Water electrolysis device and preparation method thereof
By designing a water electrolysis device that includes an oxygen evolution component, a hydrogen evolution component and a porous separator, the problems of high cost and low energy utilization efficiency of existing electrolysis water technology are solved, and efficient and low-cost electrolysis water preparation is achieved.
Patent Information
- Application Number
- CN202411544476.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-31
- Publication Date
- 2025-01-24
AI Technical Summary
The existing electrolytic water technology has problems of high cost and low energy utilization efficiency, especially the proton exchange membrane electrolytic water is more dependent on precious metal catalysts, while the ohmic resistance of alkali tank electrolytic water is relatively large.
A water electrolysis device is designed, including an oxygen evolution component, a hydrogen evolution component and a porous membrane. The oxygen evolution component and hydrogen evolution component are composed of anion exchange membrane and proton exchange membrane respectively, and are loaded with hydrolysis catalytic layer and catalyst layer on both sides respectively. The capillary action of the porous diaphragm allows liquid to enter, achieving efficient decomposition of electrolyzed water.
By carrying out hydrogen evolution reaction in acidic medium and oxygen evolution reaction in alkaline medium, the reaction rate is increased, the amount of precious metal catalyst is reduced, and the mass transfer resistance is reduced through capillary liquid feeding, achieving efficient and low-cost electrolysis. Water preparation.
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Figure CN119352055A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of water electrolysis, and in particular to a water electrolysis device and a preparation method thereof. Background Art
[0002] The electrolysis reaction of water is divided into the cathode hydrogen evolution reaction (HER) and the anode oxygen evolution reaction (OER). At present, there are three main forms of hydrogen production by electrolysis, proton exchange membrane (PEM) electrolysis, anion exchange membrane (AEM) electrolysis, and traditional diaphragm alkali cell (ALK) electrolysis. The current mainstream water electrolysis technologies mainly include proton exchange membrane water electrolysis (PEM) and alkali cell water electrolysis (ALK). The former can achieve high-power and efficient hydrogen production, but due to the stringent requirements on anode and cathode catalysts under acidic conditions, PEM water electrolysis is more dependent on precious metal catalysts, especially IrO2, which makes the cost of PEM water electrolysis high; ALK water electrolysis technology is the most mature, and the use of cheap non-precious metal catalyst electrodes at the anode and cathode can catalyze water decomposition, but due to the constraints of diaphragm materials, the system ohmic resistance is relatively large, so the energy utilization efficiency of ALK water electrolysis is low.
[0003] Ion exchange membrane is an important component of water electrolysis electrolyzer, which is mainly divided into three types: anion exchange membrane, cation exchange membrane and bipolar membrane. In the actual application of bipolar membrane, the electric field strength of the middle layer of bipolar membrane is less than the theoretical calculation, which weakens the degree of water dissociation promoted by the second Wien effect, and the weak alkaline environment promotes the dissociation of H2O to produce H + and OH - It cannot meet the large-scale application of electrolyzed water.
[0004] The traditional alkaline cell water electrolysis structure is a porous diaphragm layer in the middle, with cathode and anode on both sides. The liquid inlet method is that the electrolyte aqueous solution is pumped into the surface of the catalyst layer for water electrolysis. This will cause bubbles to form on the surface of the catalyst layer, which will then cover the active sites of the catalyst. At the same time, the bubble discharge and water entry directions are opposite, resulting in further mass transfer resistance.
[0005] Therefore, it is necessary to further improve the existing water electrolysis device, improve its performance and reduce the cost. Summary of the invention
[0006] The technical problem to be solved by the present invention is to provide a high-efficiency and low-cost water electrolysis device and a preparation method thereof in view of the deficiencies existing in the prior art.
[0007] The purpose of the present invention is achieved by at least one of the following technical solutions.
