Ionic-free membrane galvanic pile structure for hydrogen peroxide electrochemical synthesis

Abstract

The utility model relates to the field of electro-catalysis electrode materials and equipment, in particular to a non-ionic membrane galvanic pile structure for hydrogen peroxide electrochemical synthesis, which comprises an anode end plate and a cathode end plate which are used for supporting the internal structure of a galvanic pile and are respectively connected with an anode electrode and a cathode electrode. A flow field plate used for circulation and reaction of electrolyte is embedded in the anode electrode, a cathode collector plate used for providing current for the cathode electrode is arranged on the cathode electrode, and a gas plate used for controlling circulation of cathode gas is placed between the cathode end plate and the cathode collector plate. According to the galvanic pile disclosed by the utility model, under the condition that an ionic membrane is not needed, the reactions of a cathode and an anode are in the same reaction cavity through ingenious design, but hydrogen peroxide can be efficiently produced, and meanwhile, reasonable distribution of reaction gas and electrolyte on the surfaces of the electrodes is ensured; therefore, stable and efficient operation of the galvanic pile is realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to electrocatalysis electrode material and equipment field, especially in a kind of for the ion-free membrane electric pile structure of electrochemical synthesis of hydrogen peroxide. BACKGROUND

[0002] Hydrogen peroxide (H2O2), also known as hydrogen peroxide, is a widely used, clean and pollution-free efficient oxidant, and its by-products are water and oxygen, so it is often used in water treatment, food processing, chemical synthesis and integrated circuit fields. With the increasing attention of society and the public to pollution and health problems, the demand for hydrogen peroxide in various industries has gradually increased, and the market share of hydrogen peroxide has also increased year by year. At present, most of the hydrogen peroxide industrial products are mainly prepared by anthraquinone method, which requires relatively complete industrial infrastructure, high energy consumption and expensive noble metal catalysts, so high-concentration hydrogen peroxide products need to be transported to reduce costs. However, concentrated hydrogen peroxide is a hazardous chemical, which not only poses a risk of transportation and storage, but also incurs additional costs. In order to reduce the risk and cost of its use, as well as to reduce its carbon footprint during production, many researchers and engineers have begun to pay close attention to the preparation of hydrogen peroxide by electrochemical catalytic reduction of oxygen in recent years. This method is a green, environmentally friendly and energy-efficient preparation method, which uses electrochemical reaction to reduce oxygen to hydrogen peroxide, avoiding the complex process and environmental pollution of the traditional anthraquinone method. This technology can achieve in-situ preparation of hydrogen peroxide at the demand end, thereby eliminating the need for separation, purification and transportation steps, reducing costs and expanding the scope of use, and is therefore considered to be the future direction of hydrogen peroxide production. However, hydrogen peroxide electrochemical synthesis technology requires a suitable electric pile to achieve efficient and stable production. Generally, such an electric pile is composed of an anode chamber, a cathode chamber and a gas chamber. The anode chamber is used for anodic reaction (generally oxygen evolution reaction), thereby generating electrons and protons, and the electrons are transferred to the cathode through an external circuit. The cathode receives electrons in the cathode chamber and reduces oxygen to hydrogen peroxide ion (HO2-), and the hydrogen peroxide ion is converted to hydrogen peroxide after receiving protons from the anode. The gas chamber provides sufficient reaction gas, oxygen or air, for the cathode. As can be seen, in order to prevent hydrogen peroxide from being oxidized at the anode, the cathode chamber and the anode chamber are usually separated by a proton exchange membrane. However, the proton exchange membrane is expensive and easily corroded by peroxide, so the existing electric pile device needs to be redesigned to avoid the use of proton membranes while ensuring the production of hydrogen peroxide. Therefore, the design and assembly of such membrane-free electric piles are of great significance and practical prospect for the development and commercialization of hydrogen peroxide electrochemical synthesis. SUMMARY

[0003] To solve the above technical problems.

[0004] The application provides a kind of ion-free membrane electric pile structure for electrochemical synthesis of hydrogen peroxide, comprising: anode end plate and cathode end plate for supporting the internal structure of the electric pile, the anode end plate and the cathode end plate are connected with anode electrode and cathode electrode respectively, the anode electrode is embedded with flow field plate for electrolyte flow and reaction, the cathode electrode is provided with cathode current collector for providing current to the cathode electrode, a gas plate is placed between the cathode end plate and the cathode current collector for controlling the flow of cathode gas.

[0005] Further, the anode end plate is tightly attached to the anode electrode through an anode silica gel pad, and the flow field plate and the cathode electrode are tightly attached through a cathode silica gel pad respectively, and the cathode current collector and the gas plate are tightly attached through a cathode silica gel pad respectively.

