in an ultrasonic oscillator to form a uniform coating. The coating was then sprayed evenly onto a 2 cm x 2 cm carbon paper using an airbrush to achieve a catalyst loading of 0.2 mg / cm. 2 cathode oxygen reduction electrode.

[0141] NiFe hydroxide grown on 1cm×1cm nickel foam was used as the anodic oxygen evolution electrode with a loading of about 10mg / cm 2 .

[0142] The cation exchange membrane uses Nafion 117 membrane with an area of ​​2.2 cm×2.2 cm.

[0143] It is assembled in the order of cathode flow channel chamber, cathode oxygen reduction electrode, cation exchange membrane, anode oxygen evolution electrode and anode flow channel chamber.

[0144] Example 4

[0145] 500 mg of Fe nanocluster-doped carbon nanotubes were weighed and mixed with 1.6 mg of Alkmer anion exchange resin in a solvent consisting of 8 mL of isopropanol and 2 mL of water. The mixture was dispersed in an ultrasonic oscillator to form a uniform coating. The coating was then evenly sprayed onto a 20 cm × 20 cm GDL commercial carbon cloth using an ultrasonic sprayer to produce a catalyst loading of 1 mg / cm. 2 cathode oxygen reduction electrode.

[0146] A 20cm×20cm titanium mesh loaded with IrO2 was used as the anode oxygen evolution electrode, and the IrO2 loading was 2mg / cm 2 .

[0147] The cation exchange membrane adopts Nafion 117 membrane with an area of ​​22.5 cm×22.5 cm.

[0148] It is assembled in the order of cathode flow channel chamber, cathode oxygen reduction electrode, cation exchange membrane, anode oxygen evolution electrode and anode flow channel chamber.

[0149] Example 5

[0150] 100 mg of oxidized carbon nanotube catalyst was weighed and mixed with 160 μg of poly(fluorenyl-co-terphenylpiperidinium) (PFAP) in a solvent consisting of 7.8 mL of isopropanol and 2 mL of water. The mixture was dispersed in an ultrasonic oscillator to form a uniform coating. The coating was then evenly sprayed onto a 10 × 10 cm commercial carbon cloth using an ultrasonic sprayer. The carbon cloth was then placed on an 80°C hot plate to achieve a catalyst loading of 0.15 mg / cm. 2 cathode oxygen reduction electrode.

[0151] FeP / Ni2P loaded on nickel foam was used as the anode oxygen evolution electrode with a loading of 2 mg / cm 2 , area is 10×10cm.

[0152] The cation exchange membrane used was Nafion 212 membrane with an area of ​​12×12 cm.

[0153] The membrane electrolyzer is assembled in the order of cathode flow channel chamber, cathode oxygen reduction electrode, cation exchange membrane, anode oxygen evolution electrode and anode flow channel chamber.

[0154] Example 6

[0155] The preparation method is basically the same as that of Example 3, except that the cathode catalyst is replaced by graphene oxide and the anion exchange resin is replaced by Sustainion.

[0156] Example 7

[0157] The preparation method is basically the same as that of Example 3, except that the cathode catalyst is replaced by graphene oxide, and the cation regulating substance is replaced by 18-crown-6 complexed with sodium ions.

[0158] Example 8

[0159] The preparation method is basically the same as that of Example 3, except that the cathode catalyst is replaced by a carbon material doped with Fe single atoms, and the cation regulating substance is replaced by 15-crown-5 complexed with potassium ions. Example 9

[0160] The preparation method is basically the same as that of Example 3, except that the cathode catalyst is replaced by a carbon material doped with a single Fe atom, and the cation regulating substance is replaced by a quaternary amino poly(aryl perfluoroalkylene).

[0161] Example 10

[0162] The preparation method is basically the same as that of Example 3, except that the cationic regulating substance is replaced with poly(terphenylpiperidinium-trifluoroacetophenone).

[0163] Example 11

[0164] The preparation method is basically the same as that of Example 2, except that the anode oxygen evolution electrode uses IrO2 loaded on carbon paper, and the IrO2 loading amount is 0.5 mg / cm 2 .

[0165] Example 12

[0166] The preparation method is basically the same as that of Example 3, except that the cathode catalyst is replaced by a nano Pt catalyst.

[0167] Examples 13 to 15

[0168] The preparation method is basically the same as that in Example 3, except that the mass of the anion exchange resin is different. The specific mass of the anion exchange resin is added according to the mass ratio of the cathode catalyst to the anion exchange resin listed in Table 1, wherein the mass of the Co single atom catalyst is 1 mg.

[0169] Example 16

[0170] The preparation method is basically the same as that of Example 3, except that the cathode catalyst and anion exchange resin in the cathode oxygen reduction electrode are not mixed, but are separately made into coatings and layered on carbon paper. The specific preparation of the cathode oxygen reduction electrode is as follows:

[0171] 1 mg of Co single-atom catalyst was placed in a solvent consisting of 0.7 mL of isopropanol and 0.3 mL of water, and dispersed in an ultrasonic oscillation device to form a uniform coating. The coating was evenly sprayed on a 2 cm × 2 cm carbon paper using a spray pen to obtain a cathode catalyst layer.