[0008] A water electrolysis device, comprising an oxygen evolution component, a hydrogen evolution component and a porous diaphragm arranged between the oxygen evolution component and the hydrogen evolution component; the oxygen evolution component comprises an anion exchange membrane, and a first hydrolysis catalytic layer and an oxygen evolution catalytic layer respectively loaded on both sides of the anion exchange membrane; the hydrogen evolution component comprises a proton exchange membrane, and a second hydrolysis catalytic layer and a hydrogen evolution catalytic layer respectively loaded on both sides of the proton exchange membrane, and the two sides of the porous diaphragm are respectively the first hydrolysis catalytic layer and the second hydrolysis catalytic layer; the water electrolysis device also comprises a water tank, wherein pure water is arranged in the water tank, and the lower end of the porous diaphragm extends into the pure water.
[0009] Preferably, the first hydrolysis catalyst layer includes a first hydrolysis catalyst and a first anion exchange resin.
[0010] Preferably, the first hydrolysis catalyst comprises Fe2O3 or NiO.
[0011] Preferably, the ratio of the first anion exchange resin to the first hydrolysis catalyst is 0.1-1:1, and the loading of the first hydrolysis catalyst is 20-40 μg / cm 2 .
[0012] Preferably, the oxygen evolution catalytic layer comprises an oxygen evolution catalyst and a second anion exchange resin.
[0013] Preferably, the oxygen evolution catalyst comprises NiFe2O4 or Co3O4.
[0014] Preferably, the ratio of the second anion exchange resin to the oxygen evolution catalyst is 0.2-1:1, and the loading of the oxygen evolution catalyst is 2-4 mg / cm 2 .
[0015] Preferably, the hydrogen evolution catalytic layer comprises a hydrogen evolution catalyst and a first proton exchange resin.
[0016] Preferably, the hydrogen evolution catalyst comprises Pt element, carrier Pt particles, or Pt alloy.
[0017] Preferably, the ratio of the first proton exchange resin to the hydrogen evolution catalyst is 0.1-0.9:1, and the loading of the hydrogen evolution catalyst is 0.2-0.8 mg / cm 2 .
[0018] Preferably, the second hydrolysis catalyst layer comprises a second hydrolysis catalyst and a second proton exchange resin.
[0019] Preferably, the second hydrolysis catalyst comprises TiO2 or IrO2.
[0020] Preferably, the ratio of the second proton exchange resin to the second hydrolysis catalyst is 0.1-0.2:1, and the loading of the second hydrolysis catalyst is 20-40 μg / cm 2 .
[0021] Preferably, the porous membrane has a pore size ranging from 0.1 to 10 μm, a height ranging from 2.5 to 10 cm, and a thickness ranging from 50 μm to 200 μm.
[0022] Preferably, the pore size of the porous membrane is in the range of 5 to 8 μm.
[0023] The preparation method of the water electrolysis device comprises the following steps:
[0024] preparing an oxygen evolution component;
[0025] preparing a hydrogen evolution component;
[0026] Mechanically assembling the oxygen evolution component, the porous diaphragm and the hydrogen evolution component;
[0027] The lower end of the porous membrane is placed in a tank filled with pure water.
[0028] Preferably, the preparation of the oxygen evolution component specifically comprises the following steps:
[0029] Adding a first hydrolysis catalyst to a first anion exchange resin, a solvent and a viscosity modifier to prepare a slurry, and spraying the slurry onto one side of the anion exchange membrane to form a first hydrolysis catalyst layer;
[0030] Adding an oxygen evolution catalyst to a second anion exchange resin, a solvent and a viscosity regulator to prepare a slurry, and spraying the slurry onto the other side of the anion exchange membrane to form an oxygen evolution catalyst layer;
[0031] Perform heat treatment to obtain the oxygen evolution component.
[0032] Preferably, the preparation of the hydrogen evolution component specifically comprises the following steps:
[0033] Adding a second hydrolysis catalyst to a second proton exchange resin, a solvent and a viscosity regulator to prepare a slurry, and spraying the slurry onto one side of the proton exchange membrane to form a second hydrolysis catalyst layer;
[0034] Adding a hydrogen evolution catalyst to a first proton exchange resin, a solvent and a viscosity regulator to prepare a slurry, and spraying the slurry onto the other side of the proton exchange membrane to form a hydrogen evolution catalyst layer;
[0035] Hot pressing is performed to obtain the hydrogen evolution component.