[0006] Further, the anode electrode and the cathode current collector are respectively provided with anode lug and cathode lug connected to the anode and cathode of the power supply.

[0007] Further, the flow field plate is provided with liquid inlet and liquid outlet for electrolyte inlet and outlet.

[0008] Further, the gas plate is provided with gas inlet and gas outlet for gas inlet and outlet.

[0009] Further, the anode silica gel pad, the anode electrode, the flow field plate, the cathode silica gel pad, the cathode electrode, the cathode current collector and the gas plate are sequentially stacked to form an electric pile group to improve production capacity.

[0010] Further, the specific inclination angle of the cathode electrode and the flow field plate is between 10° and 40°, and the optimal inclination angle is 15°.

[0011] Further, the electric pile of the utility model comprises the following components stacked in order:

[0012] The components are stacked and assembled in order: the anode silica gel pad is placed on the anode end plate to ensure tight attachment without gap; then the anode electrode is placed on the anode silica gel pad, and the flow field plate is placed above the anode electrode to ensure that the direction of the flow field plate is correct and the flow field plate is exactly embedded in the anode electrode bayonet; the cathode silica gel pad is placed on the flow field plate, and then the cathode electrode is placed, so that the cathode electrode is stably connected with the flow field through the cathode silica gel pad; the cathode current collector is placed above the cathode electrode to provide current for the cathode electrode; the gas plate is placed on the cathode current collector to control the flow of cathode gas; finally, the cathode end plate is placed on the gas plate to complete the assembly of the entire electric pile.

[0013] Compared with the prior art, the utility model has the following beneficial effects:

[0014] 1. The present application has a unique stacking mode, the electric pile utilizes the synergies between each component, without ion membrane, through ingenious design, the cathode and anode reaction in the same reaction chamber, but can efficiently produce hydrogen peroxide, at the same time, ensure the reasonable distribution of reaction gas and electrolyte on the electrode surface, so as to realize the stable and efficient operation of the electric pile.

[0015] 2. Based on the principle of cathode two-electron oxygen reduction and anode OER reaction, the physical structure and performance characteristics of each component are utilized, and the cathode and anode reactions are stable and efficient in their respective regions without ion membrane separation. By optimizing the design of electrode materials, flow field plates, gas plates and other components, the reasonable distribution of reaction gas and electrolyte on the electrode surface is ensured, the decomposition of product hydrogen peroxide is avoided, and the normal operation of the electric pile under the condition of no ion membrane is realized.

[0016] 3. The cost of ion membrane in traditional electric pile is usually high, and the procurement cost, replacement cost and potential maintenance cost caused by ion membrane failure account for a considerable proportion in the total cost of electric pile. The electric pile structure of the present application eliminates the ion membrane, directly reducing the high cost. At the same time, due to the need to consider the special installation and maintenance process requirements of ion membrane, the labor cost and related auxiliary material cost are also reduced in the assembly and long-term operation and maintenance process of the electric pile.

[0017] 4. The present application optimizes the distribution and diffusion of reaction gas on the cathode surface by the specific inclination angle design (10-40 degrees, best 15 degrees) of the cathode electrode and the flow field plate, and improves the cathode reaction efficiency. According to experimental test, the overall energy conversion efficiency of the electric pile is improved by 30-50% compared with the traditional electric pile.

[0018] 5. In the production process of ion membrane, some complex chemical synthesis process may be involved, which may produce a certain amount of harmful waste and pollutant emission. The use of ion membrane is removed in the present application, which reduces the generation of such potential pollutants from the source of electric pile production. At the same time, due to the improvement of electric pile operation reliability, the additional energy consumption and waste emission caused by fault maintenance and component replacement are reduced. Due to the existence of ion membrane in traditional electric pile, special care is needed during assembly to ensure correct installation and sealing of ion membrane, and special detection and treatment of ion membrane are also needed during maintenance. The electric pile structure of the present application is more simple and intuitive, the stacking installation mode of each component is easy to operate, which reduces the process complexity and time cost in the assembly process. In terms of maintenance, no special maintenance operation is needed for ion membrane, only routine inspection, cleaning and replacement of each solid component are needed, which reduces the technical requirements and labor intensity of maintenance personnel. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1It is the structure schematic view of the electric pile of the utility model;

[0020] Figure 2 It is the electrolyte and gas inlet and outlet direction view of the electric pile of the utility model patent;

[0021] Figure 3 It is the side view of the reaction single set reaction electric pile;

[0022] Figure 4 It is the voltage and time relation view of the utility model embodiment;

[0023] Figure 5 It is the hydrogen peroxide effluent concentration and time relation view of the utility model embodiment;

[0024] Figure 6 It is the faraday efficiency and time relation view of the utility model embodiment.