[0172] 50 μg of quaternary ammonium poly (n-methyl-piperidinyl-co-p-terphenyl) was placed in a solvent, which was 0.7 mL of isopropyl alcohol and 0.3 mL of water. The solvent was dispersed in an ultrasonic oscillation device to form a uniform coating. The coating was evenly sprayed on the cathode catalyst layer with a spray pen to prepare a catalyst loading of 0.2 mg / cm 2 cathode oxygen reduction electrode.

[0173] The rest is the same as Example 3.

[0174] Comparative Example 1

[0175] The preparation method is basically the same as that of Example 1, except that the anion exchange resin in the cathode oxygen reduction electrode is omitted, that is, only the Ni nanocluster-supported oxidized carbon black catalyst is sprayed on the carbon paper of the cathode oxygen reduction electrode.

[0176] Comparative Example 2

[0177] The preparation method is basically the same as that in Example 1, except that the anion diffusion resin in the cathode oxygen reduction electrode is replaced by the cation exchange resin Nafion, that is, a mixed solution of Ni nanocluster-loaded oxidized carbon black catalyst and cation exchange resin is sprayed on the carbon paper of the cathode oxygen reduction electrode.

[0178] The relevant parameters of the membrane electrode reactors in Examples 1 to 15 are listed in Table 1:

[0179] Table 1

[0180] Application Examples

[0181] Application Examples 1 to 16 and Application Comparative Examples 1 to 2 are connected in sequence according to FIG7 as the reaction system for preparing hydrogen peroxide by oxygen reduction, and oxygen and pure water are mixed into the cathode flow channel chamber through a T-shaped three-way pipe, wherein the flow rate of oxygen is 25 sccm, wherein the flow rate of pure water in Application Examples 1 to 3, Application Examples 6 to 16 and Application Comparative Examples 1 to 2 is 1 mL / min, and the flow rate of pure water in Application Examples 4 to 5 is 10 mL / min. The cathode pressure is atmospheric pressure. The reactant at the anode is pure water, and its flow rate is 2 mL / min. After the fluid is stably input into the reactor for 10 minutes, the reaction current is set using the electrochemical workstation to allow the reaction to proceed, and a collection bottle is placed at the cathode outlet to collect the reaction liquid product, and the Ce 4+ The hydrogen peroxide produced by titration of ion standard solution is analyzed to determine the concentration of hydrogen peroxide C H2O2 , calculate the Faraday efficiency FE, the formula is as follows:

[0182] in is Ce involved in the reaction 4+ The concentration, V Ce 4+ is Ce added during titration 4+ The volume, is the remaining Ce measured by UV spectroscopy after the titration is completed 4+ The concentration, V H2O2is the volume of the H2O2 reaction product involved in the titration, F is the Faraday constant, which is 96485C / mol, j is the set constant current, and t is the reaction time. Among them, j is 200mA / cm 2 , t is set to 1 hour.

[0183] The membrane electrode reactors, current density, electrolysis time and volume V of the generated hydrogen peroxide solution corresponding to the application examples 1 to 16 and the application comparative example 1 H2O2 , concentration C H2O2 And the corresponding Faradaic efficiency FE is listed in Table 2 below:

[0184] Table 2

[0185] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0186] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A membrane electrode for the preparation of hydrogen peroxide by oxygen reduction, characterized in that, It includes a cathode oxygen reduction electrode, a cation exchange membrane, and an anode oxygen evolution electrode which are stacked. The cation exchange membrane is located between the cathode oxygen reduction electrode and the anode oxygen evolution electrode. The connection mode between the cathode oxygen reduction electrode, the cation exchange membrane, and the anode oxygen evolution electrode is physical connection; The cathode oxygen reduction electrode includes a cathode porous base layer, and further includes a cathode active layer provided on the cathode porous base layer or cathode active substances loaded in the cathode porous base layer. The cathode active layer or the cathode active substances respectively contain a cathode catalyst and a cation regulation substance; The anode oxygen evolution electrode includes an anode porous base layer, and further includes an anode active layer provided on the anode porous base layer or anode active substances loaded in the anode porous base layer. The anode active layer or the anode active substances respectively contain an anode catalyst.

2. The membrane electrode according to claim 1, wherein The cathode active layer is provided between the cathode porous base layer and the cation exchange membrane.

3. The membrane electrode according to claim 1 or 2, wherein The anode active layer is provided between the anode porous base layer and the cation exchange membrane.

4. The membrane electrode according to any one of claims 1 to 3, characterized in that, The cation regulation substance includes a cationic polymer and / or a crown ether complexed with metal ions; and / or, The cathode catalyst is one or more of carbon materials treated by oxidation, carbon materials doped with metal single atoms, and carbon materials doped with metal nanoclusters.