[0036] The principle of the present invention is: pure water enters the porous membrane through capillary action, the first hydrolysis catalytic layer and the second hydrolysis catalytic layer will catalyze the pure water to dissociate into hydroxide and hydrogen ions, and then under the action of the electric field, the hydrogen ions are transferred to the hydrogen evolution catalytic layer through the proton exchange membrane (PEM), and the hydroxide is transferred to the oxygen evolution catalytic layer through the anion exchange membrane (AEM), thereby achieving the effect of hydrogen evolution under acidic conditions and oxygen evolution under alkaline conditions, and improving the reaction rate. In addition, the capillary liquid inlet method reduces the mass transfer resistance.
[0037] Compared with the prior art, the present invention has the following beneficial effects:
[0038] 1) The kinetics of hydrogen evolution reaction (HER) is better in acidic medium, while the kinetics of oxygen evolution reaction (OER) is faster in alkaline medium;
[0039] 2) The introduction of non-precious metal catalysts on the alkaline oxygen evolution side can effectively reduce the amount of precious metals used in electrolyzed water;
[0040] 3) The entry of electrolyte and the desorption of generated bubbles (H2, O2) do not interfere with each other.
[0041] In summary, the present invention can effectively reduce the activation overpotential of electrolyzed water and the content of precious metal iridium, and reduce the ohmic resistance of bipolar membrane electrolysis of water by capillary inflow, thereby achieving efficient and low-cost electrolysis of water. BRIEF DESCRIPTION OF THE DRAWINGS
[0042] Figure 1 This is a schematic diagram of the structure of a water electrolysis device provided in this embodiment. DETAILED DESCRIPTION
[0043] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below with reference to the accompanying drawings.
[0044] Example 1
[0045] like Figure 1 As shown, it is a water electrolysis device provided in this embodiment. The water electrolysis device comprises an oxygen evolution component 100, a hydrogen evolution component 200 and a porous diaphragm 300 disposed between the oxygen evolution component 100 and the hydrogen evolution component 200.
[0046] The oxygen evolution component 100 includes an anion exchange membrane 102, and a first hydrolysis catalyst layer 104 and an oxygen evolution catalyst layer 106 respectively loaded on both sides of the anion exchange membrane 102. The first hydrolysis catalyst layer 104 includes a first hydrolysis catalyst and a first anion exchange resin. The first hydrolysis catalyst includes Fe2O3 or NiO, and in this embodiment, NiO. The mass ratio of the first anion exchange resin to the first hydrolysis catalyst is 0.2-1:1, and the loading of the first hydrolysis catalyst is 20-40 μg / cm2 The oxygen evolution catalyst layer 106 includes an oxygen evolution catalyst and a second anion exchange resin. The oxygen evolution catalyst includes NiFe2O4 or Co3O4, and in this embodiment, NiFe2O4. The mass ratio of the second anion exchange resin to the oxygen evolution catalyst is 0.2-1:1, and the catalyst loading is 2-4 mg / cm 2 The thickness of the anion exchange membrane 102 is in the range of 20 to 80 μm, preferably 20 to 50 μm. In this embodiment, the first anion exchange resin and the second anion exchange resin are both polybenzimidazole anion exchange resins.
[0047] The hydrogen evolution component 200 includes a proton exchange membrane 202, and a second hydrolysis catalyst layer 204 and a hydrogen evolution catalyst layer 206 respectively loaded on both sides of the proton exchange membrane 202. The second hydrolysis catalyst layer 204 includes a second hydrolysis catalyst and a second proton exchange resin. The second hydrolysis catalyst includes TiO2 or IrO2, and in this embodiment, it is IrO2. The ratio of the second proton exchange resin to the second hydrolysis catalyst is 0.1-0.2:1, and the loading of the second hydrolysis catalyst is 20-40 μg / cm 2 The hydrogen evolution catalyst layer 206 includes a hydrogen evolution catalyst and a first proton exchange resin. The hydrogen evolution catalyst includes a single substance of Pt, carrier Pt particles, or a Pt alloy. In this embodiment, the carrier Pt particles are used. The ratio of the first proton exchange resin to the hydrogen evolution catalyst is 0.1-0.9:1, and the catalyst loading is 0.2-0.8 mg / cm 2 The thickness of the proton exchange membrane 202 is in the range of 20 to 80 μm, preferably 20 to 50 μm. In this embodiment, the first proton exchange resin and the second proton exchange resin are both perfluorosulfonic acid proton exchange resins.