[0025] The figure mark is: 1-anode end plate;2-anode silica gel pad;3-anode;4-flow field plate;5-cathode silica gel pad;6-cathode electrode;7-cathode current collector plate;8-gas plate;9-cathode end plate;301-anode lug;401-liquid inlet;402-liquid outlet;701-cathode lug;801-gas inlet;802-gas outlet. DETAILED DESCRIPTION

[0026] The following description is used to disclose the utility model so that those skilled in the art can realize the utility model. The preferred embodiments in the following description are only as examples, and other obvious variants can be thought of by those skilled in the art.

[0027] The specific embodiments of the utility model are described in detail below in combination with the drawings:

[0028] An ion-free membrane electric pile structure for hydrogen peroxide electrochemical synthesis, characterized in that it comprises: an anode end plate 1 and a cathode end plate 9 for supporting the internal structure of the electric pile, the anode end plate 1 and the cathode end plate 9 are connected to an anode electrode 3 and a cathode electrode 6 respectively, the anode electrode 3 is embedded with a flow field plate 4 for electrolyte flow and reaction, the cathode electrode 6 is provided with a cathode current collector plate 7 for providing current to the cathode electrode 6, and a gas plate 8 for controlling the flow of cathode gas is placed between the cathode end plate 9 and the cathode current collector plate 7.

[0029] The anode end plate 1 is tightly attached to the anode electrode 3 through an anode silica gel pad 2, and the flow field plate 4 and the cathode electrode 6 and the cathode current collector plate 7 and the gas plate 8 are tightly attached through a cathode silica gel pad 5 respectively.

[0030] The anode electrode 3 and the cathode current collector plate 7 are respectively provided with an anode lug 301 and a cathode lug 701 connected to the anode and cathode of the power supply.

[0031] The flow field plate 4 is provided with a liquid inlet 401 and a liquid outlet 402 for the electrolyte to enter and exit.

[0032] The gas plate 8 is provided with a gas inlet 801 and a gas outlet 802 for the gas to enter and exit.

[0033] The anode silicon rubber pad 2, the anode electrode 3, the flow field plate 4, the cathode silicon rubber pad 5, the cathode electrode 6, the cathode current collector plate 7 and the gas plate 8 are sequentially and repeatedly stacked to form a stack group to improve production capacity.

[0034] The specific inclination angle of the cathode electrode 6 and the flow field plate 4 is between 10°-40°, and the optimal inclination angle is 15°.

[0035] The stack of the utility model comprises the following components which are sequentially stacked:

[0036] The anode end plate 1 is a support structure at one end of the stack, which plays a role in fixing and protecting the internal components.

[0037] The anode silicon rubber pad 2 is placed between the anode end plate 1 and the anode, which plays a role in sealing and buffering, prevents the leakage of electrolyte and ensures the good contact of the anode with adjacent components.

[0038] The anode electrode 3 is an electrode for anode oxygen evolution reaction OER, which is prepared by using a material with good catalytic activity and stability, can be a ruthenium iridium titanium plate, and a foam nickel loaded with iron-nickel to promote the efficient performance of the anode reaction.

[0039] The flow field plate 4 is used for the flow of electrolyte and provides a place for reaction to take place.

[0040] The cathode silicon rubber pad 5 is located between the flow field plate 4 and the cathode electrode 6 and between the cathode current collector plate 7 and the gas plate 8, which also plays a role in sealing and buffering, and ensures the sealing property and the stability of electrode contact in the cathode region.

[0041] The cathode electrode 6 is used for the core reaction of the device, i.e. two-electron oxygen reduction reaction, to reduce oxygen to produce hydrogen peroxide; the preparation method is to use hydrophobic carbon paper or hydrophobic carbon cloth as a substrate, and to spray two-electron oxygen reduction catalysts, respectively carbon black or modified catalysts, on the substrate to form a gas diffusion electrode.

[0042] The cathode current collector plate 7 provides stable power support for the cathode electrode 6.

[0043] The gas plate 8 is used to control the entry of cathode gas oxygen.

[0044] The cathode end plate 9 is a support structure at the other end of the stack, which corresponds to the anode end plate 1 and is used to protect the internal components.

[0045] The anode end plate 1, the flow field plate 4, the gas plate 8 and the cathode end plate 9 are all made of acrylic material.

[0046] The anode electrode 3 is cut from nickel-iron supported nickel foam.

[0047] The cathode electrode 6 is made of hydrophobic carbon paper as a substrate, and a two-electron oxygen reduction catalyst is sprayed.

[0048] The cathode current collector 7 is made of titanium plate as a current collector.