5. The membrane electrode according to claim 4, characterized in that, The cationic polymer includes one or more of Fumasep anion exchange resin, Alykmer anion exchange resin, Piperion anion exchange resin, Sustainion anion exchange resin, quaternized polyethyleneimine, crosslinked poly(diallyldimethylammonium chloride), quaternary ammonium poly(n-methyl-piperidine-co-p-terphenyl), quaternary ammonium poly(aryl perfluoroalkylene), poly(triphenylpiperidinium-trifluoroacetophenone), poly(diphenyl-co-triphenylpiperidinium) (PDTP), branched poly(triphenylpiperidinium), and poly(fluorene-co-triphenylpiperidinium) (PFAP); The crown ether complexed with metal ions includes one or more of 18-crown-6 complexed with sodium ions, 15-crown-5 complexed with potassium ions, and 12-crown-4 complexed with sodium ions.

6. The membrane electrode according to claim 4 or 5, characterized in that, The carbon materials treated by oxidation include one or more of graphene oxide, oxidized carbon nanotubes, and oxidized carbon black; and / or, The carbon materials doped with metal single atoms include one or more of carbon materials doped with Co or Fe single atoms; and / or, The carbon materials doped with metal nanoclusters include one or more of carbon materials doped with Ni nanoclusters, carbon materials doped with Cu nanoclusters, and carbon materials doped with Fe nanoclusters.

7. The membrane electrode according to any one of claims 1 to 6, characterized in that, The loading amount of the cathode catalyst in the cathode oxygen reduction electrode is 0.05 to 5 mg / cm 2 electrode, and / or the loading amount of the cation regulation substance in the cathode oxygen reduction electrode is 1 to 500 μg / cm 2 electrode.

8. The membrane electrode according to any one of claims 1 to 7, characterized in that, The mass ratio of the cathode catalyst to the cation regulation substance in the cathode oxygen reduction electrode is 1:(0.0016 - 0.06).

9. The membrane electrode according to any one of claims 1 to 8, characterized in that, The anode catalyst includes one or more of iridium oxide, ruthenium oxide, rhodium oxide, iron oxide, cobalt oxide, nickel oxide, perovskite oxide, NiFe oxide, NiFe hydroxide, iron sulfide, cobalt sulfide, nickel sulfide, copper sulfide, manganese sulfide, Ni phosphide, and Fe phosphide.

10. The membrane electrode according to any one of claims 1 to 9, characterized in that, The loading amount of the anode catalyst in the anode oxygen evolution electrode is 0.05 to 20 mg / cm 2 electrode.

11. The membrane electrode according to any one of claims 1 to 10, characterized in that, The cathode active layer includes a cathode catalyst layer and a cation regulation substance layer. The cathode catalyst layer is disposed adjacent to the cathode porous substrate layer, and the cation regulation substance layer is disposed away from the cathode porous substrate layer.

12. The membrane electrode according to any one of claims 1 to 11, characterized in that, The porosity of the cathode porous substrate layer is 20% - 80%.

13. The membrane electrode according to any one of claims 1 to 12, characterized in that, The cathode porous substrate layer is carbon paper or carbon cloth.

14. The membrane electrode according to any one of claims 1 to 13, characterized in that, The porosity of the anode porous substrate layer is 20% - 80%.

15. The membrane electrode according to any one of claims 1 to 14, characterized in that, The anode porous substrate layer is carbon paper, carbon cloth, metal mesh, or metal foam.

16. The membrane electrode according to any one of claims 1 to 15, characterized in that, The thickness of the cation exchange membrane is 10 μm - 300 μm.

17. The membrane electrode according to any one of claims 1 to 16, characterized in that, The cation exchange membrane is a Nafion membrane.

18. The membrane electrode according to any one of claims 1 to 17, characterized in that, The physical connection is non-embedded physical contact.

19. The manufacturing method of the membrane electrode according to any one of claims 1 to 18, characterized in that, It includes the following steps: Step S10: Loading the cathode catalyst and the cation regulation substance on the cathode porous substrate layer to obtain the cathode oxygen reduction electrode; Step S20: Loading the anode catalyst on the anode porous substrate layer to obtain the anode oxygen evolution electrode; And Step S30: Stacking the cathode oxygen reduction electrode, the cation exchange membrane, and the anode oxygen evolution electrode in sequence.

20. The method for preparing a membrane electrode according to claim 19, wherein Step S10 includes: Step S11: Placing the cathode catalyst and the cation regulation substance in a solvent and mixing them to obtain a mixed coating; Step S13: Coating the mixed coating on the cathode porous substrate layer.

21. The method for preparing a membrane electrode according to claim 19 or 20, characterized in that, Step S10 includes: Step S12: Placing the cathode catalyst in a solvent to obtain a cathode catalyst coating; Step S14: Coating the cathode catalyst coating on the surface of the cathode porous substrate layer to form a cathode catalyst layer; Step S16: Placing the cation regulation substance in a solvent to obtain a cation regulation substance coating; Step S18: Coating the cation regulation substance coating on the surface of the cathode catalyst layer to form a cation regulation substance layer.

22. A membrane electrode reactor, characterized in that, It includes the membrane electrode according to any one of claims 1 - 18.

Images