[0048] The first hydrolysis catalytic layer 104 and the second hydrolysis catalytic layer 204 are respectively disposed on both sides of the porous membrane 300. The pore size of the porous membrane 300 ranges from 0.1 to 10 μm; the height ranges from 2.5 to 10 cm; and the thickness ranges from 50 μm to 200 μm. Preferably, the pore size of the porous membrane 300 ranges from 5 to 8 μm. In this embodiment, the porous membrane 300 is a polyethersulfone membrane PES membrane.
[0049] The water electrolysis device further comprises a water tank 400 , in which pure water is arranged, and the lower end of the porous diaphragm 300 extends into the pure water.
[0050] Example 2
[0051] This embodiment provides a method for preparing the water electrolysis device of embodiment 1, comprising the following steps:
[0052] S101, preparing an oxygen evolution component.
[0053] Specifically, the first hydrolysis catalyst is added to the first anion exchange resin solution and an appropriate amount of solvent and viscosity modifier to prepare a slurry, and the slurry is sprayed onto one side of the anion exchange membrane 102 to form the first hydrolysis catalyst layer 104; wherein the first hydrolysis catalyst is NiO, the ratio of the first anion exchange resin to the first hydrolysis catalyst is 0.1-1:1, and the catalyst loading is determined by XRF to be 30 μg NiO / cm 2 ;
[0054] The oxygen evolution catalyst is added to the second anion exchange resin solution and an appropriate amount of solvent and viscosity modifier to prepare a slurry, and the slurry is sprayed onto the other side of the anion exchange membrane 102 to form an oxygen evolution catalyst layer 106; wherein the oxygen evolution catalyst is NiFe2O4, the ratio of the second anion exchange resin to the oxygen evolution catalyst is 0.22:1, and the catalyst loading is determined by XRF to be 2 mg NiFe2O4 / cm 2 ;
[0055] The oxygen evolution component 100 is obtained by heat treatment at 300° C. for 30 minutes.
[0056] S102, preparing a hydrogen evolution component.
[0057] Specifically, the second hydrolysis catalyst is added to the second proton exchange resin and an appropriate amount of solvent and viscosity modifier to prepare a slurry, and the slurry is sprayed onto one side of the proton exchange resin 202 to form a second hydrolysis catalyst layer 204, wherein the second hydrolysis catalyst is IrO2, and the ratio of the second proton exchange resin to the second hydrolysis catalyst is 0.1-0.2:1. The catalyst loading is determined by XRF to be 30 μg IrO2 / cm 2 ;
[0058] The hydrogen evolution catalyst is added to the first proton exchange resin and an appropriate amount of solvent and viscosity modifier to prepare a slurry, and the slurry is sprayed onto the other side of the proton exchange resin 202 to form a hydrogen evolution catalyst layer 206, wherein the hydrogen evolution catalyst is a carrier Pt particle, the ratio of the first proton exchange resin to the hydrogen evolution catalyst is 0.1:1, and the catalyst loading is determined by XRF to be 0.2-0.8 mg / cm 2 ;
[0059] Hot pressing was performed at 110° C. for 3 minutes to obtain the hydrogen evolution component.
[0060] S103, mechanically assembling the oxygen evolution component, the porous diaphragm and the hydrogen evolution component.
[0061] S104, extending the porous membrane into a water tank filled with pure water.
[0062] In this embodiment, the solvent and the viscosity modifier are water, ethanol, n-propanol or isopropanol.
[0063] Comparative Example 1
[0064] This comparative example 1 is substantially the same as the example 1, except that there is no first hydrolysis catalytic layer and second hydrolysis catalytic layer.
[0065] Comparative Example 2
[0066] This comparative example 1 is substantially the same as the example 1, except that the second hydrolysis catalyst layer is removed and the first hydrolysis catalyst is NiO. The method of the example 2 is used for preparation.
[0067] Comparative Example 3
[0068] This comparative example 3 is substantially the same as the example 1, except that the second hydrolysis catalyst layer is removed and the first hydrolysis catalyst is Fe2O3.