[0049] The stack assembly is carried out in sequence: the anode silica gel pad 2 is placed on the anode end plate 1, ensuring close fit and no gap; then the anode electrode 3 is placed on the anode silica gel pad 2, the flow field plate 4 is placed above the anode electrode 3, ensuring that the direction of the flow field plate 4 is correct and that the anode electrode 3 is exactly fitted; the cathode silica gel pad 5 is placed on the flow field plate 4, and then the cathode electrode 6 is placed, so that the cathode electrode 6 is stably connected with the flow field through the cathode silica gel pad 5; the cathode current collector 7 is placed above the cathode electrode 6 to provide current for the cathode electrode 6; the gas plate 8 is placed on the cathode current collector 7 to control the circulation of the cathode gas; finally, the cathode end plate 9 is placed on the gas plate 8 to complete the assembly of the entire stack.

[0050] The power source anode and cathode are connected to the anode lug 301 of the anode electrode 3 and the cathode lug 701 of the cathode current collector 7 respectively, the electrolyte 1 mol / L sodium hydroxide flows into the flow field plate 4 from the inlet 401 and carries the produced hydrogen peroxide out from the outlet 402, oxygen enters from the gas inlet 801, flows into the gas plate 8, and the oxygen produced by the OER reaction of the anode electrode 3 flows out along the anode lug 301 of the anode electrode 3.

[0051] In this embodiment, constant current method is used to produce hydrogen peroxide stably, the current is 1A, the electrolyte flow rate is 2ml / min, the oxygen flow rate is 40ml / min, and the data is recorded after stable operation for 2h, and the voltage is recorded every hour Figure 4 , the concentration of hydrogen peroxide is tested Figure 5 , and the Faraday efficiency is calculated Figure 6 .

[0052] During the operation of the stack, the anode electrode 3 undergoes OER reaction, the anode electrode 3 is the current collector itself, and the cathode electrode 6 undergoes two-electron oxygen reduction reaction. Oxygen enters the gas plate 8, forms a three-phase interface with the cathode gas diffusion electrode and the electrolyte, creates an oxygen supersaturation state, efficiently carries out the two-electron oxygen reduction reaction, and realizes the stable production of hydrogen peroxide by the stack.

[0053] The basic principle, main features and advantages of the present application are shown and described above. It should be understood by those skilled in the art that the present application is not limited by the above examples, and the above examples and descriptions in the specification are only the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection required by the present application is defined by the appended claims and their equivalents.

Claims

1. An ion-free membrane stack structure for electrochemical synthesis of hydrogen peroxide, characterized by, The application relates to a fuel cell stack, which comprises: an anode end plate (1) and a cathode end plate (9) for supporting the internal structure of the fuel cell stack, the anode end plate (1) and the cathode end plate (9) being connected with an anode electrode (3) and a cathode electrode (6) respectively, the anode electrode (3) being embedded with a flow field plate (4) for electrolyte flow and reaction, the cathode electrode (6) being provided with a cathode current collector plate (7) for providing current to the cathode electrode (6), and a gas plate (8) for controlling the flow of cathode gas being arranged between the cathode end plate (9) and the cathode current collector plate (7).

2. The ion-free membrane stack structure for electrochemical synthesis of hydrogen peroxide according to claim 1, characterized in that, The anode end plate (1) is tightly adhered to the anode electrode (3) through an anode silica gel pad (2), the flow field plate (4) and the cathode electrode (6) are tightly adhered through a cathode silica gel pad (5) respectively, and the cathode current collector plate (7) and the gas plate (8) are tightly adhered through a cathode silica gel pad (5) respectively.

3. The ion-free membrane stack structure for electrochemical synthesis of hydrogen peroxide according to claim 2, characterized in that, The anode electrode (3) and the cathode current collector plate (7) are respectively provided with an anode lug (301) and a cathode lug (701) for connecting the anode and the cathode of a power supply.

4. The ion-free membrane stack structure for electrochemical synthesis of hydrogen peroxide according to claim 3, characterized in that, The flow field plate (4) is provided with an inlet (401) and an outlet (402) for electrolyte.

5. The ion-free membrane stack structure for electrochemical synthesis of hydrogen peroxide according to claim 4, characterized in that, The gas plate (8) is provided with an inlet (801) and an outlet (802) for gas.

6. An ion-free membrane stack structure for electrochemical synthesis of hydrogen peroxide according to any one of claims 2-5, characterized in that, The anode silica gel pad (2), the anode electrode (3), the flow field plate (4), the cathode silica gel pad (5), the cathode electrode (6), the cathode current collector plate (7) and the gas plate (8) are sequentially and repeatedly stacked to form a fuel cell stack.

7. An ion-free membrane stack structure for electrochemical synthesis of hydrogen peroxide according to claim 6, characterized in that, The inclination angle between the cathode electrode (6) and the flow field plate (4) is 10-40 degrees, and the optimal inclination angle is 15 degrees.

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