[0069] Comparative Example 4
[0070] This comparative example 4 is substantially the same as the example 1, except that the first hydrolysis catalyst layer is removed and the second hydrolysis catalyst is IrO2. The method of the example 2 is used for preparation.
[0071] Comparative Example 5
[0072] This comparative example 5 is substantially the same as the example 1, except that the first hydrolysis catalyst layer is removed and the second hydrolysis catalyst is TiO2.
[0073] Comparative Example 6
[0074] Comparative Example 6 is substantially the same as Example 1, except that the porous diaphragm is removed and the liquid inlet method is changed, using a method of water inletting from both sides of the electrode plate instead of a capillary liquid inlet method. The hydrogen evolution side and oxygen evolution side membrane electrodes are prepared using the method of Example 2 and are assembled mechanically.
[0075] The membrane electrodes of Example 1 and Comparative Examples 1-6 were placed in a fixture for testing at a temperature of 80°C.
[0076] <![CDATA[0.1Acm -2 The corresponding voltage below (V)]]> <![CDATA[1Acm -2 The corresponding voltage below (V)]]> Example 1 1.55 1.80 Comparative Example 1 2.63 \ Comparative Example 2 1.64 1.91 Comparative Example 3 1.72 2.05 Comparative Example 4 1.70 1.99 Comparative Example 5 1.78 2.15 Comparative Example 6 1.63 1.91
[0077] The present invention greatly reduces the activation overpotential under the joint action of the first and second hydrolysis catalysts, the hydrogen evolution catalyst and the oxygen evolution catalyst. In addition, the capillary action liquid feeding method can avoid the generation of bubbles during the hydrolysis process, reducing or even eliminating the mass transfer resistance.
Claims
1. A water electrolysis device, characterized in that: The water electrolysis device comprises an oxygen evolution component, a hydrogen evolution component and a porous diaphragm arranged between the oxygen evolution component and the hydrogen evolution component; the oxygen evolution component comprises an anion exchange membrane, and a first hydrolysis catalytic layer and an oxygen evolution catalytic layer respectively loaded on both sides of the anion exchange membrane; the hydrogen evolution component comprises a proton exchange membrane, and a second hydrolysis catalytic layer and a hydrogen evolution catalytic layer respectively loaded on both sides of the proton exchange membrane, and the two sides of the porous diaphragm are the first hydrolysis catalytic layer and the second hydrolysis catalytic layer respectively; the water electrolysis device also comprises a water tank, in which pure water is arranged, and the lower end of the porous diaphragm extends into the pure water.
2. The water electrolysis device according to claim 1, characterized in that: The first hydrolysis catalyst layer includes a first hydrolysis catalyst and a first anion exchange resin.
3. The water electrolysis device according to claim 2, characterized in that: The first hydrolysis catalyst includes Fe2O3 or NiO.
4. The water electrolysis device according to claim 1, characterized in that: The oxygen evolution catalytic layer comprises an oxygen evolution catalyst and a second anion exchange resin.
5. The water electrolysis device according to claim 4, characterized in that: The oxygen evolution catalyst includes NiFe2O4 or Co3O4.
6. The water electrolysis device according to claim 1, characterized in that: The hydrogen evolution catalytic layer comprises a hydrogen evolution catalyst and a first proton exchange resin.
7. The water electrolysis device according to claim 1, characterized in that: The second hydrolysis catalyst layer includes a second hydrolysis catalyst and a second proton exchange resin.
8. The water electrolysis device according to claim 7, characterized in that: The second hydrolysis catalyst includes TiO2 or IrO2.
9. The water electrolysis device according to claim 1, characterized in that: The porous membrane has a pore size ranging from 0.1 to 10 μm, a height ranging from 2.5 to 10 cm, and a thickness ranging from 50 μm to 200 μm.
10. The method for preparing a water electrolysis device according to any one of claims 1 to 9, characterized in that: The steps include: preparing an oxygen evolution component; preparing a hydrogen evolution component; Mechanically assembling the oxygen evolution component, the porous diaphragm and the hydrogen evolution component; The lower end of the porous membrane is placed in a tank filled with pure water.